Commit Graph

20703 Commits

Author SHA1 Message Date
David Kershner 18896451ea kthread: export kthread functions
The s-Par visornic driver, currently in staging, processes a queue being
serviced by the an s-Par service partition.  We can get a message that
something has happened with the Service Partition, when that happens, we
must not access the channel until we get a message that the service
partition is back again.

The visornic driver has a thread for processing the channel, when we get
the message, we need to be able to park the thread and then resume it
when the problem clears.

We can do this with kthread_park and unpark but they are not exported
from the kernel, this patch exports the needed functions.

Signed-off-by: David Kershner <david.kershner@unisys.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:41 +03:00
Amanieu d'Antras 26135022f8 signal: fix information leak in copy_siginfo_to_user
This function may copy the si_addr_lsb, si_lower and si_upper fields to
user mode when they haven't been initialized, which can leak kernel
stack data to user mode.

Just checking the value of si_code is insufficient because the same
si_code value is shared between multiple signals.  This is solved by
checking the value of si_signo in addition to si_code.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:40 +03:00
Amanieu d'Antras 3c00cb5e68 signal: fix information leak in copy_siginfo_from_user32
This function can leak kernel stack data when the user siginfo_t has a
positive si_code value.  The top 16 bits of si_code descibe which fields
in the siginfo_t union are active, but they are treated inconsistently
between copy_siginfo_from_user32, copy_siginfo_to_user32 and
copy_siginfo_to_user.

copy_siginfo_from_user32 is called from rt_sigqueueinfo and
rt_tgsigqueueinfo in which the user has full control overthe top 16 bits
of si_code.

This fixes the following information leaks:
x86:   8 bytes leaked when sending a signal from a 32-bit process to
       itself. This leak grows to 16 bytes if the process uses x32.
       (si_code = __SI_CHLD)
x86:   100 bytes leaked when sending a signal from a 32-bit process to
       a 64-bit process. (si_code = -1)
sparc: 4 bytes leaked when sending a signal from a 32-bit process to a
       64-bit process. (si_code = any)

parsic and s390 have similar bugs, but they are not vulnerable because
rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code
to a different process.  These bugs are also fixed for consistency.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:40 +03:00
Rusty Russell fe0d34d242 module: weaken locking assertion for oops path.
We don't actually hold the module_mutex when calling find_module_all
from module_kallsyms_lookup_name: that's because it's used by the oops
code and we don't want to deadlock.

However, access to the list read-only is safe if preempt is disabled,
so we can weaken the assertion.  Keep a strong version for external
callers though.

Fixes: 0be964be0d ("module: Sanitize RCU usage and locking")
Reported-by: He Kuang <hekuang@huawei.com>
Cc: stable@kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-07-29 06:13:22 +09:30
Linus Torvalds 2800348613 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "This update contains:

   - the manual revert of the SYSCALL32 changes which caused a
     regression

   - a fix for the MPX vma handling

   - three fixes for the ioremap 'is ram' checks.

   - PAT warning fixes

   - a trivial fix for the size calculation of TLB tracepoints

   - handle old EFI structures gracefully

  This also contains a PAT fix from Jan plus a revert thereof.  Toshi
  explained why the code is correct"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/pat: Revert 'Adjust default caching mode translation tables'
  x86/asm/entry/32: Revert 'Do not use R9 in SYSCALL32' commit
  x86/mm: Fix newly introduced printk format warnings
  mm: Fix bugs in region_is_ram()
  x86/mm: Remove region_is_ram() call from ioremap
  x86/mm: Move warning from __ioremap_check_ram() to the call site
  x86/mm/pat, drivers/media/ivtv: Move the PAT warning and replace WARN() with pr_warn()
  x86/mm/pat, drivers/infiniband/ipath: Replace WARN() with pr_warn()
  x86/mm/pat: Adjust default caching mode translation tables
  x86/fpu: Disable dependent CPU features on "noxsave"
  x86/mpx: Do not set ->vm_ops on MPX VMAs
  x86/mm: Add parenthesis for TLB tracepoint size calculation
  efi: Handle memory error structures produced based on old versions of standard
2015-07-26 11:14:04 -07:00
Linus Torvalds 763e326c8b Back in 3.16 the ftrace code was redesigned and cleaned up to remove the
double iteration list (one for registered ftrace ops, and one for
 registered "global" ops), to just use one list. That simplified the code
 but also broke the function tracing filtering on pid.
 
 This updates the code to handle the filtering again with the new logic.
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Merge tag 'trace-v4.2-rc2-fix3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fix from Steven Rostedt:
 "Back in 3.16 the ftrace code was redesigned and cleaned up to remove
  the double iteration list (one for registered ftrace ops, and one for
  registered "global" ops), to just use one list.  That simplified the
  code but also broke the function tracing filtering on pid.

