Commit Graph

17299 Commits

Author SHA1 Message Date
Lai Jiangshan 79a62f957e rcu: Warn on allegedly impossible rcu_read_unlock_special() from irq
After commit #10f39bb1b2c1 (rcu: protect __rcu_read_unlock() against
scheduler-using irq handlers), it is no longer possible to enter
the main body of rcu_read_lock_special() from an NMI, interrupt, or
softirq handler.  In theory, this implies that the check for "in_irq()
|| in_serving_softirq()" must always fail, so that in theory this check
could be removed entirely.

In practice, this commit wraps this condition with a WARN_ON_ONCE().
If this warning never triggers, then the condition will be removed
entirely.

[ paulmck: And one way of triggering the WARN_ON() is if a scheduling
  clock interrupt occurs in an RCU read-side critical section, setting
  RCU_READ_UNLOCK_NEED_QS, which is handled by rcu_read_unlock_special().
  Updated this commit to return if only that bit was set. ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-12 12:34:00 -08:00
Linus Torvalds 5dec682c7f Keyrings fixes 2013-12-10
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Merge tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull misc keyrings fixes from David Howells:
 "These break down into five sets:

   - A patch to error handling in the big_key type for huge payloads.
     If the payload is larger than the "low limit" and the backing store
     allocation fails, then big_key_instantiate() doesn't clear the
     payload pointers in the key, assuming them to have been previously
     cleared - but only one of them is.

     Unfortunately, the garbage collector still calls big_key_destroy()
     when sees one of the pointers with a weird value in it (and not
     NULL) which it then tries to clean up.

   - Three patches to fix the keyring type:

     * A patch to fix the hash function to correctly divide keyrings off
       from keys in the topology of the tree inside the associative
       array.  This is only a problem if searching through nested
       keyrings - and only if the hash function incorrectly puts the a
       keyring outside of the 0 branch of the root node.

     * A patch to fix keyrings' use of the associative array.  The
       __key_link_begin() function initially passes a NULL key pointer
       to assoc_array_insert() on the basis that it's holding a place in
       the tree whilst it does more allocation and stuff.

       This is only a problem when a node contains 16 keys that match at
       that level and we want to add an also matching 17th.  This should
       easily be manufactured with a keyring full of keyrings (without
       chucking any other sort of key into the mix) - except for (a)
       above which makes it on average adding the 65th keyring.

     * A patch to fix searching down through nested keyrings, where any
       keyring in the set has more than 16 keyrings and none of the
       first keyrings we look through has a match (before the tree
       iteration needs to step to a more distal node).

     Test in keyutils test suite:

        http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=8b4ae963ed92523aea18dfbb8cab3f4979e13bd1

   - A patch to fix the big_key type's use of a shmem file as its
     backing store causing audit messages and LSM check failures.  This
     is done by setting S_PRIVATE on the file to avoid LSM checks on the
     file (access to the shmem file goes through the keyctl() interface
     and so is gated by the LSM that way).

     This isn't normally a problem if a key is used by the context that
     generated it - and it's currently only used by libkrb5.

     Test in keyutils test suite:

        http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=d9a53cbab42c293962f2f78f7190253fc73bd32e

   - A patch to add a generated file to .gitignore.

   - A patch to fix the alignment of the system certificate data such
     that it it works on s390.  As I understand it, on the S390 arch,
     symbols must be 2-byte aligned because loading the address discards
     the least-significant bit"

* tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  KEYS: correct alignment of system_certificate_list content in assembly file
  Ignore generated file kernel/x509_certificate_list
  security: shmem: implement kernel private shmem inodes
  KEYS: Fix searching of nested keyrings
  KEYS: Fix multiple key add into associative array
  KEYS: Fix the keyring hash function
  KEYS: Pre-clear struct key on allocation
2013-12-12 10:15:24 -08:00
Linus Torvalds 5cdec2d833 futex: move user address verification up to common code
When debugging the read-only hugepage case, I was confused by the fact
that get_futex_key() did an access_ok() only for the non-shared futex
case, since the user address checking really isn't in any way specific
to the private key handling.

Now, it turns out that the shared key handling does effectively do the
equivalent checks inside get_user_pages_fast() (it doesn't actually
check the address range on x86, but does check the page protections for
being a user page).  So it wasn't actually a bug, but the fact that we
treat the address differently for private and shared futexes threw me
for a loop.

Just move the check up, so that it gets done for both cases.  Also, use
the 'rw' parameter for the type, even if it doesn't actually matter any
more (it's a historical artifact of the old racy i386 "page faults from
kernel space don't check write protections").

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12 09:53:51 -08:00
Linus Torvalds f12d5bfceb futex: fix handling of read-only-mapped hugepages
The hugepage code had the exact same bug that regular pages had in
commit 7485d0d375 ("futexes: Remove rw parameter from
get_futex_key()").

The regular page case was fixed by commit 9ea71503a8 ("futex: Fix
regression with read only mappings"), but the transparent hugepage case
(added in a5b338f2b0b1: "thp: update futex compound knowledge") case
remained broken.

Found by Dave Jones and his trinity tool.

Reported-and-tested-by: Dave Jones <davej@fedoraproject.org>
Cc: stable@kernel.org # v2.6.38+
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12 09:38:42 -08:00
Wei Yongjun 0be8669dd5 cgroup: fix missing unlock on error in cgroup_load_subsys()
Add the missing unlock before return from function cgroup_load_subsys()
in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-12 10:45:36 -05:00
Peter Zijlstra c7f2e3cd6c perf: Optimize ring-buffer write by depending on control dependencies
Remove a full barrier from the ring-buffer write path by relying on
a control dependency to order a LOAD -> STORE scenario.

Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-8alv40z6ikk57jzbaobnxrjl@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-11 15:53:22 +01:00
Peter Zijlstra 9dbdb15553 sched/fair: Rework sched_fair time accounting
Christian suffers from a bad BIOS that wrecks his i5's TSC sync. This
results in him occasionally seeing time going backwards - which
crashes the scheduler ...

Most of our time accounting can actually handle that except the most
common one; the tick time update of sched_fair.

There is a further problem with that code; previously we assumed that
because we get a tick every TICK_NSEC our time delta could never
exceed 32bits and math was simpler.

However, ever since Frederic managed to get NO_HZ_FULL merged; this is
no longer the case since now a task can run for a long time indeed
without getting a tick. It only takes about ~4.2 seconds to overflow
our u32 in nanoseconds.

This means we not only need to better deal with time going backwards;
but also means we need to be able to deal with large deltas.

This patch reworks the entire code and uses mul_u64_u32_shr() as
proposed by Andy a long while ago.

We express our virtual time scale factor in a u32 multiplier and shift
right and the 32bit mul_u64_u32_shr() implementation reduces to a
single 32x32->64 multiply if the time delta is still short (common
case).

For 64bit a 64x64->128 multiply can be used if ARCH_SUPPORTS_INT128.

Reported-and-Tested-by: Christian Engelmayer <cengelma@gmx.at>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
Cc: Paul Turner <pjt@google.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131118172706.GI3866@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-11 15:52:35 +01:00
Peter Zijlstra 8e8339a3a1 sched: Initialize power_orig for overlapping groups
Yinghai reported that he saw a /0 in sg_capacity on his EX parts.
Make sure to always initialize power_orig now that we actually use it.

Ideally build_sched_domains() -> init_sched_groups_power() would also
initialize this; but for some yet unexplained reason some setups seem
to miss updates there.

Reported-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-l8ng2m9uml6fhibln8wqpom7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-11 15:47:59 +01:00
Hendrik Brueckner 62226983da KEYS: correct alignment of system_certificate_list content in assembly file
Apart from data-type specific alignment constraints, there are also
architecture-specific alignment requirements.
For example, on s390 symbols must be on even addresses implying a 2-byte
alignment.  If the system_certificate_list_end symbol is on an odd address
and if this address is loaded, the least-significant bit is ignored.  As a
result, the load_system_certificate_list() fails to load the certificates
because of a wrong certificate length calculation.

To be safe, align system_certificate_list on an 8-byte boundary.  Also improve
the length calculation of the system_certificate_list content.  Introduce a
system_certificate_list_size (8-byte aligned because of unsigned long) variable
that stores the length.  Let the linker calculate this size by introducing
a start and end label for the certificate content.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-12-10 18:25:28 +00:00
Rusty Russell 7cfe5b3310 Ignore generated file kernel/x509_certificate_list
$ git status
# On branch pending-rebases
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	kernel/x509_certificate_list
nothing added to commit but untracked files present (use "git add" to track)
$

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-12-10 18:21:34 +00:00
Paul E. McKenney 24ef659a85 rcu: Provide better diagnostics for blocking in RCU callback functions
Currently blocking in an RCU callback function will result in
"scheduling while atomic", which could be triggered for any number
of reasons.  To aid debugging, this patch introduces a rcu_callback_map
that is used to tie the inappropriate voluntary context switch back
to the fact that the function is being invoked from within a callback.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-09 15:12:39 -08:00
Paul E. McKenney bc72d962d6 rcu: Improve SRCU's grace-period comments
This commit documents the memory-barrier guarantees provided by
synchronize_srcu() and call_srcu().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-09 15:12:38 -08:00
Paul E. McKenney 04f34650ca rcu: Fix CONFIG_RCU_FANOUT_EXACT for odd fanout/leaf values
Each element of the rcu_state structure's ->levelspread[] array
is intended to contain the per-level fanout, where the zero-th
element corresponds to the root of the rcu_node tree, and the last
element corresponds to the leaves.  In the CONFIG_RCU_FANOUT_EXACT
case, this means that the last element should be filled in
from CONFIG_RCU_FANOUT_LEAF (or from the rcu_fanout_leaf boot
parameter, if provided) and that the remaining elements should
be filled in from CONFIG_RCU_FANOUT.  Unfortunately, the current
code in rcu_init_levelspread() takes the opposite approach, placing
CONFIG_RCU_FANOUT_LEAF in the zero-th element and CONFIG_RCU_FANOUT in
the remaining elements.

For typical power-of-two values, this generates odd but functional
rcu_node trees.  However, other values, for example CONFIG_RCU_FANOUT=3
and CONFIG_RCU_FANOUT_LEAF=2, generate trees that can leave some CPUs
out of the grace-period computation, resulting in too-short grace periods
and therefore a broken RCU implementation.

This commit therefore fixes rcu_init_levelspread() to set the last
->levelspread[] array element from CONFIG_RCU_FANOUT_LEAF and the
remaining elements from CONFIG_RCU_FANOUT, thus generating the
intended rcu_node trees.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-09 15:12:38 -08:00
Fengguang Wu f6f7ee9af7 rcu: Fix coccinelle warnings
This commit fixes the following coccinelle warning:

kernel/rcu/tree.c:712:9-10: WARNING: return of 0/1 in function
'rcu_lockdep_current_cpu_online' with return type bool

Return statements in functions returning bool should use
 true/false instead of 1/0.
 Generated by: coccinelle/misc/boolreturn.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-09 15:12:25 -08:00
Frederic Weisbecker 531f64fd6f posix-timers: Convert abuses of BUG_ON to WARN_ON
The posix cpu timers code makes a heavy use of BUG_ON()
but none of these concern fatal issues that require
to stop the machine. So let's just warn the user when
some internal state slips out of our hands.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:56:29 +01:00
Frederic Weisbecker e73d84e33f posix-timers: Remove remaining uses of tasklist_lock
The remaining uses of tasklist_lock were mostly about synchronizing
against sighand modifications, getting coherent and safe group samples
and also thread/process wide timers list handling.

All of this is already safely synchronizable with the target's
sighand lock. Let's use it on these places instead.

Also update the comments about locking.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:56:28 +01:00
Frederic Weisbecker 3d7a1427e4 posix-timers: Use sighand lock instead of tasklist_lock on timer deletion
Timer deletion doesn't need the tasklist lock.
We need to protect against:

* concurrent access to the lists p->cputime_expires and
  p->sighand->cputime_expires

* task reaping that may also delete the timer list entry

* timer firing

We already hold the timer lock which protects us against concurrent
timer firing.

The rest only need the targets sighand to be locked.
So hold it and drop the use of tasklist_lock there.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:51 +01:00
Frederic Weisbecker 50875788a1 posix-timers: Use sighand lock instead of tasklist_lock for task clock sample
There is no need for the tasklist_lock just to take a process
wide clock sample.

All we need is to get a coherent sample that doesn't race with
exit() and exec():

* exit() may be concurrently reaping a task and flushing its time

* sighand is unstable under exit() and exec(), and the latter also
  result in group leader that can change

To protect against these, locking the target's sighand is enough.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:51 +01:00
Frederic Weisbecker 33ab0fec33 posix-timers: Consolidate posix_cpu_clock_get()
Consolidate the clock sampling common code used for both local
and remote targets.

Note that this introduces a tiny user ABI change: if a
PID is passed to clock_gettime() along the clockid,
we used to forbid a process wide clock sample when that
PID doesn't belong to a group leader. Now after this patch
we allow process wide clock samples if that PID belongs to
the current task, even if the current task is not the
group leader.

But local process wide clock samples are allowed if PID == 0
(current task) even if the current task is not the group leader.
So in the end this should be no big deal as this actually harmonize
the behaviour when the remote sample is actually a local one.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:51 +01:00
Frederic Weisbecker af82eb3c30 posix-timers: Remove useless clock sample on timers cleanup
a0b2062b09
("posix_timers: fix racy timer delta caching on task exit") forgot
to remove the arguments used for timer caching.

Fix this leftover.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:50 +01:00
Frederic Weisbecker a3222f88fa posix-timers: Remove dead task special case
Now that we've removed all the optimizations that could
result in NULL timer's targets, we can remove all the
associated special case handling.

Also add some warnings on NULL targets to spot any possible
leftover.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:50 +01:00
Frederic Weisbecker e26d70d271 posix-timers: Cleanup reaped target handling
When a timer's target is seen to be buried, for example on calls
to timer_gettime(), the posix cpu timers code behaves a bit
like a garbage collector and releases early the reference to the
task.

Then again, this optimization complicates the code for no much
value: it's up to the user to release the timer and its associated
ressources by calling timer_delete() after it buries the target
tasks.

Remove this to simplify the code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:50 +01:00
Frederic Weisbecker d430b9173a posix-timers: Remove dead process posix cpu timers caching
Now that we removed dead thread posix cpu timers caching,
lets remove the dead process wide version. This caching
is similar to the per thread version but it should be even
more rare:

* If the process id dead, we are not reading its timers
status from a thread belonging to its group since they
are all dead. So this caching only concern remote process
timers reads. Now posix cpu timers using itimers or timer_settime()
can't do remote process timers anyway so it's not even clear if there
is actually a user for this caching.

* Unlike per thread timers caching, this only applies to
zombies targets. Buried targets' process wide timers return
0 values. But then again, timer_gettime() can't read remote
process timers, so if the process is dead, there can't be
any reader left anyway.

Then again this caching seem to complicate the code for
corner cases that are probably not worth it. So lets get
rid of it.

Also remove the sample snapshot on dying process timer
that is now useless, as suggested by Kosaki.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:53:49 +01:00
Frederic Weisbecker 724a371396 posix-timers: Remove dead thread posix cpu timers caching
When a task is exiting or has exited, its posix cpu timers
don't tick anymore and won't elapse further. It's too late
for them to expire.

So any further call to timer_gettime() on these timers will
return the same remaining expiry time.

The current code optimize this by caching the remaining delta
and storing it where we use to save the absolute expiration time.
This way, the future calls to timer_gettime() won't need to
compute the difference between the absolute expiration time and
the current time anymore.

Now this optimization doesn't seem to bring much value. Computing
the timer remaining delta is not very costly. Fetching the timer
value OTOH can be costly in two ways:

* CPUCLOCK_SCHED read requires to lock the target's rq. But some
optimizations are on the way to make task_sched_runtime() not holding
the rq lock of a non-running target.

* CPUCLOCK_VIRT/CPUCLOCK_PROF read simply consist in fetching
current->utime/current->stime except when the system uses full
dynticks cputime accounting. The latter requires a per task lock
in order to correctly compute user and system time. But once the
target is dead, this lock shouldn't be contended anyway.

All in one this caching doesn't seem to be justified.
Given that it complicates the code significantly for
few wins, let's remove it on single thread timers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
2013-12-09 16:50:57 +01:00
Khalid Aziz 4fc9bbf98f PCI: Disable Bus Master only on kexec reboot
Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel.  Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.

This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path.  The problem was introduced by
b566a22c23 ("PCI: disable Bus Master on PCI device shutdown").

This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2

Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861
Reported-by: Chang Liu <cl91tp@gmail.com>
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org	# v3.5+
2013-12-07 14:20:28 -07:00
Tejun Heo b85d20404c cgroup: remove for_each_root_subsys()
After the previous patch which introduced for_each_css(),
for_each_root_subsys() only has two users left.  This patch replaces
it with for_each_subsys() + explicit subsys_mask testing and remove
for_each_root_subsys() along with cgroupfs_root->subsys_list handling.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:57 -05:00
Tejun Heo 1c6727af4b cgroup: implement for_each_css()
There are enough places where css's of a cgroup are iterated, which
currently uses for_each_root_subsys() + explicit cgroup_css().  This
patch implements for_each_css() and replaces the above combination
with it.

This patch doesn't introduce any behavior changes.

v2: Updated to apply cleanly on top of v2 of "cgroup: fix css leaks on
    online_css() failure"

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:56 -05:00
Tejun Heo c81c925ad9 cgroup: factor out cgroup_subsys_state creation into create_css()
Now that all opertations to create a css (cgroup_subsys_state) are
collected into a single loop in cgroup_create(), it's easy to factor
it out into its own function.  Factor out css creation into
create_css().  This makes the code easier to follow and will enable
decoupling css creation from cgroup creation which is necessary for
the planned unified hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:56 -05:00
Tejun Heo 9d403e9923 cgroup: combine css handling loops in cgroup_create()
Now that css operations in cgroup_create() are back-to-back, there
isn't much point in allocating css's in one loop and onlining them in
another.  Merge the two loops so that a css is allocated and onlined
on each iteration.

css_ar[] is no longer necessary and replaced with a single pointer.
This also simplifies the error handling path.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:56 -05:00
Tejun Heo 0d80255e42 cgroup: reorder operations in cgroup_create()
cgroup_create() currently does the followings.

1. alloc cgroup
2. alloc css's
3. create the directory and commit to cgroup creation
4. online css's
5. create cgroup and css files

The sequence performs allocations before other operations but it
doesn't buy anything because each of the above steps may fail and
should be unrollable.  Reorganize the sequence such that cgroup
operations are done before css operations.

1. alloc cgroup
2. create the directory and files and commit to cgroup creation
3. alloc css's
4. create files for and online css's

This simplifies the code a bit and enables further simplification and
separating out css creation from cgroup creation which is necessary
for the planned unified hierarchy where css's will be created and
destroyed dynamically across the lifetime of a cgroup.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:56 -05:00
Tejun Heo 780cd8b347 cgroup: make for_each_subsys() useable under cgroup_root_mutex
We want to use for_each_subsys() in cgroupfs_root handling where only
cgroup_root_mutex is held.  The only way cgroup_subsys[] can change is
through module load/unload, make cgroup_[un]load_subsys() grab
cgroup_root_mutex too and update the lockdep annotation in
for_each_subsys() to allow either cgroup_mutex or cgroup_root_mutex.

* Lockdep annotation is moved from inner 'if' condition to outer 'for'
  init caluse.  There's no reason to execute the assertion every loop.

* Loop index @i is renamed to @ssid.  Indices iterating through subsys
  will be [re]named to @ssid gradually.

v2: cgroup_assert_mutex_or_root_locked() caused build failure if
    !CONFIG_LOCKEDP.  Conditionalize its definition.  The build failure
    was reported by kbuild test bot.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: kbuild test robot <fengguang.wu@intel.com>
2013-12-06 15:11:56 -05:00
Tejun Heo 87fb54f1b5 cgroup: css iterations and css_from_dir() are safe under cgroup_mutex
Currently, all css iterations and css_from_dir() require RCU read lock
whether the caller is holding cgroup_mutex or not, which is
unnecessarily restrictive.  They are all safe to use under
cgroup_mutex without holding RCU read lock.

Factor out cgroup_assert_mutex_or_rcu_locked() from css_from_id() and
apply it to all css iteration functions and css_from_dir().

v2: cgroup_assert_mutex_or_rcu_locked() definition doesn't need to be
    inside CONFIG_PROVE_RCU ifdef as rcu_lockdep_assert() is always
    defined and conditionalized.  Move it outside of the ifdef block.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-06 15:11:55 -05:00
Tejun Heo e58e1ca438 Merge branch 'for-3.13-fixes' into for-3.14
Pulling in as patches depending on 266ccd505e ("cgroup: fix
cgroup_create() error handling path") are scheduled.

Signed-off-by: Tejun Heo <tj@kernel.org>
2013-12-06 15:09:27 -05:00
Tejun Heo 266ccd505e cgroup: fix cgroup_create() error handling path
ae7f164a09 ("cgroup: move cgroup->subsys[] assignment to
online_css()") moved cgroup->subsys[] assignements later in
cgroup_create() but didn't update error handling path accordingly
leading to the following oops and leaking later css's after an
online_css() failure.  The oops is from cgroup destruction path being
invoked on the partially constructed cgroup which is not ready to
handle empty slots in cgrp->subsys[] array.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff810eeaa8>] cgroup_destroy_locked+0x118/0x2f0
  PGD a780a067 PUD aadbe067 PMD 0
  Oops: 0000 [#1] SMP
  Modules linked in:
  CPU: 6 PID: 7360 Comm: mkdir Not tainted 3.13.0-rc2+ #69
  Hardware name:
  task: ffff8800b9dbec00 ti: ffff8800a781a000 task.ti: ffff8800a781a000
  RIP: 0010:[<ffffffff810eeaa8>]  [<ffffffff810eeaa8>] cgroup_destroy_locked+0x118/0x2f0
  RSP: 0018:ffff8800a781bd98  EFLAGS: 00010282
  RAX: ffff880586903878 RBX: ffff880586903800 RCX: ffff880586903820
  RDX: ffff880586903860 RSI: ffff8800a781bdb0 RDI: ffff880586903820
  RBP: ffff8800a781bde8 R08: ffff88060e0b8048 R09: ffffffff811d7bc1
  R10: 000000000000008c R11: 0000000000000001 R12: ffff8800a72286c0
  R13: 0000000000000000 R14: ffffffff81cf7a40 R15: 0000000000000001
  FS:  00007f60ecda57a0(0000) GS:ffff8806272c0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000008 CR3: 00000000a7a03000 CR4: 00000000000007e0
  Stack:
   ffff880586903860 ffff880586903910 ffff8800a72286c0 ffff880586903820
   ffffffff81cf7a40 ffff880586903800 ffff88060e0b8018 ffffffff81cf7a40
   ffff8800b9dbec00 ffff8800b9dbf098 ffff8800a781bec8 ffffffff810ef5bf
  Call Trace:
   [<ffffffff810ef5bf>] cgroup_mkdir+0x55f/0x5f0
   [<ffffffff811c90ae>] vfs_mkdir+0xee/0x140
   [<ffffffff811cb07e>] SyS_mkdirat+0x6e/0xf0
   [<ffffffff811c6a19>] SyS_mkdir+0x19/0x20
   [<ffffffff8169e569>] system_call_fastpath+0x16/0x1b

This patch moves reference bumping inside online_css() loop, clears
css_ar[] as css's are brought online successfully, and updates
err_destroy path so that either a css is fully online and destroyed by
cgroup_destroy_locked() or the error path frees it.  This creates a
duplicate css free logic in the error path but it will be cleaned up
soon.

v2: Li pointed out that cgroup_destroy_locked() would do NULL-deref if
    invoked with a cgroup which doesn't have all css's populated.
    Update cgroup_destroy_locked() so that it skips NULL css's.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Reported-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: stable@vger.kernel.org # v3.12+
2013-12-06 15:08:50 -05:00
Linus Torvalds 843f4f4bb1 A regression showed up that there's a large delay when enabling
all events. This was prevalent when FTRACE_SELFTEST was enabled which
 enables all events several times, and caused the system bootup to
 pause for over a minute.
 
 This was tracked down to an addition of a synchronize_sched() performed
 when system call tracepoints are unregistered.
 
 The synchronize_sched() is needed between the unregistering of the
 system call tracepoint and a deletion of a tracing instance buffer.
 But placing the synchronize_sched() in the unreg of *every* system call
 tracepoint is a bit overboard. A single synchronize_sched() before
 the deletion of the instance is sufficient.
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Merge tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A regression showed up that there's a large delay when enabling all
  events.  This was prevalent when FTRACE_SELFTEST was enabled which
  enables all events several times, and caused the system bootup to
  pause for over a minute.

  This was tracked down to an addition of a synchronize_sched()
  performed when system call tracepoints are unregistered.

  The synchronize_sched() is needed between the unregistering of the
  system call tracepoint and a deletion of a tracing instance buffer.
  But placing the synchronize_sched() in the unreg of *every* system
  call tracepoint is a bit overboard.  A single synchronize_sched()
  before the deletion of the instance is sufficient"

* tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Only run synchronize_sched() at instance deletion time
2013-12-06 08:34:16 -08:00
Steven Rostedt 3ccb012392 tracing: Only run synchronize_sched() at instance deletion time
It has been reported that boot up with FTRACE_SELFTEST enabled can take a
very long time. There can be stalls of over a minute.

This was tracked down to the synchronize_sched() called when a system call
event is disabled. As the self tests enable and disable thousands of events,
this makes the synchronize_sched() get called thousands of times.

The synchornize_sched() was added with d562aff93b "tracing: Add support
for SOFT_DISABLE to syscall events" which caused this regression (added
in 3.13-rc1).

The synchronize_sched() is to protect against the events being accessed
when a tracer instance is being deleted. When an instance is being deleted
all the events associated to it are unregistered. The synchronize_sched()
makes sure that no more users are running when it finishes.

Instead of calling synchronize_sched() for all syscall events, we only
need to call it once, after the events are unregistered and before the
instance is deleted. The event_mutex is held during this action to
prevent new users from enabling events.

Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.home

Reported-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: Petr Mladek <pmladek@suse.cz>
Tested-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-05 14:22:30 -05:00
Tejun Heo 6612f05b88 cgroup: unify pidlist and other file handling
In preparation of conversion to kernfs, cgroup file handling is
updated so that it can be easily mapped to kernfs.  With the previous
changes, the difference between pidlist and other files are very
small.  Both are served by seq_file in a pretty standard way with the
only difference being !pidlist files use single_open().

This patch adds cftype->seq_start(), ->seq_next and ->seq_stop() and
implements the matching cgroup_seqfile_start/next/stop() which either
emulates single_open() behavior or invokes cftype->seq_*() operations
if specified.  This allows using single seq_operations for both
pidlist and other files and makes cgroup_pidlist_operations and
cgorup_pidlist_open() no longer necessary.  As cgroup_pidlist_open()
was the only user of cftype->open(), the method is dropped together.

This brings cftype file interface very close to kernfs interface and
mapping shouldn't be too difficult.  Once converted to kernfs, most of
the plumbing code including cgroup_seqfile_*() will be removed as
kernfs provides those facilities.

This patch does not introduce any behavior changes.

v2: Refreshed on top of the updated "cgroup: introduce struct
    cgroup_pidlist_open_file".

v3: Refreshed on top of the updated "cgroup: attach cgroup_open_file
    to all cgroup files".

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:04 -05:00
Tejun Heo 2da8ca822d cgroup: replace cftype->read_seq_string() with cftype->seq_show()
In preparation of conversion to kernfs, cgroup file handling is
updated so that it can be easily mapped to kernfs.  This patch
replaces cftype->read_seq_string() with cftype->seq_show() which is
not limited to single_open() operation and will map directcly to
kernfs seq_file interface.

The conversions are mechanical.  As ->seq_show() doesn't have @css and
@cft, the functions which make use of them are converted to use
seq_css() and seq_cft() respectively.  In several occassions, e.f. if
it has seq_string in its name, the function name is updated to fit the
new method better.

This patch does not introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Aristeu Rozanski <arozansk@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
2013-12-05 12:28:04 -05:00
Tejun Heo 7da1127927 cgroup: attach cgroup_open_file to all cgroup files
In preparation of conversion to kernfs, cgroup file handling is
updated so that it can be easily mapped to kernfs.  This patch
attaches cgroup_open_file, which used to be attached to pidlist files,
to all cgroup files, introduces seq_css/cft() accessors to determine
the cgroup_subsys_state and cftype associated with a given cgroup
seq_file, exports them as public interface.

