Commit Graph

19583 Commits

Author SHA1 Message Date
Linus Torvalds 26cdd1f76a Merge branches 'timers-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer and x86 fix from Ingo Molnar:
 "A CLOCK_TAI early expiry fix and an x86 microcode driver oops fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Fix incorrect tai offset calculation for non high-res timer systems

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode: Return error from driver init code when loader is disabled
2015-02-06 13:56:02 -08:00
Linus Torvalds 396e9099ea Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Misc fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix deadline parameter modification handling
  sched/wait: Remove might_sleep() from wait_event_cmd()
  sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumask
  sched/fair: Avoid using uninitialized variable in preferred_group_nid()
2015-02-06 13:34:26 -08:00
Linus Torvalds 29f12c48df Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core kernel fixes from Ingo Molnar:
 "Two liblockdep fixes and a CPU hotplug race fix"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/liblockdep: don't include host headers
  tools/liblockdep: ignore generated .so file
  smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()
2015-02-06 13:06:10 -08:00
John Stultz 2d926c15d6 hrtimer: Fix incorrect tai offset calculation for non high-res timer systems
I noticed some CLOCK_TAI timer test failures on one of my
less-frequently used configurations. And after digging in I
found in 76f4108892 (Cleanup hrtimer accessors to the
timekepeing state), the hrtimer_get_softirq_time tai offset
calucation was incorrectly rewritten, as the tai offset we
return shold be from CLOCK_MONOTONIC, and not CLOCK_REALTIME.

This results in CLOCK_TAI timers expiring early on non-highres
capable machines.

This patch fixes the issue, calculating the tai time properly
from the monotonic base.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.17+
Link: http://lkml.kernel.org/r/1423097126-10236-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-05 08:39:37 +01:00
Peter Zijlstra 40767b0dc7 sched/deadline: Fix deadline parameter modification handling
Commit 67dfa1b756 ("sched/deadline: Implement cancel_dl_timer() to
use in switched_from_dl()") removed the hrtimer_try_cancel() function
call out from init_dl_task_timer(), which gets called from
__setparam_dl().

The result is that we can now re-init the timer while its active --
this is bad and corrupts timer state.

Furthermore; changing the parameters of an active deadline task is
tricky in that you want to maintain guarantees, while immediately
effective change would allow one to circumvent the CBS guarantees --
this too is bad, as one (bad) task should not be able to affect the
others.

Rework things to avoid both problems. We only need to initialize the
timer once, so move that to __sched_fork() for new tasks.

Then make sure __setparam_dl() doesn't affect the current running
state but only updates the parameters used to calculate the next
scheduling period -- this guarantees the CBS functions as expected
(albeit slightly pessimistic).

This however means we need to make sure __dl_clear_params() needs to
reset the active state otherwise new (and tasks flipping between
classes) will not properly (re)compute their first instance.

Todo: close class flipping CBS hole.
Todo: implement delayed BW release.

Reported-by: Luca Abeni <luca.abeni@unitn.it>
Acked-by: Juri Lelli <juri.lelli@arm.com>
Tested-by: Luca Abeni <luca.abeni@unitn.it>
Fixes: 67dfa1b756 ("sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150128140803.GF23038@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04 07:42:48 +01:00
Linus Torvalds 00845eb968 sched: don't cause task state changes in nested sleep debugging
Commit 8eb23b9f35 ("sched: Debug nested sleeps") added code to report
on nested sleep conditions, which we generally want to avoid because the
inner sleeping operation can re-set the thread state to TASK_RUNNING,
but that will then cause the outer sleep loop not actually sleep when it
calls schedule.

However, that's actually valid traditional behavior, with the inner
sleep being some fairly rare case (like taking a sleeping lock that
normally doesn't actually need to sleep).

And the debug code would actually change the state of the task to
TASK_RUNNING internally, which makes that kind of traditional and
working code not work at all, because now the nested sleep doesn't just
sometimes cause the outer one to not block, but will cause it to happen
every time.

In particular, it will cause the cardbus kernel daemon (pccardd) to
basically busy-loop doing scheduling, converting a laptop into a heater,
as reported by Bruno Prémont.  But there may be other legacy uses of
that nested sleep model in other drivers that are also likely to never
get converted to the new model.

This fixes both cases:

 - don't set TASK_RUNNING when the nested condition happens (note: even
   if WARN_ONCE() only _warns_ once, the return value isn't whether the
   warning happened, but whether the condition for the warning was true.
   So despite the warning only happening once, the "if (WARN_ON(..))"
   would trigger for every nested sleep.

 - in the cases where we knowingly disable the warning by using
   "sched_annotate_sleep()", don't change the task state (that is used
   for all core scheduling decisions), instead use '->task_state_change'
   that is used for the debugging decision itself.

(Credit for the second part of the fix goes to Oleg Nesterov: "Can't we
avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the
suggested change to use 'task_state_change' as part of the test)

Reported-and-bisected-by: Bruno Prémont <bonbons@linux-vserver.org>
Tested-by: Rafael J Wysocki <rjw@rjwysocki.net>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Cc: Ilya Dryomov <ilya.dryomov@inktank.com>,
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>,
Cc: Davidlohr Bueso <dave@stgolabs.net>,
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-01 12:23:32 -08:00
Linus Torvalds 6155bc1431 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also an event groups fix, two PMU driver
  fixes and a CPU model variant addition"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Tighten (and fix) the grouping condition
  perf/x86/intel: Add model number for Airmont
  perf/rapl: Fix crash in rapl_scale()
  perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization
  perf probe: Fix probing kretprobes
  perf symbols: Introduce 'for' method to iterate over the symbols with a given name
  perf probe: Do not rely on map__load() filter to find symbols
  perf symbols: Introduce method to iterate symbols ordered by name
  perf symbols: Return the first entry with a given name in find_by_name method
  perf annotate: Fix memory leaks in LOCK handling
  perf annotate: Handle ins parsing failures
  perf scripting perl: Force to use stdbool
  perf evlist: Remove extraneous 'was' on error message
2015-01-30 14:34:55 -08:00
Mike Galbraith bb2bc55a69 sched: Fix crash if cpuset_cpumask_can_shrink() is passed an empty cpumask
While creating an exclusive cpuset, we passed cpuset_cpumask_can_shrink()
an empty cpumask (cur), and dl_bw_of(cpumask_any(cur)) made boom with it:

 CPU: 0 PID: 6942 Comm: shield.sh Not tainted 3.19.0-master #19
 Hardware name: MEDIONPC MS-7502/MS-7502, BIOS 6.00 PG 12/26/2007
 task: ffff880224552450 ti: ffff8800caab8000 task.ti: ffff8800caab8000
 RIP: 0010:[<ffffffff81073846>]  [<ffffffff81073846>] cpuset_cpumask_can_shrink+0x56/0xb0
 [...]
 Call Trace:
  [<ffffffff810cb82a>] validate_change+0x18a/0x200
  [<ffffffff810cc877>] cpuset_write_resmask+0x3b7/0x720
  [<ffffffff810c4d58>] cgroup_file_write+0x38/0x100
  [<ffffffff811d953a>] kernfs_fop_write+0x12a/0x180
  [<ffffffff8116e1a3>] vfs_write+0xb3/0x1d0
  [<ffffffff8116ed06>] SyS_write+0x46/0xb0
  [<ffffffff8159ced6>] system_call_fastpath+0x16/0x1b

Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Fixes: f82f80426f ("sched/deadline: Ensure that updates to exclusive cpusets don't break AC")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1422417235.5716.5.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-28 15:28:15 +01:00
Peter Zijlstra c3c87e7704 perf: Tighten (and fix) the grouping condition
The fix from 9fc81d8742 ("perf: Fix events installation during
moving group") was incomplete in that it failed to recognise that
creating a group with events for different CPUs is semantically
broken -- they cannot be co-scheduled.