  This updates the code to handle the filtering again with the new
  logic"

* tag 'trace-v4.2-rc2-fix3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix breakage of set_ftrace_pid
2015-07-25 11:42:54 -07:00
Steven Rostedt (Red Hat) e3eea1404f ftrace: Fix breakage of set_ftrace_pid
Commit 4104d326b6 ("ftrace: Remove global function list and call function
directly") simplified the ftrace code by removing the global_ops list with a
new design. But this cleanup also broke the filtering of PIDs that are added
to the set_ftrace_pid file.

Add back the proper hooks to have pid filtering working once again.

Cc: stable@vger.kernel.org # 3.16+
Reported-by: Matt Fleming <matt@console-pimps.org>
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-24 13:58:14 -04:00
Toshi Kani 8c38de992b mm: Fix bugs in region_is_ram()
region_is_ram() looks up the iomem_resource table to check if
a target range is in RAM.  However, it always returns with -1
due to invalid range checks. It always breaks the loop at the
first entry of the table.

Another issue is that it compares p->flags and flags, but it always
fails. flags is declared as int, which makes it as a negative value
with IORESOURCE_BUSY (0x80000000) set while p->flags is unsigned long.

Fix the range check and flags so that region_is_ram() works as
advertised.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1437088996-28511-4-git-send-email-toshi.kani@hp.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-22 17:20:34 +02:00
Linus Torvalds 0e1dbccd8f Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Two families of fixes:

   - Fix an FPU context related boot crash on newer x86 hardware with
     larger context sizes than what most people test.  To fix this
     without ugly kludges or extensive reverts we had to touch core task
     allocator, to allow x86 to determine the task size dynamically, at
     boot time.

     I've tested it on a number of x86 platforms, and I cross-built it
     to a handful of architectures:

                                        (warns)               (warns)
       testing     x86-64:  -git:  pass (    0),  -tip:  pass (    0)
       testing     x86-32:  -git:  pass (    0),  -tip:  pass (    0)
       testing        arm:  -git:  pass ( 1359),  -tip:  pass ( 1359)
       testing       cris:  -git:  pass ( 1031),  -tip:  pass ( 1031)
       testing       m32r:  -git:  pass ( 1135),  -tip:  pass ( 1135)
       testing       m68k:  -git:  pass ( 1471),  -tip:  pass ( 1471)
       testing       mips:  -git:  pass ( 1162),  -tip:  pass ( 1162)
       testing    mn10300:  -git:  pass ( 1058),  -tip:  pass ( 1058)
       testing     parisc:  -git:  pass ( 1846),  -tip:  pass ( 1846)
       testing      sparc:  -git:  pass ( 1185),  -tip:  pass ( 1185)

     ... so I hope the cross-arch impact 'none', as intended.

     (by Dave Hansen)

   - Fix various NMI handling related bugs unearthed by the big asm code
     rewrite and generally make the NMI code more robust and more
     maintainable while at it.  These changes are a bit late in the
     cycle, I hope they are still acceptable.

     (by Andy Lutomirski)"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86
  x86/fpu, sched: Dynamically allocate 'struct fpu'
  x86/entry/64, x86/nmi/64: Add CONFIG_DEBUG_ENTRY NMI testing code
  x86/nmi/64: Make the "NMI executing" variable more consistent
  x86/nmi/64: Minor asm simplification
  x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detection
  x86/nmi/64: Reorder nested NMI checks
  x86/nmi/64: Improve nested NMI comments
  x86/nmi/64: Switch stacks on userspace NMI entry
  x86/nmi/64: Remove asm code that saves CR2
  x86/nmi: Enable nested do_nmi() handling for 64-bit kernels
2015-07-18 10:49:57 -07:00
Linus Torvalds dae57fb64e Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
 "Fix for a misplaced export that can cause build failures in certain
  (rare) Kconfig situations"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: Move the export of tick_broadcast_oneshot_control to the proper place
2015-07-18 10:49:11 -07:00
Linus Torvalds d65b78f5d8 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
 "A oneliner rq throttling fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Test list head instead of list entry in throttle_cfs_rq()
2015-07-18 10:47:44 -07:00
Linus Torvalds 59ee762156 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Ingo Molnar:
 "Misc irq fixes:

   - two driver fixes
   - a Xen regression fix
   - a nested irq thread crash fix"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gicv3-its: Fix mapping of LPIs to collections
  genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD
  genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now
  gpio/davinci: Fix race in installing chained irq handler
2015-07-18 10:27:12 -07:00
Ingo Molnar 5aaeb5c01c x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86
Don't burden architectures without dynamic task_struct sizing
with the overhead of dynamic sizing.