This doesn't cause any behavior changes but unifies cgroup file
handling across different file types and will help converting them to
kernfs seq_show() interface.

v2: Li pointed out that the original patch was using
    single_open_size() incorrectly assuming that the size param is
    private data size.  Fix it by allocating @of separately and
    passing it to single_open() and explicitly freeing it in the
    release path.  This isn't the prettiest but this path is gonna be
    restructured by the following patches pretty soon.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:04 -05:00
Tejun Heo 5d22444f42 cgroup: generalize cgroup_pidlist_open_file
In preparation of conversion to kernfs, cgroup file handling is
updated so that it can be easily mapped to kernfs.  This patch renames
cgroup_pidlist_open_file to cgroup_open_file and updates it so that it
only contains a field to identify the specific file, ->cfe, and an
opaque ->priv pointer.  When cgroup is converted to kernfs, this will
be replaced by kernfs_open_file which contains about the same
information.

As whether the file is "cgroup.procs" or "tasks" should now be
determined from cgroup_open_file->cfe, the cftype->private for the two
files now carry the file type and cgroup_pidlist_start() reads the
type through cfe->type->private.  This makes the distinction between
cgroup_tasks_open() and cgroup_procs_open() unnecessary.
cgroup_pidlist_open() is now directly used as the open method.

This patch doesn't make any behavior changes.

v2: Refreshed on top of the updated "cgroup: introduce struct
    cgroup_pidlist_open_file".

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:04 -05:00
Tejun Heo 896f519963 cgroup: unify read path so that seq_file is always used
With the recent removal of cftype->read() and ->read_map(), only three
operations are remaining, ->read_u64(), ->read_s64() and
->read_seq_string().  Currently, the first two are handled directly
while the last is handled through seq_file.

It is trivial to serve the first two through the seq_file path too.
This patch restructures read path so that all operations are served
through cgroup_seqfile_show().  This makes all cgroup files seq_file -
single_open/release() are now used by default,
cgroup_seqfile_operations is dropped, and cgroup_file_operations uses
seq_read() for read.

This simplifies the code and makes the read path easy to convert to
use kernfs.

Note that, while cgroup_file_operations uses seq_read() for read, it
still uses generic_file_llseek() for seeking instead of seq_lseek().
This is different from cgroup_seqfile_operations but shouldn't break
anything and brings the seeking behavior aligned with kernfs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:04 -05:00
Tejun Heo a742c59de6 cgroup: unify cgroup_write_X64() and cgroup_write_string()
cgroup_write_X64() and cgroup_write_string() both implement about the
same buffering logic.  Unify the two into cgroup_file_write() which
always allocates dynamic buffer for simplicity and uses kstrto*()
instead of simple_strto*().

This patch doesn't make any visible behavior changes except for
possibly different error value from kstrsto*().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:03 -05:00
Tejun Heo 6e0755b08d cgroup: remove cftype->read(), ->read_map() and ->write()
In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.

After recent updates, ->read() and ->read_map() don't have any user
left and ->write() never had any user.  Remove them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:03 -05:00
Tejun Heo 51ffe41178 cpuset: convert away from cftype->read()
In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.

All users of cftype->read() can be easily served, usually better, by
seq_file and other methods.  Rename cpuset_common_file_read() to
cpuset_common_read_seq_string() and convert it to use
read_seq_string() interface instead.  This not only simplifies the
code but also makes it more versatile.  Before, the file couldn't
output if the result is longer than PAGE_SIZE.  After the conversion,
seq_file automatically grows the buffer until the output can fit.

This patch doesn't make any visible behavior changes except for being
able to handle output larger than PAGE_SIZE.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-12-05 12:28:02 -05:00
Tejun Heo 44ffc75ba9 cgroup, sched: convert away from cftype->read_map()
In preparation of conversion to kernfs, cgroup file handling is being
consolidated so that it can be easily mapped to the seq_file based
interface of kernfs.

cftype->read_map() doesn't add any value and being replaced with
->read_seq_string().  Update cpu_stats_show() and cpuacct_stats_show()
accordingly.

This patch doesn't make any visible behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2013-12-05 12:28:01 -05:00
Mathias Krause c0e656b7a6 padata: Fix wrong usage of rcu_dereference()
A kernel with enabled lockdep complains about the wrong usage of
rcu_dereference() under a rcu_read_lock_bh() protected region.

  ===============================
  [ INFO: suspicious RCU usage. ]
  3.13.0-rc1+ #126 Not tainted
  -------------------------------
  linux/kernel/padata.c:115 suspicious rcu_dereference_check() usage!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 1
  1 lock held by cryptomgr_test/153:
   #0:  (rcu_read_lock_bh){.+....}, at: [<ffffffff8115c235>] padata_do_parallel+0x5/0x270

Fix that by using rcu_dereference_bh() instead.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-12-05 21:28:42 +08:00
Wanpeng Li 40ea2b42d7 sched/numa: Drop idx field of task_numa_env struct
Drop unused idx field of task_numa_env struct.

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1386241817-5051-2-git-send-email-liwanp@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-05 13:38:36 +01:00
Linus Torvalds 1ab231b274 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:

 - timekeeping: Cure a subtle drift issue on GENERIC_TIME_VSYSCALL_OLD

 - nohz: Make CONFIG_NO_HZ=n and nohz=off command line option behave the
   same way.  Fixes a long standing load accounting wreckage.

 - clocksource/ARM: Kconfig update to avoid ARM=n wreckage

 - clocksource/ARM: Fixlets for the AT91 and SH clocksource/clockevents

 - Trivial documentation update and kzalloc conversion from akpms pile

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off
  time: Fix 1ns/tick drift w/ GENERIC_TIME_VSYSCALL_OLD
  clocksource: arm_arch_timer: Hide eventstream Kconfig on non-ARM
  clocksource: sh_tmu: Add clk_prepare/unprepare support
  clocksource: sh_tmu: Release clock when sh_tmu_register() fails
  clocksource: sh_mtu2: Add clk_prepare/unprepare support
  clocksource: sh_mtu2: Release clock when sh_mtu2_register() fails
  ARM: at91: rm9200: switch back to clockevents_config_and_register
  tick: Document tick_do_timer_cpu
  timer: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...)
  NOHZ: Check for nohz active instead of nohz enabled
2013-12-04 08:52:09 -08:00
Ingo Molnar a934a56e12 Merge branch 'timers/core-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core
Pull dynticks updates from Frederic Weisbecker:

  * Fix a bug where posix cpu timers requeued due to interval got ignored on full
    dynticks CPUs (not a regression though as it only impacts full dynticks and the
    bug is there since we merged full dynticks).

  * Optimizations and cleanups on the use of per CPU APIs to improve code readability,
    performance and debuggability in the nohz subsystem;

  * Optimize posix cpu timer by sparing stub workqueue queue with full dynticks off case

  * Rename some functions to extend with *_this_cpu() suffix for clarity

  * Refine the naming of some context tracking subsystem state accessors

  * Trivial spelling fix by Paul Gortmaker

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-04 10:09:53 +01:00
Felipe Contreras 88a88b320a params: improve standard definitions
We are repeating the functionality of kstrtol in param_set_long, and the
same for kstrtoint. We can get rid of the extra code by using the right
functions.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-12-04 14:09:46 +10:30
Paul E. McKenney 3947909814 rcu: Let the world know when RCU adjusts its geometry
Some RCU bugs have been specific to the layout of the rcu_node tree,
but RCU will silently adjust the tree at boot time if appropriate.
This obscures valuable debugging information, so print a message when
this happens.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-03 10:10:19 -08:00
Paul E. McKenney 4461212aa0 rcu: Fix srcu_barrier() docbook header
The srcu_barrier() docbook header left out the "sp" argument, so this
commit adds that argument's docbook text.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-03 10:10:19 -08:00
Paul E. McKenney 3a5924052a rcu: Allow task-level idle entry/exit nesting
The current task-level idle entry/exit code forces an entry/exit on
each call, regardless of the nesting level.  This commit therefore
properly accounts for nesting.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
2013-12-03 10:10:19 -08:00
Paul E. McKenney 96d3fd0d31 rcu: Break call_rcu() deadlock involving scheduler and perf
Dave Jones got the following lockdep splat:

>  ======================================================
>  [ INFO: possible circular locking dependency detected ]
>  3.12.0-rc3+ #92 Not tainted
>  -------------------------------------------------------
>  trinity-child2/15191 is trying to acquire lock:
>   (&rdp->nocb_wq){......}, at: [<ffffffff8108ff43>] __wake_up+0x23/0x50
>
> but task is already holding lock:
>   (&ctx->lock){-.-...}, at: [<ffffffff81154c19>] perf_event_exit_task+0x109/0x230
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #3 (&ctx->lock){-.-...}:
>         [<ffffffff810cc243>] lock_acquire+0x93/0x200
>         [<ffffffff81733f90>] _raw_spin_lock+0x40/0x80
>         [<ffffffff811500ff>] __perf_event_task_sched_out+0x2df/0x5e0
>         [<ffffffff81091b83>] perf_event_task_sched_out+0x93/0xa0
>         [<ffffffff81732052>] __schedule+0x1d2/0xa20
>         [<ffffffff81732f30>] preempt_schedule_irq+0x50/0xb0
>         [<ffffffff817352b6>] retint_kernel+0x26/0x30
>         [<ffffffff813eed04>] tty_flip_buffer_push+0x34/0x50
>         [<ffffffff813f0504>] pty_write+0x54/0x60
>         [<ffffffff813e900d>] n_tty_write+0x32d/0x4e0
>         [<ffffffff813e5838>] tty_write+0x158/0x2d0
>         [<ffffffff811c4850>] vfs_write+0xc0/0x1f0
>         [<ffffffff811c52cc>] SyS_write+0x4c/0xa0
>         [<ffffffff8173d4e4>] tracesys+0xdd/0xe2
>
> -> #2 (&rq->lock){-.-.-.}:
>         [<ffffffff810cc243>] lock_acquire+0x93/0x200
>         [<ffffffff81733f90>] _raw_spin_lock+0x40/0x80
>         [<ffffffff810980b2>] wake_up_new_task+0xc2/0x2e0
>         [<ffffffff81054336>] do_fork+0x126/0x460
>         [<ffffffff81054696>] kernel_thread+0x26/0x30
>         [<ffffffff8171ff93>] rest_init+0x23/0x140
>         [<ffffffff81ee1e4b>] start_kernel+0x3f6/0x403
>         [<ffffffff81ee1571>] x86_64_start_reservations+0x2a/0x2c
>         [<ffffffff81ee1664>] x86_64_start_kernel+0xf1/0xf4
>
> -> #1 (&p->pi_lock){-.-.-.}:
>         [<ffffffff810cc243>] lock_acquire+0x93/0x200
>         [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
>         [<ffffffff810979d1>] try_to_wake_up+0x31/0x350
>         [<ffffffff81097d62>] default_wake_function+0x12/0x20
>         [<ffffffff81084af8>] autoremove_wake_function+0x18/0x40
>         [<ffffffff8108ea38>] __wake_up_common+0x58/0x90
>         [<ffffffff8108ff59>] __wake_up+0x39/0x50
>         [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
>         [<ffffffff81111450>] __call_rcu+0x140/0x820
>         [<ffffffff81111b8d>] call_rcu+0x1d/0x20
>         [<ffffffff81093697>] cpu_attach_domain+0x287/0x360
>         [<ffffffff81099d7e>] build_sched_domains+0xe5e/0x10a0
>         [<ffffffff81efa7fc>] sched_init_smp+0x3b7/0x47a
>         [<ffffffff81ee1f4e>] kernel_init_freeable+0xf6/0x202
>         [<ffffffff817200be>] kernel_init+0xe/0x190
>         [<ffffffff8173d22c>] ret_from_fork+0x7c/0xb0
>
> -> #0 (&rdp->nocb_wq){......}:
>         [<ffffffff810cb7ca>] __lock_acquire+0x191a/0x1be0
>         [<ffffffff810cc243>] lock_acquire+0x93/0x200
>         [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
>         [<ffffffff8108ff43>] __wake_up+0x23/0x50
>         [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
>         [<ffffffff81111450>] __call_rcu+0x140/0x820
>         [<ffffffff81111bb0>] kfree_call_rcu+0x20/0x30
>         [<ffffffff81149abf>] put_ctx+0x4f/0x70
>         [<ffffffff81154c3e>] perf_event_exit_task+0x12e/0x230
>         [<ffffffff81056b8d>] do_exit+0x30d/0xcc0
>         [<ffffffff8105893c>] do_group_exit+0x4c/0xc0
>         [<ffffffff810589c4>] SyS_exit_group+0x14/0x20
>         [<ffffffff8173d4e4>] tracesys+0xdd/0xe2
>
> other info that might help us debug this:
>
> Chain exists of:
>   &rdp->nocb_wq --> &rq->lock --> &ctx->lock
>
>   Possible unsafe locking scenario:
>
>         CPU0                    CPU1
>         ----                    ----
>    lock(&ctx->lock);
>                                 lock(&rq->lock);
>                                 lock(&ctx->lock);
>    lock(&rdp->nocb_wq);
>
>  *** DEADLOCK ***
>
> 1 lock held by trinity-child2/15191:
>  #0:  (&ctx->lock){-.-...}, at: [<ffffffff81154c19>] perf_event_exit_task+0x109/0x230
>
> stack backtrace:
> CPU: 2 PID: 15191 Comm: trinity-child2 Not tainted 3.12.0-rc3+ #92
>  ffffffff82565b70 ffff880070c2dbf8 ffffffff8172a363 ffffffff824edf40
>  ffff880070c2dc38 ffffffff81726741 ffff880070c2dc90 ffff88022383b1c0
>  ffff88022383aac0 0000000000000000 ffff88022383b188 ffff88022383b1c0
> Call Trace:
>  [<ffffffff8172a363>] dump_stack+0x4e/0x82
>  [<ffffffff81726741>] print_circular_bug+0x200/0x20f
>  [<ffffffff810cb7ca>] __lock_acquire+0x191a/0x1be0
>  [<ffffffff810c6439>] ? get_lock_stats+0x19/0x60
>  [<ffffffff8100b2f4>] ? native_sched_clock+0x24/0x80
>  [<ffffffff810cc243>] lock_acquire+0x93/0x200
>  [<ffffffff8108ff43>] ? __wake_up+0x23/0x50
>  [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
>  [<ffffffff8108ff43>] ? __wake_up+0x23/0x50
>  [<ffffffff8108ff43>] __wake_up+0x23/0x50
>  [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
>  [<ffffffff81111450>] __call_rcu+0x140/0x820
>  [<ffffffff8109bc8f>] ? local_clock+0x3f/0x50
>  [<ffffffff81111bb0>] kfree_call_rcu+0x20/0x30
>  [<ffffffff81149abf>] put_ctx+0x4f/0x70
>  [<ffffffff81154c3e>] perf_event_exit_task+0x12e/0x230
>  [<ffffffff81056b8d>] do_exit+0x30d/0xcc0
>  [<ffffffff810c9af5>] ? trace_hardirqs_on_caller+0x115/0x1e0
>  [<ffffffff810c9bcd>] ? trace_hardirqs_on+0xd/0x10
>  [<ffffffff8105893c>] do_group_exit+0x4c/0xc0
>  [<ffffffff810589c4>] SyS_exit_group+0x14/0x20
>  [<ffffffff8173d4e4>] tracesys+0xdd/0xe2

The underlying problem is that perf is invoking call_rcu() with the
scheduler locks held, but in NOCB mode, call_rcu() will with high
probability invoke the scheduler -- which just might want to use its
locks.  The reason that call_rcu() needs to invoke the scheduler is
to wake up the corresponding rcuo callback-offload kthread, which
does the job of starting up a grace period and invoking the callbacks
afterwards.

One solution (championed on a related problem by Lai Jiangshan) is to
simply defer the wakeup to some point where scheduler locks are no longer
held.  Since we don't want to unnecessarily incur the cost of such
deferral, the task before us is threefold:

1.	Determine when it is likely that a relevant scheduler lock is held.

2.	Defer the wakeup in such cases.

3.	Ensure that all deferred wakeups eventually happen, preferably
	sooner rather than later.

We use irqs_disabled_flags() as a proxy for relevant scheduler locks
being held.  This works because the relevant locks are always acquired
with interrupts disabled.  We may defer more often than needed, but that
is at least safe.

The wakeup deferral is tracked via a new field in the per-CPU and
per-RCU-flavor rcu_data structure, namely ->nocb_defer_wakeup.

This flag is checked by the RCU core processing.  The __rcu_pending()
function now checks this flag, which causes rcu_check_callbacks()
to initiate RCU core processing at each scheduling-clock interrupt
where this flag is set.  Of course this is not sufficient because
scheduling-clock interrupts are often turned off (the things we used to
be able to count on!).  So the flags are also checked on entry to any
state that RCU considers to be idle, which includes both NO_HZ_IDLE idle
state and NO_HZ_FULL user-mode-execution state.

This approach should allow call_rcu() to be invoked regardless of what
locks you might be holding, the key word being "should".

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2013-12-03 10:10:18 -08:00
Paul E. McKenney 78e4bc34e5 rcu: Fix and comment ordering around wait_event()
It is all too easy to forget that wait_event() does not necessarily
imply a full memory barrier.  The case where it does not is where the
condition transitions to true just as wait_event() starts execution.
This is actually a feature: The standard use of wait_event() involves
locking, in which case the locks provide the needed ordering (you hold a
lock across the wake_up() and acquire that same lock after wait_event()
returns).

Given that I did forget that wait_event() does not necessarily imply a
full memory barrier in one case, this commit fixes that case.  This commit
also adds comments calling out the placement of existing memory barriers
relied on by wait_event() calls.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-03 10:10:18 -08:00
Paul E. McKenney 6193c76aba rcu: Kick CPU halfway to RCU CPU stall warning
When an RCU CPU stall warning occurs, the CPU invokes resched_cpu() on
itself.  This can help move the grace period forward in some situations,
but it would be even better to do this -before- the RCU CPU stall warning.
This commit therefore causes resched_cpu() to be called every five jiffies
once the system is halfway to an RCU CPU stall warning.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-03 10:10:18 -08:00
Frederic Weisbecker c925077c33 posix-timers: Fix full dynticks CPUs kick on timer rescheduling
A posix CPU timer can be rearmed while it is firing or after it is
notified with a signal. This can happen for example with timers that
were set with a non zero interval in timer_settime().

This rearming can happen in two places:

1) On timer firing time, which happens on the target's tick. If the timer
can't trigger a signal because it is ignored, it reschedules itself
to honour the timer interval.

2) On signal handling from the timer's notification target. This one
can be a different task than the timer's target itself. Once the
signal is notified, the notification target rearms the timer, again
to honour the timer interval.

When a timer is rearmed, we need to notify the full dynticks CPUs
such that they restart their tick in case they are running tasks that
may have a share in elapsing this timer.

Now the 1st case above handles full dynticks CPUs with a call to
posix_cpu_timer_kick_nohz() from the posix cpu timer firing code. But
the second case ignores the fact that some CPUs may run non-idle tasks
with their tick off. As a result, when a timer is resheduled after its signal
notification, the full dynticks CPUs may completely ignore it and not
tick on the timer as expected

This patch fixes this bug by handling both cases in one. All we need
is to move the kick to the rearming common code in posix_cpu_timer_schedule().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Olivier Langlois <olivier@olivierlanglois.net>
2013-12-02 20:46:27 +01:00
Frederic Weisbecker d4283c6541 posix-timers: Spare workqueue if there is no full dynticks CPU to kick
After a posix cpu timer is set, a workqueue is scheduled in order to
kick the full dynticks CPUs and let them restart their tick if
necessary in case the task they are running is concerned by the
new timer.

This kick is implemented by way of IPIs, which require interrupts
to be enabled, hence the need for a workqueue to raise them because
the posix cpu timer set path has interrupts disabled.

Now if there is no full dynticks CPU on the system, the workqueue is
still scheduled but it simply won't send any IPI and return immediately.

So lets spare that worqueue when it is not needed.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-12-02 20:43:16 +01:00
Frederic Weisbecker 58135f574f context_tracking: Wrap static key check into more intuitive function name
Use a function with a meaningful name to check the global context
tracking state. static_key_false() is a bit confusing for reviewers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-12-02 20:43:14 +01:00
Frederic Weisbecker e8fcaa5c54 nohz: Convert a few places to use local per cpu accesses
A few functions use remote per CPU access APIs when they
deal with local values.

Just do the right conversion to improve performance, code
readability and debug checks.

While at it, lets extend some of these function names with *_this_cpu()
suffix in order to display their purpose more clearly.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-12-02 20:39:30 +01:00
Linus Torvalds a45299e727 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 - Correction of fuzzy and fragile IRQ_RETVAL macro
 - IRQ related resume fix affecting only XEN
 - ARM/GIC fix for chained GIC controllers

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Gic: fix boot for chained gics
  irq: Enable all irqs unconditionally in irq_resume
  genirq: Correct fuzzy and fragile IRQ_RETVAL() definition
2013-12-02 10:15:39 -08:00
Linus Torvalds a0b57ca33e Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Various smaller fixlets, all over the place"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Fix generation of device-drivers
  sched: Expose preempt_schedule_irq()
  sched: Fix a trivial typo in comments
  sched: Remove unused variable in 'struct sched_domain'
  sched: Avoid NULL dereference on sd_busy
  sched: Check sched_domain before computing group power
  MAINTAINERS: Update file patterns in the lockdep and scheduler entries
2013-12-02 10:13:44 -08:00
Linus Torvalds e321ae4c20 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Misc kernel and tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools lib traceevent: Fix conversion of pointer to integer of different size
  perf/trace: Properly use u64 to hold event_id
  perf: Remove fragile swevent hlist optimization
  ftrace, perf: Avoid infinite event generation loop
  tools lib traceevent: Fix use of multiple options in processing field
  perf header: Fix possible memory leaks in process_group_desc()
  perf header: Fix bogus group name
  perf tools: Tag thread comm as overriden
2013-12-02 10:13:09 -08:00
Leonardo Potenza e0c7855e36 PM / hibernate: export hibernation_set_ops
To support the ability to implement PM hibernation code as modules
the hibernation_set_ops function requires to be exported.

Similar solution already available for suspend_set_ops
(please refer to commit a5e4fd8783).

Signed-off-by: Leonardo Potenza <leonardo.potenza@intel.com>
Signed-off-by: Edwin Verplanke <edwin.verplanke@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-30 15:12:16 +01:00
Linus Torvalds 7224b31bd5 Merge branch 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
 "This contains one important fix.  The NUMA support added a while back
  broke ordering guarantees on ordered workqueues.  It was enforced by
  having single frontend interface with @max_active == 1 but the NUMA
  support puts multiple interfaces on unbound workqueues on NUMA
  machines thus breaking the ordered guarantee.  This is fixed by
  disabling NUMA support on ordered workqueues.

  The above and a couple other patches were sitting in for-3.12-fixes
  but I forgot to push that out, so they ended up waiting a bit too
  long.  My aplogies.

  Other fixes are minor"

* 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix pool ID allocation leakage and remove BUILD_BUG_ON() in init_workqueues
  workqueue: fix comment typo for __queue_work()
  workqueue: fix ordered workqueues in NUMA setups
  workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY
2013-11-29 09:49:08 -08:00
Linus Torvalds 2855987d13 Merge branch 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "Fixes for three issues.

   - cgroup destruction path could swamp system_wq possibly leading to
     deadlock.  This actually seems to happen in the wild with memcg
     because memcg destruction path adds nested dependency on system_wq.

     Resolved by isolating cgroup destruction work items on its
     dedicated workqueue.

   - Possible locking context deadlock through seqcount reported by
     lockdep

   - Memory leak under certain conditions"

* 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix cgroup_subsys_state leak for seq_files
  cpuset: Fix memory allocator deadlock
  cgroup: use a dedicated workqueue for cgroup destruction
2013-11-29 09:47:06 -08:00
Tejun Heo afb2bc14e1 cgroup: don't guarantee cgroup.procs is sorted if sane_behavior
For some reason, tasks and cgroup.procs guarantee that the result is
sorted.  This is the only reason this whole pidlist logic is necessary
instead of just iterating through sorted member tasks.  We can't do
anything about the existing interface but at least ensure that such
expectation doesn't exist for the new interface so that pidlist logic
may be removed in the distant future.

This patch scrambles the sort order if sane_behavior so that the
output is usually not sorted in the new interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:59 -05:00
Tejun Heo 045023658c cgroup: remove cgroup_pidlist->use_count
After the recent changes, pidlist ref is held only between
cgroup_pidlist_start() and cgroup_pidlist_stop() during which
cgroup->pidlist_mutex is also held.  IOW, the reference count is
redundant now.  While in use, it's always one and pidlist_mutex is
held - holding the mutex has exactly the same protection.

This patch collapses destroy_dwork queueing into cgroup_pidlist_stop()
so that pidlist_mutex is not released inbetween and drops
pidlist->use_count.

This patch shouldn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:59 -05:00
Tejun Heo 4bac00d16a cgroup: load and release pidlists from seq_file start and stop respectively
Currently, pidlists are reference counted from file open and release
methods.  This means that holding onto an open file may waste memory
and reads may return data which is very stale.  Both aren't critical
because pidlists are keyed and shared per namespace and, well, the
user isn't supposed to have large delay between open and reads.

cgroup is planned to be converted to use kernfs and it'd be best if we
can stick to just the seq_file operations - start, next, stop and
show.  This can be achieved by loading pidlist on demand from start
and release with time delay from stop, so that consecutive reads don't
end up reloading the pidlist on each iteration.  This would remove the
need for hooking into open and release while also avoiding issues with
holding onto pidlist for too long.

The previous patches implemented delayed release and restructured
pidlist handling so that pidlists can be loaded and released from
seq_file start / stop.  This patch actually moves pidlist load to
start and release to stop.

This means that pidlist is pinned only between start and stop and may
go away between two consecutive read calls if the two calls are apart
by more than CGROUP_PIDLIST_DESTROY_DELAY.  cgroup_pidlist_start()
thus can't re-use the stored cgroup_pid_list_open_file->pidlist
directly.  During start, it's only used as a hint indicating whether
this is the first start after open or not and pidlist is always looked
up or created.

pidlist_mutex locking and reference counting are moved out of
pidlist_array_load() so that pidlist_array_load() can perform lookup
and creation atomically.  While this enlarges the area covered by
pidlist_mutex, given how the lock is used, it's highly unlikely to be
noticeable.

v2: Refreshed on top of the updated "cgroup: introduce struct
    cgroup_pidlist_open_file".

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:59 -05:00
Tejun Heo 069df3b7ae cgroup: remove cgroup_pidlist->rwsem
cgroup_pidlist locking is needlessly complicated.  It has outer
cgroup->pidlist_mutex to protect the list of pidlists associated with
a cgroup and then each pidlist has rwsem to synchronize updates and
reads.  Given that the only read access is from seq_file operations
which are always invoked back-to-back, the rwsem is a giant overkill.
All it does is adding unnecessary complexity.

This patch removes cgroup_pidlist->rwsem and protects all accesses to
pidlists belonging to a cgroup with cgroup->pidlist_mutex.
pidlist->rwsem locking is removed if it's nested inside
cgroup->pidlist_mutex; otherwise, it's replaced with
cgroup->pidlist_mutex locking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:59 -05:00
Tejun Heo e6b817103d cgroup: refactor cgroup_pidlist_find()
Rename cgroup_pidlist_find() to cgroup_pidlist_find_create() and
separate out finding proper to cgroup_pidlist_find().  Also, move
locking to the caller.

This patch is preparation for pidlist restructure and doesn't
introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:59 -05:00
Tejun Heo 62236858f3 cgroup: introduce struct cgroup_pidlist_open_file
For pidlist files, seq_file->private pointed to the loaded
cgroup_pidlist; however, pidlist loading is planned to be moved to
cgroup_pidlist_start() for kernfs conversion and seq_file->private
needs to carry more information from open to allow that.

This patch introduces struct cgroup_pidlist_open_file which contains
type, cgrp and pidlist and updates pidlist seq_file->private to point
to it using seq_open_private() and seq_release_private().  Note that
this eventually will be replaced by kernfs_open_file.

While this patch makes more information available to seq_file
operations, they don't use it yet and this patch doesn't introduce any
behavior changes except for allocation of the extra private struct.

v2: use __seq_open_private() instead of seq_open_private() for brevity
    as suggested by Li.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:58 -05:00
Tejun Heo b1a2136731 cgroup: implement delayed destruction for cgroup_pidlist
Currently, pidlists are reference counted from file open and release
methods.  This means that holding onto an open file may waste memory
and reads may return data which is very stale.  Both aren't critical
because pidlists are keyed and shared per namespace and, well, the
user isn't supposed to have large delay between open and reads.

cgroup is planned to be converted to use kernfs and it'd be best if we
can stick to just the seq_file operations - start, next, stop and
show.  This can be achieved by loading pidlist on demand from start
and release with time delay from stop, so that consecutive reads don't
end up reloading the pidlist on each iteration.  This would remove the
need for hooking into open and release while also avoiding issues with
holding onto pidlist for too long.