Furthermore, it leads to real breakage where, when we create an event
for CPU Y and then migrate it to form a group on CPU X, the code gets
confused where the counter is programmed -- triggered in practice
as well by me via the perf fuzzer.

Fix this by tightening the rules for creating groups. Only allow
grouping of counters that can be co-scheduled in the same context.
This means for the same task and/or the same cpu.

Fixes: 9fc81d8742 ("perf: Fix events installation during moving group")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-28 13:17:35 +01:00
Jan Beulich 81907478c4 sched/fair: Avoid using uninitialized variable in preferred_group_nid()
At least some gcc versions - validly afaict - warn about potentially
using max_group uninitialized: There's no way the compiler can prove
that the body of the conditional where it and max_faults get set/
updated gets executed; in fact, without knowing all the details of
other scheduler code, I can't prove this either.

Generally the necessary change would appear to be to clear max_group
prior to entering the inner loop, and break out of the outer loop when
it ends up being all clear after the inner one. This, however, seems
inefficient, and afaict the same effect can be achieved by exiting the
outer loop when max_faults is still zero after the inner loop.

[ mingo: changed the solution to zero initialization: uninitialized_var()
  needs to die, as it's an actively dangerous construct: if in the future
  a known-proven-good piece of code is changed to have a true, buggy
  uninitialized variable, the compiler warning is then supressed...

  The better long term solution is to clean up the code flow, so that
  even simple minded compilers (and humans!) are able to read it without
  getting a headache.  ]

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/54C2139202000078000588F7@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-28 13:14:12 +01:00
Linus Torvalds 59343cd7c4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Don't OOPS on socket AIO, from Christoph Hellwig.

 2) Scheduled scans should be aborted upon RFKILL, from Emmanuel
    Grumbach.

 3) Fix sleep in atomic context in kvaser_usb, from Ahmed S Darwish.

 4) Fix RCU locking across copy_to_user() in bpf code, from Alexei
    Starovoitov.

 5) Lots of crash, memory leak, short TX packet et al bug fixes in
    sh_eth from Ben Hutchings.

 6) Fix memory corruption in SCTP wrt.  INIT collitions, from Daniel
    Borkmann.

 7) Fix return value logic for poll handlers in netxen, enic, and bnx2x.
    From Eric Dumazet and Govindarajulu Varadarajan.

 8) Header length calculation fix in mac80211 from Fred Chou.

 9) mv643xx_eth doesn't handle highmem correctly in non-TSO code paths.
    From Ezequiel Garcia.

10) udp_diag has bogus logic in it's hash chain skipping, copy same fix
    tcp diag used.  From Herbert Xu.

11) amd-xgbe programs wrong rx flow control register, from Thomas
    Lendacky.

12) Fix race leading to use after free in ping receive path, from Subash
    Abhinov Kasiviswanathan.

13) Cache redirect routes otherwise we can get a heavy backlog of rcu
    jobs liberating DST_NOCACHE entries.  From Hannes Frederic Sowa.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits)
  net: don't OOPS on socket aio
  stmmac: prevent probe drivers to crash kernel
  bnx2x: fix napi poll return value for repoll
  ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too
  sh_eth: Fix DMA-API usage for RX buffers
  sh_eth: Check for DMA mapping errors on transmit
  sh_eth: Ensure DMA engines are stopped before freeing buffers
  sh_eth: Remove RX overflow log messages
  ping: Fix race in free in receive path
  udp_diag: Fix socket skipping within chain
  can: kvaser_usb: Fix state handling upon BUS_ERROR events
  can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT
  can: kvaser_usb: Send correct context to URB completion
  can: kvaser_usb: Do not sleep in atomic context
  ipv4: try to cache dst_entries which would cause a redirect
  samples: bpf: relax test_maps check
  bpf: rcu lock must not be held when calling copy_to_user()
  net: sctp: fix slab corruption from use after free on INIT collisions
  net: mv643xx_eth: Fix highmem support in non-TSO egress path
  sh_eth: Fix serialisation of interrupt disable with interrupt & NAPI handlers
  ...
2015-01-27 13:55:36 -08:00
Alexei Starovoitov 8ebe667c41 bpf: rcu lock must not be held when calling copy_to_user()
BUG: sleeping function called from invalid context at mm/memory.c:3732
in_atomic(): 0, irqs_disabled(): 0, pid: 671, name: test_maps
1 lock held by test_maps/671:
 #0:  (rcu_read_lock){......}, at: [<0000000000264190>] map_lookup_elem+0xe8/0x260
Call Trace:
([<0000000000115b7e>] show_trace+0x12e/0x150)
 [<0000000000115c40>] show_stack+0xa0/0x100
 [<00000000009b163c>] dump_stack+0x74/0xc8
 [<000000000017424a>] ___might_sleep+0x23a/0x248
 [<00000000002b58e8>] might_fault+0x70/0xe8
 [<0000000000264230>] map_lookup_elem+0x188/0x260
 [<0000000000264716>] SyS_bpf+0x20e/0x840

Fix it by allocating temporary buffer to store map element value.

Fixes: db20fd2b01 ("bpf: add lookup/update/delete/iterate methods to BPF maps")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-26 17:20:40 -08:00
Linus Torvalds c976a67b02 Merge branch 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "The lifetime rules of cgroup hierarchies always have been somewhat
  counter-intuitive and cgroup core tried to enforce that hierarchies
  w/o userland-visible usages must die in finite amount of time so that
  the controllers can be reused for other hierarchies; unfortunately,
  this can't be implemented reasonably for the memory controller - the
  kmemcg part doesn't have any way to forcefully drain the existing
  usages, leading to an interruptible hang if a following mount attempts
  to use the controller in any way.

  So, it seems like we're stuck with "hierarchies live on till they die
  whenever that may be" at least for now.  This pretty much confines
  attaching controllers to hierarchies to before the hierarchies are
  actively used by making dynamic configurations post active usages
  unreliable.  This has never been reliable and should be fine in
  practice given how cgroups are used.