Also optimize the x86 code a bit by caching task_struct_size.

Acked-and-Tested-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437128892-9831-3-git-send-email-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18 03:42:51 +02:00
Dave Hansen 0c8c0f03e3 x86/fpu, sched: Dynamically allocate 'struct fpu'
The FPU rewrite removed the dynamic allocations of 'struct fpu'.
But, this potentially wastes massive amounts of memory (2k per
task on systems that do not have AVX-512 for instance).

Instead of having a separate slab, this patch just appends the
space that we need to the 'task_struct' which we dynamically
allocate already.  This saves from doing an extra slab
allocation at fork().

The only real downside here is that we have to stick everything
and the end of the task_struct.  But, I think the
BUILD_BUG_ON()s I stuck in there should keep that from being too
fragile.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437128892-9831-2-git-send-email-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-18 03:42:35 +02:00
Thomas Gleixner 75a06189fc genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD
The resend mechanism happily calls the interrupt handler of interrupts
which are marked IRQ_NESTED_THREAD from softirq context. This can
result in crashes because the interrupt handler is not the proper way
to invoke the device handlers. They must be invoked via
handle_nested_irq.

Prevent the resend even if the interrupt has no valid parent irq
set. Its better to have a lost interrupt than a crashing machine.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2015-07-17 11:29:34 +02:00
Linus Torvalds 7558009751 Fengguang Wu discovered a crash that happened to be because of the branch
tracer (traces unlikely and likely branches) when enabled with certain
 debug options.
 
 What happened was that various debug options like lockdep and DEBUG_PREEMPT
 can cause parts of the branch tracer to recurse outside its recursion
 protection. In fact, part of its recursion protection used these features
 that caused the lockup. This cleans up the code a little and makes the
 recursion protection a bit more robust.
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Merge tag 'trace-v4.2-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fengguang Wu discovered a crash that happened to be because of the
  branch tracer (traces unlikely and likely branches) when enabled with
  certain debug options.

  What happened was that various debug options like lockdep and
  DEBUG_PREEMPT can cause parts of the branch tracer to recurse outside
  its recursion protection.  In fact, part of its recursion protection
  used these features that caused the lockup.  This cleans up the code a
  little and makes the recursion protection a bit more robust"

* tag 'trace-v4.2-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have branch tracer use recursive field of task struct
2015-07-15 11:14:10 -07:00
Thomas Gleixner ce0d3c0a6f genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now
Boris reported that the sparse_irq protection around __cpu_up() in the
generic code causes a regression on Xen. Xen allocates interrupts and
some more in the xen_cpu_up() function, so it deadlocks on the
sparse_irq_lock.

There is no simple fix for this and we really should have the
protection for all architectures, but for now the only solution is to
move it to x86 where actual wreckage due to the lack of protection has
been observed.

Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Fixes: a899418167 'hotplug: Prevent alloc/free of irq descriptors during cpu up/down'
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>
2015-07-15 10:39:17 +02:00
Thomas Gleixner 0f44705175 tick: Move the export of tick_broadcast_oneshot_control to the proper place
tick_broadcast_oneshot_control got moved from tick-broadcast to
tick-common, but the export stayed in the old place. Fix it up.

Fixes: f32dd11705 'tick/broadcast: Make idle check independent from mode and config'
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-14 12:01:04 +02:00
Linus Torvalds 7b732169e9 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "This update from the timer departement contains:

   - A series of patches which address a shortcoming in the tick
     broadcast code.

     If the broadcast device is not available or an hrtimer emulated
     broadcast device, some of the original assumptions lead to boot
     failures.  I rather plugged all of the corner cases instead of only
     addressing the issue reported, so the change got a little larger.

     Has been extensivly tested on x86 and arm.

   - Get rid of the last holdouts using do_posix_clock_monotonic_gettime()

   - A regression fix for the imx clocksource driver

   - An update to the new state callbacks mechanism for clockevents.
     This is required to simplify the conversion, which will take place
     in 4.3"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/broadcast: Prevent NULL pointer dereference
  time: Get rid of do_posix_clock_monotonic_gettime
  cris: Replace do_posix_clock_monotonic_gettime()
  tick/broadcast: Unbreak CONFIG_GENERIC_CLOCKEVENTS=n build
  tick/broadcast: Handle spurious interrupts gracefully
  tick/broadcast: Check for hrtimer broadcast active early
  tick/broadcast: Return busy when IPI is pending
  tick/broadcast: Return busy if periodic mode and hrtimer broadcast
  tick/broadcast: Move the check for periodic mode inside state handling
  tick/broadcast: Prevent deep idle if no broadcast device available
  tick/broadcast: Make idle check independent from mode and config
  tick/broadcast: Sanity check the shutdown of the local clock_event
  tick/broadcast: Prevent hrtimer recursion
  clockevents: Allow set-state callbacks to be optional
  clocksource/imx: Define clocksource for mx27
2015-07-12 09:36:59 -07:00
Linus Torvalds c4bc680cf7 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
 "A single fix for a cpu hotplug race vs. interrupt descriptors:

  Prevent irq setup/teardown across the cpu starting/dying parts of cpu
  hotplug so that the starting/dying cpu has a stable view of the
  descriptor space.  This has been an issue for all architectures in the
  cpu dying phase, where interrupts are migrated away from the dying
  cpu.  In the starting phase its mostly a x86 issue vs the vector space
  update"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hotplug: Prevent alloc/free of irq descriptors during cpu up/down
2015-07-12 09:15:02 -07:00
Thomas Gleixner c4d029f2d4 tick/broadcast: Prevent NULL pointer dereference
Dan reported that the recent changes to the broadcast code introduced
a potential NULL dereference.

Add the proper check.

Fixes: e045431190 "tick/broadcast: Sanity check the shutdown of the local clock_event"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-11 14:26:34 +02:00
Peter Zijlstra 758556bdc1 module: Fix load_module() error path
The load_module() error path frees a module but forgot to take it out
of the mod_tree, leaving a dangling entry in the tree, causing havoc.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Tested-by: Arthur Marsh <arthur.marsh@internode.on.net>
Fixes: 93c2e105f6 ("module: Optimize __module_address() using a latched RB-tree")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-07-09 06:57:12 +09:30
Linus Torvalds 45820c294f Fix broken audit tests for exec arg len
The "fix" in commit 0b08c5e594 ("audit: Fix check of return value of
strnlen_user()") didn't fix anything, it broke things.  As reported by
Steven Rostedt:

 "Yes, strnlen_user() returns 0 on fault, but if you look at what len is
  set to, than you would notice that on fault len would be -1"

because we just subtracted one from the return value.  So testing
against 0 doesn't test for a fault condition, it tests against a
perfectly valid empty string.

Also fix up the usual braindamage wrt using WARN_ON() inside a
conditional - make it part of the conditional and remove the explicit
unlikely() (which is already part of the WARN_ON*() logic, exactly so
that you don't have to write unreadable code.

Reported-and-tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Paul Moore <pmoore@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-08 09:33:38 -07:00
Steven Rostedt (Red Hat) 6224beb12e tracing: Have branch tracer use recursive field of task struct
Fengguang Wu's tests triggered a bug in the branch tracer's start up
test when CONFIG_DEBUG_PREEMPT set. This was because that config
adds some debug logic in the per cpu field, which calls back into
the branch tracer.

The branch tracer has its own recursive checks, but uses a per cpu
variable to implement it. If retrieving the per cpu variable calls
back into the branch tracer, you can see how things will break.

Instead of using a per cpu variable, use the trace_recursion field
of the current task struct. Simply set a bit when entering the
branch tracing and clear it when leaving. If the bit is set on
entry, just don't do the tracing.

There's also the case with lockdep, as the local_irq_save() called
before the recursion can also trigger code that can call back into
the function. Changing that to a raw_local_irq_save() will protect
that as well.

This prevents the recursion and the inevitable crash that follows.

Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com

Cc: stable@vger.kernel.org # 3.10+
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-08 11:53:45 -04:00
Thomas Gleixner a899418167 hotplug: Prevent alloc/free of irq descriptors during cpu up/down
When a cpu goes up some architectures (e.g. x86) have to walk the irq
space to set up the vector space for the cpu. While this needs extra
protection at the architecture level we can avoid a few race
conditions by preventing the concurrent allocation/free of irq
descriptors and the associated data.

When a cpu goes down it moves the interrupts which are targeted to
this cpu away by reassigning the affinities. While this happens
interrupts can be allocated and freed, which opens a can of race
conditions in the code which reassignes the affinities because
interrupt descriptors might be freed underneath.