This patch implements delayed release of pidlist.  As pidlists could
be lingering on cgroup removal waiting for the timer to expire, cgroup
free path needs to queue the destruction work item immediately and
flush.  As those work items are self-destroying, each work item can't
be flushed directly.  A new workqueue - cgroup_pidlist_destroy_wq - is
added to serve as flush domain.

Note that this patch just adds delayed release on top of the current
implementation and doesn't change where pidlist is loaded and
released.  Following patches will make those changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:58 -05:00
Tejun Heo b9f3cecaba cgroup: remove cftype->release()
Now that pidlist files don't use cftype->release(), it doesn't have
any user left.  Remove it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:58 -05:00
Tejun Heo ac1e69aa78 cgroup: don't skip seq_open on write only opens on pidlist files
Currently, cgroup_pidlist_open() skips seq_open() and pidlist loading
if the file is opened write-only, which is a sensible optimization as
pidlist loading can be costly and there often are occasions where
tasks or cgroup.procs is opened write-only.  However, pidlist init and
release are planned to be moved to cgroup_pidlist_start/stop()
respectively which would make this optimization unnecessary.

This patch removes the optimization and always fully initializes
pidlist files regardless of open mode.  This will help moving pidlist
handling to start/stop by unifying rw paths and removes the need for
specifying cftype->release() in addition to .release in
cgroup_pidlist_operations as file->f_op is now always overridden.  As
pidlist files were the only user of cftype->release(), the next patch
will remove the method.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
2013-11-29 10:42:58 -05:00
Thomas Gleixner 0e576acbc1 nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off
If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ.

If CONFIG_NO_HZ=y and the nohz functionality is disabled via the
command line option "nohz=off" or not enabled due to missing hardware
support, then tick_nohz_get_sleep_length() returns 0. That happens
because ts->sleep_length is never set in that case.

Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive.

Reported-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-11-29 12:23:03 +01:00
Helge Deller 5ecbe3c3c6 kernel/extable: fix address-checks for core_kernel and init areas
The init_kernel_text() and core_kernel_text() functions should not
include the labels _einittext and _etext when checking if an address is
inside the .text or .init sections.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-28 09:49:41 -08:00
Tejun Heo c729b11edf cgroup: Merge branch 'for-3.13-fixes' into for-3.14
Pull to receive e605b36575 ("cgroup: fix cgroup_subsys_state leak
for seq_files") as for-3.14 is scheduled to have a lot of changes
which depend on it.

Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-27 18:17:27 -05:00
Tejun Heo e605b36575 cgroup: fix cgroup_subsys_state leak for seq_files
If a cgroup file implements either read_map() or read_seq_string(),
such file is served using seq_file by overriding file->f_op to
cgroup_seqfile_operations, which also overrides the release method to
single_release() from cgroup_file_release().

Because cgroup_file_open() didn't use to acquire any resources, this
used to be fine, but since f7d58818ba ("cgroup: pin
cgroup_subsys_state when opening a cgroupfs file"), cgroup_file_open()
pins the css (cgroup_subsys_state) which is put by
cgroup_file_release().  The patch forgot to update the release path
for seq_files and each open/release cycle leaks a css reference.

Fix it by updating cgroup_file_release() to also handle seq_files and
using it for seq_file release path too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v3.12
2013-11-27 18:16:21 -05:00
Peter Zijlstra 0fc0287c9e cpuset: Fix memory allocator deadlock
Juri hit the below lockdep report:

[    4.303391] ======================================================
[    4.303392] [ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]
[    4.303394] 3.12.0-dl-peterz+ #144 Not tainted
[    4.303395] ------------------------------------------------------
[    4.303397] kworker/u4:3/689 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[    4.303399]  (&p->mems_allowed_seq){+.+...}, at: [<ffffffff8114e63c>] new_slab+0x6c/0x290
[    4.303417]
[    4.303417] and this task is already holding:
[    4.303418]  (&(&q->__queue_lock)->rlock){..-...}, at: [<ffffffff812d2dfb>] blk_execute_rq_nowait+0x5b/0x100
[    4.303431] which would create a new lock dependency:
[    4.303432]  (&(&q->__queue_lock)->rlock){..-...} -> (&p->mems_allowed_seq){+.+...}
[    4.303436]

[    4.303898] the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock:
[    4.303918] -> (&p->mems_allowed_seq){+.+...} ops: 2762 {
[    4.303922]    HARDIRQ-ON-W at:
[    4.303923]                     [<ffffffff8108ab9a>] __lock_acquire+0x65a/0x1ff0
[    4.303926]                     [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303929]                     [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303931]                     [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303933]    SOFTIRQ-ON-W at:
[    4.303933]                     [<ffffffff8108abcc>] __lock_acquire+0x68c/0x1ff0
[    4.303935]                     [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303940]                     [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303955]                     [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303959]    INITIAL USE at:
[    4.303960]                    [<ffffffff8108a884>] __lock_acquire+0x344/0x1ff0
[    4.303963]                    [<ffffffff8108cbe3>] lock_acquire+0x93/0x140
[    4.303966]                    [<ffffffff81063dd6>] kthreadd+0x86/0x180
[    4.303969]                    [<ffffffff816ded6c>] ret_from_fork+0x7c/0xb0
[    4.303972]  }

Which reports that we take mems_allowed_seq with interrupts enabled. A
little digging found that this can only be from
cpuset_change_task_nodemask().

This is an actual deadlock because an interrupt doing an allocation will
hit get_mems_allowed()->...->__read_seqcount_begin(), which will spin
forever waiting for the write side to complete.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Reported-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Juri Lelli <juri.lelli@gmail.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
2013-11-27 13:52:47 -05:00
Dario Faggioli e6c390f2df sched: Add sched_class->task_dead() method
Add a new function to the scheduling class interface. It is called
at the end of a context switch, if the prev task is in TASK_DEAD state.

It will be useful for the scheduling classes that want to be notified
when one of their tasks dies, e.g. to perform some cleanup actions,
such as SCHED_DEADLINE.

Signed-off-by: Dario Faggioli <raistlin@linux.it>
Reviewed-by: Paul Turner <pjt@google.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Cc: bruce.ashfield@windriver.com
Cc: claudio@evidence.eu.com
Cc: darren@dvhart.com
Cc: dhaval.giani@gmail.com
Cc: fchecconi@gmail.com
Cc: fweisbec@gmail.com
Cc: harald.gustafsson@ericsson.com
Cc: hgu1972@gmail.com
Cc: insop.song@gmail.com
Cc: jkacur@redhat.com
Cc: johan.eker@ericsson.com
Cc: liming.wang@windriver.com
Cc: luca.abeni@unitn.it
Cc: michael@amarulasolutions.com
Cc: nicola.manica@disi.unitn.it
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: p.faure@akatech.ch
Cc: rostedt@goodmis.org
Cc: tommaso.cucinotta@sssup.it
Cc: vincent.guittot@linaro.org
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1383831828-15501-2-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 14:08:50 +01:00
Kamalesh Babulal 380c9077b3 sched/fair: Clean up update_sg_lb_stats() a bit
Add rq->nr_running to sgs->sum_nr_running directly instead of
assigning it through an intermediate variable nr_running.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1384508212-25032-1-git-send-email-kamalesh@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 13:50:57 +01:00
Vincent Guittot c44f2a0200 sched/fair: Move load idx selection in find_idlest_group
load_idx is used in find_idlest_group but initialized in select_task_rq_fair
even when not used. The load_idx initialisation is moved in find_idlest_group
and the sd_flag replaces it in the function's args.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: len.brown@intel.com
Cc: amit.kucheria@linaro.org
Cc: pjt@google.com
Cc: l.majewski@samsung.com
Cc: Morten.Rasmussen@arm.com
Cc: cmetcalf@tilera.com
Cc: tony.luck@intel.com
Cc: alex.shi@intel.com
Cc: preeti@linux.vnet.ibm.com
Cc: linaro-kernel@lists.linaro.org
Cc: rjw@sisk.pl
Cc: paulmck@linux.vnet.ibm.com
Cc: corbet@lwn.net
Cc: arjan@linux.intel.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1382097147-30088-8-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 13:50:54 +01:00
Oleg Nesterov 192301e70a sched: Check TASK_DEAD rather than EXIT_DEAD in schedule_debug()
schedule_debug() ignores in_atomic() if prev->exit_state != 0.
This is not what we want, ->exit_state is set by exit_notify()
but we should complain until the task does the last schedule()
in TASK_DEAD.

See also 7407251a0e "PF_DEAD cleanup", I think this ancient
commit explains why schedule() had to rely on ->exit_state,
until that commit exit_notify() disabled preemption and set
PF_DEAD which was used to detect the exiting task.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131113154538.GB15810@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 13:50:53 +01:00
Oleg Nesterov bb8cbbfee6 tasks/fork: Remove unnecessary child->exit_state
A zombie task obviously can't fork(), remove the unnecessary
initialization of child->exit_state. It is zero anyway after
dup_task_struct().

Note: copy_process() is huge and it has a lot of chaotic
initializations, probably it makes sense to move them into the
new helper called by dup_task_struct().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131113143612.GA10540@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 13:50:50 +01:00
Sasha Levin 8dce7a9a6f lockdep: Be nice about building from userspace
Lockdep is an awesome piece of code which detects locking issues
which are relevant both to userspace and kernelspace. We can
easily make lockdep work in userspace since there is really no
kernel spacific magic going on in the code.

All we need is to wrap two functions which are used by lockdep
and are very kernel specific.

Doing that will allow tools located in tools/ to easily utilize
lockdep's code for their own use.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: penberg@kernel.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/1352753446-24109-1-git-send-email-sasha.levin@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 11:55:20 +01:00
Stephane Eranian 71ad88efeb perf: Add active_entry list head to struct perf_event
This patch adds a new field to the struct perf_event.
It is intended to be used to chain events which are
active (enabled). It helps in the hardware layer
for PMUs which do not have actual counter restrictions, i.e.,
free running read-only counters. Active events are chained
as opposed to being tracked via the counter they use.

To save space we use a union with hlist_entry as both
are mutually exclusive (suggested by Jiri Olsa).

Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: acme@redhat.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: maria.n.dimakopoulou@gmail.com
Link: http://lkml.kernel.org/r/1384275531-10892-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 11:16:38 +01:00
Frederic Weisbecker 5c4853b60c lockdep: Simplify a bit hardirq <-> softirq transitions
Instead of saving the hardirq state on a per CPU variable, which require
an explicit call before the softirq handling and some complication,
just save and restore the hardirq tracing state through functions
return values and parameters.

It simplifies a bit the black magic that works around the fact that
softirqs can be called from hardirqs while hardirqs can nest on softirqs
but those two cases have very different semantics and only the latter
case assume both states.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1384906054-30676-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 11:09:40 +01:00
Ingo Molnar 7d5b158310 Merge branch 'core/urgent' into core/locking
Prepare for dependent patch.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 11:09:19 +01:00
Thomas Gleixner 32e475d76a sched: Expose preempt_schedule_irq()
Tony reported that aa0d532605 ("ia64: Use preempt_schedule_irq")
broke PREEMPT=n builds on ia64.

Ok, wrapped my brain around it. I tripped over the magic asm foo which
has a single need_resched check and schedule point for both sys call
return and interrupt return.

So you need the schedule_preempt_irq() for kernel preemption from
interrupt return while on a normal syscall preemption a schedule would
be sufficient. But using schedule_preempt_irq() is not harmful here in
any way. It just sets the preempt_active bit also in cases where it
would not be required.

Even on preempt=n kernels adding the preempt_active bit is completely
harmless. So instead of having an extra function, moving the existing
one out of the ifdef PREEMPT looks like the sanest thing to do.

It would also allow getting rid of various other sti/schedule/cli asm
magic in other archs.

Reported-and-Tested-by: Tony Luck <tony.luck@gmail.com>
Fixes: aa0d532605 ("ia64: Use preempt_schedule_irq")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[slightly edited Changelog]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311211230030.30673@ionos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-27 11:04:53 +01:00
Eric W. Biederman 1f7f4dde5c fork: Allow CLONE_PARENT after setns(CLONE_NEWPID)
Serge Hallyn <serge.hallyn@ubuntu.com> writes:
> Hi Oleg,
>
> commit 40a0d32d1e :
> "fork: unify and tighten up CLONE_NEWUSER/CLONE_NEWPID checks"
> breaks lxc-attach in 3.12.  That code forks a child which does
> setns() and then does a clone(CLONE_PARENT).  That way the
> grandchild can be in the right namespaces (which the child was
> not) and be a child of the original task, which is the monitor.
>
> lxc-attach in 3.11 was working fine with no side effects that I
> could see.  Is there a real danger in allowing CLONE_PARENT
> when current->nsproxy->pidns_for_children is not our pidns,
> or was this done out of an "over-abundance of caution"?  Can we
> safely revert that new extra check?

The two fundamental things I know we can not allow are:
- A shared signal queue aka CLONE_THREAD.  Because we compute the pid
  and uid of the signal when we place it in the queue.

- Changing the pid and by extention pid_namespace of an existing
  process.

From a parents perspective there is nothing special about the pid
namespace, to deny CLONE_PARENT, because the parent simply won't know or
care.

From the childs perspective all that is special really are shared signal
queues.

User mode threading with CLONE_PARENT|CLONE_VM|CLONE_SIGHAND and tasks
in different pid namespaces is almost certainly going to break because
it is complicated.  But shared signal handlers can look at per thread
information to know which pid namespace a process is in, so I don't know
of any reason not to support CLONE_PARENT|CLONE_VM|CLONE_SIGHAND threads
at the kernel level.  It would be absolutely stupid to implement but
that is a different thing.

So hmm.

Because it can do no harm, and because it is a regression let's remove
the CLONE_PARENT check and send it stable.

Cc: stable@vger.kernel.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-11-26 20:54:15 -08:00
Linus Torvalds 8ae516aa8b This includes two fixes.
1) is a bug fix that happens when root does the following:
 
   echo function_graph > current_tracer
   modprobe foo
   echo nop > current_tracer
 
 This causes the ftrace internal accounting to get screwed up and
 crashes ftrace, preventing the user from using the function tracer
 after that.
 
 2) if a TRACE_EVENT has a string field, and NULL is given for it.
 
 The internal trace event code does a strlen() and strcpy() on the
 source of field. If it is NULL it causes the system to oops.
 
 This bug has been there since 2.6.31, but no TRACE_EVENT ever passed
 in a NULL to the string field, until now.
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Merge tag 'trace-fixes-v3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This includes two fixes.

  1) is a bug fix that happens when root does the following:

     echo function_graph > current_tracer
     modprobe foo
     echo nop > current_tracer

   This causes the ftrace internal accounting to get screwed up and
   crashes ftrace, preventing the user from using the function tracer
   after that.

  2) if a TRACE_EVENT has a string field, and NULL is given for it.

   The internal trace event code does a strlen() and strcpy() on the
   source of field.  If it is NULL it causes the system to oops.

   This bug has been there since 2.6.31, but no TRACE_EVENT ever passed
   in a NULL to the string field, until now"

* tag 'trace-fixes-v3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function graph with loading of modules
  tracing: Allow events to have NULL strings
2013-11-26 18:04:21 -08:00
Shigeru Yoshida 39e24d8ffb sched: Fix a trivial syntax misuse
Use if statement instead of while loop.

Signed-off-by: Shigeru Yoshida <shigeru.yoshida@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <trivial@kernel.org>
Link: http://lkml.kernel.org/r/20131123.183801.769652906919404319.shigeru.yoshida@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-26 18:37:55 +01:00
Steven Rostedt (Red Hat) 8a56d7761d ftrace: Fix function graph with loading of modules
Commit 8c4f3c3fa9 "ftrace: Check module functions being traced on reload"
fixed module loading and unloading with respect to function tracing, but
it missed the function graph tracer. If you perform the following

 # cd /sys/kernel/debug/tracing
 # echo function_graph > current_tracer
 # modprobe nfsd
 # echo nop > current_tracer

You'll get the following oops message:

 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 2910 at /linux.git/kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.35+0x168/0x1b9()
 Modules linked in: nfsd exportfs nfs_acl lockd ipt_MASQUERADE sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables uinput snd_hda_codec_idt
 CPU: 2 PID: 2910 Comm: bash Not tainted 3.13.0-rc1-test #7
 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
  0000000000000668 ffff8800787efcf8 ffffffff814fe193 ffff88007d500000
  0000000000000000 ffff8800787efd38 ffffffff8103b80a 0000000000000668
  ffffffff810b2b9a ffffffff81a48370 0000000000000001 ffff880037aea000
 Call Trace:
  [<ffffffff814fe193>] dump_stack+0x4f/0x7c
  [<ffffffff8103b80a>] warn_slowpath_common+0x81/0x9b
  [<ffffffff810b2b9a>] ? __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [<ffffffff8103b83e>] warn_slowpath_null+0x1a/0x1c
  [<ffffffff810b2b9a>] __ftrace_hash_rec_update.part.35+0x168/0x1b9
  [<ffffffff81502f89>] ? __mutex_lock_slowpath+0x364/0x364
  [<ffffffff810b2cc2>] ftrace_shutdown+0xd7/0x12b
  [<ffffffff810b47f0>] unregister_ftrace_graph+0x49/0x78
  [<ffffffff810c4b30>] graph_trace_reset+0xe/0x10
  [<ffffffff810bf393>] tracing_set_tracer+0xa7/0x26a
  [<ffffffff810bf5e1>] tracing_set_trace_write+0x8b/0xbd
  [<ffffffff810c501c>] ? ftrace_return_to_handler+0xb2/0xde
  [<ffffffff811240a8>] ? __sb_end_write+0x5e/0x5e
  [<ffffffff81122aed>] vfs_write+0xab/0xf6
  [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
  [<ffffffff81122dbd>] SyS_write+0x59/0x82
  [<ffffffff8150a185>] ftrace_graph_caller+0x85/0x85
  [<ffffffff8150a2d2>] system_call_fastpath+0x16/0x1b
 ---[ end trace 940358030751eafb ]---

The above mentioned commit didn't go far enough. Well, it covered the
function tracer by adding checks in __register_ftrace_function(). The
problem is that the function graph tracer circumvents that (for a slight
efficiency gain when function graph trace is running with a function
tracer. The gain was not worth this).

The problem came with ftrace_startup() which should always be called after
__register_ftrace_function(), if you want this bug to be completely fixed.

Anyway, this solution moves __register_ftrace_function() inside of
ftrace_startup() and removes the need to call them both.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Fixes: ed926f9b35 ("ftrace: Use counters to enable functions to trace")
Cc: stable@vger.kernel.org # 3.0+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-26 10:36:50 -05:00
Jason Baron 5800dc3cff panic: Make panic_timeout configurable
The panic_timeout value can be set via the command line option
'panic=x', or via /proc/sys/kernel/panic, however that is not
sufficient when the panic occurs before we are able to set up
these values. Thus, add a CONFIG_PANIC_TIMEOUT so that we can
set the desired value from the .config.

The default panic_timeout value continues to be 0 - wait
forever. Also adds set_arch_panic_timeout(new_timeout,
arch_default_timeout), which is intended to be used by arches in
arch_setup(). The idea being that the new_timeout is only set if
the user hasn't changed from the arch_default_timeout.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: benh@kernel.crashing.org
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: mpe@ellerman.id.au
Cc: felipe.contreras@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1a1674daec27c534df409697025ac568ebcee91e.1385418410.git.jbaron@akamai.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-26 12:12:26 +01:00
Bjorn Helgaas 12997d1a99 Revert "workqueue: allow work_on_cpu() to be called recursively"
This reverts commit c2fda50966.

c2fda50966 removed lockdep annotation from work_on_cpu() to work around
the PCI path that calls work_on_cpu() from within a work_on_cpu() work item
(PF driver .probe() method -> pci_enable_sriov() -> add VFs -> VF driver
.probe method).

961da7fb6b22 ("PCI: Avoid unnecessary CPU switch when calling driver
.probe() method) avoids that recursive work_on_cpu() use in a different
way, so this revert restores the work_on_cpu() lockdep annotation.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
2013-11-25 14:37:22 -07:00
Laxman Dewangan ac01810c9d irq: Enable all irqs unconditionally in irq_resume
When the system enters suspend, it disables all interrupts in
suspend_device_irqs(), including the interrupts marked EARLY_RESUME.

On the resume side things are different. The EARLY_RESUME interrupts
are reenabled in sys_core_ops->resume and the non EARLY_RESUME
interrupts are reenabled in the normal system resume path.

When suspend_noirq() failed or suspend is aborted for any other
reason, we might omit the resume side call to sys_core_ops->resume()
and therefor the interrupts marked EARLY_RESUME are not reenabled and
stay disabled forever.

To solve this, enable all irqs unconditionally in irq_resume()
regardless whether interrupts marked EARLY_RESUMEhave been already
enabled or not.

This might try to reenable already enabled interrupts in the non
failure case, but the only affected platform is XEN and it has been
confirmed that it does not cause any side effects.

[ tglx: Massaged changelog. ]

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by-and-tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Cc: <ian.campbell@citrix.com>
Cc: <rjw@rjwysocki.net>
Cc: <len.brown@intel.com>
Cc: <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1385388587-16442-1-git-send-email-ldewangan@nvidia.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-11-25 22:20:02 +01:00
Kent Overstreet 4f024f3797 block: Abstract out bvec iterator
Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchand@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peng Tao <tao.peng@emc.com>
Cc: Andy Adamson <andros@netapp.com>
Cc: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Pankaj Kumar <pankaj.km@samsung.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>6
2013-11-23 22:33:47 -08:00
Linus Torvalds 26b265cd29 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 - Made x86 ablk_helper generic for ARM
 - Phase out chainiv in favour of eseqiv (affects IPsec)
 - Fixed aes-cbc IV corruption on s390
 - Added constant-time crypto_memneq which replaces memcmp
 - Fixed aes-ctr in omap-aes
 - Added OMAP3 ROM RNG support
 - Add PRNG support for MSM SoC's
 - Add and use Job Ring API in caam
 - Misc fixes

[ NOTE! This pull request was sent within the merge window, but Herbert
  has some questionable email sending setup that makes him public enemy
  #1 as far as gmail is concerned.  So most of his emails seem to be
  trapped by gmail as spam, resulting in me not seeing them.  - Linus ]

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (49 commits)
  crypto: s390 - Fix aes-cbc IV corruption
  crypto: omap-aes - Fix CTR mode counter length
  crypto: omap-sham - Add missing modalias
  padata: make the sequence counter an atomic_t
  crypto: caam - Modify the interface layers to use JR API's
  crypto: caam - Add API's to allocate/free Job Rings
  crypto: caam - Add Platform driver for Job Ring
  hwrng: msm - Add PRNG support for MSM SoC's
  ARM: DT: msm: Add Qualcomm's PRNG driver binding document
  crypto: skcipher - Use eseqiv even on UP machines
  crypto: talitos - Simplify key parsing
  crypto: picoxcell - Simplify and harden key parsing
  crypto: ixp4xx - Simplify and harden key parsing
  crypto: authencesn - Simplify key parsing
  crypto: authenc - Export key parsing helper function
  crypto: mv_cesa: remove deprecated IRQF_DISABLED
  hwrng: OMAP3 ROM Random Number Generator support
  crypto: sha256_ssse3 - also test for BMI2
  crypto: mv_cesa - Remove redundant of_match_ptr
  crypto: sahara - Remove redundant of_match_ptr
  ...
2013-11-23 16:18:25 -08:00
Eric Paris fc582aef7d Linux 3.12
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Merge tag 'v3.12'

Linux 3.12

Conflicts:
	fs/exec.c
2013-11-22 18:57:54 -05:00
Tejun Heo edab95103d cgroup: Merge branch 'memcg_event' into for-3.14
Merge v3.12 based patch series to move cgroup_event implementation to
memcg into for-3.14.  The following two commits cause a conflict in
kernel/cgroup.c

  2ff2a7d03b ("cgroup: kill css_id")
  79bd9814e5 ("cgroup, memcg: move cgroup_event implementation to memcg")

Each patch removes a struct definition from kernel/cgroup.c.  As the
two are adjacent, they cause a context conflict.  Easily resolved by
removing both structs.

Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-22 18:32:25 -05:00
Tejun Heo b36824c75c cgroup: unexport cgroup_css() and remove __file_cft()
Now that cgroup_event is made memcg specific, the temporarily exported
functions are no longer necessary.  Unexport cgroup_css() and remove
__file_cft() which doesn't have any user left.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
2013-11-22 18:20:44 -05:00
Tejun Heo fba9480783 cgroup, memcg: move cgroup->event_list[_lock] and event callbacks into memcg
cgroup_event is being moved from cgroup core to memcg and the
implementation is already moved by the previous patch.  This patch
moves the data fields and callbacks.

* cgroup->event_list[_lock] are moved to mem_cgroup.

* cftype->[un]register_event() are moved to cgroup_event.  This makes
  it impossible for individual cftype definitions to specify their
  event callbacks.  This is worked around by simply hard-coding
  filename to event callback mapping in cgroup_write_event_control().
  This is awkward and inflexible, which is actually desirable given
  that we don't want to grow more usages of this feature.

* eventfd_ctx declaration is removed from cgroup.h, which makes
  vmpressure.h miss eventfd_ctx declaration.  Include eventfd.h from
  vmpressure.h.

v2: Use file name from dentry instead of cftype.  This will allow
    removing all cftype handling in the function.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
2013-11-22 18:20:43 -05:00
Tejun Heo 79bd9814e5 cgroup, memcg: move cgroup_event implementation to memcg
cgroup_event is way over-designed and tries to build a generic
flexible event mechanism into cgroup - fully customizable event
specification for each user of the interface.  This is utterly
unnecessary and overboard especially in the light of the planned
unified hierarchy as there's gonna be single agent.  Simply generating
events at fixed points, or if that's too restrictive, configureable
cadence or single set of configureable points should be enough.

Thankfully, memcg is the only user and gets to keep it.  Replacing it
with something simpler on sane_behavior is strongly recommended.

This patch moves cgroup_event and "cgroup.event_control"
implementation to mm/memcontrol.c.  Clearing of events on cgroup
destruction is moved from cgroup_destroy_locked() to
mem_cgroup_css_offline(), which shouldn't make any noticeable
difference.

cgroup_css() and __file_cft() are exported to enable the move;
however, this will soon be reverted once the event code is updated to
be memcg specific.

Note that "cgroup.event_control" will now exist only on the hierarchy
with memcg attached to it.  While this change is visible to userland,
it is unlikely to be noticeable as the file has never been meaningful
outside memcg.

Aside from the above change, this is pure code relocation.

v2: Per Li Zefan's comments, init/Kconfig updated accordingly and
    poll.h inclusion moved from cgroup.c to memcontrol.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
2013-11-22 18:20:42 -05:00
Li Bin 4e8b22bd1a workqueue: fix pool ID allocation leakage and remove BUILD_BUG_ON() in init_workqueues
When one work starts execution, the high bits of work's data contain
pool ID. It can represent a maximum of WORK_OFFQ_POOL_NONE. Pool ID
is assigned WORK_OFFQ_POOL_NONE when the work being initialized
indicating that no pool is associated and get_work_pool() uses it to
check the associated pool. So if worker_pool_assign_id() assigns a
ID greater than or equal WORK_OFFQ_POOL_NONE to a pool, it triggers
leakage, and it may break the non-reentrance guarantee.

This patch fix this issue by modifying the worker_pool_assign_id()
function calling idr_alloc() by setting @end param WORK_OFFQ_POOL_NONE.

Furthermore, in the current implementation, the BUILD_BUG_ON() in
init_workqueues makes no sense. The number of worker pools needed
cannot be determined at compile time, because the number of backing
pools for UNBOUND workqueues is dynamic based on the assigned custom
attributes. So remove it.

tj: Minor comment and indentation updates.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-22 18:14:47 -05:00
Li Bin 9ef28a73ff workqueue: fix comment typo for __queue_work()
It seems the "dying" should be "draining" here.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-22 18:14:27 -05:00
Tejun Heo 8a2b753844 workqueue: fix ordered workqueues in NUMA setups
An ordered workqueue implements execution ordering by using single
pool_workqueue with max_active == 1.  On a given pool_workqueue, work
items are processed in FIFO order and limiting max_active to 1
enforces the queued work items to be processed one by one.

Unfortunately, 4c16bd327c ("workqueue: implement NUMA affinity for
unbound workqueues") accidentally broke this guarantee by applying
NUMA affinity to ordered workqueues too.  On NUMA setups, an ordered
workqueue would end up with separate pool_workqueues for different
nodes.  Each pool_workqueue still limits max_active to 1 but multiple
work items may be executed concurrently and out of order depending on
which node they are queued to.