  After the patch, hierarchies aren't killed if it isn't already
  drained.  A following mount attempt of the same mount options will
  reuse the existing hierarchy.  Mount attempts with differing options
  will fail w/ -EBUSY"

* 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: prevent mount hang due to memory controller lifetime
2015-01-26 15:17:34 -08:00
Linus Torvalds 14746306af Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "Hopefully the last round of fixes for 3.19

   - regression fix for the LDT changes
   - regression fix for XEN interrupt handling caused by the APIC
     changes
   - regression fixes for the PAT changes
   - last minute fixes for new the MPX support
   - regression fix for 32bit UP
   - fix for a long standing relocation issue on 64bit tagged for stable
   - functional fix for the Hyper-V clocksource tagged for stable
   - downgrade of a pr_err which tends to confuse users

  Looks a bit on the large side, but almost half of it are valuable
  comments"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Change Fast TSC calibration failed from error to info
  x86/apic: Re-enable PCI_MSI support for non-SMP X86_32
  x86, mm: Change cachemode exports to non-gpl
  x86, tls: Interpret an all-zero struct user_desc as "no segment"
  x86, tls, ldt: Stop checking lm in LDT_empty
  x86, mpx: Strictly enforce empty prctl() args
  x86, mpx: Fix potential performance issue on unmaps
  x86, mpx: Explicitly disable 32-bit MPX support on 64-bit kernels
  x86, hyperv: Mark the Hyper-V clocksource as being continuous
  x86: Don't rely on VMWare emulating PAT MSR correctly
  x86, irq: Properly tag virtualization entry in /proc/interrupts
  x86, boot: Skip relocs when load address unchanged
  x86/xen: Override ACPI IRQ management callback __acpi_unregister_gsi
  ACPI: pci: Do not clear pci_dev->irq in acpi_pci_irq_disable()
  x86/xen: Treat SCI interrupt as normal GSI interrupt
2015-01-25 18:11:17 -08:00
Linus Torvalds b73f0c8f4b Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "A set of small fixes:

   - regression fix for exynos_mct clocksource

   - trivial build fix for kona clocksource

   - functional one liner fix for the sh_tmu clocksource

   - two validation fixes to prevent (root only) data corruption in the
     kernel via settimeofday and adjtimex.  Tagged for stable"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: adjtimex: Validate the ADJ_FREQUENCY values
  time: settimeofday: Validate the values of tv from user
  clocksource: sh_tmu: Set cpu_possible_mask to fix SMP broadcast
  clocksource: kona: fix __iomem annotation
  clocksource: exynos_mct: Fix bitmask regression for exynos4_mct_write
2015-01-25 17:47:34 -08:00
Lai Jiangshan 4bee96860a smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()
The following race exists in the smpboot percpu threads management:

CPU0	      	   	     CPU1
cpu_up(2)
  get_online_cpus();
  smpboot_create_threads(2);
			     smpboot_register_percpu_thread();
			     for_each_online_cpu();
			       __smpboot_create_thread();
  __cpu_up(2);

This results in a missing per cpu thread for the newly onlined cpu2 and
in a NULL pointer dereference on a consecutive offline of that cpu.

Proctect smpboot_register_percpu_thread() with get_online_cpus() to
prevent that.

[ tglx: Massaged changelog and removed the change in
        smpboot_unregister_percpu_thread() because that's an
        optimization and therefor not stable material. ]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1406777421-12830-1-git-send-email-laijs@cn.fujitsu.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-23 11:33:51 +01:00
Dave Hansen e9d1b4f3c6 x86, mpx: Strictly enforce empty prctl() args
Description from Michael Kerrisk.  He suggested an identical patch
to one I had already coded up and tested.

commit fe3d197f84 "x86, mpx: On-demand kernel allocation of bounds
tables" added two new prctl() operations, PR_MPX_ENABLE_MANAGEMENT and
PR_MPX_DISABLE_MANAGEMENT.  However, no checks were included to ensure
that unused arguments are zero, as is done in many existing prctl()s
and as should be done for all new prctl()s. This patch adds the
required checks.

Suggested-by: Andy Lutomirski <luto@amacapital.net>
Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20150108223022.7F56FD13@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-22 21:11:06 +01:00
Linus Torvalds 193934123c Surprising number of fixes this merge window :(
First two are minor fallout from the param rework which went in this merge
 window.
 
 Next three are a series which fixes a longstanding (but never previously
 reported and unlikely , so no CC stable) race between kallsyms and freeing
 the init section.
 
 Finally, a minor cleanup as our module refcount will now be -1 during
 unload.
 
 Thanks,
 Rusty.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUwEmwAAoJENkgDmzRrbjx77kP/1cNQR2eG2sBwokg3q0tvHnQ
 IKqEXErW7NvxRa+RAMEmy2uQoGt6+uNklAbtyJEYM9oR1NieFbPi2yrt9Xn5SAXS
 Brp1S8WYBMilA3W3o6I0trFDRWHdpdtkKIQwLWgJNSEWjbTXh8bSwp/2X1rlOPyI
 ZmphCMOQMU2/uFEyJhTz1WMEV8eVXiRLN8OxSkPxToxdZoGln2U8IBCCCJC9OG+f
 Cf3eMgEcNdEXNcPKqr11NIcHkAx6M6qI/eMDOqk151PslHa8lbis6di9Z87aE0ps
 i8PyrkJGTmgM9cCjXwE8deNseeCmuKYlbPIF+NoxcqtvZstfaMrISwTIEuzV4JHi
 p13YhDxy4XiC3H6pKHub/jo7UCl+wWtFh9SqpqGgduFX/p6FtUHQJm0S0X/DFFZt
 C+2MFVSe6HRHE8B7bFz86+619Qd/rU7+806CLCE+NbYlYAKIBYKzWt/bml6VH3RJ
 OjwXhQqmznWhJjsfD3BUUUpZpHijmylI9gAe2F1oErb8YjRU6gIm7P8hlkOzD7AS
 TfGHPFq2raQcfAiGdVmvkbvvhvYZXnB3WVsAexrYoqrT9I8eEfRI+7SkL75MLR2E
 ikzhJS3SHkAUAd7fUVMt7xMwh0jmhsPjWCCqc13m6UUFoXhTaDgKgPGftltN0bI2
 g85+enZ3/eca6xh/KxvW
 =Kf9b
 -----END PGP SIGNATURE-----

Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module and param fixes from Rusty Russell:
 "Surprising number of fixes this merge window :(

  The first two are minor fallout from the param rework which went in
  this merge window.

  The next three are a series which fixes a longstanding (but never
  previously reported and unlikely , so no CC stable) race between
  kallsyms and freeing the init section.