Example:

CPU1				CPU2
cpu_up/down
 irq_desc = irq_to_desc(irq);
				remove_from_radix_tree(desc);
 raw_spin_lock(&desc->lock);
				free(desc);

We could protect the irq descriptors with RCU, but that would require
a full tree change of all accesses to interrupt descriptors. But
fortunately these kind of race conditions are rather limited to a few
things like cpu hotplug. The normal setup/teardown is very well
serialized. So the simpler and obvious solution is:

Prevent allocation and freeing of interrupt descriptors accross cpu
hotplug.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/20150705171102.063519515@linutronix.de
2015-07-08 11:32:25 +02:00
Thomas Gleixner c428833481 tick/broadcast: Handle spurious interrupts gracefully
Andriy reported that on a virtual machine the warning about negative
expiry time in the clock events programming code triggered:

hpet: hpet0 irq 40 for MSI
hpet: hpet1 irq 41 for MSI
Switching to clocksource hpet
WARNING: at kernel/time/clockevents.c:239

[<ffffffff810ce6eb>] clockevents_program_event+0xdb/0xf0
[<ffffffff810cf211>] tick_handle_periodic_broadcast+0x41/0x50
[<ffffffff81016525>] timer_interrupt+0x15/0x20

When the second hpet is installed as a per cpu timer the broadcast
event is not longer required and stopped, which sets the next_evt of
the broadcast device to KTIME_MAX.

If after that a spurious interrupt happens on the broadcast device,
then the current code blindly handles it and tries to reprogram the
broadcast device afterwards, which adds the period to
next_evt. KTIME_MAX + period results in a negative expiry value
causing the WARN_ON in the clockevents code to trigger.

Add a proper check for the state of the broadcast device into the
interrupt handler and return if the interrupt is spurious.

[ Folded in pointer fix from Sudeep ]

Reported-by: Andriy Gapon <avg@FreeBSD.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150705205221.802094647@linutronix.de
2015-07-07 18:46:48 +02:00
Thomas Gleixner d5113e13a5 tick/broadcast: Check for hrtimer broadcast active early
If the current cpu is the one which has the hrtimer based broadcast
queued then we better return busy immediately instead of going through
loops and hoops to figure that out.

[ Split out from a larger combo patch ]

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:48 +02:00
Thomas Gleixner 0cc5281aa5 tick/broadcast: Return busy when IPI is pending
Tell the idle code not to go deep if the broadcast IPI is about to
arrive.

[ Split out from a larger combo patch ]

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:48 +02:00
Thomas Gleixner d33257264b tick/broadcast: Return busy if periodic mode and hrtimer broadcast
If the system is in periodic mode and the broadcast device is hrtimer
based, return busy as we have no proper handling for this.

[ Split out from a larger combo patch ]

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:48 +02:00
Thomas Gleixner e3ac79e087 tick/broadcast: Move the check for periodic mode inside state handling
We need to check more than the periodic mode for proper operation in
all runtime combinations. To avoid code duplication move the check
into the enter state handling.

No functional change.

[ Split out from a larger combo patch ]

Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:47 +02:00
Thomas Gleixner b78f3f3c89 tick/broadcast: Prevent deep idle if no broadcast device available
Add a check for a installed broadcast device to the oneshot control
function and return busy if not.

[ Split out from a larger combo patch ]

Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:47 +02:00
Thomas Gleixner f32dd11705 tick/broadcast: Make idle check independent from mode and config
Currently the broadcast busy check, which prevents the idle code from
going into deep idle, works only in one shot mode.

If NOHZ and HIGHRES are off (config or command line) there is no
sanity check at all, so under certain conditions cpus are allowed to
go into deep idle, where the local timer stops, and are not woken up
again because there is no broadcast timer installed or a hrtimer based
broadcast device is not evaluated.

Move tick_broadcast_oneshot_control() into the common code and provide
proper subfunctions for the various config combinations.

The common check in tick_broadcast_oneshot_control() is for the C3STOP
misfeature flag of the local clock event device. If its not set, idle
can proceed. If set, further checks are necessary.

Provide checks for the trivial cases:

 - If broadcast is disabled in the config, then return busy

 - If oneshot mode (NOHZ/HIGHES) is disabled in the config, return
   busy if the broadcast device is hrtimer based.

 - If oneshot mode is enabled in the config call the original
   tick_broadcast_oneshot_control() function. That function needs
   extra checks which will be implemented in seperate patches.

[ Split out from a larger combo patch ]

Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:47 +02:00
Thomas Gleixner e045431190 tick/broadcast: Sanity check the shutdown of the local clock_event
The broadcast code shuts down the local clock event unconditionally
even if no broadcast device is installed or if the broadcast device is
hrtimer based.

Add proper sanity checks.

[ Split out from a larger combo patch ]

Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:47 +02:00
Thomas Gleixner 8eb231261f tick/broadcast: Prevent hrtimer recursion
The hrtimer based broadcast vehicle can cause a hrtimer recursion
which went unnoticed until we changed the hrtimer expiry code to keep
track of the currently running timer.

local_timer_interrupt()
  local_handler()
    hrtimer_interrupt()
      expire_hrtimers()
        broadcast_hrtimer()
	  send_ipis()
	  local_handler()
	    hrtimer_interrupt()
	     ....