Fix it by using dedicated ordered_wq_attrs[] when creating ordered
workqueues.  The new attrs match the unbound ones except that no_numa
is always set thus forcing all NUMA nodes to share the default
pool_workqueue.

While at it, add sanity check in workqueue creation path which
verifies that an ordered workqueues has only the default
pool_workqueue.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Libin <huawei.libin@huawei.com>
Cc: stable@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
2013-11-22 18:14:02 -05:00
Oleg Nesterov 9115122806 workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY
Move the setting of PF_NO_SETAFFINITY up before set_cpus_allowed()
in create_worker(). Otherwise userland can change ->cpus_allowed
in between.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-22 18:13:20 -05:00
Tejun Heo e5fca243ab cgroup: use a dedicated workqueue for cgroup destruction
Since be44562613 ("cgroup: remove synchronize_rcu() from
cgroup_diput()"), cgroup destruction path makes use of workqueue.  css
freeing is performed from a work item from that point on and a later
commit, ea15f8ccdb ("cgroup: split cgroup destruction into two
steps"), moves css offlining to workqueue too.

As cgroup destruction isn't depended upon for memory reclaim, the
destruction work items were put on the system_wq; unfortunately, some
controller may block in the destruction path for considerable duration
while holding cgroup_mutex.  As large part of destruction path is
synchronized through cgroup_mutex, when combined with high rate of
cgroup removals, this has potential to fill up system_wq's max_active
of 256.

Also, it turns out that memcg's css destruction path ends up queueing
and waiting for work items on system_wq through work_on_cpu().  If
such operation happens while system_wq is fully occupied by cgroup
destruction work items, work_on_cpu() can't make forward progress
because system_wq is full and other destruction work items on
system_wq can't make forward progress because the work item waiting
for work_on_cpu() is holding cgroup_mutex, leading to deadlock.

This can be fixed by queueing destruction work items on a separate
workqueue.  This patch creates a dedicated workqueue -
cgroup_destroy_wq - for this purpose.  As these work items shouldn't
have inter-dependencies and mostly serialized by cgroup_mutex anyway,
giving high concurrency level doesn't buy anything and the workqueue's
@max_active is set to 1 so that destruction work items are executed
one by one on each CPU.

Hugh Dickins: Because cgroup_init() is run before init_workqueues(),
cgroup_destroy_wq can't be allocated from cgroup_init().  Do it from a
separate core_initcall().  In the future, we probably want to reorder
so that workqueue init happens before cgroup_init().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Hugh Dickins <hughd@google.com>
Reported-by: Shawn Bohrer <shawn.bohrer@gmail.com>
Link: http://lkml.kernel.org/r/20131111220626.GA7509@sbohrermbp13-local.rgmadvisors.com
Link: http://lkml.kernel.org/g/alpine.LNX.2.00.1310301606080.2333@eggly.anvils
Cc: stable@vger.kernel.org # v3.9+
2013-11-22 17:14:39 -05:00
Martin Schwidefsky 4be77398ac time: Fix 1ns/tick drift w/ GENERIC_TIME_VSYSCALL_OLD
Since commit 1e75fa8be9 (time: Condense timekeeper.xtime
into xtime_sec - merged in v3.6), there has been an problem
with the error accounting in the timekeeping code, such that
when truncating to nanoseconds, we round up to the next nsec,
but the balancing adjustment to the ntp_error value was dropped.

This causes 1ns per tick drift forward of the clock.

In 3.7, this logic was isolated to only GENERIC_TIME_VSYSCALL_OLD
architectures (s390, ia64, powerpc).

The fix is simply to balance the accounting and to subtract the
added nanosecond from ntp_error. This allows the internal long-term
clock steering to keep the clock accurate.

While this fix removes the regression added in 1e75fa8be9, the
ideal solution is to move away from GENERIC_TIME_VSYSCALL_OLD
and use the new VSYSCALL method, which avoids entirely the
nanosecond granular rounding, and the resulting short-term clock
adjustment oscillation needed to keep long term accurate time.

[ jstultz: Many thanks to Martin for his efforts identifying this
  	   subtle bug, and providing the fix. ]

Originally-from: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org>  #v3.6+
Link: http://lkml.kernel.org/r/1385149491-20307-1-git-send-email-john.stultz@linaro.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-11-22 21:08:11 +01:00
Linus Torvalds 78dc53c422 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "In this patchset, we finally get an SELinux update, with Paul Moore
  taking over as maintainer of that code.

  Also a significant update for the Keys subsystem, as well as
  maintenance updates to Smack, IMA, TPM, and Apparmor"

and since I wanted to know more about the updates to key handling,
here's the explanation from David Howells on that:

 "Okay.  There are a number of separate bits.  I'll go over the big bits
  and the odd important other bit, most of the smaller bits are just
  fixes and cleanups.  If you want the small bits accounting for, I can
  do that too.

   (1) Keyring capacity expansion.

        KEYS: Consolidate the concept of an 'index key' for key access
        KEYS: Introduce a search context structure
        KEYS: Search for auth-key by name rather than target key ID
        Add a generic associative array implementation.
        KEYS: Expand the capacity of a keyring

     Several of the patches are providing an expansion of the capacity of a
     keyring.  Currently, the maximum size of a keyring payload is one page.
     Subtract a small header and then divide up into pointers, that only gives
     you ~500 pointers on an x86_64 box.  However, since the NFS idmapper uses
     a keyring to store ID mapping data, that has proven to be insufficient to
     the cause.

     Whatever data structure I use to handle the keyring payload, it can only
     store pointers to keys, not the keys themselves because several keyrings
     may point to a single key.  This precludes inserting, say, and rb_node
     struct into the key struct for this purpose.

     I could make an rbtree of records such that each record has an rb_node
     and a key pointer, but that would use four words of space per key stored
     in the keyring.  It would, however, be able to use much existing code.

     I selected instead a non-rebalancing radix-tree type approach as that
     could have a better space-used/key-pointer ratio.  I could have used the
     radix tree implementation that we already have and insert keys into it by
     their serial numbers, but that means any sort of search must iterate over
     the whole radix tree.  Further, its nodes are a bit on the capacious side
     for what I want - especially given that key serial numbers are randomly
     allocated, thus leaving a lot of empty space in the tree.

     So what I have is an associative array that internally is a radix-tree
     with 16 pointers per node where the index key is constructed from the key
     type pointer and the key description.  This means that an exact lookup by
     type+description is very fast as this tells us how to navigate directly to
     the target key.

     I made the data structure general in lib/assoc_array.c as far as it is
     concerned, its index key is just a sequence of bits that leads to a
     pointer.  It's possible that someone else will be able to make use of it
     also.  FS-Cache might, for example.

   (2) Mark keys as 'trusted' and keyrings as 'trusted only'.

        KEYS: verify a certificate is signed by a 'trusted' key
        KEYS: Make the system 'trusted' keyring viewable by userspace
        KEYS: Add a 'trusted' flag and a 'trusted only' flag
        KEYS: Separate the kernel signature checking keyring from module signing

     These patches allow keys carrying asymmetric public keys to be marked as
     being 'trusted' and allow keyrings to be marked as only permitting the
     addition or linkage of trusted keys.

     Keys loaded from hardware during kernel boot or compiled into the kernel
     during build are marked as being trusted automatically.  New keys can be
     loaded at runtime with add_key().  They are checked against the system
     keyring contents and if their signatures can be validated with keys that
     are already marked trusted, then they are marked trusted also and can
     thus be added into the master keyring.

     Patches from Mimi Zohar make this usable with the IMA keyrings also.

   (3) Remove the date checks on the key used to validate a module signature.

        X.509: Remove certificate date checks

     It's not reasonable to reject a signature just because the key that it was
     generated with is no longer valid datewise - especially if the kernel
     hasn't yet managed to set the system clock when the first module is
     loaded - so just remove those checks.

   (4) Make it simpler to deal with additional X.509 being loaded into the kernel.

        KEYS: Load *.x509 files into kernel keyring
        KEYS: Have make canonicalise the paths of the X.509 certs better to deduplicate

     The builder of the kernel now just places files with the extension ".x509"
     into the kernel source or build trees and they're concatenated by the
     kernel build and stuffed into the appropriate section.

   (5) Add support for userspace kerberos to use keyrings.

        KEYS: Add per-user_namespace registers for persistent per-UID kerberos caches
        KEYS: Implement a big key type that can save to tmpfs

     Fedora went to, by default, storing kerberos tickets and tokens in tmpfs.
     We looked at storing it in keyrings instead as that confers certain
     advantages such as tickets being automatically deleted after a certain
     amount of time and the ability for the kernel to get at these tokens more
     easily.

     To make this work, two things were needed:

     (a) A way for the tickets to persist beyond the lifetime of all a user's
         sessions so that cron-driven processes can still use them.

         The problem is that a user's session keyrings are deleted when the
         session that spawned them logs out and the user's user keyring is
         deleted when the UID is deleted (typically when the last log out
         happens), so neither of these places is suitable.

         I've added a system keyring into which a 'persistent' keyring is
         created for each UID on request.  Each time a user requests their
         persistent keyring, the expiry time on it is set anew.  If the user
         doesn't ask for it for, say, three days, the keyring is automatically
         expired and garbage collected using the existing gc.  All the kerberos
         tokens it held are then also gc'd.

     (b) A key type that can hold really big tickets (up to 1MB in size).

         The problem is that Active Directory can return huge tickets with lots
         of auxiliary data attached.  We don't, however, want to eat up huge
         tracts of unswappable kernel space for this, so if the ticket is
         greater than a certain size, we create a swappable shmem file and dump
         the contents in there and just live with the fact we then have an
         inode and a dentry overhead.  If the ticket is smaller than that, we
         slap it in a kmalloc()'d buffer"

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (121 commits)
  KEYS: Fix keyring content gc scanner
  KEYS: Fix error handling in big_key instantiation
  KEYS: Fix UID check in keyctl_get_persistent()
  KEYS: The RSA public key algorithm needs to select MPILIB
  ima: define '_ima' as a builtin 'trusted' keyring
  ima: extend the measurement list to include the file signature
  kernel/system_certificate.S: use real contents instead of macro GLOBAL()
  KEYS: fix error return code in big_key_instantiate()
  KEYS: Fix keyring quota misaccounting on key replacement and unlink
  KEYS: Fix a race between negating a key and reading the error set
  KEYS: Make BIG_KEYS boolean
  apparmor: remove the "task" arg from may_change_ptraced_domain()
  apparmor: remove parent task info from audit logging
  apparmor: remove tsk field from the apparmor_audit_struct
  apparmor: fix capability to not use the current task, during reporting
  Smack: Ptrace access check mode
  ima: provide hash algo info in the xattr
  ima: enable support for larger default filedata hash algorithms
  ima: define kernel parameter 'ima_template=' to change configured default
  ima: add Kconfig default measurement list template
  ...
2013-11-21 19:46:00 -08:00
Linus Torvalds 3eaded86ac Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris:
 "Nothing amazing.  Formatting, small bug fixes, couple of fixes where
  we didn't get records due to some old VFS changes, and a change to how
  we collect execve info..."

Fixed conflict in fs/exec.c as per Eric and linux-next.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  audit: fix type of sessionid in audit_set_loginuid()
  audit: call audit_bprm() only once to add AUDIT_EXECVE information
  audit: move audit_aux_data_execve contents into audit_context union
  audit: remove unused envc member of audit_aux_data_execve
  audit: Kill the unused struct audit_aux_data_capset
  audit: do not reject all AUDIT_INODE filter types
  audit: suppress stock memalloc failure warnings since already managed
  audit: log the audit_names record type
  audit: add child record before the create to handle case where create fails
  audit: use given values in tty_audit enable api
  audit: use nlmsg_len() to get message payload length
  audit: use memset instead of trying to initialize field by field
  audit: fix info leak in AUDIT_GET requests
  audit: update AUDIT_INODE filter rule to comparator function
  audit: audit feature to set loginuid immutable
  audit: audit feature to only allow unsetting the loginuid
  audit: allow unsetting the loginuid (with priv)
  audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE
  audit: loginuid functions coding style
  selinux: apply selinux checks on new audit message types
  ...
2013-11-21 19:18:14 -08:00
Ingo Molnar 09897d78db Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core
Pull uprobes cleanups from Oleg Nesterov.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-21 09:59:27 +01:00
Linus Torvalds b5898cd057 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs bits and pieces from Al Viro:
 "Assorted bits that got missed in the first pull request + fixes for a
  couple of coredump regressions"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fold try_to_ascend() into the sole remaining caller
  dcache.c: get rid of pointless macros
  take read_seqbegin_or_lock() and friends to seqlock.h
  consolidate simple ->d_delete() instances
  gfs2: endianness misannotations
  dump_emit(): use __kernel_write(), not vfs_write()
  dump_align(): fix the dumb braino
2013-11-20 14:25:39 -08:00
Linus Torvalds 82023bb7f7 More ACPI and power management updates for 3.13-rc1
- ACPI-based device hotplug fixes for issues introduced recently and
   a fix for an older error code path bug in the ACPI PCI host bridge
   driver.
 
 - Fix for recently broken OMAP cpufreq build from Viresh Kumar.
 
 - Fix for a recent hibernation regression related to s2disk.
 
 - Fix for a locking-related regression in the ACPI EC driver from
   Puneet Kumar.
 
 - System suspend error code path fix related to runtime PM and
   runtime PM documentation update from Ulf Hansson.
 
 - cpufreq's conservative governor fix from Xiaoguang Chen.
 
 - New processor IDs for intel_idle and turbostat and removal of
   an obsolete Kconfig option from Len Brown.
 
 - New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and
   ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg.
 
 - Removal of several ACPI video DMI blacklist entries that are not
   necessary any more from Aaron Lu.
 
 - Rework of the ACPI companion representation in struct device and
   code cleanup related to that change from Rafael J Wysocki,
   Lan Tianyu and Jarkko Nikula.
 
 - Fixes for assigning names to ACPI-enumerated I2C and SPI devices
   from Jarkko Nikula.
 
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Merge tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:

 - ACPI-based device hotplug fixes for issues introduced recently and a
   fix for an older error code path bug in the ACPI PCI host bridge
   driver

 - Fix for recently broken OMAP cpufreq build from Viresh Kumar

 - Fix for a recent hibernation regression related to s2disk

 - Fix for a locking-related regression in the ACPI EC driver from
   Puneet Kumar

 - System suspend error code path fix related to runtime PM and runtime
   PM documentation update from Ulf Hansson

 - cpufreq's conservative governor fix from Xiaoguang Chen

 - New processor IDs for intel_idle and turbostat and removal of an
   obsolete Kconfig option from Len Brown

 - New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and
   ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg

 - Removal of several ACPI video DMI blacklist entries that are not
   necessary any more from Aaron Lu

 - Rework of the ACPI companion representation in struct device and code
   cleanup related to that change from Rafael J Wysocki, Lan Tianyu and
   Jarkko Nikula

 - Fixes for assigning names to ACPI-enumerated I2C and SPI devices from
   Jarkko Nikula

* tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits)
  PCI / hotplug / ACPI: Drop unused acpiphp_debug declaration
  ACPI / scan: Set flags.match_driver in acpi_bus_scan_fixed()
  ACPI / PCI root: Clear driver_data before failing enumeration
  ACPI / hotplug: Fix PCI host bridge hot removal
  ACPI / hotplug: Fix acpi_bus_get_device() return value check
  cpufreq: governor: Remove fossil comment in the cpufreq_governor_dbs()
  ACPI / video: clean up DMI table for initial black screen problem
  ACPI / EC: Ensure lock is acquired before accessing ec struct members
  PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
  ACPI / AC: Remove struct acpi_device pointer from struct acpi_ac
  spi: Use stable dev_name for ACPI enumerated SPI slaves
  i2c: Use stable dev_name for ACPI enumerated I2C slaves
  ACPI: Provide acpi_dev_name accessor for struct acpi_device device name
  ACPI / bind: Use (put|get)_device() on ACPI device objects too
  ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro
  ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node
  cpufreq: OMAP: Fix compilation error 'r & ret undeclared'
  PM / Runtime: Fix error path for prepare
  PM / Runtime: Update documentation around probe|remove|suspend
  cpufreq: conservative: set requested_freq to policy max when it is over policy max
  ...
2013-11-20 13:25:04 -08:00
Oleg Nesterov ad439356ae uprobes: Document xol_area and arch_uprobe->insn/ixol
Document xol_area and arch_uprobe.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-11-20 16:31:07 +01:00
Oleg Nesterov c912dae60a uprobes: Cleanup !CONFIG_UPROBES decls, unexport xol_area
1. Don't include asm/uprobes.h unconditionally, we only need
   it if CONFIG_UPROBES.

2. Move the definition of "struct xol_area" into uprobes.c.

   Perhaps we should simply kill struct uprobes_state, it buys
   nothing.

3. Kill the dummy definition of uprobe_get_swbp_addr(), nobody
   except handle_swbp() needs it.

4. Purely cosmetic, but move the decl of uprobe_get_swbp_addr()
   up, close to other __weak helpers.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-11-20 16:31:01 +01:00
Oleg Nesterov 803200e24a uprobes: Don't assume that arch_uprobe->insn/ixol is u8[MAX_UINSN_BYTES]
arch_uprobe should be opaque as much as possible to the generic
code, but currently it assumes that insn/ixol must be u8[] of the
known size. Remove this unnecessary dependency, we can use "&" and
and sizeof() with the same effect.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-11-20 16:31:00 +01:00
Oleg Nesterov 3247343118 uprobes: Add uprobe_task->dup_xol_work/dup_xol_addr
uprobe_task->vaddr is a bit strange. The generic code uses it only
to pass the additional argument to arch_uprobe_pre_xol(), and since
it is always equal to instruction_pointer() this looks even more
strange.

And both utask->vaddr and and utask->autask have the same scope,
they only have the meaning when the task executes the probed insn
out-of-line, so it is safe to reuse both in UTASK_RUNNING state.

This all means that logically ->vaddr belongs to arch_uprobe_task
and we should probably move it there, arch_uprobe_pre_xol() can
record instruction_pointer() itself.

OTOH, it is also used by uprobe_copy_process() and dup_xol_work()
for another purpose, this doesn't look clean and doesn't allow to
move this member into arch_uprobe_task.

This patch adds the union with 2 anonymous structs into uprobe_task.

The first struct is autask + vaddr, this way we "almost" move vaddr
into autask.

The second struct has 2 new members for uprobe_copy_process() paths:
->dup_xol_addr which can be used instead ->vaddr, and ->dup_xol_work
which can be used to avoid kmalloc() and simplify the code.

Note that this union will likely have another member(s), we need
something like "private_data_for_handlers" so that the tracing
handlers could use it to communicate with call_fetch() methods.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-11-20 16:30:57 +01:00
Linus Torvalds 1ee2dcc224 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Mostly these are fixes for fallout due to merge window changes, as
  well as cures for problems that have been with us for a much longer
  period of time"

 1) Johannes Berg noticed two major deficiencies in our genetlink
    registration.  Some genetlink protocols we passing in constant
    counts for their ops array rather than something like
    ARRAY_SIZE(ops) or similar.  Also, some genetlink protocols were
    using fixed IDs for their multicast groups.

    We have to retain these fixed IDs to keep existing userland tools
    working, but reserve them so that other multicast groups used by
    other protocols can not possibly conflict.

    In dealing with these two problems, we actually now use less state
    management for genetlink operations and multicast groups.

 2) When configuring interface hardware timestamping, fix several
    drivers that simply do not validate that the hwtstamp_config value
    is one the driver actually supports.  From Ben Hutchings.

 3) Invalid memory references in mwifiex driver, from Amitkumar Karwar.

 4) In dev_forward_skb(), set the skb->protocol in the right order
    relative to skb_scrub_packet().  From Alexei Starovoitov.

 5) Bridge erroneously fails to use the proper wrapper functions to make
    calls to netdev_ops->ndo_vlan_rx_{add,kill}_vid.  Fix from Toshiaki
    Makita.

 6) When detaching a bridge port, make sure to flush all VLAN IDs to
    prevent them from leaking, also from Toshiaki Makita.

 7) Put in a compromise for TCP Small Queues so that deep queued devices
    that delay TX reclaim non-trivially don't have such a performance
    decrease.  One particularly problematic area is 802.11 AMPDU in
    wireless.  From Eric Dumazet.

 8) Fix crashes in tcp_fastopen_cache_get(), we can see NULL socket dsts
    here.  Fix from Eric Dumzaet, reported by Dave Jones.

 9) Fix use after free in ipv6 SIT driver, from Willem de Bruijn.

10) When computing mergeable buffer sizes, virtio-net fails to take the
    virtio-net header into account.  From Michael Dalton.

11) Fix seqlock deadlock in ip4_datagram_connect() wrt.  statistic
    bumping, this one has been with us for a while.  From Eric Dumazet.

12) Fix NULL deref in the new TIPC fragmentation handling, from Erik
    Hugne.

13) 6lowpan bit used for traffic classification was wrong, from Jukka
    Rissanen.

14) macvlan has the same issue as normal vlans did wrt.  propagating LRO
    disabling down to the real device, fix it the same way.  From Michal
    Kubecek.

15) CPSW driver needs to soft reset all slaves during suspend, from
    Daniel Mack.

16) Fix small frame pacing in FQ packet scheduler, from Eric Dumazet.

17) The xen-netfront RX buffer refill timer isn't properly scheduled on
    partial RX allocation success, from Ma JieYue.

18) When ipv6 ping protocol support was added, the AF_INET6 protocol
    initialization cleanup path on failure was borked a little.  Fix
    from Vlad Yasevich.

19) If a socket disconnects during a read/recvmsg/recvfrom/etc that
    blocks we can do the wrong thing with the msg_name we write back to
    userspace.  From Hannes Frederic Sowa.  There is another fix in the
    works from Hannes which will prevent future problems of this nature.

20) Fix route leak in VTI tunnel transmit, from Fan Du.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (106 commits)
  genetlink: make multicast groups const, prevent abuse
  genetlink: pass family to functions using groups
  genetlink: add and use genl_set_err()
  genetlink: remove family pointer from genl_multicast_group
  genetlink: remove genl_unregister_mc_group()
  hsr: don't call genl_unregister_mc_group()
  quota/genetlink: use proper genetlink multicast APIs
  drop_monitor/genetlink: use proper genetlink multicast APIs
  genetlink: only pass array to genl_register_family_with_ops()
  tcp: don't update snd_nxt, when a socket is switched from repair mode
  atm: idt77252: fix dev refcnt leak
  xfrm: Release dst if this dst is improper for vti tunnel
  netlink: fix documentation typo in netlink_set_err()
  be2net: Delete secondary unicast MAC addresses during be_close
  be2net: Fix unconditional enabling of Rx interface options
  net, virtio_net: replace the magic value
  ping: prevent NULL pointer dereference on write to msg_name
  bnx2x: Prevent "timeout waiting for state X"
  bnx2x: prevent CFC attention
  bnx2x: Prevent panic during DMAE timeout
  ...
2013-11-19 15:50:47 -08:00
Kirill A. Shutemov 24b9fdc59a kernel/bounds: avoid circular dependencies in generated headers
<linux/spinlock.h> has heavy dependencies on other header files.
It triggers circular dependencies in generated headers on IA64, at
least:

  CC      kernel/bounds.s
In file included from /home/space/kas/git/public/linux/arch/ia64/include/asm/thread_info.h:9:0,
                 from include/linux/thread_info.h:54,
                 from include/asm-generic/preempt.h:4,
                 from arch/ia64/include/generated/asm/preempt.h:1,
                 from include/linux/preempt.h:18,
                 from include/linux/spinlock.h:50,
                 from kernel/bounds.c:14:
/home/space/kas/git/public/linux/arch/ia64/include/asm/asm-offsets.h:1:35: fatal error: generated/asm-offsets.h: No such file or directory
compilation terminated.

Let's replace <linux/spinlock.h> with <linux/spinlock_types.h>, it's
enough to find out size of spinlock_t.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-and-Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-11-19 14:20:12 -08:00
Johannes Berg c53ed74236 genetlink: only pass array to genl_register_family_with_ops()
As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.

The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-19 16:39:05 -05:00
Linus Torvalds 4007162647 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq cleanups from Ingo Molnar:
 "This is a multi-arch cleanup series from Thomas Gleixner, which we
  kept to near the end of the merge window, to not interfere with
  architecture updates.

  This series (motivated by the -rt kernel) unifies more aspects of IRQ
  handling and generalizes PREEMPT_ACTIVE"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  preempt: Make PREEMPT_ACTIVE generic
  sparc: Use preempt_schedule_irq
  ia64: Use preempt_schedule_irq
  m32r: Use preempt_schedule_irq
  hardirq: Make hardirq bits generic
  m68k: Simplify low level interrupt handling code
  genirq: Prevent spurious detection for unconditionally polled interrupts
2013-11-19 10:40:00 -08:00
Peter Zijlstra f1a83e652b lockdep: Correctly annotate hardirq context in irq_exit()
There was a reported deadlock on -rt which lockdep didn't report.

It turns out that in irq_exit() we tell lockdep that the hardirq
context ends and then do all kinds of locking afterwards.

To fix it, move trace_hardirq_exit() to the very end of irq_exit(), this
ensures all locking in tick_irq_exit() and rcu_irq_exit() are properly
recorded as happening from hardirq context.

This however leads to the 'fun' little problem of running softirqs
while in hardirq context. To cure this make the softirq code a little
more complex (in the CONFIG_TRACE_IRQFLAGS case).

Due to stack swizzling arch dependent trickery we cannot pass an
argument to __do_softirq() to tell it if it was done from hardirq
context or not; so use a side-band argument.

When we do __do_softirq() from hardirq context, 'atomically' flip to
softirq context and back, so that no locking goes without being in
either hard- or soft-irq context.

I didn't find any new problems in mainline using this patch, but it
did show the -rt problem.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-dgwc5cdksbn0jk09vbmcc9sa@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 17:07:00 +01:00
Shigeru Yoshida 0515973ffb sched: Fix a trivial typo in comments
Fix a trivial typo in rq_attach_root().

Signed-off-by: Shigeru Yoshida <shigeru.yoshida@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131117.121236.1990617639803941055.shigeru.yoshida@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 17:01:18 +01:00
Peter Zijlstra 42eb088ed2 sched: Avoid NULL dereference on sd_busy
Commit 37dc6b50ce ("sched: Remove unnecessary iteration over sched
domains to update nr_busy_cpus") forgot to clear 'sd_busy' under some
conditions leading to a possible NULL deref in set_cpu_sd_state_idle().

Reported-by: Anton Blanchard <anton@samba.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131118113701.GF3866@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 17:01:16 +01:00
Srikar Dronamraju 9abf24d465 sched: Check sched_domain before computing group power
After commit 863bffc808 ("sched/fair: Fix group power_orig
computation"), we can dereference rq->sd before it is set.

Fix this by falling back to power_of() in this case and add a comment
explaining things.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[ Added comment and tweaked patch. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: mikey@neuling.org
Link: http://lkml.kernel.org/r/20131113151718.GN21461@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 17:01:15 +01:00
Vince Weaver 0022cedd4a perf/trace: Properly use u64 to hold event_id
The 64-bit attr.config value for perf trace events was being copied into
an "int" before doing a comparison, meaning the top 32 bits were
being truncated.

As far as I can tell this didn't cause any errors, but it did mean
it was possible to create valid aliases for all the tracepoint ids
which I don't think was intended.  (For example, 0xffffffff00000018
and 0x18 both enable the same tracepoint).

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1311151236100.11932@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 16:57:44 +01:00
Peter Zijlstra 06db0b2171 perf: Remove fragile swevent hlist optimization
Currently we only allocate a single cpu hashtable for per-cpu
swevents; do away with this optimization for it is fragile in the face
of things like perf_pmu_migrate_context().

The easiest thing is to make sure all CPUs are consistent wrt state.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130913111447.GN31370@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 16:57:42 +01:00
Peter Zijlstra d5b5f391d4 ftrace, perf: Avoid infinite event generation loop
Vince's perf-trinity fuzzer found yet another 'interesting' problem.

When we sample the irq_work_exit tracepoint with period==1 (or
PERF_SAMPLE_PERIOD) and we add an fasync SIGNAL handler we create an
infinite event generation loop:

  ,-> <IPI>
  |     irq_work_exit() ->
  |       trace_irq_work_exit() ->
  |         ...
  |           __perf_event_overflow() -> (due to fasync)
  |             irq_work_queue() -> (irq_work_list must be empty)
  '---------      arch_irq_work_raise()

Similar things can happen due to regular poll() wakeups if we exceed
the ring-buffer wakeup watermark, or have an event_limit.

To avoid this, dis-allow sampling this particular tracepoint.

In order to achieve this, create a special perf_perm function pointer
for each event and call this (when set) on trying to create a
tracepoint perf event.

