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  1. 03 May, 2014 5 commits
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 98facf0e
      Linus Torvalds authored 
      Pull timer fixes from Thomas Gleixner:
 "This update brings along:

   - Two fixes for long standing bugs in the hrtimer code, one which
     prevents remote enqueuing and the other preventing arbitrary delays
     after a interrupt hang was detected

   - A fix in the timer wheel which prevents math overflow

   - A fix for a long standing issue with the architected ARM timer
     related to the C3STOP mechanism.

   - A trivial compile fix for nspire SoC clocksource"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Prevent overflow in apply_slack
  hrtimer: Prevent remote enqueue of leftmost timers
  hrtimer: Prevent all reprogramming if hang detected
  clocksource: nspire: Fix compiler warning
  clocksource: arch_arm_timer: Fix age-old arch timer C3STOP detection issue
      98facf0e
    • Linus Torvalds's avatar
      Merge tag 'trace-fixes-v3.15-rc3' of... · 00622e61
      Linus Torvalds authored 
      Merge tag 'trace-fixes-v3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "This is a small fix where the trigger code used the wrong
  rcu_dereference().  It required rcu_dereference_sched() instead of the
  normal rcu_dereference().  It produces a nasty RCU lockdep splat due
  to the incorrect rcu notation"
Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>

* tag 'trace-fixes-v3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Use rcu_dereference_sched() for trace event triggers
      00622e61
    • Steven Rostedt (Red Hat)'s avatar
      tracing: Use rcu_dereference_sched() for trace event triggers · 561a4fe8
      Steven Rostedt (Red Hat) authored 
      As trace event triggers are now part of the mainline kernel, I added
my trace event trigger tests to my test suite I run on all my kernels.
Now these tests get run under different config options, and one of
those options is CONFIG_PROVE_RCU, which checks under lockdep that
the rcu locking primitives are being used correctly. This triggered
the following splat:

===============================
[ INFO: suspicious RCU usage. ]
3.15.0-rc2-test+ #11 Not tainted
-------------------------------
kernel/trace/trace_events_trigger.c:80 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
4 locks held by swapper/1/0:
 #0:  ((&(&j_cdbs->work)->timer)){..-...}, at: [<ffffffff8104d2cc>] call_timer_fn+0x5/0x1be
 #1:  (&(&pool->lock)->rlock){-.-...}, at: [<ffffffff81059856>] __queue_work+0x140/0x283
 #2:  (&p->pi_lock){-.-.-.}, at: [<ffffffff8106e961>] try_to_wake_up+0x2e/0x1e8
 #3:  (&rq->lock){-.-.-.}, at: [<ffffffff8106ead3>] try_to_wake_up+0x1a0/0x1e8

stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc2-test+ #11
Hardware name:                  /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006
 0000000000000001 ffff88007e083b98 ffffffff819f53a5 0000000000000006
 ffff88007b0942c0 ffff88007e083bc8 ffffffff81081307 ffff88007ad96d20
 0000000000000000 ffff88007af2d840 ffff88007b2e701c ffff88007e083c18
Call Trace:
 <IRQ>  [<ffffffff819f53a5>] dump_stack+0x4f/0x7c
 [<ffffffff81081307>] lockdep_rcu_suspicious+0x107/0x110
 [<ffffffff810ee51c>] event_triggers_call+0x99/0x108
 [<ffffffff810e8174>] ftrace_event_buffer_commit+0x42/0xa4
 [<ffffffff8106aadc>] ftrace_raw_event_sched_wakeup_template+0x71/0x7c
 [<ffffffff8106bcbf>] ttwu_do_wakeup+0x7f/0xff
 [<ffffffff8106bd9b>] ttwu_do_activate.constprop.126+0x5c/0x61
 [<ffffffff8106eadf>] try_to_wake_up+0x1ac/0x1e8
 [<ffffffff8106eb77>] wake_up_process+0x36/0x3b
 [<ffffffff810575cc>] wake_up_worker+0x24/0x26
 [<ffffffff810578bc>] insert_work+0x5c/0x65
 [<ffffffff81059982>] __queue_work+0x26c/0x283
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff810599b7>] delayed_work_timer_fn+0x1e/0x20
 [<ffffffff8104d3a6>] call_timer_fn+0xdf/0x1be^M
 [<ffffffff8104d2cc>] ? call_timer_fn+0x5/0x1be
 [<ffffffff81059999>] ? __queue_work+0x283/0x283
 [<ffffffff8104d823>] run_timer_softirq+0x1a4/0x22f^M
 [<ffffffff8104696d>] __do_softirq+0x17b/0x31b^M
 [<ffffffff81046d03>] irq_exit+0x42/0x97
 [<ffffffff81a08db6>] smp_apic_timer_interrupt+0x37/0x44
 [<ffffffff81a07a2f>] apic_timer_interrupt+0x6f/0x80
 <EOI>  [<ffffffff8100a5d8>] ? default_idle+0x21/0x32
 [<ffffffff8100a5d6>] ? default_idle+0x1f/0x32
 [<ffffffff8100ac10>] arch_cpu_idle+0xf/0x11
 [<ffffffff8107b3a4>] cpu_startup_entry+0x1a3/0x213
 [<ffffffff8102a23c>] start_secondary+0x212/0x219