Solution is simple: Prevent the local handler call from the broadcast
code when the broadcast 'device' is hrtimer based.

[ Split out from a larger combo patch ]

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07 18:46:47 +02:00
Viresh Kumar 7c4a976cd5 clockevents: Allow set-state callbacks to be optional
Its mandatory for the drivers to provide set_state_{oneshot|periodic}()
(only if related modes are supported) and set_state_shutdown() callbacks
today, if they are implementing the new set-state interface.

But this leads to unnecessary noop callbacks for drivers which don't
want to implement them. Over that, it will lead to a full function call
for nothing really useful.

Lets make all set-state callbacks optional.

Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1436256875-15562-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-07 10:44:45 +02:00
Cong Wang d49db342f0 sched/fair: Test list head instead of list entry in throttle_cfs_rq()
According to the comments, we need to test if this is
the first throttled task, however, list_empty() tests on
the entry cfs_rq->throttled_list, not the head, this is wrong.

This is a bug because we don't re-init the list entry after
removing it from the list, so list_empty() could return false
even if the list is really empty.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435174907-432-1-git-send-email-xiyou.wangcong@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 14:15:08 +02:00
Peter Zijlstra 57ffc5ca67 perf: Fix AUX buffer refcounting
Its currently possible to drop the last refcount to the aux buffer
from NMI context, which results in the expected fireworks.

The refcounting needs a bigger overhaul, but to cure the immediate
problem, delay the freeing by using an irq_work.

Reviewed-and-tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150618103249.GK19282@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 14:08:30 +02:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds 1b3618b60a Except for the preempt notifiers fix, these are all small bugfixes
that could have been waited for -rc2.  Sending them now since I
 was taking care of Peter's patch anyway.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Except for the preempt notifiers fix, these are all small bugfixes
  that could have been waited for -rc2.  Sending them now since I was
  taking care of Peter's patch anyway"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: add hyper-v crash msrs values
  KVM: x86: remove data variable from kvm_get_msr_common
  KVM: s390: virtio-ccw: don't overwrite config space values
  KVM: x86: keep track of LVT0 changes under APICv
  KVM: x86: properly restore LVT0
  KVM: x86: make vapics_in_nmi_mode atomic
  sched, preempt_notifier: separate notifier registration from static_key inc/dec
2015-07-04 11:29:59 -07:00
Linus Torvalds 22a093b2fb Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Debug info and other statistics fixes and related enhancements"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/numa: Fix numa balancing stats in /proc/pid/sched
  sched/numa: Show numa_group ID in /proc/sched_debug task listings
  sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h
  sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=y
  sched/stat: Simplify the sched_info accounting dependency
2015-07-04 08:56:53 -07:00
Srikar Dronamraju 397f2378f1 sched/numa: Fix numa balancing stats in /proc/pid/sched
Commit 44dba3d5d6 ("sched: Refactor task_struct to use
numa_faults instead of numa_* pointers") modified the way
tsk->numa_faults stats are accounted.

However that commit never touched show_numa_stats() that is displayed
in /proc/pid/sched and thus the numbers displayed in /proc/pid/sched
don't match the actual numbers.

Fix it by making sure that /proc/pid/sched reflects the task
fault numbers. Also add group fault stats too.

Also couple of more modifications are added here:

1. Format changes:

  - Previously we would list two entries per node, one for private
    and one for shared. Also the home node info was listed in each entry.

  - Now preferred node, total_faults and current node are
    displayed separately.

  - Now there is one entry per node, that lists private,shared task and
    group faults.

2. Unit changes:

  - p->numa_pages_migrated was getting reset after every read of
    /proc/pid/sched. It's more useful to have absolute numbers since
    differential migrations between two accesses can be more easily
    calculated.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Iulia Manda <iulia.manda21@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435252903-1081-4-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-04 10:04:33 +02:00
Srikar Dronamraju e3d24d0a60 sched/numa: Show numa_group ID in /proc/sched_debug task listings
Having the numa group ID in /proc/sched_debug helps to see how
the numa groups have spread across the system.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Iulia Manda <iulia.manda21@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435252903-1081-3-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-04 10:04:32 +02:00
Srikar Dronamraju 6b55c9654f sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h
Currently print_cfs_rq() is declared in include/linux/sched.h.
However it's not used outside kernel/sched. Hence move the
declaration to kernel/sched/sched.h

Also some functions are only available for CONFIG_SCHED_DEBUG=y.
Hence move the declarations to within the #ifdef.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Iulia Manda <iulia.manda21@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435252903-1081-2-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-04 10:04:31 +02:00
Naveen N. Rao f6db834799 sched/stat: Simplify the sched_info accounting dependency
Both CONFIG_SCHEDSTATS=y and CONFIG_TASK_DELAY_ACCT=y track task
sched_info, which results in ugly #if clauses.