  Finally, a minor cleanup as our module refcount will now be -1 during
  unload"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: make module_refcount() a signed integer.
  module: fix race in kallsyms resolution during module load success.
  module: remove mod arg from module_free, rename module_memfree().
  module_arch_freeing_init(): new hook for archs before module->module_init freed.
  param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC
  param: initialize store function to NULL if not available.
2015-01-23 06:40:36 +12:00
Johannes Weiner 3c606d35fe cgroup: prevent mount hang due to memory controller lifetime
Since b2052564e6 ("mm: memcontrol: continue cache reclaim from
offlined groups"), re-mounting the memory controller after using it is
very likely to hang.

The cgroup core assumes that any remaining references after deleting a
cgroup are temporary in nature, and synchroneously waits for them, but
the above-mentioned commit has left-over page cache pin its css until
it is reclaimed naturally.  That being said, swap entries and charged
kernel memory have been doing the same indefinite pinning forever, the
bug is just more likely to trigger with left-over page cache.

Reparenting kernel memory is highly impractical, which leaves changing
the cgroup assumptions to reflect this: once a controller has been
mounted and used, it has internal state that is independent from mount
and cgroup lifetime.  It can be unmounted and remounted, but it can't
be reconfigured during subsequent mounts.

Don't offline the controller root as long as there are any children,
dead or alive.  A remount will no longer wait for these old references
to drain, it will simply mount the persistent controller state again.

Reported-by: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-01-22 10:26:43 -05:00
Thomas Gleixner 5fbaba8603 Merge branch 'fortglx/3.19-stable/time' of https://git.linaro.org/people/john.stultz/linux into timers/urgent
Pull urgent fixes from John Stultz:

  Two urgent fixes for user triggerable time related overflow issues
2015-01-22 12:28:02 +01:00
Rusty Russell d5db139ab3 module: make module_refcount() a signed integer.
James Bottomley points out that it will be -1 during unload.  It's
only used for diagnostics, so let's not hide that as it could be a
clue as to what's gone wrong.

Cc: Jason Wessel <jason.wessel@windriver.com>
Acked-and-documention-added-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Masami Hiramatsu <maasami.hiramatsu.pt@hitachi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-22 11:15:54 +10:30
Linus Torvalds d4b2d0061d Merge branch 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
 "The xfs folks have been running into weird and very rare lockups for
  some time now.  I didn't think this could have been from workqueue
  side because no one else was reporting it.  This time, Eric had a
  kdump which we looked into and it turned out this actually was a
  workqueue bug and the bug has been there since the beginning of
  concurrency managed workqueue.

  A worker pool ensures forward progress of the workqueues associated
  with it by always having at least one worker reserved from executing
  work items.  When the pool is under contention, the idle one tries to
  create more workers for the pool and if that doesn't succeed quickly
  enough, it calls the rescuers to the pool.

  This logic had a subtle race condition in an early exit path.  When a
  worker invokes this manager function, the function may return %false
  indicating that the caller may proceed to executing work items either
  because another worker is already performing the role or conditions
  have changed and the pool is no longer under contention.

  The latter part depended on the assumption that whether more workers
  are necessary or not remains stable while the pool is locked; however,
  pool->nr_running (concurrency count) may change asynchronously and it
  getting bumped from zero asynchronously could send off the last idle
  worker to execute work items.

  The race window is fairly narrow, and, even when it gets triggered,
  the pool deadlocks iff if all work items get blocked on pending work
  items of the pool, which is highly unlikely but can be triggered by
  xfs.

  The patch removes the race window by removing the early exit path,
  which doesn't server any purpose anymore anyway"

* 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix subtle pool management issue which can stall whole worker_pool
2015-01-21 07:51:46 +12:00
Rusty Russell c749637909 module: fix race in kallsyms resolution during module load success.
The kallsyms routines (module_symbol_name, lookup_module_* etc) disable
preemption to walk the modules rather than taking the module_mutex:
this is because they are used for symbol resolution during oopses.

This works because there are synchronize_sched() and synchronize_rcu()
in the unload and failure paths.  However, there's one case which doesn't
have that: the normal case where module loading succeeds, and we free
the init section.

We don't want a synchronize_rcu() there, because it would slow down
module loading: this bug was introduced in 2009 to speed module
loading in the first place.

Thus, we want to do the free in an RCU callback.  We do this in the
simplest possible way by allocating a new rcu_head: if we put it in
the module structure we'd have to worry about that getting freed.

Reported-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-20 11:38:34 +10:30
Rusty Russell be1f221c04 module: remove mod arg from module_free, rename module_memfree().
Nothing needs the module pointer any more, and the next patch will
call it from RCU, where the module itself might no longer exist.
Removing the arg is the safest approach.

This just codifies the use of the module_alloc/module_free pattern
which ftrace and bpf use.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: x86@kernel.org
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: netdev@vger.kernel.org
2015-01-20 11:38:33 +10:30
Rusty Russell d453cded05 module_arch_freeing_init(): new hook for archs before module->module_init freed.
Archs have been abusing module_free() to clean up their arch-specific
allocations.  Since module_free() is also (ab)used by BPF and trace code,
let's keep it to simple allocations, and provide a hook called before
that.

This means that avr32, ia64, parisc and s390 no longer need to implement
their own module_free() at all.  avr32 doesn't need module_finalize()
either.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
2015-01-20 11:38:32 +10:30
Rusty Russell c772be5231 param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC
ignore_lockdep is uninitialized, and sysfs_attr_init() doesn't initialize
it, so memset to 0.

Reported-by: Huang Ying <ying.huang@intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-20 11:38:31 +10:30
Louis Langholtz fc7f0dd381 kernel: avoid overflow in cmp_range
Avoid overflow possibility.

[ The overflow is purely theoretical, since this is used for memory
  ranges that aren't even close to using the full 64 bits, but this is
  the right thing to do regardless.  - Linus ]

Signed-off-by: Louis Langholtz <lou_langholtz@me.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Peter Anvin <hpa@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-17 10:02:23 +13:00
Tejun Heo 29187a9eea workqueue: fix subtle pool management issue which can stall whole worker_pool
A worker_pool's forward progress is guaranteed by the fact that the
last idle worker assumes the manager role to create more workers and
summon the rescuers if creating workers doesn't succeed in timely
manner before proceeding to execute work items.

This manager role is implemented in manage_workers(), which indicates
whether the worker may proceed to work item execution with its return
value.  This is necessary because multiple workers may contend for the
manager role, and, if there already is a manager, others should
proceed to work item execution.

Unfortunately, the function also indicates that the worker may proceed
to work item execution if need_to_create_worker() is false at the head
of the function.  need_to_create_worker() tests the following
conditions.

	pending work items && !nr_running && !nr_idle

The first and third conditions are protected by pool->lock and thus
won't change while holding pool->lock; however, nr_running can change
asynchronously as other workers block and resume and while it's likely
to be zero, as someone woke this worker up in the first place, some
other workers could have become runnable inbetween making it non-zero.