[ roasted: use expr... to allow for ',' in your expression ]

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131114152304.GC5364@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-19 16:57:40 +01:00
Andrew Morton 050ded1bba tick: Document tick_do_timer_cpu
Taken straight from a tglx email ;)

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-11-19 14:59:50 +01:00
Joe Perches da554eba2e timer: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...)
Use the helper function instead of __GFP_ZERO.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-11-19 14:59:50 +01:00
Thomas Gleixner d689fe222a NOHZ: Check for nohz active instead of nohz enabled
RCU and the fine grained idle time accounting functions check
tick_nohz_enabled. But that variable is merily telling that NOHZ has
been enabled in the config and not been disabled on the command line.

But it does not tell anything about nohz being active. That's what all
this should check for.

Matthew reported, that the idle accounting on his old P1 machine
showed bogus values, when he enabled NOHZ in the config and did not
disable it on the kernel command line. The reason is that his machine
uses (refined) jiffies as a clocksource which explains why the "fine"
grained accounting went into lala land, because it depends on when the
system goes and leaves idle relative to the jiffies increment.

Provide a tick_nohz_active indicator and let RCU and the accounting
code use this instead of tick_nohz_enable.

Reported-and-tested-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: john.stultz@linaro.org
Cc: mwhitehe@redhat.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311132052240.30673@ionos.tec.linutronix.de
2013-11-19 14:59:50 +01:00
Rafael J. Wysocki b38f67c4ae Merge branch 'pm-sleep'
* pm-sleep:
  PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
2013-11-19 01:07:08 +01:00
Linus Torvalds b29c8306a3 This batch of changes is mostly clean ups and small bug fixes.
The only real feature that was added this release is from Namhyung Kim,
 who introduced "set_graph_notrace" filter that lets you run the function
 graph tracer and not trace particular functions and their call chain.
 
 Tom Zanussi added some updates to the ftrace multibuffer tracing that
 made it more consistent with the top level tracing.
 
 One of the fixes for perf function tracing required an API change in
 RCU; the addition of "rcu_is_watching()". As Paul McKenney is pushing
 that change in this release too, he gave me a branch that included
 all the changes to get that working, and I pulled that into my tree
 in order to complete the perf function tracing fix.
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Merge tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing update from Steven Rostedt:
 "This batch of changes is mostly clean ups and small bug fixes.  The
  only real feature that was added this release is from Namhyung Kim,
  who introduced "set_graph_notrace" filter that lets you run the
  function graph tracer and not trace particular functions and their
  call chain.

  Tom Zanussi added some updates to the ftrace multibuffer tracing that
  made it more consistent with the top level tracing.

  One of the fixes for perf function tracing required an API change in
  RCU; the addition of "rcu_is_watching()".  As Paul McKenney is pushing
  that change in this release too, he gave me a branch that included all
  the changes to get that working, and I pulled that into my tree in
  order to complete the perf function tracing fix"

* tag 'trace-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add rcu annotation for syscall trace descriptors
  tracing: Do not use signed enums with unsigned long long in fgragh output
  tracing: Remove unused function ftrace_off_permanent()
  tracing: Do not assign filp->private_data to freed memory
  tracing: Add helper function tracing_is_disabled()
  tracing: Open tracer when ftrace_dump_on_oops is used
  tracing: Add support for SOFT_DISABLE to syscall events
  tracing: Make register/unregister_ftrace_command __init
  tracing: Update event filters for multibuffer
  recordmcount.pl: Add support for __fentry__
  ftrace: Have control op function callback only trace when RCU is watching
  rcu: Do not trace rcu_is_watching() functions
  ftrace/x86: skip over the breakpoint for ftrace caller
  trace/trace_stat: use rbtree postorder iteration helper instead of opencoding
  ftrace: Add set_graph_notrace filter
  ftrace: Narrow down the protected area of graph_lock
  ftrace: Introduce struct ftrace_graph_data
  ftrace: Get rid of ftrace_graph_filter_enabled
  tracing: Fix potential out-of-bounds in trace_get_user()
  tracing: Show more exact help information about snapshot
2013-11-16 12:23:18 -08:00
Al Viro b26d4cd385 consolidate simple ->d_delete() instances
Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-15 22:04:17 -05:00
Linus Torvalds 9073e1a804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual earth-shaking, news-breaking, rocket science pile from
  trivial.git"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
  doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
  doc: add missing files to timers/00-INDEX
  timekeeping: Fix some trivial typos in comments
  mm: Fix some trivial typos in comments
  irq: Fix some trivial typos in comments
  NUMA: fix typos in Kconfig help text
  mm: update 00-INDEX
  doc: Documentation/DMA-attributes.txt fix typo
  DRM: comment: `halve' -> `half'
  Docs: Kconfig: `devlopers' -> `developers'
  doc: typo on word accounting in kprobes.c in mutliple architectures
  treewide: fix "usefull" typo
  treewide: fix "distingush" typo
  mm/Kconfig: Grammar s/an/a/
  kexec: Typo s/the/then/
  Documentation/kvm: Update cpuid documentation for steal time and pv eoi
  treewide: Fix common typo in "identify"
  __page_to_pfn: Fix typo in comment
  Correct some typos for word frequency
  clk: fixed-factor: Fix a trivial typo
  ...
2013-11-15 16:47:22 -08:00
Linus Torvalds f080480488 Here are the 3.13 KVM changes. There was a lot of work on the PPC
side: the HV and emulation flavors can now coexist in a single kernel
 is probably the most interesting change from a user point of view.
 On the x86 side there are nested virtualization improvements and a
 few bugfixes.  ARM got transparent huge page support, improved
 overcommit, and support for big endian guests.
 
 Finally, there is a new interface to connect KVM with VFIO.  This
 helps with devices that use NoSnoop PCI transactions, letting the
 driver in the guest execute WBINVD instructions.  This includes
 some nVidia cards on Windows, that fail to start without these
 patches and the corresponding userspace changes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM changes from Paolo Bonzini:
 "Here are the 3.13 KVM changes.  There was a lot of work on the PPC
  side: the HV and emulation flavors can now coexist in a single kernel
  is probably the most interesting change from a user point of view.

  On the x86 side there are nested virtualization improvements and a few
  bugfixes.

  ARM got transparent huge page support, improved overcommit, and
  support for big endian guests.

  Finally, there is a new interface to connect KVM with VFIO.  This
  helps with devices that use NoSnoop PCI transactions, letting the
  driver in the guest execute WBINVD instructions.  This includes some
  nVidia cards on Windows, that fail to start without these patches and
  the corresponding userspace changes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits)
  kvm, vmx: Fix lazy FPU on nested guest
  arm/arm64: KVM: PSCI: propagate caller endianness to the incoming vcpu
  arm/arm64: KVM: MMIO support for BE guest
  kvm, cpuid: Fix sparse warning
  kvm: Delete prototype for non-existent function kvm_check_iopl
  kvm: Delete prototype for non-existent function complete_pio
  hung_task: add method to reset detector
  pvclock: detect watchdog reset at pvclock read
  kvm: optimize out smp_mb after srcu_read_unlock
  srcu: API for barrier after srcu read unlock
  KVM: remove vm mmap method
  KVM: IOMMU: hva align mapping page size
  KVM: x86: trace cpuid emulation when called from emulator
  KVM: emulator: cleanup decode_register_operand() a bit
  KVM: emulator: check rex prefix inside decode_register()
  KVM: x86: fix emulation of "movzbl %bpl, %eax"
  kvm_host: typo fix
  KVM: x86: emulate SAHF instruction
  MAINTAINERS: add tree for kvm.git
  Documentation/kvm: add a 00-INDEX file
  ...
2013-11-15 13:51:36 +09:00
Linus Torvalds ce6513f758 Mainly boring here, too. rmmod --wait finally removed, though.
Cheers,
 Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "Mainly boring here, too.  rmmod --wait finally removed, though"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  modpost: fix bogus 'exported twice' warnings.
  init: fix in-place parameter modification regression
  asmlinkage, module: Make ksymtab and kcrctab symbols and __this_module __visible
  kernel: add support for init_array constructors
  modpost: Optionally ignore secondary errors seen if a single module build fails
  module: remove rmmod --wait option.
2013-11-15 13:27:50 +09:00
Christoph Hellwig ca5ecd64c2 kernel: fix generic_exec_single indentation
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:22 +09:00
Christoph Hellwig 40c01e8bd5 kernel: provide a __smp_call_function_single stub for !CONFIG_SMP
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:22 +09:00
Christoph Hellwig 0a06ff068f kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS
We've switched over every architecture that supports SMP to it, so
remove the new useless config variable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:22 +09:00
Christoph Hellwig fc21c0cff2 revert "softirq: Add support for triggering softirq work on softirqs"
This commit was incomplete in that code to remove items from the per-cpu
lists was missing and never acquired a user in the 5 years it has been in
the tree.  We're going to implement what it seems to try to archive in a
simpler way, and this code is in the way of doing so.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:22 +09:00
Peter Zijlstra 539edb5846 mm: properly separate the bloated ptl from the regular case
Use kernel/bounds.c to convert build-time spinlock_t size check into a
preprocessor symbol and apply that to properly separate the page::ptl
situation.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:20 +09:00
Kirill A. Shutemov e009bb30c8 mm: implement split page table lock for PMD level
The basic idea is the same as with PTE level: the lock is embedded into
struct page of table's page.

We can't use mm->pmd_huge_pte to store pgtables for THP, since we don't
take mm->page_table_lock anymore.  Let's reuse page->lru of table's page
for that.

pgtable_pmd_page_ctor() returns true, if initialization is successful
and false otherwise.  Current implementation never fails, but assumption
that constructor can fail will help to port it to -rt where spinlock_t
is rather huge and cannot be embedded into struct page -- dynamic
allocation is required.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:15 +09:00
Kirill A. Shutemov e1f56c89b0 mm: convert mm->nr_ptes to atomic_long_t
With split page table lock for PMD level we can't hold mm->page_table_lock
while updating nr_ptes.

Let's convert it to atomic_long_t to avoid races.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:14 +09:00
Rafael J. Wysocki 6a0c7cd330 PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
I have received a report about the BUG_ON() in free_basic_memory_bitmaps()
triggering mysteriously during an aborted s2disk hibernation attempt.
The only way I can explain that is that /dev/snapshot was first
opened for writing (resume mode), then closed and then opened again
for reading and closed again without freezing tasks.  In that case
the first invocation of snapshot_open() would set the free_bitmaps
flag in snapshot_state, which is a static variable.  That flag
wouldn't be cleared later and the second invocation of snapshot_open()
would just leave it like that, so the subsequent snapshot_release()
would see data->frozen set and free_basic_memory_bitmaps() would be
called unnecessarily.

To prevent that from happening clear data->free_bitmaps in
snapshot_open() when the file is being opened for reading (hibernate
mode).

In addition to that, replace the BUG_ON() in free_basic_memory_bitmaps()
with a WARN_ON() as the kernel can continue just fine if the condition
checked by that macro occurs.

Fixes: aab1728915 (PM / hibernate: Fix user space driven resume regression)
Reported-by: Oliver Lorenz <olli@olorenz.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
2013-11-14 23:26:58 +01:00
Johannes Berg 4534de8305 genetlink: make all genl_ops users const
Now that genl_ops are no longer modified in place when
registering, they can be made const. This patch was done
mostly with spatch:

@@
identifier ops;
@@
+const
 struct genl_ops ops[] = {
 ...
 };

(except the struct thing in net/openvswitch/datapath.c)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-14 17:10:41 -05:00
Johannes Berg 88d36a9949 taskstats: use genl_register_family_with_ops()
This simplifies the code since there's no longer a
need to have error handling in the registration.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-14 17:10:40 -05:00
Linus Torvalds fe8a45df36 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Four bugfixes and one performance fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Avoid integer overflow
  sched: Optimize task_sched_runtime()
  sched/numa: Cure update_numa_stats() vs. hotplug
  sched/numa: Fix NULL pointer dereference in task_numa_migrate()
  sched: Fix endless sync_sched/rcu() loop inside _cpu_down()
2013-11-14 16:55:11 +09:00
Linus Torvalds 5e30025a31 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking changes from Ingo Molnar:
 "The biggest changes:

   - add lockdep support for seqcount/seqlocks structures, this
     unearthed both bugs and required extra annotation.

   - move the various kernel locking primitives to the new
     kernel/locking/ directory"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  block: Use u64_stats_init() to initialize seqcounts
  locking/lockdep: Mark __lockdep_count_forward_deps() as static
  lockdep/proc: Fix lock-time avg computation
  locking/doc: Update references to kernel/mutex.c
  ipv6: Fix possible ipv6 seqlock deadlock
  cpuset: Fix potential deadlock w/ set_mems_allowed
  seqcount: Add lockdep functionality to seqcount/seqlock structures
  net: Explicitly initialize u64_stats_sync structures for lockdep
  locking: Move the percpu-rwsem code to kernel/locking/
  locking: Move the lglocks code to kernel/locking/
  locking: Move the rwsem code to kernel/locking/
  locking: Move the rtmutex code to kernel/locking/
  locking: Move the semaphore core to kernel/locking/
  locking: Move the spinlock code to kernel/locking/
  locking: Move the lockdep code to kernel/locking/
  locking: Move the mutex code to kernel/locking/
  hung_task debugging: Add tracepoint to report the hang
  x86/locking/kconfig: Update paravirt spinlock Kconfig description
  lockstat: Report avg wait and hold times
  lockdep, x86/alternatives: Drop ancient lockdep fixup message
  ...
2013-11-14 16:30:30 +09:00
Linus Torvalds f9300eaaac ACPI and power management updates for 3.13-rc1
- New power capping framework and the the Intel Running Average Power
    Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.
 
  - Addition of the in-kernel switching feature to the arm_big_little
    cpufreq driver from Viresh Kumar and Nicolas Pitre.
 
  - cpufreq support for iMac G5 from Aaro Koskinen.
 
  - Baytrail processors support for intel_pstate from Dirk Brandewie.
 
  - cpufreq support for Midway/ECX-2000 from Mark Langsdorf.
 
  - ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.
 
  - ACPI power management support for the I2C and SPI bus types from
    Mika Westerberg and Lv Zheng.
 
  - cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
    Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.
 
  - cpufreq drivers updates (mostly fixes and cleanups) from Viresh Kumar,
    Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz Majewski,
    Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.
 
  - intel_pstate updates from Dirk Brandewie and Adrian Huang.
 
  - ACPICA update to version 20130927 includig fixes and cleanups and
    some reduction of divergences between the ACPICA code in the kernel
    and ACPICA upstream in order to improve the automatic ACPICA patch
    generation process.  From Bob Moore, Lv Zheng, Tomasz Nowicki,
    Naresh Bhat, Bjorn Helgaas, David E Box.
 
  - ACPI IPMI driver fixes and cleanups from Lv Zheng.
 
  - ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani,
    Zhang Yanfei, Rafael J Wysocki.
 
  - Conversion of the ACPI AC driver to the platform bus type and
    multiple driver fixes and cleanups related to ACPI from Zhang Rui.
 
  - ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
    Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.
 
  - Fixes and cleanups and new blacklist entries related to the ACPI
    video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
    Kirill Tkhai.
 
  - cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.
 
  - cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
    Bartlomiej Zolnierkiewicz, Prarit Bhargava.
 
  - devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.
 
  - Operation Performance Points (OPP) core updates from Nishanth Menon.
 
  - Runtime power management core fix from Rafael J Wysocki and update
    from Ulf Hansson.
 
  - Hibernation fixes from Aaron Lu and Rafael J Wysocki.
 
  - Device suspend/resume lockup detection mechanism from Benoit Goby.
 
  - Removal of unused proc directories created for various ACPI drivers
    from Lan Tianyu.
 
  - ACPI LPSS driver fix and new device IDs for the ACPI platform scan
    handler from Heikki Krogerus and Jarkko Nikula.
 
  - New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.
 
  - Assorted fixes and cleanups related to ACPI from Andy Shevchenko,
    Al Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
    Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
    Liu Chuansheng.
 
  - Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
    Jean-Christophe Plagniol-Villard.
 
 /
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Merge tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael J Wysocki:

 - New power capping framework and the the Intel Running Average Power
   Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.

 - Addition of the in-kernel switching feature to the arm_big_little
   cpufreq driver from Viresh Kumar and Nicolas Pitre.

 - cpufreq support for iMac G5 from Aaro Koskinen.

 - Baytrail processors support for intel_pstate from Dirk Brandewie.

 - cpufreq support for Midway/ECX-2000 from Mark Langsdorf.

 - ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.

 - ACPI power management support for the I2C and SPI bus types from Mika
   Westerberg and Lv Zheng.

 - cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
   Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.

 - cpufreq drivers updates (mostly fixes and cleanups) from Viresh
   Kumar, Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz
   Majewski, Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.

 - intel_pstate updates from Dirk Brandewie and Adrian Huang.

 - ACPICA update to version 20130927 includig fixes and cleanups and
   some reduction of divergences between the ACPICA code in the kernel
   and ACPICA upstream in order to improve the automatic ACPICA patch
   generation process.  From Bob Moore, Lv Zheng, Tomasz Nowicki, Naresh
   Bhat, Bjorn Helgaas, David E Box.

 - ACPI IPMI driver fixes and cleanups from Lv Zheng.

 - ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani, Zhang
   Yanfei, Rafael J Wysocki.

 - Conversion of the ACPI AC driver to the platform bus type and
   multiple driver fixes and cleanups related to ACPI from Zhang Rui.

 - ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
   Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.

 - Fixes and cleanups and new blacklist entries related to the ACPI
   video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
   Kirill Tkhai.

 - cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.

 - cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
   Bartlomiej Zolnierkiewicz, Prarit Bhargava.

 - devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.

 - Operation Performance Points (OPP) core updates from Nishanth Menon.

 - Runtime power management core fix from Rafael J Wysocki and update
   from Ulf Hansson.

 - Hibernation fixes from Aaron Lu and Rafael J Wysocki.

 - Device suspend/resume lockup detection mechanism from Benoit Goby.

 - Removal of unused proc directories created for various ACPI drivers
   from Lan Tianyu.

 - ACPI LPSS driver fix and new device IDs for the ACPI platform scan
   handler from Heikki Krogerus and Jarkko Nikula.

 - New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.

 - Assorted fixes and cleanups related to ACPI from Andy Shevchenko, Al
   Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
   Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
   Liu Chuansheng.

 - Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
   Jean-Christophe Plagniol-Villard.

* tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (386 commits)
  cpufreq: conservative: fix requested_freq reduction issue
  ACPI / hotplug: Consolidate deferred execution of ACPI hotplug routines
  PM / runtime: Use pm_runtime_put_sync() in __device_release_driver()
  ACPI / event: remove unneeded NULL pointer check
  Revert "ACPI / video: Ignore BIOS initial backlight value for HP 250 G1"
  ACPI / video: Quirk initial backlight level 0
  ACPI / video: Fix initial level validity test
  intel_pstate: skip the driver if ACPI has power mgmt option
  PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
  ACPI / hotplug: Do not execute "insert in progress" _OST
  ACPI / hotplug: Carry out PCI root eject directly
  ACPI / hotplug: Merge device hot-removal routines
  ACPI / hotplug: Make acpi_bus_hot_remove_device() internal
  ACPI / hotplug: Simplify device ejection routines
  ACPI / hotplug: Fix handle_root_bridge_removal()
  ACPI / hotplug: Refuse to hot-remove all objects with disabled hotplug
  ACPI / scan: Start matching drivers after trying scan handlers
  ACPI: Remove acpi_pci_slot_init() headers from internal.h
  ACPI / blacklist: fix name of ThinkPad Edge E530
  PowerCap: Fix build error with option -Werror=format-security
  ...

Conflicts:
	arch/arm/mach-omap2/opp.c
	drivers/Kconfig
	drivers/spi/spi.c
2013-11-14 13:41:48 +09:00
Linus Torvalds 0910c0bdf7 Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block
Pull block IO core updates from Jens Axboe:
 "This is the pull request for the core changes in the block layer for
  3.13.  It contains:

   - The new blk-mq request interface.

     This is a new and more scalable queueing model that marries the
     best part of the request based interface we currently have (which
     is fully featured, but scales poorly) and the bio based "interface"
     which the new drivers for high IOPS devices end up using because
     it's much faster than the request based one.

     The bio interface has no block layer support, since it taps into
     the stack much earlier.  This means that drivers end up having to
     implement a lot of functionality on their own, like tagging,
     timeout handling, requeue, etc.  The blk-mq interface provides all
     these.  Some drivers even provide a switch to select bio or rq and
     has code to handle both, since things like merging only works in
     the rq model and hence is faster for some workloads.  This is a
     huge mess.  Conversion of these drivers nets us a substantial code
     reduction.  Initial results on converting SCSI to this model even
     shows an 8x improvement on single queue devices.  So while the
     model was intended to work on the newer multiqueue devices, it has
     substantial improvements for "classic" hardware as well.  This code
     has gone through extensive testing and development, it's now ready
     to go.  A pull request is coming to convert virtio-blk to this
     model will be will be coming as well, with more drivers scheduled
     for 3.14 conversion.

   - Two blktrace fixes from Jan and Chen Gang.

   - A plug merge fix from Alireza Haghdoost.

   - Conversion of __get_cpu_var() from Christoph Lameter.

   - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven.

   - A fix for a race between request completion and the timeout
     handling from Jeff Moyer.  This is what caused the merge conflict
     with blk-mq/core, in case you are looking at that.

   - A dm stacking fix from Mike Snitzer.

   - A code consolidation fix and duplicated code removal from Kent
     Overstreet.

   - A handful of block bug fixes from Mikulas Patocka, fixing a loop
     crash and memory corruption on blk cg.

   - Elevator switch bug fix from Tomoki Sekiyama.

  A heads-up that I had to rebase this branch.  Initially the immutable
  bio_vecs had been queued up for inclusion, but a week later, it became
  clear that it wasn't fully cooked yet.  So the decision was made to
  pull this out and postpone it until 3.14.  It was a straight forward
  rebase, just pruning out the immutable series and the later fixes of
  problems with it.  The rest of the patches applied directly and no
  further changes were made"

* 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits)
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  block: Do not call sector_div() with a 64-bit divisor
  kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()
  block: Consolidate duplicated bio_trim() implementations
  block: Use rw_copy_check_uvector()
  block: Enable sysfs nomerge control for I/O requests in the plug list
  block: properly stack underlying max_segment_size to DM device
  elevator: acquire q->sysfs_lock in elevator_change()
  elevator: Fix a race in elevator switching and md device initialization
  block: Replace __get_cpu_var uses
  bdi: test bdi_init failure
  block: fix a probe argument to blk_register_region
  loop: fix crash if blk_alloc_queue fails
  blk-core: Fix memory corruption if blkcg_init_queue fails
  block: fix race between request completion and timeout handling
  blktrace: Send BLK_TN_PROCESS events to all running traces
  blk-mq: don't disallow request merges for req->special being set
  blk-mq: mq plug list breakage
  blk-mq: fix for flush deadlock
  ...
2013-11-14 12:08:14 +09:00
Thomas Gleixner b39898cd40 genirq: Prevent spurious detection for unconditionally polled interrupts
On a 68k platform a couple of interrupts are demultiplexed and
"polled" from a top level interrupt. Unfortunately there is no way to
determine which of the sub interrupts raised the top level interrupt,
so all of the demultiplexed interrupt handlers need to be
invoked. Given a high enough frequency this can trigger the spurious
interrupt detection mechanism, if one of the demultiplex interrupts
returns IRQ_NONE continuously. But this is a false positive as the
polling causes this behaviour and not buggy hardware/software.

Introduce IRQ_POLLED which can be set at interrupt chip setup time via
irq_set_status_flags(). The flag excludes the interrupt from the
spurious detector and from all core polling activities.

Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311061149250.23353@ionos.tec.linutronix.de
2013-11-13 16:03:02 +01:00
Fengguang Wu 5216d530bb locking/lockdep: Mark __lockdep_count_forward_deps() as static
There are new Sparse warnings:

  >> kernel/locking/lockdep.c:1235:15: sparse: symbol '__lockdep_count_forward_deps' was not declared. Should it be static?
  >> kernel/locking/lockdep.c:1261:15: sparse: symbol '__lockdep_count_backward_deps' was not declared. Should it be static?

Please consider folding the attached diff :-)

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/527d1787.ThzXGoUspZWehFDl\%fengguang.wu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:50:17 +01:00
Michal Nazarewicz 85b088e934 sched/fair: Avoid integer overflow
sa->runnable_avg_sum is of type u32 but after shifting it by NICE_0_SHIFT
bits it is promoted to u64.  This of course makes no sense, since the
result will never be more then 32-bit long.  Casting sa->runnable_avg_sum
to u64 before it is shifted, fixes this problem.

Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1384112521-25177-1-git-send-email-mpn@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:55 +01:00
Peter Zijlstra 911b2898b3 sched: Optimize task_sched_runtime()
Large multi-threaded apps like to hit this using do_sys_times() and
then queue up on the rq->lock.

Avoid when possible.

Larry reported ~20% performance increase his test case.

Reported-by: Larry Woodman <lwoodman@redhat.com>
Suggested-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131111172925.GG26898@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:54 +01:00
Peter Zijlstra 5eca82a9ac sched/numa: Cure update_numa_stats() vs. hotplug
Because we're completely unserialized against hotplug its well
possible to try and generate numa stats for an offlined node.

Bail out early (and avoid a /0) in this case. The resulting stats are
all 0 which should result in an undesirable balance target -- not to
mention that actually trying to migrate to an offline CPU will fail.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/n/tip-orja0qylcvyhxfsuebcyL5sI@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:52 +01:00
Rik van Riel 46a73e8a1c sched/numa: Fix NULL pointer dereference in task_numa_migrate()
The cpusets code can split up the scheduler's domain tree into
smaller domains.  Some of those smaller domains may not cross
NUMA nodes at all, leading to a NULL pointer dereference on the
per-cpu sd_numa pointer.

Tasks cannot be migrated out of their domain, so the patch
also sets p->numa_preferred_nid to whereever they are, to
prevent the migration from being retried over and over again.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/n/tip-oosqomw0Jput0Jkvoowhrqtu@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:51 +01:00
Michael wang 106dd5afde sched: Fix endless sync_sched/rcu() loop inside _cpu_down()
Commit 6acce3ef8:

	sched: Remove get_online_cpus() usage

tries to do sync_sched/rcu() inside _cpu_down() but triggers:

	INFO: task swapper/0:1 blocked for more than 120 seconds.
	...
	[<ffffffff811263dc>] synchronize_rcu+0x2c/0x30
	[<ffffffff81d1bd82>] _cpu_down+0x2b2/0x340
	...

It was caused by that in the rcu boost case we rely on smpboot thread to
finish the rcu callback, which has already been parked before sync in here
and leads to the endless sync_sched/rcu().

This patch exchanges the sequence of smpboot_park_threads() and
sync_sched/rcu() to fix the bug.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5282EDC0.6060003@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-13 13:33:50 +01:00
Linus Torvalds 42a2d923cc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) The addition of nftables.  No longer will we need protocol aware
    firewall filtering modules, it can all live in userspace.

    At the core of nftables is a, for lack of a better term, virtual
    machine that executes byte codes to inspect packet or metadata
    (arriving interface index, etc.) and make verdict decisions.

    Besides support for loading packet contents and comparing them, the
    interpreter supports lookups in various datastructures as
    fundamental operations.  For example sets are supports, and
    therefore one could create a set of whitelist IP address entries
    which have ACCEPT verdicts attached to them, and use the appropriate
    byte codes to do such lookups.

    Since the interpreted code is composed in userspace, userspace can
    do things like optimize things before giving it to the kernel.

    Another major improvement is the capability of atomically updating
    portions of the ruleset.  In the existing netfilter implementation,
    one has to update the entire rule set in order to make a change and
    this is very expensive.

    Userspace tools exist to create nftables rules using existing
    netfilter rule sets, but both kernel implementations will need to
    co-exist for quite some time as we transition from the old to the
    new stuff.

    Kudos to Patrick McHardy, Pablo Neira Ayuso, and others who have
    worked so hard on this.

 2) Daniel Borkmann and Hannes Frederic Sowa made several improvements
    to our pseudo-random number generator, mostly used for things like
    UDP port randomization and netfitler, amongst other things.

    In particular the taus88 generater is updated to taus113, and test
    cases are added.

 3) Support 64-bit rates in HTB and TBF schedulers, from Eric Dumazet
    and Yang Yingliang.

 4) Add support for new 577xx tigon3 chips to tg3 driver, from Nithin
    Sujir.

 5) Fix two fatal flaws in TCP dynamic right sizing, from Eric Dumazet,
    Neal Cardwell, and Yuchung Cheng.