Simplify the code by introducing a synthethic CONFIG_SCHED_INFO
switch, selected by both.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Cc: ricklind@us.ibm.com
Link: http://lkml.kernel.org/r/8d19eef800811a94b0f91bcbeb27430a884d7433.1435255405.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-04 10:04:30 +02:00
Linus Torvalds 0cbee99269 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "Long ago and far away when user namespaces where young it was realized
  that allowing fresh mounts of proc and sysfs with only user namespace
  permissions could violate the basic rule that only root gets to decide
  if proc or sysfs should be mounted at all.

  Some hacks were put in place to reduce the worst of the damage could
  be done, and the common sense rule was adopted that fresh mounts of
  proc and sysfs should allow no more than bind mounts of proc and
  sysfs.  Unfortunately that rule has not been fully enforced.

  There are two kinds of gaps in that enforcement.  Only filesystems
  mounted on empty directories of proc and sysfs should be ignored but
  the test for empty directories was insufficient.  So in my tree
  directories on proc, sysctl and sysfs that will always be empty are
  created specially.  Every other technique is imperfect as an ordinary
  directory can have entries added even after a readdir returns and
  shows that the directory is empty.  Special creation of directories
  for mount points makes the code in the kernel a smidge clearer about
  it's purpose.  I asked container developers from the various container
  projects to help test this and no holes were found in the set of mount
  points on proc and sysfs that are created specially.

  This set of changes also starts enforcing the mount flags of fresh
  mounts of proc and sysfs are consistent with the existing mount of
  proc and sysfs.  I expected this to be the boring part of the work but
  unfortunately unprivileged userspace winds up mounting fresh copies of
  proc and sysfs with noexec and nosuid clear when root set those flags
  on the previous mount of proc and sysfs.  So for now only the atime,
  read-only and nodev attributes which userspace happens to keep
  consistent are enforced.  Dealing with the noexec and nosuid
  attributes remains for another time.

  This set of changes also addresses an issue with how open file
  descriptors from /proc/<pid>/ns/* are displayed.  Recently readlink of
  /proc/<pid>/fd has been triggering a WARN_ON that has not been
  meaningful since it was added (as all of the code in the kernel was
  converted) and is not now actively wrong.

  There is also a short list of issues that have not been fixed yet that
  I will mention briefly.

  It is possible to rename a directory from below to above a bind mount.
  At which point any directory pointers below the renamed directory can
  be walked up to the root directory of the filesystem.  With user
  namespaces enabled a bind mount of the bind mount can be created
  allowing the user to pick a directory whose children they can rename
  to outside of the bind mount.  This is challenging to fix and doubly
  so because all obvious solutions must touch code that is in the
  performance part of pathname resolution.

  As mentioned above there is also a question of how to ensure that
  developers by accident or with purpose do not introduce exectuable
  files on sysfs and proc and in doing so introduce security regressions
  in the current userspace that will not be immediately obvious and as
  such are likely to require breaking userspace in painful ways once
  they are recognized"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Remove incorrect debugging WARN in prepend_path
  mnt: Update fs_fully_visible to test for permanently empty directories
  sysfs: Create mountpoints with sysfs_create_mount_point
  sysfs: Add support for permanently empty directories to serve as mount points.
  kernfs: Add support for always empty directories.
  proc: Allow creating permanently empty directories that serve as mount points
  sysctl: Allow creating permanently empty directories that serve as mountpoints.
  fs: Add helper functions for permanently empty directories.
  vfs: Ignore unlocked mounts in fs_fully_visible
  mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
  mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-03 15:20:57 -07:00
Peter Zijlstra 2ecd9d29ab sched, preempt_notifier: separate notifier registration from static_key inc/dec
Commit 1cde2930e1 ("sched/preempt: Add static_key() to preempt_notifiers")
had two problems.  First, the preempt-notifier API needs to sleep with the
addition of the static_key, we do however need to hold off preemption
while modifying the preempt notifier list, otherwise a preemption could
observe an inconsistent list state.  KVM correctly registers and
unregisters preempt notifiers with preemption disabled, so the sleep
caused dmesg splats.

Second, KVM registers and unregisters preemption notifiers very often
(in vcpu_load/vcpu_put).  With a single uniprocessor guest the static key
would move between 0 and 1 continuously, hitting the slow path on every
userspace exit.

To fix this, wrap the static_key inc/dec in a new API, and call it from
KVM.