If this happens, manage_worker() could return false even with zero
nr_idle making the worker, the last idle one, proceed to execute work
items.  If then all workers of the pool end up blocking on a resource
which can only be released by a work item which is pending on that
pool, the whole pool can deadlock as there's no one to create more
workers or summon the rescuers.

This patch fixes the problem by removing the early exit condition from
maybe_create_worker() and making manage_workers() return false iff
there's already another manager, which ensures that the last worker
doesn't start executing work items.

We can leave the early exit condition alone and just ignore the return
value but the only reason it was put there is because the
manage_workers() used to perform both creations and destructions of
workers and thus the function may be invoked while the pool is trying
to reduce the number of workers.  Now that manage_workers() is called
only when more workers are needed, the only case this early exit
condition is triggered is rare race conditions rendering it pointless.

Tested with simulated workload and modified workqueue code which
trigger the pool deadlock reliably without this patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Eric Sandeen <sandeen@sandeen.net>
Link: http://lkml.kernel.org/g/54B019F4.8030009@sandeen.net
Cc: Dave Chinner <david@fromorbit.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: stable@vger.kernel.org
2015-01-16 14:21:16 -05:00
Linus Torvalds 23aa4b416a This holds a few fixes to the ftrace infrastructure as well as
the mixture of function graph tracing and kprobes.
 
 When jprobes and function graph tracing is enabled at the same time
 it will crash the system.
 
   # modprobe jprobe_example
   # echo function_graph > /sys/kernel/debug/tracing/current_tracer
 
 After the first fork (jprobe_example probes it), the system will crash.
 This is due to the way jprobes copies the stack frame and does not
 do a normal function return. This messes up with the function graph
 tracing accounting which hijacks the return address from the stack
 and replaces it with a hook function. It saves the return addresses in
 a separate stack to put back the correct return address when done.
 But because the jprobe functions do not do a normal return, their
 stack addresses are not put back until the function they probe is called,
 which means that the probed function will get the return address of
 the jprobe handler instead of its own.
 
 The simple fix here was to disable function graph tracing while the
 jprobe handler is being called.
 
 While debugging this I found two minor bugs with the function graph
 tracing.
 
 The first was about the function graph tracer sharing its function hash
 with the function tracer (they both get filtered by the same input).
 The changing of the set_ftrace_filter would not sync the function recording
 records after a change if the function tracer was disabled but the
 function graph tracer was enabled. This was due to the update only checking
 one of the ops instead of the shared ops to see if they were enabled and
 should perform the sync. This caused the ftrace accounting to break and
 a ftrace_bug() would be triggered, disabling ftrace until a reboot.
 
 The second was that the check to update records only checked one of the
 filter hashes. It needs to test both the "filter" and "notrace" hashes.
 The "filter" hash determines what functions to trace where as the "notrace"
 hash determines what functions not to trace (trace all but these).
 Both hashes need to be passed to the update code to find out what change
 is being done during the update. This also broke the ftrace record
 accounting and triggered a ftrace_bug().
 
 This patch set also include two more fixes that were reported separately
 from the kprobe issue.
 
 One was that init_ftrace_syscalls() was called twice at boot up.
 This is not a major bug, but that call performed a rather large kmalloc
 (NR_syscalls * sizeof(*syscalls_metadata)). The second call made the first
 one a memory leak, and wastes memory.
 
 The other fix is a regression caused by an update in the v3.19 merge window.
 The moving to enable events early, moved the enabling before PID 1 was
 created. The syscall events require setting the TIF_SYSCALL_TRACEPOINT
 for all tasks. But for_each_process_thread() does not include the swapper
 task (PID 0), and ended up being a nop. A suggested fix was to add
 the init_task() to have its flag set, but I didn't really want to mess
 with PID 0 for this minor bug. Instead I disable and re-enable events again
 at early_initcall() where it use to be enabled. This also handles any other
 event that might have its own reg function that could break at early
 boot up.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUt9vmAAoJEEjnJuOKh9ldLHEIAJ9XrPW2xMIY5yI69jT1F7pv
 PkSRqENnOK0l4UulD52SvIBecQTTBcEEjao4yVGkc7DCJBOws/1LZ5gW8OfNlKjq
 rMB8yaosL1tXJ1ARVPMjcQVy+228zkgTXznwEZCjku1g7LuScQ28qyXsXO7B6yiK
 xKoHqKjygmM/a2aVn+8tdiVKiDp6jdmkbYicbaFT4xP7XB5DaMmIiXRHxdvW6xdR
 azKrVfYiMyJqTZNt/EVSWUk2WjeaYhoXyNtvgPx515wTo/llCnzhjcsocXBtH2P/
 YOtwl+1L7Z89ukV9oXqrtrUJZ6Ps7+g7I1flJuL7/1FlNGnklcP9JojD+t6HeT8=
 =vkec
 -----END PGP SIGNATURE-----

Merge tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fixes from Steven Rostedt:
 "This holds a few fixes to the ftrace infrastructure as well as the
  mixture of function graph tracing and kprobes.

  When jprobes and function graph tracing is enabled at the same time it
  will crash the system:

      # modprobe jprobe_example
      # echo function_graph > /sys/kernel/debug/tracing/current_tracer

  After the first fork (jprobe_example probes it), the system will
  crash.

  This is due to the way jprobes copies the stack frame and does not do
  a normal function return.  This messes up with the function graph
  tracing accounting which hijacks the return address from the stack and
  replaces it with a hook function.  It saves the return addresses in a
  separate stack to put back the correct return address when done.  But
  because the jprobe functions do not do a normal return, their stack
  addresses are not put back until the function they probe is called,
  which means that the probed function will get the return address of
  the jprobe handler instead of its own.

  The simple fix here was to disable function graph tracing while the
  jprobe handler is being called.

  While debugging this I found two minor bugs with the function graph
  tracing.

  The first was about the function graph tracer sharing its function
  hash with the function tracer (they both get filtered by the same
  input).  The changing of the set_ftrace_filter would not sync the
  function recording records after a change if the function tracer was
  disabled but the function graph tracer was enabled.  This was due to
  the update only checking one of the ops instead of the shared ops to
  see if they were enabled and should perform the sync.  This caused the
  ftrace accounting to break and a ftrace_bug() would be triggered,
  disabling ftrace until a reboot.

  The second was that the check to update records only checked one of
  the filter hashes.  It needs to test both the "filter" and "notrace"
  hashes.  The "filter" hash determines what functions to trace where as
  the "notrace" hash determines what functions not to trace (trace all
  but these).  Both hashes need to be passed to the update code to find
  out what change is being done during the update.  This also broke the
  ftrace record accounting and triggered a ftrace_bug().

  This patch set also include two more fixes that were reported
  separately from the kprobe issue.

  One was that init_ftrace_syscalls() was called twice at boot up.  This
  is not a major bug, but that call performed a rather large kmalloc
  (NR_syscalls * sizeof(*syscalls_metadata)).  The second call made the
  first one a memory leak, and wastes memory.