 6) Allow IP_TOS and IP_TTL to be specified in sendmsg() ancillary
    control message data, much like other socket option attributes.
    From Francesco Fusco.

 7) Allow applications to specify a cap on the rate computed
    automatically by the kernel for pacing flows, via a new
    SO_MAX_PACING_RATE socket option.  From Eric Dumazet.

 8) Make the initial autotuned send buffer sizing in TCP more closely
    reflect actual needs, from Eric Dumazet.

 9) Currently early socket demux only happens for TCP sockets, but we
    can do it for connected UDP sockets too.  Implementation from Shawn
    Bohrer.

10) Refactor inet socket demux with the goal of improving hash demux
    performance for listening sockets.  With the main goals being able
    to use RCU lookups on even request sockets, and eliminating the
    listening lock contention.  From Eric Dumazet.

11) The bonding layer has many demuxes in it's fast path, and an RCU
    conversion was started back in 3.11, several changes here extend the
    RCU usage to even more locations.  From Ding Tianhong and Wang
    Yufen, based upon suggestions by Nikolay Aleksandrov and Veaceslav
    Falico.

12) Allow stackability of segmentation offloads to, in particular, allow
    segmentation offloading over tunnels.  From Eric Dumazet.

13) Significantly improve the handling of secret keys we input into the
    various hash functions in the inet hashtables, TCP fast open, as
    well as syncookies.  From Hannes Frederic Sowa.  The key fundamental
    operation is "net_get_random_once()" which uses static keys.

    Hannes even extended this to ipv4/ipv6 fragmentation handling and
    our generic flow dissector.

14) The generic driver layer takes care now to set the driver data to
    NULL on device removal, so it's no longer necessary for drivers to
    explicitly set it to NULL any more.  Many drivers have been cleaned
    up in this way, from Jingoo Han.

15) Add a BPF based packet scheduler classifier, from Daniel Borkmann.

16) Improve CRC32 interfaces and generic SKB checksum iterators so that
    SCTP's checksumming can more cleanly be handled.  Also from Daniel
    Borkmann.

17) Add a new PMTU discovery mode, IP_PMTUDISC_INTERFACE, which forces
    using the interface MTU value.  This helps avoid PMTU attacks,
    particularly on DNS servers.  From Hannes Frederic Sowa.

18) Use generic XPS for transmit queue steering rather than internal
    (re-)implementation in virtio-net.  From Jason Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits)
  random32: add test cases for taus113 implementation
  random32: upgrade taus88 generator to taus113 from errata paper
  random32: move rnd_state to linux/random.h
  random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized
  random32: add periodic reseeding
  random32: fix off-by-one in seeding requirement
  PHY: Add RTL8201CP phy_driver to realtek
  xtsonic: add missing platform_set_drvdata() in xtsonic_probe()
  macmace: add missing platform_set_drvdata() in mace_probe()
  ethernet/arc/arc_emac: add missing platform_set_drvdata() in arc_emac_probe()
  ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh
  vlan: Implement vlan_dev_get_egress_qos_mask as an inline.
  ixgbe: add warning when max_vfs is out of range.
  igb: Update link modes display in ethtool
  netfilter: push reasm skb through instead of original frag skbs
  ip6_output: fragment outgoing reassembled skb properly
  MAINTAINERS: mv643xx_eth: take over maintainership from Lennart
  net_sched: tbf: support of 64bit rates
  ixgbe: deleting dfwd stations out of order can cause null ptr deref
  ixgbe: fix build err, num_rx_queues is only available with CONFIG_RPS
  ...
2013-11-13 17:40:34 +09:00
Linus Torvalds 5cbb3d216e Merge branch 'akpm' (patches from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 "Quite a lot of other stuff is banked up awaiting further
  next->mainline merging, but this batch contains:

   - Lots of random misc patches
   - OCFS2
   - Most of MM
   - backlight updates
   - lib/ updates
   - printk updates
   - checkpatch updates
   - epoll tweaking
   - rtc updates
   - hfs
   - hfsplus
   - documentation
   - procfs
   - update gcov to gcc-4.7 format
   - IPC"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits)
  ipc, msg: fix message length check for negative values
  ipc/util.c: remove unnecessary work pending test
  devpts: plug the memory leak in kill_sb
  ./Makefile: export initial ramdisk compression config option
  init/Kconfig: add option to disable kernel compression
  drivers: w1: make w1_slave::flags long to avoid memory corruption
  drivers/w1/masters/ds1wm.cuse dev_get_platdata()
  drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page()
  drivers/memstick/core/mspro_block.c: fix attributes array allocation
  drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr
  kernel/panic.c: reduce 1 byte usage for print tainted buffer
  gcov: reuse kbasename helper
  kernel/gcov/fs.c: use pr_warn()
  kernel/module.c: use pr_foo()
  gcov: compile specific gcov implementation based on gcc version
  gcov: add support for gcc 4.7 gcov format
  gcov: move gcov structs definitions to a gcc version specific file
  kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener()
  kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end()
  kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
  ...
2013-11-13 15:45:43 +09:00
Linus Torvalds 9bc9ccd7db Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "All kinds of stuff this time around; some more notable parts:

   - RCU'd vfsmounts handling
   - new primitives for coredump handling
   - files_lock is gone
   - Bruce's delegations handling series
   - exportfs fixes

  plus misc stuff all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits)
  ecryptfs: ->f_op is never NULL
  locks: break delegations on any attribute modification
  locks: break delegations on link
  locks: break delegations on rename
  locks: helper functions for delegation breaking
  locks: break delegations on unlink
  namei: minor vfs_unlink cleanup
  locks: implement delegations
  locks: introduce new FL_DELEG lock flag
  vfs: take i_mutex on renamed file
  vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
  vfs: don't use PARENT/CHILD lock classes for non-directories
  vfs: pull ext4's double-i_mutex-locking into common code
  exportfs: fix quadratic behavior in filehandle lookup
  exportfs: better variable name
  exportfs: move most of reconnect_path to helper function
  exportfs: eliminate unused "noprogress" counter
  exportfs: stop retrying once we race with rename/remove
  exportfs: clear DISCONNECTED on all parents sooner
  exportfs: more detailed comment for path_reconnect
  ...
2013-11-13 15:34:18 +09:00
Linus Torvalds a998646456 Merge branch 'for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
 "Not too much activity this time around.  css_id is finally killed and
  a minor update to device_cgroup"

* 'for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  device_cgroup: remove can_attach
  cgroup: kill css_id
  memcg: stop using css id
  memcg: fail to create cgroup if the cgroup id is too big
  memcg: convert to use cgroup id
  memcg: convert to use cgroup_is_descendant()
2013-11-13 15:21:53 +09:00
Chen Gang 0128476471 kernel/panic.c: reduce 1 byte usage for print tainted buffer
sizeof("Tainted: ") already counts '\0', and after first sprintf(), 's'
will start from the current string end (its' value is '\0').

So need not add additional 1 byte for maximized usage of 'buf' in
print_tainted().

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:35 +09:00
Andy Shevchenko 1931d433d7 gcov: reuse kbasename helper
To get name of the file from a pathname let's use kbasename() helper.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Andrew Morton a5ebb87508 kernel/gcov/fs.c: use pr_warn()
pr_warning() is deprecated in favor of pr_warn()

Cc: Andy Gospodarek <agospoda@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Frantisek Hrbata <fhrbata@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Andrew Morton bddb12b32f kernel/module.c: use pr_foo()
kernel/module.c uses a mix of printk(KERN_foo and pr_foo().  Convert it
all to pr_foo and make the offered cleanups.

Not sure what to do about the printk(KERN_DEFAULT).  We don't have a
pr_default().

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Joe Perches <joe@perches.com>
Cc: Frantisek Hrbata <fhrbata@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Frantisek Hrbata 17c568d60a gcov: compile specific gcov implementation based on gcc version
Compile the correct gcov implementation file for the specific gcc version.

Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Gospodarek <agospoda@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Frantisek Hrbata 5f41ea0386 gcov: add support for gcc 4.7 gcov format
The gcov in-memory format changed in gcc 4.7.  The biggest change, which
requires this special implementation, is that gcov_info no longer contains
array of counters for each counter type for all functions and gcov_fn_info
is not used for mapping of function's counters to these arrays(offset).
Now each gcov_fn_info contans it's counters, which makes things a little
bit easier.

This is heavily based on the previous gcc_3_4.c implementation and patches
provided by Peter Oberparleiter.  Specially the buffer gcda implementation
for iterator.

[akpm@linux-foundation.org: use kmemdup() and kcalloc()]
[oberpar@linux.vnet.ibm.com: gcc_4_7.c needs vmalloc.h]
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Gospodarek <agospoda@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Frantisek Hrbata 8cbce376e3 gcov: move gcov structs definitions to a gcc version specific file
Since also the gcov structures(gcov_info, gcov_fn_info, gcov_ctr_info) can
change between gcc releases, as shown in gcc 4.7, they cannot be defined
in a common header and need to be moved to a specific gcc implemention
file.  This also requires to make the gcov_info structure opaque for the
common code and to introduce simple helpers for accessing data inside
gcov_info.

Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Gospodarek <agospoda@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Chen Gang 0d20633b04 kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener()
For registering in add_del_listener(), when kmalloc_node() fails, need
return -ENOMEM instead of success code, and cmd_attr_register_cpumask()
wants to know about it.

After modification, give a simple common test "build -> boot up ->
kernel/controllers/cgroup/getdelays by LTP tools".

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:34 +09:00
Chen Gang 3fa5826631 kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end()
When failure occurs between nla_nest_start() and nla_nest_end(), we should
call nla_nest_cancel() to clean up related things.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
Chen Gang f02147ef19 kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
snprintf() will return the 'ideal' length which may be larger than real
buffer length, if we only want to use real length, need use scnprintf()
instead of.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
Chen Gang 7833819d2e kernel/sysctl.c: check return value after call proc_put_char() in __do_proc_doulongvec_minmax()
Need to check the return value of proc_put_char(), as was done in
__do_proc_doulongvec_minmax().

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
Kees Cook d049f74f2d exec/ptrace: fix get_dumpable() incorrect tests
The get_dumpable() return value is not boolean.  Most users of the
function actually want to be testing for non-SUID_DUMP_USER(1) rather than
SUID_DUMP_DISABLE(0).  The SUID_DUMP_ROOT(2) is also considered a
protected state.  Almost all places did this correctly, excepting the two
places fixed in this patch.

Wrong logic:
    if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ }
        or
    if (dumpable == 0) { /* be protective */ }
        or
    if (!dumpable) { /* be protective */ }

Correct logic:
    if (dumpable != SUID_DUMP_USER) { /* be protective */ }
        or
    if (dumpable != 1) { /* be protective */ }

Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a
user was able to ptrace attach to processes that had dropped privileges to
that user.  (This may have been partially mitigated if Yama was enabled.)

The macros have been moved into the file that declares get/set_dumpable(),
which means things like the ia64 code can see them too.

CVE-2013-2929

Reported-by: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:33 +09:00
Joe Mario ab76786561 kprobes: use KSYM_NAME_LEN to size identifier buffers
Use KSYM_NAME_LEN to size identifier buffers, so that it can be easier
increased.

Signed-off-by: Joe Mario <jmario@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:26 +09:00
Oleg Nesterov 008208c6b2 list: introduce list_next_entry() and list_prev_entry()
Add two trivial helpers list_next_entry() and list_prev_entry(), they
can have a lot of users including list.h itself.  In fact the 1st one is
already defined in events/core.c and bnx2x_sp.c, so the patch simply
moves the definition to list.h.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:23 +09:00
Dirk Gouders 4c1ace6408 printk.c: comments should refer to /proc/vmcore instead of /proc/vmcoreinfo
In one of those comments a typo was fixed, too.

Signed-off-by: Dirk Gouders <dirk@gouders.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Dave Young 29e9d22559 kernel/printk/printk.c: enable boot delay for earlyprintk
boot_delay does not work for earlyprintk because the kernel cmdline
parsing is late.

Change to use early_param so early kernel messages can also be delayed.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Andrew Morton 27083baca5 kernel/printk/printk.c: convert to pr_foo()
It was half-and-half.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:14 +09:00
Kees Cook 6b80239447 printk: report console names during cut-over
This reports the names of consoles as they're being disabled to help
identify which is which during cut-over.  Helps answer the question
"which boot console actually got activated?" once the regular console is
running, mostly when debugging boot console failures.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:13 +09:00
Geert Uytterhoeven 81e41ea25b kernel/sys.c: remove obsolete #include <linux/kexec.h>
Commit 15d94b8256 ("reboot: move shutdown/reboot related functions to
kernel/reboot.c") moved all kexec-related functionality to
kernel/reboot.c, so kernel/sys.c no longer needs to include
<linux/kexec.h>.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:13 +09:00
Chen Gang 324d666a53 kernel/delayacct.c: remove redundant checking in __delayacct_add_tsk()
The wrapper function delayacct_add_tsk() already checked 'tsk->delays',
and __delayacct_add_tsk() has no another direct callers, so can remove the
redundancy checking code.

And the label 'done' is also useless, so remove it, too.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:12 +09:00
Toshi Kani 01b0f19707 cpu/mem hotplug: add try_online_node() for cpu_up()
cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call
mem_online_node() to put its node online if offlined and then call
build_all_zonelists() to initialize the zone list.

These steps are specific to memory hotplug, and should be managed in
mm/memory_hotplug.c.  lock_memory_hotplug() should also be held for the
whole steps.

For this reason, this patch replaces mem_online_node() with
try_online_node(), which performs the whole steps with
lock_memory_hotplug() held.  try_online_node() is named after
try_offline_node() as they have similar purpose.

There is no functional change in this patch.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Tetsuo Handa 786235eeba kthread: make kthread_create() killable
Any user process callers of wait_for_completion() except global init
process might be chosen by the OOM killer while waiting for completion()
call by some other process which does memory allocation.  See
CVE-2012-4398 "kernel: request_module() OOM local DoS" can happen.

When such users are chosen by the OOM killer when they are waiting for
completion() in TASK_UNINTERRUPTIBLE, the system will be kept stressed
due to memory starvation because the OOM killer cannot kill such users.

kthread_create() is one of such users and this patch fixes the problem
for kthreadd by making kthread_create() killable - the same approach
used for fixing CVE-2012-4398.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:08:59 +09:00
Linus Torvalds 10d0c9705e DeviceTree updates for 3.13. This is a bit larger pull request than
usual for this cycle with lots of clean-up.
 
 - Cross arch clean-up and consolidation of early DT scanning code.
 - Clean-up and removal of arch prom.h headers. Makes arch specific
   prom.h optional on all but Sparc.
 - Addition of interrupts-extended property for devices connected to
   multiple interrupt controllers.
 - Refactoring of DT interrupt parsing code in preparation for deferred
   probe of interrupts.
 - ARM cpu and cpu topology bindings documentation.
 - Various DT vendor binding documentation updates.
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Merge tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:
 "DeviceTree updates for 3.13.  This is a bit larger pull request than
  usual for this cycle with lots of clean-up.

   - Cross arch clean-up and consolidation of early DT scanning code.
   - Clean-up and removal of arch prom.h headers.  Makes arch specific
     prom.h optional on all but Sparc.
   - Addition of interrupts-extended property for devices connected to
     multiple interrupt controllers.
   - Refactoring of DT interrupt parsing code in preparation for
     deferred probe of interrupts.
   - ARM cpu and cpu topology bindings documentation.
   - Various DT vendor binding documentation updates"

* tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (82 commits)
  powerpc: add missing explicit OF includes for ppc
  dt/irq: add empty of_irq_count for !OF_IRQ
  dt: disable self-tests for !OF_IRQ
  of: irq: Fix interrupt-map entry matching
  MIPS: Netlogic: replace early_init_devtree() call
  of: Add Panasonic Corporation vendor prefix
  of: Add Chunghwa Picture Tubes Ltd. vendor prefix
  of: Add AU Optronics Corporation vendor prefix
  of/irq: Fix potential buffer overflow
  of/irq: Fix bug in interrupt parsing refactor.
  of: set dma_mask to point to coherent_dma_mask
  of: add vendor prefix for PHYTEC Messtechnik GmbH
  DT: sort vendor-prefixes.txt
  of: Add vendor prefix for Cadence
  of: Add empty for_each_available_child_of_node() macro definition
  arm/versatile: Fix versatile irq specifications.
  of/irq: create interrupts-extended property
  microblaze/pci: Drop PowerPC-ism from irq parsing
  of/irq: Create of_irq_parse_and_map_pci() to consolidate arch code.
  of/irq: Use irq_of_parse_and_map()
  ...
2013-11-12 16:52:17 +09:00
Linus Torvalds 9b66bfb280 Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 UV debug changes from Ingo Molnar:
 "Various SGI UV debuggability improvements, amongst them KDB support,
  with related core KDB enabling patches changing kernel/debug/kdb/"

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86/UV: Add uvtrace support"
  x86/UV: Add call to KGDB/KDB from NMI handler
  kdb: Add support for external NMI handler to call KGDB/KDB
  x86/UV: Check for alloc_cpumask_var() failures properly in uv_nmi_setup()
  x86/UV: Add uvtrace support
  x86/UV: Add kdump to UV NMI handler
  x86/UV: Add summary of cpu activity to UV NMI handler
  x86/UV: Update UV support for external NMI signals
  x86/UV: Move NMI support
2013-11-12 12:01:14 +09:00
Linus Torvalds 014d595c23 Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot changes from Ingo Molnar:
 "Two changes that prettify and compactify the SMP bootup output from:

     smpboot: Booting Node   0, Processors  #1 #2 #3 OK
     smpboot: Booting Node   1, Processors  #4 #5 #6 #7 OK
     smpboot: Booting Node   2, Processors  #8 #9 #10 #11 OK
     smpboot: Booting Node   3, Processors  #12 #13 #14 #15 OK
     Brought up 16 CPUs

  to something like:

     x86: Booting SMP configuration:
     .... node  #0, CPUs:        #1  #2  #3
     .... node  #1, CPUs:    #4  #5  #6  #7
     .... node  #2, CPUs:    #8  #9 #10 #11
     .... node  #3, CPUs:   #12 #13 #14 #15
     x86: Booted up 4 nodes, 16 CPUs"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Further compress CPUs bootup message
  x86: Improve the printout of the SMP bootup CPU table
2013-11-12 10:41:10 +09:00
Linus Torvalds 87093826aa Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer changes from Ingo Molnar:
 "Main changes in this cycle were:

   - Updated full dynticks support.

   - Event stream support for architected (ARM) timers.

   - ARM clocksource driver updates.

   - Move arm64 to using the generic sched_clock framework & resulting
     cleanup in the generic sched_clock code.

   - Misc fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC
  clocksource: sun4i: remove IRQF_DISABLED
  clocksource: sun4i: Report the minimum tick that we can program
  clocksource: sun4i: Select CLKSRC_MMIO
  clocksource: Provide timekeeping for efm32 SoCs
  clocksource: em_sti: convert to clk_prepare/unprepare
  time: Fix signedness bug in sysfs_get_uname() and its callers
  timekeeping: Fix some trivial typos in comments
  alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist
  clocksource: arch_timer: Do not register arch_sys_counter twice
  timer stats: Add a 'Collection: active/inactive' line to timer usage statistics
  sched_clock: Remove sched_clock_func() hook
  arch_timer: Move to generic sched_clock framework
  clocksource: tcb_clksrc: Remove IRQF_DISABLED
  clocksource: tcb_clksrc: Improve driver robustness
  clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare
  clocksource: arm_arch_timer: Use clocksource for suspend timekeeping
  clocksource: dw_apb_timer_of: Mark a few more functions as __init
  clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally
  arm: zynq: Enable arm_global_timer
  ...
2013-11-12 10:36:00 +09:00
Linus Torvalds 39cf275a1a Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle are:

   - (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik
     van Riel, Peter Zijlstra et al.  Yay!

   - optimize preemption counter handling: merge the NEED_RESCHED flag
     into the preempt_count variable, by Peter Zijlstra.

   - wait.h fixes and code reorganization from Peter Zijlstra

   - cfs_bandwidth fixes from Ben Segall

   - SMP load-balancer cleanups from Peter Zijstra

   - idle balancer improvements from Jason Low

   - other fixes and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
  stop_machine: Fix race between stop_two_cpus() and stop_cpus()
  sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
  sched: Fix asymmetric scheduling for POWER7
  sched: Move completion code from core.c to completion.c
  sched: Move wait code from core.c to wait.c
  sched: Move wait.c into kernel/sched/
  sched/wait: Fix __wait_event_interruptible_lock_irq_timeout()
  sched: Avoid throttle_cfs_rq() racing with period_timer stopping
  sched: Guarantee new group-entities always have weight
  sched: Fix hrtimer_cancel()/rq->lock deadlock
  sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
  sched: Fix race on toggling cfs_bandwidth_used
  sched: Remove extra put_online_cpus() inside sched_setaffinity()
  sched/rt: Fix task_tick_rt() comment
  sched/wait: Fix build breakage
  sched/wait: Introduce prepare_to_wait_event()
  sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
  sched: Remove get_online_cpus() usage
  sched: Fix race in migrate_swap_stop()
  ...
2013-11-12 10:20:12 +09:00
Linus Torvalds ad5d69899e Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "As a first remark I'd like to note that the way to build perf tooling
  has been simplified and sped up, in the future it should be enough for
  you to build perf via:

        cd tools/perf/
        make install

  (ie without the -j option.) The build system will figure out the
  number of CPUs and will do a parallel build+install.

  The various build system inefficiencies and breakages Linus reported
  against the v3.12 pull request should now be resolved - please
  (re-)report any remaining annoyances or bugs.

  Main changes on the perf kernel side:

   * Performance optimizations:
      . perf ring-buffer code optimizations,          by Peter Zijlstra
      . perf ring-buffer code optimizations,          by Oleg Nesterov
      . x86 NMI call-stack processing optimizations,  by Peter Zijlstra
      . perf context-switch optimizations,            by Peter Zijlstra
      . perf sampling speedups,                       by Peter Zijlstra
      . x86 Intel PEBS processing speedups,           by Peter Zijlstra

   * Enhanced hardware support:
      . for Intel Ivy Bridge-EP uncore PMUs,          by Zheng Yan
      . for Haswell transactions,                     by Andi Kleen, Peter Zijlstra

   * Core perf events code enhancements and fixes by Oleg Nesterov:
      . for uprobes, if fork() is called with pending ret-probes
      . for uprobes platform support code

   * New ABI details by Andi Kleen:
      . Report x86 Haswell TSX transaction abort cost as weight

  Main changes on the perf tooling side (some of these tooling changes
  utilize the above kernel side changes):

   * 'perf report/top' enhancements:

      . Convert callchain children list to rbtree, greatly reducing the
        time taken for callchain processing, from Namhyung Kim.

      . Add new COMM infrastructure, further improving histogram
        processing, from Frédéric Weisbecker, one fix from Namhyung Kim.

      . Add /proc/kcore based live-annotation improvements, including
        build-id cache support, multi map 'call' instruction navigation
        fixes, kcore address validation, objdump workarounds.  From
        Adrian Hunter.

      . Show progress on histogram collapsing, that can take a long
        time, from Namhyung Kim.

      . Add --max-stack option to limit callchain stack scan in 'top'
        and 'report', improving callchain processing when reducing the
        stack depth is an option, from Waiman Long.

      . Add new option --ignore-vmlinux for perf top, from Willy
        Tarreau.

   * 'perf trace' enhancements:

      . 'perf trace' now can can use a 'perf probe' dynamic tracepoints
        to hook into the userspace -> kernel pathname copy so that it
        can map fds to pathnames without reading /proc/pid/fd/ symlinks.
        From Arnaldo Carvalho de Melo.

      . Show VFS path associated with fd in live sessions, using a
        'vfs_getname' 'perf probe' created dynamic tracepoint or by
        looking at /proc/pid/fd, from Arnaldo Carvalho de Melo.

      . Add 'trace' beautifiers for lots of syscall arguments, from
        Arnaldo Carvalho de Melo.

      . Implement more compact 'trace' output by suppressing zeroed
        args, from Arnaldo Carvalho de Melo.

      . Show thread COMM by default in 'trace', from Arnaldo Carvalho de
        Melo.

      . Add option to show full timestamp in 'trace', from David Ahern.

      . Add 'record' command in 'trace', to record raw_syscalls:*, from
        David Ahern.

      . Add summary option to dump syscall statistics in 'trace', from
        David Ahern.

      . Improve error messages in 'trace', providing hints about system
        configuration steps needed for using it, from Ramkumar
        Ramachandra.

      . 'perf trace' now emits hints as to why tracing is not possible,
        helping the user to setup the system to allow tracing in the
        desired permission granularity, telling if the problem is due to
        debugfs not being mounted or with not enough permission for
        !root, /proc/sys/kernel/perf_event_paranoit value, etc.  From
        Arnaldo Carvalho de Melo.

   * 'perf record' enhancements:

      . Check maximum frequency rate for record/top, emitting better
        error messages, from Jiri Olsa.

      . 'perf record' code cleanups, from David Ahern.

      . Improve write_output error message in 'perf record', from Adrian
        Hunter.

      . Allow specifying B/K/M/G unit to the --mmap-pages arguments,
        from Jiri Olsa.

      . Fix command line callchain attribute tests to handle the new
        -g/--call-chain semantics, from Arnaldo Carvalho de Melo.

   * 'perf kvm' enhancements:

      . Disable live kvm command if timerfd is not supported, from David
        Ahern.

      . Fix detection of non-core features, from David Ahern.

   * 'perf list' enhancements:

      . Add usage to 'perf list', from David Ahern.

      . Show error in 'perf list' if tracepoints not available, from
        Pekka Enberg.

   * 'perf probe' enhancements:

      . Support "$vars" meta argument syntax for local variables,
        allowing asking for all possible variables at a given probe
        point to be collected when it hits, from Masami Hiramatsu.

   * 'perf sched' enhancements:

      . Address the root cause of that 'perf sched' stack initialization
        build slowdown, by programmatically setting a big array after
        moving the global variable back to the stack.  Fix from Adrian
        Hunter.

   * 'perf script' enhancements:

      . Set up output options for in-stream attributes, from Adrian
        Hunter.

      . Print addr by default for BTS in 'perf script', from Adrian
        Juntmer

   * 'perf stat' enhancements:

      . Improved messages when doing profiling in all or a subset of
        CPUs using a workload as the session delimitator, as in:

         'perf stat --cpu 0,2 sleep 10s'

        from Arnaldo Carvalho de Melo.

      . Add units to nanosec-based counters in 'perf stat', from David
        Ahern.

      . Remove bogus info when using 'perf stat' -e cycles/instructions,
        from Ramkumar Ramachandra.

   * 'perf lock' enhancements:

      . 'perf lock' fixes and cleanups, from Davidlohr Bueso.

   * 'perf test' enhancements:

      . Fixup PERF_SAMPLE_TRANSACTION handling in sample synthesizing
        and 'perf test', from Adrian Hunter.

      . Clarify the "sample parsing" test entry, from Arnaldo Carvalho
        de Melo.

      . Consider PERF_SAMPLE_TRANSACTION in the "sample parsing" test,
        from Arnaldo Carvalho de Melo.

      . Memory leak fixes in 'perf test', from Felipe Pena.

   * 'perf bench' enhancements:

      . Change the procps visible command-name of invididual benchmark
        tests plus cleanups, from Ingo Molnar.

   * Generic perf tooling infrastructure/plumbing changes:

      . Separating data file properties from session, code
        reorganization from Jiri Olsa.

      . Fix version when building out of tree, as when using one of
        these:

        $ make help | grep perf
          perf-tar-src-pkg    - Build perf-3.12.0.tar source tarball
          perf-targz-src-pkg  - Build perf-3.12.0.tar.gz source tarball
          perf-tarbz2-src-pkg - Build perf-3.12.0.tar.bz2 source tarball
          perf-tarxz-src-pkg  - Build perf-3.12.0.tar.xz source tarball
        $

        from David Ahern.

      . Enhance option parse error message, showing just the help lines
        of the options affected, from Namhyung Kim.

      . libtraceevent updates from upstream trace-cmd repo, from Steven
        Rostedt.

      . Always use perf_evsel__set_sample_bit to set sample_type, from
        Adrian Hunter.

      . Memory and mmap leak fixes from Chenggang Qin.

      . Assorted build fixes for from David Ahern and Jiri Olsa.

      . Speed up and prettify the build system, from Ingo Molnar.

      . Implement addr2line directly using libbfd, from Roberto Vitillo.

      . Separate the GTK support in a separate libperf-gtk.so DSO, that
        is only loaded when --gtk is specified, from Namhyung Kim.

      . perf bash completion fixes and improvements from Ramkumar
        Ramachandra.

      . Support for Openembedded/Yocto -dbg packages, from Ricardo
        Ribalda Delgado.