Fixes: 1cde2930e1 ("sched/preempt: Add static_key() to preempt_notifiers")
Reported-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Reported-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-03 18:55:00 +02:00
Linus Torvalds 7df9ab845c make certificate list change message more useful
It's a bug in our Makefile rules, make it show what the changing
certificate list was, and make it a warning so that people actually see
it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-02 16:42:13 -07:00
Linus Torvalds 2d01eedf1d Merge branch 'akpm' (patches from Andrew)
Merge third patchbomb from Andrew Morton:

 - the rest of MM

 - scripts/gdb updates

 - ipc/ updates

 - lib/ updates

 - MAINTAINERS updates

 - various other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (67 commits)
  genalloc: rename of_get_named_gen_pool() to of_gen_pool_get()
  genalloc: rename dev_get_gen_pool() to gen_pool_get()
  x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
  MAINTAINERS: add zpool
  MAINTAINERS: BCACHE: Kent Overstreet has changed email address
  MAINTAINERS: move Jens Osterkamp to CREDITS
  MAINTAINERS: remove unused nbd.h pattern
  MAINTAINERS: update brcm gpio filename pattern
  MAINTAINERS: update brcm dts pattern
  MAINTAINERS: update sound soc intel patterns
  MAINTAINERS: remove website for paride
  MAINTAINERS: update Emulex ocrdma email addresses
  bcache: use kvfree() in various places
  libcxgbi: use kvfree() in cxgbi_free_big_mem()
  target: use kvfree() in session alloc and free
  IB/ehca: use kvfree() in ipz_queue_{cd}tor()
  drm/nouveau/gem: use kvfree() in u_free()
  drm: use kvfree() in drm_free_large()
  cxgb4: use kvfree() in t4_free_mem()
  cxgb3: use kvfree() in cxgb_free_mem()
  ...
2015-07-01 17:47:51 -07:00
Linus Torvalds 6ac15baacb Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "This contains:

   - a build regression fix introduced by the timeconst move

   - a hotplug regression fix introduced by the timer wheel diet

   - a cpu hotplug bug fix for the exynos clocksource driver"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Remove development rules from Kbuild/Makefile
  timer: Fix hotplug regression
  clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier
2015-07-01 15:44:18 -07:00
Linus Torvalds 5c3950970b Power management and ACPI fixes for v4.2-rc1
- Fix a recently added memory leak in an error path in the ACPI
    resources management code (Dan Carpenter).
 
  - Fix a build warning triggered by an ACPI video header function
    that should be static inline (Borislav Petkov).
 
  - Change names of helper function converting struct fwnode_handle
    pointers to either struct device_node or struct acpi_device
    pointers so they don't conflict with local variable names
    (Alexander Sverdlin).
 
  - Make the hibernate core re-enable nonboot CPUs on failures to
    disable them as expected (Vitaly Kuznetsov).
 
  - Increase the default timeout of the device suspend watchdog to
    prevent it from triggering too early on some systems (Takashi Iwai).
 
  - Prevent the cpuidle powernv driver from registering idle
    states with CPUIDLE_FLAG_TIMER_STOP set if CONFIG_TICK_ONESHOT
    is unset which leads to boot hangs (Preeti U Murthy).
 
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Merge tag 'pm+acpi-4.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes that didn't make it to the previous PM+ACPI pull
  request or are fixing issues introduced by it.

  Specifics:

   - Fix a recently added memory leak in an error path in the ACPI
     resources management code (Dan Carpenter)

   - Fix a build warning triggered by an ACPI video header function that
     should be static inline (Borislav Petkov)

   - Change names of helper function converting struct fwnode_handle
     pointers to either struct device_node or struct acpi_device
     pointers so they don't conflict with local variable names
     (Alexander Sverdlin)

   - Make the hibernate core re-enable nonboot CPUs on failures to
     disable them as expected (Vitaly Kuznetsov)

   - Increase the default timeout of the device suspend watchdog to
     prevent it from triggering too early on some systems (Takashi Iwai)

   - Prevent the cpuidle powernv driver from registering idle states
     with CPUIDLE_FLAG_TIMER_STOP set if CONFIG_TICK_ONESHOT is unset
     which leads to boot hangs (Preeti U Murthy)"

* tag 'pm+acpi-4.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  tick/idle/powerpc: Do not register idle states with CPUIDLE_FLAG_TIMER_STOP set in periodic mode
  PM / sleep: Increase default DPM watchdog timeout to 60
  PM / hibernate: re-enable nonboot cpus on disable_nonboot_cpus() failure
  ACPI / OF: Rename of_node() and acpi_node() to to_of_node() and to_acpi_node()
  ACPI / video: Inline acpi_video_set_dmi_backlight_type
  ACPI / resources: free memory on error in add_region_before()
2015-07-01 14:17:44 -07:00