  The other fix is a regression caused by an update in the v3.19 merge
  window.  The moving to enable events early, moved the enabling before
  PID 1 was created.  The syscall events require setting the
  TIF_SYSCALL_TRACEPOINT for all tasks.  But for_each_process_thread()
  does not include the swapper task (PID 0), and ended up being a nop.

  A suggested fix was to add the init_task() to have its flag set, but I
  didn't really want to mess with PID 0 for this minor bug.  Instead I
  disable and re-enable events again at early_initcall() where it use to
  be enabled.  This also handles any other event that might have its own
  reg function that could break at early boot up"

* tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix enabling of syscall events on the command line
  tracing: Remove extra call to init_ftrace_syscalls()
  ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing
  ftrace: Check both notrace and filter for old hash
  ftrace: Fix updating of filters for shared global_ops filters
2015-01-17 07:55:52 +13:00
Steven Rostedt (Red Hat) ce1039bd3a tracing: Fix enabling of syscall events on the command line
Commit 5f893b2639 "tracing: Move enabling tracepoints to just after
rcu_init()" broke the enabling of system call events from the command
line. The reason was that the enabling of command line trace events
was moved before PID 1 started, and the syscall tracepoints require
that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the
swapper task (pid 0) is not part of that. Since the swapper task is the
only task that is running at this early in boot, no task gets the
flag set, and the tracepoint never gets reached.

Instead of setting the swapper task flag (there should be no reason to
do that), re-enabled trace events again after the init thread (PID 1)
has been started. It requires disabling all command line events and
re-enabling them, as just enabling them again will not reset the logic
to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will
be fooled into thinking that it was already set, and wont try setting
it again. For this reason, we must first disable it and re-enable it.

Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:42:50 -05:00
Steven Rostedt (Red Hat) 83829b74f5 tracing: Remove extra call to init_ftrace_syscalls()
trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().

Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.

Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org

Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:41:11 -05:00
Steven Rostedt (Red Hat) 7485058eea ftrace: Check both notrace and filter for old hash
Using just the filter for checking for trampolines or regs is not enough
when updating the code against the records that represent all functions.
Both the filter hash and the notrace hash need to be checked.

To trigger this bug (using trace-cmd and perf):

 # perf probe -a do_fork
 # trace-cmd start -B foo -e probe
 # trace-cmd record -p function_graph -n do_fork sleep 1

The trace-cmd record at the end clears the filter before it disables
function_graph tracing and then that causes the accounting of the
ftrace function records to become incorrect and causes ftrace to bug.

Link: http://lkml.kernel.org/r/20150114154329.358378039@goodmis.org

Cc: stable@vger.kernel.org
[ still need to switch old_hash_ops to old_ops_hash ]
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:37:33 -05:00
Steven Rostedt (Red Hat) 8f86f83709 ftrace: Fix updating of filters for shared global_ops filters
As the set_ftrace_filter affects both the function tracer as well as the
function graph tracer, the ops that represent each have a shared
ftrace_ops_hash structure. This allows both to be updated when the filter
files are updated.

But if function graph is enabled and the global_ops (function tracing) ops
is not, then it is possible that the filter could be changed without the
update happening for the function graph ops. This will cause the changes
to not take place and may even cause a ftrace_bug to occur as it could mess
with the trampoline accounting.

The solution is to check if the ops uses the shared global_ops filter and
if the ops itself is not enabled, to check if there's another ops that is
enabled and also shares the global_ops filter. In that case, the
modification still needs to be executed.

Link: http://lkml.kernel.org/r/20150114154329.055980438@goodmis.org

Cc: stable@vger.kernel.org # 3.17+
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:37:07 -05:00
Linus Torvalds 5ab551d662 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: group scheduling corner case fix, two deadline scheduler
  fixes, effective_load() overflow fix, nested sleep fix, 6144 CPUs
  system fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
  sched/deadline: Avoid double-accounting in case of missed deadlines
  sched/deadline: Fix migration of SCHED_DEADLINE tasks
  sched: Fix odd values in effective_load() calculations
  sched, fanotify: Deal with nested sleeps
  sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation
2015-01-11 11:51:49 -08:00
Linus Torvalds ddb321a8dd Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also some kernel side fixes: uncore PMU
  driver fix, user regs sampling fix and an instruction decoder fix that
  unbreaks PEBS precise sampling"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore/hsw-ep: Handle systems with only two SBOXes
  perf/x86_64: Improve user regs sampling
  perf: Move task_pt_regs sampling into arch code
  x86: Fix off-by-one in instruction decoder
  perf hists browser: Fix segfault when showing callchain
  perf callchain: Free callchains when hist entries are deleted
  perf hists: Fix children sort key behavior
  perf diff: Fix to sort by baseline field by default
  perf list: Fix --raw-dump option
  perf probe: Fix crash in dwarf_getcfi_elf
  perf probe: Fix to fall back to find probe point in symbols
  perf callchain: Append callchains only when requested
  perf ui/tui: Print backtrace symbols when segfault occurs
  perf report: Show progress bar for output resorting
2015-01-11 11:47:45 -08:00
Linus Torvalds 1e6c3e8f8f Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "A liblockdep fix and a mutex_unlock() mutex-debugging fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Always clear owner field upon mutex_unlock()
  tools/liblockdep: Fix debug_check thinko in mutex destroy
2015-01-11 11:46:31 -08:00
Linus Torvalds aa9291355e KGDB/KDB fixes and cleanups
Cleanups
    kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE
 
  Fixes
    kgdb/kdb: Allow access on a single core, if a CPU round up is deemed
       impossible, which will allow inspection of the now "trashed" kernel
    kdb: Add enable mask for the command groups
    kdb: access controls to restrict sensitive commands
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUrq8WAAoJEIciOldedpOj+C8P/AjSUVBZdBLWzCU2VG150sQ0
 UacwFVLve9heoColHBF7VqIDCRkZokIKJmCbHUBPZTbs22auLRpNI+D6CY5lZD17
 jEHxrkKY4ragRRc/W3Y1MSc3aeGnS0i5AR8PJermMWxyUBfN3FBxgFHzTaLB2ZTT
 8A+tvmwiG4mHue52gSiYZPCl/52WWOh+NjDe7T9OZ+mNmQKwZ5ssQZmmyUkxrs3b
 LKXVXVtTUXxfEgB2x+lYTYAztcTsM5h+NbkT74FpSmwPjvU/p81Ptqveh+3JTdmX
 H+Jz/SqD1/NfxC1Eenh5Mc++p/UVxeRbBulV9jwqjOyJqDjw3qHs1cjm8tZZj1qG
 J3LODKi3GWhujMCfwdu5EJRnrFxgHCPiWInc2708oLbRi5SyOe6P6hNQ3K3Y4JtF
 VkYa62wSaI0fDNQUFRc3bXUOUdMOCXjuzw3BtTi93tcUNcQwCXuYCmWtVvBgmK1h
 LTrFCJmzbopiwpomxCwZ4BQm8id9HxP5pod95ypYb8K5aheXHCuSgibqj0nswWMm
 ix0YTd4UNTn79r6p4d0fXFjOOYpXZA80ojeVI27D9zW7dBYc5CGVA1IDNH0ZfiPo
 qySPUNUMXIjiTSOGZdUehByEC7tliLZczelRPnNh/9fmhJkJ745S7zs3DNQ7Ypg4
 xDKthlRGNjn6cXOPl7gX
 =cf1c
 -----END PGP SIGNATURE-----

Merge tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

Pull kgdb/kdb fixes from Jason Wessel:
 "These have been around since 3.17 and in kgdb-next for the last 9
  weeks and some will go back to -stable.