  And lots and lots of other fixes and code reorganizations that did not
  make it into the list, see the shortlog, diffstat and the Git log for
  details!"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (300 commits)
  uprobes: Fix the memory out of bound overwrite in copy_insn()
  uprobes: Fix the wrong usage of current->utask in uprobe_copy_process()
  perf tools: Remove unneeded include
  perf record: Remove post_processing_offset variable
  perf record: Remove advance_output function
  perf record: Refactor feature handling into a separate function
  perf trace: Don't relookup fields by name in each sample
  perf tools: Fix version when building out of tree
  perf evsel: Ditch evsel->handler.data field
  uprobes: Export write_opcode() as uprobe_write_opcode()
  uprobes: Introduce arch_uprobe->ixol
  uprobes: Kill module_init() and module_exit()
  uprobes: Move function declarations out of arch
  perf/x86/intel: Add Ivy Bridge-EP uncore IRP box support
  perf/x86/intel/uncore: Add filter support for IvyBridge-EP QPI boxes
  perf: Factor out strncpy() in perf_event_mmap_event()
  tools/perf: Add required memory barriers
  perf: Fix arch_perf_out_copy_user default
  perf: Update a stale comment
  perf: Optimize perf_output_begin() -- address calculation
  ...
2013-11-12 10:06:34 +09:00
Linus Torvalds ef1417a5a6 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull leftover IRQ fixes from Ingo Molnar:
 "Two (minor) fixlets that missed v3.12"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Set the irq thread policy without checking CAP_SYS_NICE
  irq: DocBook/genericirq.tmpl: Correct various typos
2013-11-12 10:04:41 +09:00
Linus Torvalds 1006fae359 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull IRQ changes from Ingo Molnar:
 "The biggest change this cycle are the softirq/hardirq stack
  interaction and nesting fixes, cleanups and reorganizations from
  Frederic.  This is the longer followup story to the softirq nesting
  fix that is already upstream (commit ded797547548: "irq: Force hardirq
  exit's softirq processing on its own stack")"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro
  powerpc: Tell about irq stack coverage
  x86: Tell about irq stack coverage
  irq: Optimize softirq stack selection in irq exit
  irq: Justify the various softirq stack choices
  irq: Improve a bit softirq debugging
  irq: Optimize call to softirq on hardirq exit
  irq: Consolidate do_softirq() arch overriden implementations
  x86/irq: Correct comment about i8259 initialization
2013-11-12 10:02:59 +09:00
Linus Torvalds 70fdcb83db Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle are:

   - Idle entry/exit changes, to throttle callback execution and other
     refinements to speed up kbuild, primarily to address performance
     issues located by Tibor Billes.

   - Grace-period related changes, primarily to aid in debugging,
     inspired by an -rt debugging session.

   - Code reorganization moving RCU's source files into its own
     kernel/rcu/ directory.

   - RCU documentation updates

   - Miscellaneous fixes.

  Note, the following commit:

    5c889690aa mm: Place preemption point in do_mlockall() loop

  is identical to the commit already in your tree via email:

    22356f447c mm: Place preemption point in do_mlockall() loop

  [ Your version of the changelog nicely demonstrates it how kernel oops
    messages should be trimmed properly :-/ ]"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  rcu: Move RCU-related source code to kernel/rcu directory
  rcu: Fix occurrence of "the the" in checklist.txt
  kthread: Add pointer to vmstat-avoidance patch
  rcu: Update stall-warning documentation
  rcu: Consistent rcu_is_watching() naming
  rcu: Change EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL()
  rcu: Is it safe to enter an RCU read-side critical section?
  rcu: Throttle invoke_rcu_core() invocations due to non-lazy callbacks
  rcu: Throttle rcu_try_advance_all_cbs() execution
  rcu: Remove redundant code from rcu_cleanup_after_idle()
  rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask
  rcu: Avoid sparse warnings in rcu_nocb_wake trace event
  rcu: Track rcu_nocb_kthread()'s sleeping and awakening
  rcu: Distinguish between NOCB and non-NOCB rcu_callback trace events
  rcu: Add tracing for rcuo no-CBs CPU wakeup handshake
  rcu: Add tracing of normal (non-NOCB) grace-period requests
  rcu: Add tracing to rcu_gp_kthread()
  rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE()
  rcu: Prevent spurious-wakeup DoS attack on rcu_gp_kthread()
  rcu: Improve grace-period start logic
  ...
2013-11-12 10:00:04 +09:00
Steven Rostedt (Red Hat) 3a81a5210b tracing: Add rcu annotation for syscall trace descriptors
sparse complains about the enter/exit_sysycall_files[] variables being
dereferenced with rcu_dereference_sched(). The fields need to be
annotated with __rcu.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-11 11:47:06 -05:00
Peter Zijlstra e5137b50a0 ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
Since the introduction of PREEMPT_NEED_RESCHED in:

  f27dde8dee ("sched: Add NEED_RESCHED to the preempt_count")

we need to be able to look at both TIF_NEED_RESCHED and
PREEMPT_NEED_RESCHED to understand the full preemption behaviour.

Add it to the trace output.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11 12:43:39 +01:00
Rik van Riel 7053ea1a34 stop_machine: Fix race between stop_two_cpus() and stop_cpus()
There is a race between stop_two_cpus, and the global stop_cpus.

It is possible for two CPUs to get their stopper functions queued
"backwards" from one another, resulting in the stopper threads
getting stuck, and the system hanging. This can happen because
queuing up stoppers is not synchronized.

This patch adds synchronization between stop_cpus (a rare operation),
and stop_two_cpus.

Reported-and-Tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/20131101104146.03d1e043@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11 12:43:38 +01:00
Peter Zijlstra 838cc7b488 lockdep/proc: Fix lock-time avg computation
>    kernel/locking/lockdep_proc.c: In function 'seq_lock_time':
> >> kernel/locking/lockdep_proc.c:424:23: warning: comparison of distinct pointer types lacks a cast [enabled by default]
>
>    418	static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
>    419	{
>    420		seq_printf(m, "%14lu", lt->nr);
>    421		seq_time(m, lt->min);
>    422		seq_time(m, lt->max);
>    423		seq_time(m, lt->total);
>  > 424		seq_time(m, lt->nr ? do_div(lt->total, lt->nr) : 0);
>    425	}

My compiler refuses to actually say that; but it looks wrong in that
do_div() returns the remainder, not the divisor.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Link: http://lkml.kernel.org/r/20131106164230.GE16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11 12:41:34 +01:00
Peter Zijlstra 67a6de49bf locking/doc: Update references to kernel/mutex.c
Fix this docbook error:

  >> docproc: kernel/mutex.c: No such file or directory

by updating the stale references to kernel/mutex.c.

Reported-by: fengguang.wu@intel.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-34pikw1tlsskj65rrt5iusrq@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11 12:41:33 +01:00
Oleg Nesterov 2ded0980a6 uprobes: Fix the memory out of bound overwrite in copy_insn()
1. copy_insn() doesn't look very nice, all calculations are
   confusing and it is not immediately clear why do we read
   the 2nd page first.

2. The usage of inode->i_size is wrong on 32-bit machines.

3. "Instruction at end of binary" logic is simply wrong, it
   doesn't handle the case when uprobe->offset > inode->i_size.

   In this case "bytes" overflows, and __copy_insn() writes to
   the memory outside of uprobe->arch.insn.

   Yes, uprobe_register() checks i_size_read(), but this file
   can be truncated after that. All i_size checks are racy, we
   do this only to catch the obvious mistakes.

Change copy_insn() to call __copy_insn() in a loop, simplify
and fix the bytes/nbytes calculations.

Note: we do not care if we read extra bytes after inode->i_size
if we got the valid page. This is fine because the task gets the
same page after page-fault, and arch_uprobe_analyze_insn() can't
know how many bytes were actually read anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-09 17:05:43 +01:00
Oleg Nesterov 70d7f98722 uprobes: Fix the wrong usage of current->utask in uprobe_copy_process()
Commit aa59c53fd4 "uprobes: Change uprobe_copy_process() to dup
xol_area" has a stupid typo, we need to setup t->utask->vaddr but
the code wrongly uses current->utask.

Even with this bug dup_xol_work() works "in practice", but only
because get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE) likely
returns the same address every time.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-09 17:05:41 +01:00
Al Viro ce39596048 constify copy_siginfo_to_user{,32}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:29 -05:00
Al Viro 506f21c556 switch elf_core_write_extra_phdrs() to dump_emit()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:23 -05:00
Jens Axboe e37459b8e2 Merge branch 'blk-mq/core' into for-3.13/core
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Conflicts:
	block/blk-timeout.c
2013-11-08 09:08:12 -07:00
Chen Gang f8c5e94486 kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()
do_blk_trace_setup() will fully initialize 'buts.name', so can remove
the related memcpy(). And also use BLKTRACE_BDEV_SIZE and ARRAY_SIZE
instead of hard code number '32'.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 09:04:30 -07:00
Jan Kara a404d5576b blktrace: Send BLK_TN_PROCESS events to all running traces
Currently each task sends BLK_TN_PROCESS event to the first traced
device it interacts with after a new trace is started. When there are
several traced devices and the task accesses more devices, this logic
can result in BLK_TN_PROCESS being sent several times to some devices
while it is never sent to other devices. Thus blkparse doesn't display
command name when parsing some blktrace files.

Fix the problem by sending BLK_TN_PROCESS event to all traced devices
when a task interacts with any of them.

Signed-off-by: Jan Kara <jack@suse.cz>
Review-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 08:59:00 -07:00
Linus Torvalds 6c86ae2928 Dave Jones's trinity program was able to enable the function tracer
from a normal user account via the perf syscall "perf_event_open()".
 When I was able to reproduce it with trinity, I was able to track down
 exactly how it happened.
 
 I discovered that the check for whether the function tracepoint should
 be activated or not was using the "perf_paranoid_kernel()" check which
 by default, lets the user continue. The user should not by default be
 able to enable function tracing. The fix is to use
 "perf_paranoid_tracepoint_raw()" which will not let the user enable
 function tracing.
 
 This is a security fix as normal users should never be allowed to
 enable the function tracer.
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Merge tag 'ftrace-urgent-3.12-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull perf/ftrace fix from Steven Rostedt:
 "Dave Jones's trinity program was able to enable the function tracer
  from a normal user account via the perf syscall "perf_event_open()".
  When I was able to reproduce it with trinity, I was able to track down
  exactly how it happened.

  I discovered that the check for whether the function tracepoint should
  be activated or not was using the "perf_paranoid_kernel()" check which
  by default, lets the user continue.  The user should not by default be
  able to enable function tracing.

  The fix is to use "perf_paranoid_tracepoint_raw()" which will not let
  the user enable function tracing.  This is a security fix as normal
  users should never be allowed to enable the function tracer"

* tag 'ftrace-urgent-3.12-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  perf/ftrace: Fix paranoid level for enabling function tracer
2013-11-08 08:54:53 +09:00
Rafael J. Wysocki feba070dba Merge branch 'pm-sleep'
* pm-sleep:
  PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
2013-11-07 19:26:55 +01:00
Linus Torvalds 56edff7529 TTY/Serial driver updates for 3.13-rc1
Here's the big tty/serial driver update for 3.13-rc1.
 
 There's some more minor n_tty work here, but nothing like previous
 kernel releases.  Also some new driver ids, driver updates for new
 hardware, and other small things.
 
 All of this has been in linux-next for a while with no issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver update for 3.13-rc1.

  There's some more minor n_tty work here, but nothing like previous
  kernel releases.  Also some new driver ids, driver updates for new
  hardware, and other small things.

  All of this has been in linux-next for a while with no issues"

* tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
  serial: omap: fix missing comma
  serial: sh-sci: Enable the driver on all ARM platforms
  serial: mfd: Staticize local symbols
  serial: omap: fix a few checkpatch warnings
  serial: omap: improve RS-485 performance
  mrst_max3110: fix unbalanced IRQ issue during resume
  serial: omap: Add support for optional wake-up
  serial: sirf: remove duplicate defines
  tty: xuartps: Fix build error when COMMON_CLK is not set
  tty: xuartps: Fix build error due to missing forward declaration
  tty: xuartps: Fix "may be used uninitialized" build warning
  serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8
  tty: xuartps: Update copyright information
  tty: xuartps: Implement suspend/resume callbacks
  tty: xuartps: Dynamically adjust to input frequency changes
  tty: xuartps: Updating set_baud_rate()
  tty: xuartps: Force enable the UART in xuartps_console_write
  tty: xuartps: support 64 byte FIFO size
  tty: xuartps: Add polled mode support for xuartps
  tty: xuartps: Implement BREAK detection, add SYSRQ support
  ...
2013-11-07 12:17:06 +09:00
Linus Torvalds 0324e74534 Driver Core / sysfs patches for 3.13-rc1
Here's the big driver core / sysfs update for 3.13-rc1.
 
 There's lots of dev_groups updates for different subsystems, as they all
 get slowly migrated over to the safe versions of the attribute groups
 (removing userspace races with the creation of the sysfs files.)  Also
 in here are some kobject updates, devres expansions, and the first round
 of Tejun's sysfs reworking to enable it to be used by other subsystems
 as a backend for an in-kernel filesystem.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...
2013-11-07 11:42:15 +09:00
Aaron Lu fd432b9f8c PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
When system has a lot of highmem (e.g. 16GiB using a 32 bits kernel),
the code to calculate how much memory we need to preallocate in
normal zone may cause overflow. As Leon has analysed:

 It looks that during computing 'alloc' variable there is overflow:
 alloc = (3943404 - 1970542) - 1978280 = -5418 (signed)
 And this function goes to err_out.

Fix this by avoiding that overflow.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60817
Reported-and-tested-by: Leon Drugi <eyak@wp.pl>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-07 01:58:39 +01:00
Steven Rostedt (Red Hat) 6fc84ea70e tracing: Do not use signed enums with unsigned long long in fgragh output
The duration field of print_graph_duration() can also be used
to do the space filling by passing an enum in it:

  DURATION_FILL_FULL
  DURATION_FILL_START
  DURATION_FILL_END

The problem is that these are enums and defined as negative,
but the duration field is unsigned long long. Most archs are
fine with this but blackfin fails to compile because of it:

kernel/built-in.o: In function `print_graph_duration':
kernel/trace/trace_functions_graph.c:782: undefined reference to `__ucmpdi2'

Overloading a unsigned long long with an signed enum is just
bad in principle. We can accomplish the same thing by using
part of the flags field instead.

Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 15:26:56 -05:00
Steven Rostedt (Red Hat) 042b10d83d tracing: Remove unused function ftrace_off_permanent()
In the past, ftrace_off_permanent() was called if something
strange was detected. But the ftrace_bug() now handles all the
anomolies that can happen with ftrace (function tracing), and there
are no uses of ftrace_off_permanent(). Get rid of it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 15:26:55 -05:00
Geyslan G. Bem d6d3523caa tracing: Do not assign filp->private_data to freed memory
In system_tr_open(), the filp->private_data can be assigned the 'dir'
variable even if it was freed. This is on the error path, and is
harmless because the error return code will prevent filp->private_data
from being used. But for correctness, we should not assign it to
a recently freed variable, as that can cause static tools to give
false warnings.

Also have both subsystem_open() and system_tr_open() return -ENODEV
if tracing has been disabled.

Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 15:26:54 -05:00
Steven Rostedt 12ae030d54 perf/ftrace: Fix paranoid level for enabling function tracer
The current default perf paranoid level is "1" which has
"perf_paranoid_kernel()" return false, and giving any operations that
use it, access to normal users. Unfortunately, this includes function
tracing and normal users should not be allowed to enable function
tracing by default.

The proper level is defined at "-1" (full perf access), which
"perf_paranoid_tracepoint_raw()" will only give access to. Use that
check instead for enabling function tracing.

Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org # 3.4+
CVE: CVE-2013-2930
Fixes: ced39002f5 ("ftrace, perf: Add support to use function tracepoint in perf")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 14:44:49 -05:00
Oleg Nesterov f72d41fa90 uprobes: Export write_opcode() as uprobe_write_opcode()
set_swbp() and set_orig_insn() are __weak, but this is pointless
because write_opcode() is static.

Export write_opcode() as uprobe_write_opcode() for the upcoming
arm port, this way it can actually override set_swbp() and use
__opcode_to_mem_arm(bpinsn) instead if UPROBE_SWBP_INSN.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06 20:00:09 +01:00
Oleg Nesterov 8a8de66c4f uprobes: Introduce arch_uprobe->ixol
Currently xol_get_insn_slot() assumes that we should simply copy
arch_uprobe->insn[] which is (ignoring arch_uprobe_analyze_insn)
just the copy of the original insn.

This is not true for arm which needs to create another insn to
execute it out-of-line.

So this patch simply adds the new member, ->ixol into the union.
This doesn't make any difference for x86 and powerpc, but arm
can divorce insn/ixol and initialize the correct xol insn in
arch_uprobe_analyze_insn().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06 20:00:05 +01:00
Oleg Nesterov 736e89d9f7 uprobes: Kill module_init() and module_exit()
Turn module_init() into __initcall() and kill module_exit().

This code can't be compiled as a module so these module_*()
calls only add the confusion, especially if arch-dependant
code needs its own initialization hooks.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06 19:59:50 +01:00
Eric Paris 9175c9d2ae audit: fix type of sessionid in audit_set_loginuid()
sfr pointed out that with CONFIG_UIDGID_STRICT_TYPE_CHECKS set the audit
tree would not build.  This is because the oldsessionid in
audit_set_loginuid() was accidentally being declared as a kuid_t.  This
patch fixes that declaration mistake.

Example of problem:
kernel/auditsc.c: In function 'audit_set_loginuid':
kernel/auditsc.c:2003:15: error: incompatible types when assigning to
type 'kuid_t' from type 'int'
  oldsessionid = audit_get_sessionid(current);

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-06 11:47:24 -05:00
Geyslan G. Bem 2e86421deb tracing: Add helper function tracing_is_disabled()
This patch creates the function 'tracing_is_disabled', which
can be used outside of trace.c.

Link: http://lkml.kernel.org/r/1382141754-12155-1-git-send-email-geyslan@gmail.com

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 11:06:00 -05:00
Cody P Schafer b2f974d6af tracing: Open tracer when ftrace_dump_on_oops is used
With ftrace_dump_on_oops, we previously did not open the tracer in
question, sometimes causing the trace output to be useless.

For example, the function_graph tracer with tracing_thresh set dumped via
ftrace_dump_on_oops would show a series of '}' indented at different levels,
but no function names.

call trace->open() (and do a few other fixups copied from the normal dump
path) to make the output more intelligible.

Link: http://lkml.kernel.org/r/1382554197-16961-1-git-send-email-cody@linux.vnet.ibm.com

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06 10:03:11 -05:00
Preeti U Murthy 37dc6b50ce sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
nr_busy_cpus parameter is used by nohz_kick_needed() to find out the
number of busy cpus in a sched domain which has SD_SHARE_PKG_RESOURCES
flag set.  Therefore instead of updating nr_busy_cpus at every level
of sched domain, since it is irrelevant, we can update this parameter
only at the parent domain of the sd which has this flag set. Introduce
a per-cpu parameter sd_busy which represents this parent domain.

In nohz_kick_needed() we directly query the nr_busy_cpus parameter
associated with the groups of sd_busy.

By associating sd_busy with the highest domain which has
SD_SHARE_PKG_RESOURCES flag set, we cover all lower level domains
which could have this flag set and trigger nohz_idle_balancing if any
of the levels have more than one busy cpu.

sd_busy is irrelevant for asymmetric load balancing. However sd_asym
has been introduced to represent the highest sched domain which has
SD_ASYM_PACKING flag set so that it can be queried directly when
required.

While we are at it, we might as well change the nohz_idle parameter to
be updated at the sd_busy domain level alone and not the base domain
level of a CPU.  This will unify the concept of busy cpus at just one
level of sched domain where it is currently used.

Signed-off-by: Preeti U Murthy<preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: svaidy@linux.vnet.ibm.com
Cc: vincent.guittot@linaro.org
Cc: bitbucket@online.de
Cc: benh@kernel.crashing.org
Cc: anton@samba.org
Cc: Morten.Rasmussen@arm.com
Cc: pjt@google.com
Cc: peterz@infradead.org
Cc: mikey@neuling.org
Link: http://lkml.kernel.org/r/20131030031252.23426.4417.stgit@preeti.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:37:55 +01:00
Vaidyanathan Srinivasan 2042abe797 sched: Fix asymmetric scheduling for POWER7
Asymmetric scheduling within a core is a scheduler loadbalancing
feature that is triggered when SD_ASYM_PACKING flag is set.  The goal
for the load balancer is to move tasks to lower order idle SMT threads
within a core on a POWER7 system.

In nohz_kick_needed(), we intend to check if our sched domain (core)
is completely busy or we have idle cpu.

The following check for SD_ASYM_PACKING:

    (cpumask_first_and(nohz.idle_cpus_mask, sched_domain_span(sd)) < cpu)

already covers the case of checking if the domain has an idle cpu,
because cpumask_first_and() will not yield any set bits if this domain
has no idle cpu.

Hence, nr_busy check against group weight can be removed.

Reported-by: Michael Neuling <michael.neuling@au1.ibm.com>
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: vincent.guittot@linaro.org
Cc: bitbucket@online.de
Cc: benh@kernel.crashing.org
Cc: anton@samba.org
Cc: Morten.Rasmussen@arm.com
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131030031242.23426.13019.stgit@preeti.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:37:54 +01:00
Oleg Nesterov c7e548b45c perf: Factor out strncpy() in perf_event_mmap_event()
While this is really minor, but strncpy() does the unnecessary
zero-padding till the end of tmp[16] and it is called every time
we are going to use the string literal.

Turn these strncpy()'s into the single strlcpy() under the new
label, saves 72 bytes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131017182417.GA17753@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:28 +01:00
Peter Zijlstra 0a196848ca perf: Fix arch_perf_out_copy_user default
The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.

Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.

Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:25 +01:00
Peter Zijlstra 394570b793 perf: Update a stale comment
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-9s5mze78gmlz19agt39i8rii@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:23 +01:00
Peter Zijlstra 524feca5e9 perf: Optimize perf_output_begin() -- address calculation
Rewrite the handle address calculation code to be clearer.

Saves 8 bytes on x86_64-defconfig.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-3trb2n2henb9m27tncef3ag7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:22 +01:00
Peter Zijlstra d20a973f46 perf: Optimize perf_output_begin() -- lost_event case
Avoid touching the lost_event and sample_data cachelines twince. Its
not like we end up doing less work, but it might help to keep all
accesses to these cachelines in one place.

Due to code shuffle, this looses 4 bytes on x86_64-defconfig.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-zfxnc58qxj0eawdoj31hhupv@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:21 +01:00
Peter Zijlstra 85f59edf96 perf: Optimize perf_output_begin()
There's no point in re-doing the memory-barrier when we fail the
cmpxchg(). Also placing it after the space reservation loop makes it
clearer it only separates the userpage->tail read from the data
stores.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-c19u6egfldyx86tpyc3zgkw9@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:20 +01:00
Peter Zijlstra c72b42a3dd perf: Add unlikely() to the ring-buffer code
Add unlikely() annotations to 'slow' paths:

When having a sampling event but no output buffer; you have bigger
issues -- also the bail is still faster than actually doing the work.

When having a sampling event but a control page only buffer, you have
bigger issues -- again the bail is still faster than actually doing
work.

Optimize for the case where you're not loosing events -- again, not
doing the work is still faster but make sure that when you have to
actually do work its as fast as possible.

The typical watermark is 1/2 the buffer size, so most events will not
take this path.

Shrinks perf_output_begin() by 16 bytes on x86_64-defconfig.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-wlg3jew3qnutm8opd0hyeuwn@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:19 +01:00
Peter Zijlstra 26c86da882 perf: Simplify the ring-buffer code
By using CIRC_SPACE() we can obviate the need for perf_output_space().

Shrinks the size of perf_output_begin() by 17 bytes on
x86_64-defconfig.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Link: http://lkml.kernel.org/n/tip-vtb0xb0llebmsdlfn1v5vtfj@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:34:18 +01:00
Peter Zijlstra 32cf7c3c94 locking: Move the percpu-rwsem code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-52bjmtty46we26hbfd9sc9iy@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 09:24:22 +01:00
Peter Zijlstra cd4d241d57 locking: Move the lglocks code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-amd6pg1mif6tikbyktfvby3y@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 09:24:20 +01:00
Peter Zijlstra ed428bfc3c locking: Move the rwsem code to kernel/locking/
Notably: changed lib/rwsem* targets from lib- to obj-, no idea about
the ramifications of that.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-g0kynfh5feriwc6p3h6kpbw6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 09:24:18 +01:00
Peter Zijlstra 1696a8bee3 locking: Move the rtmutex code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-p9ijt8div0hwldexwfm4nlhj@git.kernel.org
[ Fixed build failure in kernel/rcu/tree_plugin.h. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 09:23:59 +01:00
Marcelo Tosatti 8b414521bc hung_task: add method to reset detector
In certain occasions it is possible for a hung task detector
positive to be false: continuation from a paused VM, for example.

Add a method to reset detection, similar as is done
with other kernel watchdogs.

Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-06 09:49:02 +02:00
Peter Zijlstra e25a64c401 locking: Move the semaphore core to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-vmw5sf6vzmua1z6nx1cg69h2@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:55:22 +01:00
Peter Zijlstra 60fc28746a locking: Move the spinlock code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-b81ol0z3mon45m51o131yc9j@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:55:21 +01:00
Peter Zijlstra 8eddac3f10 locking: Move the lockdep code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-wl7s3tta5isufzfguc23et06@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:55:08 +01:00
Peter Zijlstra 01768b42dc locking: Move the mutex code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-1ditvncg30dgbpvrz2bxfmke@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:55:07 +01:00
Ingo Molnar c90423d1de Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ file move
Conflicts:
	kernel/Makefile

There are conflicts in kernel/Makefile due to file moving in the
scheduler tree - resolve them.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:50:37 +01:00
Peter Zijlstra b8a216269e sched: Move completion code from core.c to completion.c
Completions already have their own header file: linux/completion.h
Move the implementation out of kernel/sched/core.c and into its own
file: kernel/sched/completion.c.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-x2y49rmxu5dljt66ai2lcfuw@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:49:19 +01:00
Peter Zijlstra b4145872f7 sched: Move wait code from core.c to wait.c
For some reason only the wait part of the wait api lives in
kernel/sched/wait.c and the wake part still lives in kernel/sched/core.c;
ammend this.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-ftycee88naznulqk7ei5mbci@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:49:18 +01:00
Peter Zijlstra 7a6354e241 sched: Move wait.c into kernel/sched/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-5q5yqvdaen0rmapwloeaotx3@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:49:16 +01:00
Ingo Molnar ecf1f01432 Merge branch 'core/rcu' into core/locking, to prepare the kernel/locking/ file move
There are conflicts in lockdep.c due to RCU changes, and also the RCU
tree changes kernel/Makefile - so pre-merge it to ease the moving of
locking related .c files to kernel/locking/.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:43:37 +01:00
Ingo Molnar 97c53b402f Linux 3.12
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Merge tag 'v3.12' into core/locking to pick up mutex upates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 06:39:45 +01:00
Tom Zanussi d562aff93b tracing: Add support for SOFT_DISABLE to syscall events
The original SOFT_DISABLE patches didn't add support for soft disable
of syscall events; this adds it.

Add an array of ftrace_event_file pointers indexed by syscall number
to the trace array and remove the existing enabled bitmaps, which as a
result are now redundant.  The ftrace_event_file structs in turn
contain the soft disable flags we need for per-syscall soft disable
accounting.

Adding ftrace_event_files also means we can remove the USE_CALL_FILTER
bit, thus enabling multibuffer filter support for syscall events.

Link: http://lkml.kernel.org/r/6e72b566e85d8df8042f133efbc6c30e21fb017e.1382620672.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 17:48:49 -05:00
Tom Zanussi 38de93abec tracing: Make register/unregister_ftrace_command __init
register/unregister_ftrace_command() are only ever called from __init
functions, so can themselves be made __init.

Also make register_snapshot_cmd() __init for the same reason.

Link: http://lkml.kernel.org/r/d4042c8cadb7ae6f843ac9a89a24e1c6a3099727.1382620672.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 17:43:40 -05:00
Tom Zanussi f306cc82a9 tracing: Update event filters for multibuffer
The trace event filters are still tied to event calls rather than
event files, which means you don't get what you'd expect when using
filters in the multibuffer case:

Before:

  # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  bytes_alloc > 8192
  # mkdir /sys/kernel/debug/tracing/instances/test1
  # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
  # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  bytes_alloc > 2048
  # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
  bytes_alloc > 2048

Setting the filter in tracing/instances/test1/events shouldn't affect
the same event in tracing/events as it does above.