The cause is that the triggers are protected by rcu_read_lock_sched() but
the data is dereferenced with rcu_dereference() which expects it to
be protected with rcu_read_lock(). The proper reference should be
rcu_dereference_sched().

Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      561a4fe8
    • Linus Torvalds's avatar
      Merge tag 'pm+acpi-3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 6c6ca9c2
      Linus Torvalds authored 
      Pull ACPI and power management fixes from Rafael Wysocki:
 "A bunch of regression fixes this time.  They fix two regressions in
  the PNP subsystem, one in the ACPI processor driver and one in the
  ACPI EC driver, four cpufreq driver regressions and an unrelated bug
  in one of the drivers.  The regressions are recent or introduced in
  3.14.

  Specifics:

   - There are two bugs in the ACPI PNP core that cause errors to be
     returned if optional ACPI methods are not present.  After an ACPI
     core change made in 3.14 one of those errors leads to serial port
     suspend failures on some systems.  Fix from Rafael J Wysocki.

   - A recently added PNP quirk related to Intel chipsets intorduced a
     build error in unusual configurations (PNP without PCI).  Fix from
     Bjorn Helgaas.

   - An ACPI EC workaround related to system suspend on Samsung machines
     added in 3.14 introduced a race causing some valid EC events to be
     discarded.  Fix from Kieran Clancy.

   - The acpi-cpufreq driver fails to load on some systems after a 3.14
     commit related to APIC ID parsing that overlooked one corner case.
     Fix from Lan Tianyu.

   - Fix for a recently introduced build problem in the ppc-corenet
     cpufreq driver from Tim Gardner.

   - A recent cpufreq core change to ensure serialization of frequency
     transitions for drivers with a ->target_index() callback overlooked
     the fact that some of those drivers had been doing operations
     introduced by it into the core already by themselves.  That
     resulted in a mess in which the core and the drivers try to do the
     same thing and block each other which leads to deadlocks.  Fixes
     for the powernow-k7, powernow-k6, and longhaul cpufreq drivers from
     Srivatsa S Bhat.

   - Fix for a computational error in the powernow-k6 cpufreq driver
     from Srivatsa S Bhat"

* tag 'pm+acpi-3.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / processor: Fix failure of loading acpi-cpufreq driver
  PNP / ACPI: Do not return errors if _DIS or _SRS are not present
  PNP: Fix compile error in quirks.c
  ACPI / EC: Process rather than discard events in acpi_ec_clear
  cpufreq: ppc-corenet-cpufreq: Fix __udivdi3 modpost error
  cpufreq: powernow-k7: Fix double invocation of cpufreq_freq_transition_begin/end
  cpufreq: powernow-k6: Fix double invocation of cpufreq_freq_transition_begin/end
  cpufreq: powernow-k6: Fix incorrect comparison with max_multipler
  cpufreq: longhaul: Fix double invocation of cpufreq_freq_transition_begin/end
      6c6ca9c2
    • Linus Torvalds's avatar
      Merge tag 'dt-for-linus' of git://git.secretlab.ca/git/linux · e981e795
      Linus Torvalds authored 
      Pull driver core deferred probe fix from Grant Likely:
 "Drivercore race condition fix (exposed by devicetree)

  This branch fixes a bug where a device can get stuck in the deferred
  list even though all its dependencies are met.  The bug has existed
  for a long time, but new platform conversions to device tree have
  exposed it.  This patch is needed to get those platforms working.

  This was the pending bug fix I mentioned in my previous pull request.
  Normally this would go through Greg's tree seeing that it is a
  drivercore change, but devicetree exposes the problem.  I've discussed
  with Greg and he okayed me asking you to pull directly"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
  drivercore: deferral race condition fix
      e981e795
  3. 02 May, 2014 8 commits
  5. 01 May, 2014 14 commits
  7. 30 Apr, 2014 13 commits
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