  Summary of changes:

  Cleanups
   - kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE

  Fixes
   - kgdb/kdb: Allow access on a single core, if a CPU round up is
     deemed impossible, which will allow inspection of the now "trashed"
     kernel
   - kdb: Add enable mask for the command groups
   - kdb: access controls to restrict sensitive commands"

* tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kernel/debug/debug_core.c: Logging clean-up
  kgdb: timeout if secondary CPUs ignore the roundup
  kdb: Allow access to sensitive commands to be restricted by default
  kdb: Add enable mask for groups of commands
  kdb: Categorize kdb commands (similar to SysRq categorization)
  kdb: Remove KDB_REPEAT_NONE flag
  kdb: Use KDB_REPEAT_* values as flags
  kdb: Rename kdb_register_repeat() to kdb_register_flags()
  kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
  kdb: Remove currently unused kdbtab_t->cmd_flags
2015-01-09 20:51:10 -08:00
Chris Wilson a63b03e2d2 mutex: Always clear owner field upon mutex_unlock()
Currently if DEBUG_MUTEXES is enabled, the mutex->owner field is only
cleared iff debug_locks is active. This exposes a race to other users of
the field where the mutex->owner may be still set to a stale value,
potentially upsetting mutex_spin_on_owner() among others.

References: https://bugs.freedesktop.org/show_bug.cgi?id=87955
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1420540175-30204-1-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:20:39 +01:00
Tetsuo Handa 7f1a169b88 sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
When alloc_fair_sched_group() in sched_create_group() fails,
free_sched_group() is called, and free_fair_sched_group() is called by
free_sched_group(). Since destroy_cfs_bandwidth() is called by
free_fair_sched_group() without calling init_cfs_bandwidth(),
RCU stall occurs at hrtimer_cancel():

  INFO: rcu_sched self-detected stall on CPU { 1}  (t=60000 jiffies g=13074 c=13073 q=0)
  Task dump for CPU 1:
  (fprintd)       R  running task        0  6249      1 0x00000088
  ...
  Call Trace:
   <IRQ>  [<ffffffff81094988>] sched_show_task+0xa8/0x110
   [<ffffffff81097acd>] dump_cpu_task+0x3d/0x50
   [<ffffffff810c3a80>] rcu_dump_cpu_stacks+0x90/0xd0
   [<ffffffff810c7751>] rcu_check_callbacks+0x491/0x700
   [<ffffffff810cbf2b>] update_process_times+0x4b/0x80
   [<ffffffff810db046>] tick_sched_handle.isra.20+0x36/0x50
   [<ffffffff810db0a2>] tick_sched_timer+0x42/0x70
   [<ffffffff810ccb19>] __run_hrtimer+0x69/0x1a0
   [<ffffffff810db060>] ? tick_sched_handle.isra.20+0x50/0x50
   [<ffffffff810ccedf>] hrtimer_interrupt+0xef/0x230
   [<ffffffff810452cb>] local_apic_timer_interrupt+0x3b/0x70
   [<ffffffff8164a465>] smp_apic_timer_interrupt+0x45/0x60
   [<ffffffff816485bd>] apic_timer_interrupt+0x6d/0x80
   <EOI>  [<ffffffff810cc588>] ? lock_hrtimer_base.isra.23+0x18/0x50
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810cc9d2>] hrtimer_try_to_cancel+0x22/0xd0
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810ccaa2>] hrtimer_cancel+0x22/0x30
   [<ffffffff810a3cb5>] free_fair_sched_group+0x25/0xd0
   [<ffffffff8108df46>] free_sched_group+0x16/0x40
   [<ffffffff810971bb>] sched_create_group+0x4b/0x80
   [<ffffffff810aa383>] sched_autogroup_create_attach+0x43/0x1c0
   [<ffffffff8107dc9c>] sys_setsid+0x7c/0x110
   [<ffffffff81647729>] system_call_fastpath+0x12/0x17

Check whether init_cfs_bandwidth() was called before calling
destroy_cfs_bandwidth().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
[ Move the check into destroy_cfs_bandwidth() to aid compilability. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/201412252210.GCC30204.SOMVFFOtQJFLOH@I-love.SAKURA.ne.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:19:00 +01:00
Luca Abeni 269ad8015a sched/deadline: Avoid double-accounting in case of missed deadlines
The dl_runtime_exceeded() function is supposed to ckeck if
a SCHED_DEADLINE task must be throttled, by checking if its
current runtime is <= 0. However, it also checks if the
scheduling deadline has been missed (the current time is
larger than the current scheduling deadline), further
decreasing the runtime if this happens.
This "double accounting" is wrong:

- In case of partitioned scheduling (or single CPU), this
  happens if task_tick_dl() has been called later than expected
  (due to small HZ values). In this case, the current runtime is
  also negative, and replenish_dl_entity() can take care of the
  deadline miss by recharging the current runtime to a value smaller
  than dl_runtime

- In case of global scheduling on multiple CPUs, scheduling
  deadlines can be missed even if the task did not consume more
  runtime than expected, hence penalizing the task is wrong

This patch fix this problem by throttling a SCHED_DEADLINE task
only when its runtime becomes negative, and not modifying the runtime

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1418813432-20797-3-git-send-email-luca.abeni@unitn.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:18:57 +01:00
Luca Abeni 6a503c3be9 sched/deadline: Fix migration of SCHED_DEADLINE tasks
According to global EDF, tasks should be migrated between runqueues
without checking if their scheduling deadlines and runtimes are valid.
However, SCHED_DEADLINE currently performs such a check:
a migration happens doing:

	deactivate_task(rq, next_task, 0);
	set_task_cpu(next_task, later_rq->cpu);
	activate_task(later_rq, next_task, 0);

which ends up calling dequeue_task_dl(), setting the new CPU, and then
calling enqueue_task_dl().

enqueue_task_dl() then calls enqueue_dl_entity(), which calls
update_dl_entity(), which can modify scheduling deadline and runtime,
breaking global EDF scheduling.

As a result, some of the properties of global EDF are not respected:
for example, a taskset {(30, 80), (40, 80), (120, 170)} scheduled on
two cores can have unbounded response times for the third task even
if 30/80+40/80+120/170 = 1.5809 < 2

This can be fixed by invoking update_dl_entity() only in case of
wakeup, or if this is a new SCHED_DEADLINE task.

Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1418813432-20797-2-git-send-email-luca.abeni@unitn.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:18:56 +01:00
Yuyang Du 32a8df4e0b sched: Fix odd values in effective_load() calculations
In effective_load, we have (long w * unsigned long tg->shares) / long W,
when w is negative, it is cast to unsigned long and hence the product is
insanely large. Fix this by casting tg->shares to long.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141219002956.GA25405@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:18:54 +01:00
Andy Lutomirski 88a7c26af8 perf: Move task_pt_regs sampling into arch code
On x86_64, at least, task_pt_regs may be only partially initialized
in many contexts, so x86_64 should not use it without extra care
from interrupt context, let alone NMI context.

This will allow x86_64 to override the logic and will supply some
scratch space to use to make a cleaner copy of user regs.

Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: chenggang.qcg@taobao.com
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:12:28 +01:00
Oleg Nesterov 3245d6acab exit: fix race between wait_consider_task() and wait_task_zombie()
wait_consider_task() checks EXIT_ZOMBIE after EXIT_DEAD/EXIT_TRACE and
both checks can fail if we race with EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE
change in between, gcc needs to reload p->exit_state after
security_task_wait().  In this case ->notask_error will be wrongly
cleared and do_wait() can hang forever if it was the last eligible
child.

Many thanks to Arne who carefully investigated the problem.

Note: this bug is very old but it was pure theoretical until commit
b3ab03160d ("wait: completely ignore the EXIT_DEAD tasks").  Before
this commit "-O2" was probably enough to guarantee that compiler won't
read ->exit_state twice.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Arne Goedeke <el@laramies.com>
Tested-by: Arne Goedeke <el@laramies.com>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-08 15:10:51 -08:00
Sasha Levin 5e5aeb4367 time: adjtimex: Validate the ADJ_FREQUENCY values
Verify that the frequency value from userspace is valid and makes sense.

Unverified values can cause overflows later on.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
[jstultz: Fix up bug for negative values and drop redunent cap check]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-07 09:50:32 -08:00
Sasha Levin 6ada1fc0e1 time: settimeofday: Validate the values of tv from user
An unvalidated user input is multiplied by a constant, which can result in
an undefined behaviour for large values. While this is validated later,
we should avoid triggering undefined behaviour.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
[jstultz: include trivial milisecond->microsecond correction noticed
by Andy]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-07 09:49:14 -08:00
Linus Torvalds 5e0f872c7d Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fix from Paul Moore:
 "One audit patch to resolve a panic/oops when recording filenames in
  the audit log, see the mail archive link below.

  The fix isn't as nice as I would like, as it involves an allocate/copy
  of the filename, but it solves the problem and the overhead should
  only affect users who have configured audit rules involving file
  names.

  We'll revisit this issue with future kernels in an attempt to make
  this suck less, but in the meantime I think this fix should go into
  the next release of v3.19-rcX.

  [ https://marc.info/?t=141986927600001&r=1&w=2 ]"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: create private file name copies when auditing inodes
2014-12-31 14:52:18 -08:00
Linus Torvalds 2c90331cf5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix double SKB free in bluetooth 6lowpan layer, from Jukka Rissanen.

 2) Fix receive checksum handling in enic driver, from Govindarajulu
    Varadarajan.

 3) Fix NAPI poll list corruption in virtio_net and caif_virtio, from
    Herbert Xu.  Also, add code to detect drivers that have this mistake
    in the future.

 4) Fix doorbell endianness handling in mlx4 driver, from Amir Vadai.

 5) Don't clobber IP6CB() before xfrm6_policy_check() is called in TCP
    input path,f rom Nicolas Dichtel.

 6) Fix MPLS action validation in openvswitch, from Pravin B Shelar.

 7) Fix double SKB free in vxlan driver, also from Pravin.

 8) When we scrub a packet, which happens when we are switching the
    context of the packet (namespace, etc.), we should reset the
    secmark.  From Thomas Graf.

 9) ->ndo_gso_check() needs to do more than return true/false, it also
    has to allow the driver to clear netdev feature bits in order for
    the caller to be able to proceed properly.  From Jesse Gross.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (62 commits)
  genetlink: A genl_bind() to an out-of-range multicast group should not WARN().
  netlink/genetlink: pass network namespace to bind/unbind
  ne2k-pci: Add pci_disable_device in error handling
  bonding: change error message to debug message in __bond_release_one()
  genetlink: pass multicast bind/unbind to families
  netlink: call unbind when releasing socket
  netlink: update listeners directly when removing socket
  genetlink: pass only network namespace to genl_has_listeners()
  netlink: rename netlink_unbind() to netlink_undo_bind()
  net: Generalize ndo_gso_check to ndo_features_check
  net: incorrect use of init_completion fixup
  neigh: remove next ptr from struct neigh_table
  net: xilinx: Remove unnecessary temac_property in the driver
  net: phy: micrel: use generic config_init for KSZ8021/KSZ8031
  net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding
  openvswitch: fix odd_ptr_err.cocci warnings
  Bluetooth: Fix accepting connections when not using mgmt
  Bluetooth: Fix controller configuration with HCI_QUIRK_INVALID_BDADDR
  brcmfmac: Do not crash if platform data is not populated
  ipw2200: select CFG80211_WEXT
  ...
2014-12-30 10:45:47 -08:00
Paul Moore fcf22d8267 audit: create private file name copies when auditing inodes
Unfortunately, while commit 4a928436 ("audit: correctly record file
names with different path name types") fixed a problem where we were
not recording filenames, it created a new problem by attempting to use
these file names after they had been freed.  This patch resolves the
issue by creating a copy of the filename which the audit subsystem
frees after it is done with the string.

At some point it would be nice to resolve this issue with refcounts,
or something similar, instead of having to allocate/copy strings, but
that is almost surely beyond the scope of a -rcX patch so we'll defer
that for later.  On the plus side, only audit users should be impacted
by the string copying.

Reported-by: Toralf Foerster <toralf.foerster@gmx.de>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2014-12-30 09:26:21 -05:00
Johannes Berg 023e2cfa36 netlink/genetlink: pass network namespace to bind/unbind
Netlink families can exist in multiple namespaces, and for the most
part multicast subscriptions are per network namespace. Thus it only
makes sense to have bind/unbind notifications per network namespace.

To achieve this, pass the network namespace of a given client socket
to the bind/unbind functions.

Also do this in generic netlink, and there also make sure that any
bind for multicast groups that only exist in init_net is rejected.
This isn't really a problem if it is accepted since a client in a
different namespace will never receive any notifications from such
a group, but it can confuse the family if not rejected (it's also
possible to silently (without telling the family) accept it, but it
would also have to be ignored on unbind so families that take any
kind of action on bind/unbind won't do unnecessary work for invalid
clients like that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-27 03:07:50 -05:00