After:

  # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  bytes_alloc > 8192
  # mkdir /sys/kernel/debug/tracing/instances/test1
  # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
  # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
  bytes_alloc > 8192
  # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
  bytes_alloc > 2048

We'd like to just move the filter directly from ftrace_event_call to
ftrace_event_file, but there are a couple cases that don't yet have
multibuffer support and therefore have to continue using the current
event_call-based filters.  For those cases, a new USE_CALL_FILTER bit
is added to the event_call flags, whose main purpose is to keep the
old behavior for those cases until they can be updated with
multibuffer support; at that point, the USE_CALL_FILTER flag (and the
new associated call_filter_check_discard() function) can go away.

The multibuffer support also made filter_current_check_discard()
redundant, so this change removes that function as well and replaces
it with filter_check_discard() (or call_filter_check_discard() as
appropriate).

Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 16:50:20 -05:00
Steven Rostedt (Red Hat) b5aa3a472b ftrace: Have control op function callback only trace when RCU is watching
Dave Jones reported that trinity would be able to trigger the following
back trace:

 ===============================
 [ INFO: suspicious RCU usage. ]
 3.10.0-rc2+ #38 Not tainted
 -------------------------------
 include/linux/rcupdate.h:771 rcu_read_lock() used illegally while idle!
 other info that might help us debug this:

 RCU used illegally from idle CPU!  rcu_scheduler_active = 1, debug_locks = 0
 RCU used illegally from extended quiescent state!
 1 lock held by trinity-child1/18786:
  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff8113dd48>] __perf_event_overflow+0x108/0x310
 stack backtrace:
 CPU: 3 PID: 18786 Comm: trinity-child1 Not tainted 3.10.0-rc2+ #38
  0000000000000000 ffff88020767bac8 ffffffff816e2f6b ffff88020767baf8
  ffffffff810b5897 ffff88021de92520 0000000000000000 ffff88020767bbf8
  0000000000000000 ffff88020767bb78 ffffffff8113ded4 ffffffff8113dd48
 Call Trace:
  [<ffffffff816e2f6b>] dump_stack+0x19/0x1b
  [<ffffffff810b5897>] lockdep_rcu_suspicious+0xe7/0x120
  [<ffffffff8113ded4>] __perf_event_overflow+0x294/0x310
  [<ffffffff8113dd48>] ? __perf_event_overflow+0x108/0x310
  [<ffffffff81309289>] ? __const_udelay+0x29/0x30
  [<ffffffff81076054>] ? __rcu_read_unlock+0x54/0xa0
  [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f
  [<ffffffff8113dfa1>] perf_swevent_overflow+0x51/0xe0
  [<ffffffff8113e08f>] perf_swevent_event+0x5f/0x90
  [<ffffffff8113e1c9>] perf_tp_event+0x109/0x4f0
  [<ffffffff8113e36f>] ? perf_tp_event+0x2af/0x4f0
  [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20
  [<ffffffff8112d79f>] perf_ftrace_function_call+0xbf/0xd0
  [<ffffffff8110e1e1>] ? ftrace_ops_control_func+0x181/0x210
  [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20
  [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470
  [<ffffffff8110e1e1>] ftrace_ops_control_func+0x181/0x210
  [<ffffffff816f4000>] ftrace_call+0x5/0x2f
  [<ffffffff8110e229>] ? ftrace_ops_control_func+0x1c9/0x210
  [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f
  [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40
  [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40
  [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470
  [<ffffffff8110112a>] rcu_eqs_enter+0x6a/0xb0
  [<ffffffff81103673>] rcu_user_enter+0x13/0x20
  [<ffffffff8114541a>] user_enter+0x6a/0xd0
  [<ffffffff8100f6d8>] syscall_trace_leave+0x78/0x140
  [<ffffffff816f46af>] int_check_syscall_exit_work+0x34/0x3d
 ------------[ cut here ]------------

Perf uses rcu_read_lock() but as the function tracer can trace functions
even when RCU is not currently active, this makes the rcu_read_lock()
used by perf ineffective.

As perf is currently the only user of the ftrace_ops_control_func() and
perf is also the only function callback that actively uses rcu_read_lock(),
the quick fix is to prevent the ftrace_ops_control_func() from calling
its callbacks if RCU is not active.

With Paul's new "rcu_is_watching()" we can tell if RCU is active or not.

Reported-by: Dave Jones <davej@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 16:04:26 -05:00
Steven Rostedt 9418fb2080 rcu: Do not trace rcu_is_watching() functions
As perf uses the rcu_read_lock() primitives for recording into its
ring buffer, perf tracing can not be called when RCU in inactive.
With the perf function tracing, there are functions that can be
traced when RCU is not active, and perf must not have its function
callback called when this is the case.

Luckily, Paul McKenney has created a way to detect when RCU is
active or not with the rcu_is_watching() function. Unfortunately,
this function can also be traced, and if that happens it can cause
a bit of overhead for the perf function calls that do the check.
Recursion protection prevents anything bad from happening, but
there is a bit of added overhead for every function being traced that
must detect that the rcu_is_watching() is also being traced.

As rcu_is_watching() is a helper routine and not part of the
critical logic in RCU, it does not need to be traced in order to
debug RCU itself. Add the "notrace" annotation to all the rcu_is_watching()
calls such that we never trace it.

Link: http://lkml.kernel.org/r/20131104202736.72dd8e45@gandalf.local.home

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 16:04:08 -05:00
Steven Rostedt (Red Hat) 44847da1b9 Merge branch 'idle.2013.09.25a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into HEAD
Need to use Paul McKenney's "rcu_is_watching()" changes to fix
a perf/ftrace bug.
2013-11-05 16:03:17 -05:00
Cody P Schafer 9cd804ac1f trace/trace_stat: use rbtree postorder iteration helper instead of opencoding
Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Link: http://lkml.kernel.org/r/1383345566-25087-2-git-send-email-cody@linux.vnet.ibm.com

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05 16:01:47 -05:00
Richard Guy Briggs 9410d228a4 audit: call audit_bprm() only once to add AUDIT_EXECVE information
Move the audit_bprm() call from search_binary_handler() to exec_binprm().  This
allows us to get rid of the mm member of struct audit_aux_data_execve since
bprm->mm will equal current->mm.

This also mitigates the issue that ->argc could be modified by the
load_binary() call in search_binary_handler().

audit_bprm() was being called to add an AUDIT_EXECVE record to the audit
context every time search_binary_handler() was recursively called.  Only one
reference is necessary.

Reported-by: Oleg Nesterov <onestero@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
---
This patch is against 3.11, but was developed on Oleg's post-3.11 patches that
introduce exec_binprm().
2013-11-05 11:15:03 -05:00
Richard Guy Briggs d9cfea91e9 audit: move audit_aux_data_execve contents into audit_context union
audit_bprm() was being called to add an AUDIT_EXECVE record to the audit
context every time search_binary_handler() was recursively called.  Only one
reference is necessary, so just update it.  Move the the contents of
audit_aux_data_execve into the union in audit_context, removing dependence on a
kmalloc along the way.

Reported-by: Oleg Nesterov <onestero@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:36 -05:00
Richard Guy Briggs 9462dc5981 audit: remove unused envc member of audit_aux_data_execve
Get rid of write-only audit_aux_data_exeve structure member envc.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:31 -05:00
Eric W. Biederman bd131fb1aa audit: Kill the unused struct audit_aux_data_capset
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
(cherry picked from ebiederman commit 6904431d6b41190e42d6b94430b67cb4e7e6a4b7)
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:20 -05:00
Eric Paris 78122037b7 audit: do not reject all AUDIT_INODE filter types
commit ab61d38ed8 tried to merge the
invalid filter checking into a single function.  However AUDIT_INODE
filters were not verified in the new generic checker.  Thus such rules
were being denied even though they were perfectly valid.

Ex:
$ auditctl -a exit,always -F arch=b64 -S open -F key=/foo -F inode=6955 -F devmajor=9 -F devminor=1
Error sending add rule data request (Invalid argument)

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:16 -05:00
Jeff Layton d3aea84a4a audit: log the audit_names record type
...to make it clear what the intent behind each record's operation was.

In many cases you can infer this, based on the context of the syscall
and the result. In other cases it's not so obvious. For instance, in
the case where you have a file being renamed over another, you'll have
two different records with the same filename but different inode info.
By logging this information we can clearly tell which one was created
and which was deleted.

This fixes what was broken in commit bfcec708.
Commit 79f6530c should also be backported to stable v3.7+.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:09:04 -05:00
Richard Guy Briggs b95d77fe34 audit: use given values in tty_audit enable api
In send/GET, we don't want the kernel to lie about what value is set.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:42 -05:00
Mathias Krause 4d8fe7376a audit: use nlmsg_len() to get message payload length
Using the nlmsg_len member of the netlink header to test if the message
is valid is wrong as it includes the size of the netlink header itself.
Thereby allowing to send short netlink messages that pass those checks.

Use nlmsg_len() instead to test for the right message length. The result
of nlmsg_len() is guaranteed to be non-negative as the netlink message
already passed the checks of nlmsg_ok().

Also switch to min_t() to please checkpatch.pl.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org  # v2.6.6+ for the 1st hunk, v2.6.23+ for the 2nd
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:37 -05:00
Eric Paris e13f91e3c5 audit: use memset instead of trying to initialize field by field
We currently are setting fields to 0 to initialize the structure
declared on the stack.  This is a bad idea as if the structure has holes
or unpacked space these will not be initialized.  Just use memset.  This
is not a performance critical section of code.

Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:35 -05:00
Mathias Krause 64fbff9ae0 audit: fix info leak in AUDIT_GET requests
We leak 4 bytes of kernel stack in response to an AUDIT_GET request as
we miss to initialize the mask member of status_set. Fix that.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org  # v2.6.6+
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:30 -05:00
Richard Guy Briggs db510fc5cd audit: update AUDIT_INODE filter rule to comparator function
It appears this one comparison function got missed in f368c07d (and 9c937dcc).

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:24 -05:00
Eric Paris 21b85c31d2 audit: audit feature to set loginuid immutable
This adds a new 'audit_feature' bit which allows userspace to set it
such that the loginuid is absolutely immutable, even if you have
CAP_AUDIT_CONTROL.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:17 -05:00
Eric Paris d040e5af38 audit: audit feature to only allow unsetting the loginuid
This is a new audit feature which only grants processes with
CAP_AUDIT_CONTROL the ability to unset their loginuid.  They cannot
directly set it from a valid uid to another valid uid.  The ability to
unset the loginuid is nice because a priviledged task, like that of
container creation, can unset the loginuid and then priv is not needed
inside the container when a login daemon needs to set the loginuid.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:13 -05:00
Eric Paris 81407c84ac audit: allow unsetting the loginuid (with priv)
If a task has CAP_AUDIT_CONTROL allow that task to unset their loginuid.
This would allow a child of that task to set their loginuid without
CAP_AUDIT_CONTROL.  Thus when launching a new login daemon, a
priviledged helper would be able to unset the loginuid and then the
daemon, which may be malicious user facing, do not need priv to function
correctly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:09 -05:00
Eric Paris 83fa6bbe4c audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE
After trying to use this feature in Fedora we found the hard coding
policy like this into the kernel was a bad idea.  Surprise surprise.
We ran into these problems because it was impossible to launch a
container as a logged in user and run a login daemon inside that container.
This reverts back to the old behavior before this option was added.  The
option will be re-added in a userspace selectable manor such that
userspace can choose when it is and when it is not appropriate.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:08:01 -05:00
Eric Paris da0a610497 audit: loginuid functions coding style
This is just a code rework.  It makes things more readable.  It does not
make any functional changes.

It does change the log messages to include both the old session id as
well the new and it includes a new res field, which means we get
messages even when the user did not have permission to change the
loginuid.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:56 -05:00
Eric Paris b0fed40214 audit: implement generic feature setting and retrieving
The audit_status structure was not designed with extensibility in mind.
Define a new AUDIT_SET_FEATURE message type which takes a new structure
of bits where things can be enabled/disabled/locked one at a time.  This
structure should be able to grow in the future while maintaining forward
and backward compatibility (based loosly on the ideas from capabilities
and prctl)

This does not actually add any features, but is just infrastructure to
allow new on/off types of audit system features.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:30 -05:00
Richard Guy Briggs 42f74461a5 audit: change decimal constant to macro for invalid uid
SFR reported this 2013-05-15:

> After merging the final tree, today's linux-next build (i386 defconfig)
> produced this warning:
>
> kernel/auditfilter.c: In function 'audit_data_to_entry':
> kernel/auditfilter.c:426:3: warning: this decimal constant is unsigned only
> in ISO C90 [enabled by default]
>
> Introduced by commit 780a7654ce ("audit: Make testing for a valid
> loginuid explicit") from Linus' tree.

Replace this decimal constant in the code with a macro to make it more readable
(add to the unsigned cast to quiet the warning).

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:27 -05:00
Tyler Hicks 0868a5e150 audit: printk USER_AVC messages when audit isn't enabled
When the audit=1 kernel parameter is absent and auditd is not running,
AUDIT_USER_AVC messages are being silently discarded.

AUDIT_USER_AVC messages should be sent to userspace using printk(), as
mentioned in the commit message of 4a4cd633 ("AUDIT: Optimise the
audit-disabled case for discarding user messages").

When audit_enabled is 0, audit_receive_msg() discards all user messages
except for AUDIT_USER_AVC messages. However, audit_log_common_recv_msg()
refuses to allocate an audit_buffer if audit_enabled is 0. The fix is to
special case AUDIT_USER_AVC messages in both functions.

It looks like commit 50397bd1 ("[AUDIT] clean up audit_receive_msg()")
introduced this bug.

Cc: <stable@kernel.org> # v2.6.25+
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:23 -05:00
Oleg Nesterov d48d805122 audit_alloc: clear TIF_SYSCALL_AUDIT if !audit_context
If audit_filter_task() nacks the new thread it makes sense
to clear TIF_SYSCALL_AUDIT which can be copied from parent
by dup_task_struct().

A wrong TIF_SYSCALL_AUDIT is not really bad but it triggers
the "slow" audit paths in entry.S to ensure the task can not
miss audit_syscall_*() calls, this is pointless if the task
has no ->audit_context.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:18 -05:00
Gao feng af0e493d30 Audit: remove duplicate comments
Remove it.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:14 -05:00
Richard Guy Briggs b8f89caafe audit: remove newline accidentally added during session id helper refactor
A newline was accidentally added during session ID helper refactorization in
commit 4d3fb709.  This needlessly uses up buffer space, messes up syslog
formatting and makes userspace processing less efficient.  Remove it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:07:09 -05:00
Ilya V. Matveychikov 47145705e3 audit: remove duplicate inclusion of the netlink header
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:06:53 -05:00
Richard Guy Briggs b50eba7e2d audit: format user messages to size of MAX_AUDIT_MESSAGE_LENGTH
Messages of type AUDIT_USER_TTY were being formatted to 1024 octets,
truncating messages approaching MAX_AUDIT_MESSAGE_LENGTH (8970 octets).

Set the formatting to 8560 characters, given maximum estimates for prefix and
suffix budgets.

See the problem discussion:
https://www.redhat.com/archives/linux-audit/2009-January/msg00030.html

And the new size rationale:
https://www.redhat.com/archives/linux-audit/2013-September/msg00016.html

Test ~8k messages with:
auditctl -m "$(for i in $(seq -w 001 820);do echo -n "${i}0______";done)"

Reported-by: LC Bruzenak <lenny@magitekltd.com>
Reported-by: Justin Stephenson <jstephen@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-05 11:06:49 -05:00
David S. Miller 394efd19d5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/netconsole.c
	net/bridge/br_private.h

Three mostly trivial conflicts.

The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.

In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".

Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-04 13:48:30 -05:00
Ingo Molnar 2a3ede8cb2 Merge branch 'perf/urgent' into perf/core to fix conflicts
Conflicts:
	tools/perf/bench/numa.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-04 07:49:35 +01:00
Ingo Molnar fb10d5b7ef Merge branch 'linus' into sched/core
Resolve cherry-picking conflicts:

Conflicts:
	mm/huge_memory.c
	mm/memory.c
	mm/mprotect.c

See this upstream merge commit for more details:

  52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-01 08:24:41 +01:00
Oleg Nesterov 6a716c90a5 hung_task debugging: Add tracepoint to report the hang
Currently check_hung_task() prints a warning if it detects the
problem, but it is not convenient to watch the system logs if
user-space wants to be notified about the hang.

Add the new trace_sched_process_hang() into check_hung_task(),
this way a user-space monitor can easily wait for the hang and
potentially resolve a problem.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Sullivan <dsulliva@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20131019161828.GA7439@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-31 11:16:18 +01:00
Chen Gang 6ef4d2eaf5 kernel/system_certificate.S: use real contents instead of macro GLOBAL()
If a macro is only used within 2 times, and also its contents are
within 2 lines, recommend to expand it to shrink code line.

For our case, the macro is not portable either: some architectures'
assembler may use another character to mark newline in a macro (e.g.
'`' for arc), which will cause issue.

If still want to use macro and let it portable enough, it will also
need include additional header file (e.g "#include <linux/linkage.h>",
although it also need be fixed).


Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-10-30 12:58:00 +00:00
Mathias Krause 0b6b098efc padata: make the sequence counter an atomic_t
Using a spinlock to atomically increase a counter sounds wrong -- we've
atomic_t for this!

Also move 'seq_nr' to a different cache line than 'lock' to reduce cache
line trashing. This has the nice side effect of decreasing the size of
struct parallel_data from 192 to 128 bytes for a x86-64 build, e.g.
occupying only two instead of three cache lines.

Those changes results in a 5% performance increase on an IPsec test run
using pcrypt.

Btw. the seq_lock spinlock was never explicitly initialized -- one more
reason to get rid of it.

Signed-off-by: Mathias Krause <mathias.krause@secunet.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-10-30 12:02:58 +08:00
Oleg Nesterov 3ab6796617 uprobes: Teach uprobe_copy_process() to handle CLONE_VFORK
uprobe_copy_process() does nothing if the child shares ->mm with
the forking process, but there is a special case: CLONE_VFORK.
In this case it would be more correct to do dup_utask() but avoid
dup_xol(). This is not that important, the child should not unwind
its stack too much, this can corrupt the parent's stack, but at
least we need this to allow to ret-probe __vfork() itself.

Note: in theory, it would be better to check task_pt_regs(p)->sp
instead of CLONE_VFORK, we need to dup_utask() if and only if the
child can return from the function called by the parent. But this
needs the arch-dependant helper, and I think that nobody actually
does clone(same_stack, CLONE_VM).

Reported-by: Martin Cermak <mcermak@redhat.com>
Reported-by: David Smith <dsmith@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-10-29 18:02:55 +01:00
Oleg Nesterov aa59c53fd4 uprobes: Change uprobe_copy_process() to dup xol_area
This finally fixes the serious bug in uretprobes: a forked child
crashes if the parent called fork() with the pending ret probe.

Trivial test-case:

	# perf probe -x /lib/libc.so.6 __fork%return
	# perf record -e probe_libc:__fork perl -le 'fork || print "OK"'

(the child doesn't print "OK", it is killed by SIGSEGV)

If the child returns from the probed function it actually returns
to trampoline_vaddr, because it got the copy of parent's stack
mangled by prepare_uretprobe() when the parent entered this func.

It crashes because a) this address is not mapped and b) until the
previous change it doesn't have the proper->return_instances info.

This means that uprobe_copy_process() has to create xol_area which
has the trampoline slot, and its vaddr should be equal to parent's
xol_area->vaddr.

Unfortunately, uprobe_copy_process() can not simply do
__create_xol_area(child, xol_area->vaddr). This could actually work
but perf_event_mmap() doesn't expect the usage of foreign ->mm. So
we offload this to task_work_run(), and pass the argument via not
yet used utask->vaddr.

We know that this vaddr is fine for install_special_mapping(), the
necessary hole was recently "created" by dup_mmap() which skips the
parent's VM_DONTCOPY area, and nobody else could use the new mm.

Unfortunately, this also means that we can not handle the errors
properly, we obviously can not abort the already completed fork().
So we simply print the warning if GFP_KERNEL allocation (the only
possible reason) fails.

Reported-by: Martin Cermak <mcermak@redhat.com>
Reported-by: David Smith <dsmith@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29 18:02:54 +01:00
Oleg Nesterov 248d3a7b2f uprobes: Change uprobe_copy_process() to dup return_instances
uprobe_copy_process() assumes that the new child doesn't need
->utask, it should be allocated by demand.

But this is not true if the forking task has the pending ret-
probes, the child should report them as well and thus it needs
the copy of parent's ->return_instances chain. Otherwise the
child crashes when it returns from the probed function.

Alternatively we could cleanup the child's stack, but this needs
per-arch changes and this is not what we want. At least systemtap
expects a .return in the child too.

Note: this change alone doesn't fix the problem, see the next
change.

Reported-by: Martin Cermak <mcermak@redhat.com>
Reported-by: David Smith <dsmith@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29 18:02:53 +01:00
Oleg Nesterov af0d95af79 uprobes: Teach __create_xol_area() to accept the predefined vaddr
Currently xol_add_vma() uses get_unmapped_area() for area->vaddr,
but the next patches need to use the fixed address. So this patch
adds the new "vaddr" argument to __create_xol_area() which should
be used as area->vaddr if it is nonzero.

xol_add_vma() doesn't bother to verify that the predefined addr is
not used, insert_vm_struct() should fail if find_vma_links() detects
the overlap with the existing vma.

Also, __create_xol_area() doesn't need __GFP_ZERO to allocate area.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29 18:02:51 +01:00
Oleg Nesterov 6441ec8b7c uprobes: Introduce __create_xol_area()
No functional changes, preparation.

Extract the code which actually allocates/installs the new area
into the new helper, __create_xol_area().

While at it remove the unnecessary "ret = ENOMEM" and "ret = 0"
in xol_add_vma(), they both have no effect.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29 18:02:50 +01:00
Oleg Nesterov b68e074910 uprobes: Change the callsite of uprobe_copy_process()
Preparation for the next patches.

Move the callsite of uprobe_copy_process() in copy_process() down
to the succesfull return. We do not care if copy_process() fails,
uprobe_free_utask() won't be called in this case so the wrong
->utask != NULL doesn't matter.

OTOH, with this change we know that copy_process() can't fail when
uprobe_copy_process() is called, the new task should either return
to user-mode or call do_exit(). This way uprobe_copy_process() can:

	1. setup p->utask != NULL if necessary

	2. setup uprobes_state.xol_area

	3. use task_work_add(p)

Also, move the definition of uprobe_copy_process() down so that it
can see get_utask().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-10-29 18:02:48 +01:00
Peter Zijlstra 5a3126d4fe perf: Fix the perf context switch optimization
Currently we only optimize the context switch between two
contexts that have the same parent; this forgoes the
optimization between parent and child context, even though these
contexts could be equivalent too.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Shishkin, Alexander <alexander.shishkin@intel.com>
Link: http://lkml.kernel.org/r/20131007164257.GH3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 14:13:01 +01:00
Peter Zijlstra 2c42cfbfe1 perf: Change zero-padding of strings in perf_event_mmap_event()
Oleg complained about the excessive 0-ing in perf_event_mmap_event(),
so try and be smarter about it while keeping it fairly fool proof and
avoid leaking random bits out to userspace.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-8jirlm99m6if2z13wd6rbyu6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:53 +01:00
Oleg Nesterov 3ea2f2b96f perf: Do not waste PAGE_SIZE bytes for ALIGN(8) in perf_event_mmap_event()
perf_event_mmap_event() does kzalloc(PATH_MAX + sizeof(u64)) to
ensure we can align the size later. However this means that we
actually allocate PAGE_SIZE * 2 buffer, seems too much.

Change this code to allocate PATH_MAX==PAGE_SIZE bytes, but tell
d_path() to not use the last sizeof(u64) bytes.

Note: it is not clear why do we need __GFP_ZERO, see the next patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016201004.GC23214@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:52 +01:00
Oleg Nesterov 32c5fb7e7d perf: Kill the dead !vma->vm_mm code in perf_event_mmap_event()
1. perf_event_mmap(vma) is never called with a gate_vma-like arg,
   remove the "if (!vma->vm_mm)" code.

2. arch_vma_name() can use the chached value of mmap_event->vma.

3. Change the code to not call arch_vma_name() twice.

4. Purely cosmetic, but since we use "goto got_name" all the time
   remove "else" from "[stack]" branch just for symmetry.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016200945.GB23214@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:51 +01:00
Peter Zijlstra d9494cb429 perf: Remove useless atomic_t
There's nothing atomic about atomic_set vs atomic_read; so remove the
atomic_t usage.

Also, make running_sample_length static as it really is (and should
be) local to this translation unit.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: eranian@google.com
Cc: Don Zickus <dzickus@redhat.com>
Cc: jmario@redhat.com
Cc: acme@infradead.org
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/n/tip-vw9lg588x1ic248whybjon0c@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:49 +01:00
Ben Segall f9f9ffc237 sched: Avoid throttle_cfs_rq() racing with period_timer stopping
throttle_cfs_rq() doesn't check to make sure that period_timer is running,
and while update_curr/assign_cfs_runtime does, a concurrently running
period_timer on another cpu could cancel itself between this cpu's
update_curr and throttle_cfs_rq(). If there are no other cfs_rqs running
in the tg to restart the timer, this causes the cfs_rq to be stranded
forever.

Fix this by calling __start_cfs_bandwidth() in throttle if the timer is
inactive.

(Also add some sched_debug lines for cfs_bandwidth.)

Tested: make a run/sleep task in a cgroup, loop switching the cgroup
between 1ms/100ms quota and unlimited, checking for timer_active=0 and
throttled=1 as a failure. With the throttle_cfs_rq() change commented out
this fails, with the full patch it passes.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181632.22647.84174.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:32 +01:00
Paul Turner 0ac9b1c218 sched: Guarantee new group-entities always have weight
Currently, group entity load-weights are initialized to zero. This
admits some races with respect to the first time they are re-weighted in
earlty use. ( Let g[x] denote the se for "g" on cpu "x". )

Suppose that we have root->a and that a enters a throttled state,
immediately followed by a[0]->t1 (the only task running on cpu[0])
blocking:

  put_prev_task(group_cfs_rq(a[0]), t1)
  put_prev_entity(..., t1)
  check_cfs_rq_runtime(group_cfs_rq(a[0]))
  throttle_cfs_rq(group_cfs_rq(a[0]))

Then, before unthrottling occurs, let a[0]->b[0]->t2 wake for the first
time:

  enqueue_task_fair(rq[0], t2)
  enqueue_entity(group_cfs_rq(b[0]), t2)
  enqueue_entity_load_avg(group_cfs_rq(b[0]), t2)
  account_entity_enqueue(group_cfs_ra(b[0]), t2)
  update_cfs_shares(group_cfs_rq(b[0]))
  < skipped because b is part of a throttled hierarchy >
  enqueue_entity(group_cfs_rq(a[0]), b[0])
  ...

We now have b[0] enqueued, yet group_cfs_rq(a[0])->load.weight == 0
which violates invariants in several code-paths. Eliminate the
possibility of this by initializing group entity weight.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016181627.22647.47543.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:23 +01:00
Ben Segall 927b54fccb sched: Fix hrtimer_cancel()/rq->lock deadlock
__start_cfs_bandwidth calls hrtimer_cancel while holding rq->lock,
waiting for the hrtimer to finish. However, if sched_cfs_period_timer
runs for another loop iteration, the hrtimer can attempt to take
rq->lock, resulting in deadlock.

Fix this by ensuring that cfs_b->timer_active is cleared only if the
_latest_ call to do_sched_cfs_period_timer is returning as idle. Then
__start_cfs_bandwidth can just call hrtimer_try_to_cancel and wait for
that to succeed or timer_active == 1.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181622.22647.16643.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:21 +01:00
Ben Segall db06e78cc1 sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
hrtimer_expires_remaining does not take internal hrtimer locks and thus
must be guarded against concurrent __hrtimer_start_range_ns (but
returning HRTIMER_RESTART is safe). Use cfs_b->lock to make it safe.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181617.22647.73829.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:20 +01:00
Ben Segall 1ee14e6c8c sched: Fix race on toggling cfs_bandwidth_used
When we transition cfs_bandwidth_used to false, any currently
throttled groups will incorrectly return false from cfs_rq_throttled.
While tg_set_cfs_bandwidth will unthrottle them eventually, currently
running code (including at least dequeue_task_fair and
distribute_cfs_runtime) will cause errors.

Fix this by turning off cfs_bandwidth_used only after unthrottling all
cfs_rqs.

Tested: toggle bandwidth back and forth on a loaded cgroup. Caused
crashes in minutes without the patch, hasn't crashed with it.

Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181611.22647.80365.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 12:02:19 +01:00