linux-stable.git, branch v3.18.7

Linux 3.18.7

2015-02-11T07:01:12+00:00

x86: mm: move mmap_sem unlock from mm_fault_error() to caller

2015-02-11T07:00:57+00:00

commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 upstream.

This replaces four copies in various stages of mm_fault_error() handling
with just a single one.  It will also allow for more natural placement
of the unlocking after some further cleanup.

Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86/tlb/trace: Do not trace on CPU that is offline

2015-02-11T07:00:57+00:00

commit 6c8465a82a605bc692304bab42703017dcfff013 upstream.

When taking a CPU down for suspend and resume, a tracepoint may be called
when the CPU has been designated offline. As tracepoints require RCU for
protection, they must not be called if the current CPU is offline.

Unfortunately, trace_tlb_flush() is called in this scenario as was noted
by LOCKDEP:

...

 Disabling non-boot CPUs ...
 intel_pstate CPU 1 exiting

 ===============================
 smpboot: CPU 1 didn't die...
 [ INFO: suspicious RCU usage. ]
 3.19.0-rc7-next-20150204.1-iniza-small #1 Not tainted
 -------------------------------
 include/trace/events/tlb.h:35 suspicious rcu_dereference_check() usage!

 other info that might help us debug this:

 RCU used illegally from offline CPU!
 rcu_scheduler_active = 1, debug_locks = 0
 no locks held by swapper/1/0.

 stack backtrace:
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.19.0-rc7-next-20150204.1-iniza-small #1
 Hardware name: SAMSUNG ELECTRONICS CO., LTD. 530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013
  0000000000000001 ffff88011a44fe18 ffffffff817e370d 0000000000000011
  ffff88011a448290 ffff88011a44fe48 ffffffff810d6847 ffff8800c66b9600
  0000000000000001 ffff88011a44c000 ffffffff81cb3900 ffff88011a44fe78
 Call Trace:
  [] dump_stack+0x4c/0x65
  [] lockdep_rcu_suspicious+0xe7/0x120
  [] idle_task_exit+0x205/0x2c0
  [] play_dead_common+0xe/0x50
  [] native_play_dead+0x15/0x140
  [] arch_cpu_idle_dead+0xf/0x20
  [] cpu_startup_entry+0x37e/0x580
  [] start_secondary+0x140/0x150
 intel_pstate CPU 2 exiting

...

By converting the tlb_flush tracepoint to a TRACE_EVENT_CONDITION where the
condition is cpu_online(smp_processor_id()), we can avoid calling RCU protected
code when the CPU is offline.

Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com

Fixes: d17d8f9dedb9 "x86/mm: Add tracepoints for TLB flushes"
Reported-by: Sedat Dilek 
Tested-by: Sedat Dilek 
Suggested-by: Paul E. McKenney 
Acked-by: Paul E. McKenney 
Acked-by: Dave Hansen 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

tracing: Add condition check to RCU lockdep checks

2015-02-11T07:00:56+00:00

commit a05d59a5673339ef6936d6940cdf68172ce75b9f upstream.

The trace_tlb_flush() tracepoint can be called when a CPU is going offline.
When a CPU is offline, RCU is no longer watching that CPU and since the
tracepoint is protected by RCU, it must not be called. To prevent the
tlb_flush tracepoint from being called when the CPU is offline, it was
converted to a TRACE_EVENT_CONDITION where the condition checks if the
CPU is online before calling the tracepoint.

Unfortunately, this was not enough to stop lockdep from complaining about
it. Even though the RCU protected code of the tracepoint will never be
called, the condition is hidden within the tracepoint, and even though the
condition prevents RCU code from being called, the lockdep checks are
outside the tracepoint (this is to test tracepoints even when they are not
enabled).

Even though tracepoints should be checked to be RCU safe when they are not
enabled, the condition should still be considered when checking RCU.

Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com

Fixes: 3a630178fd5f "tracing: generate RCU warnings even when tracepoints are disabled"
Acked-by: Dave Hansen 
Reported-by: Sedat Dilek 
Tested-by: Sedat Dilek 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

hrtimer: Fix incorrect tai offset calculation for non high-res timer systems

2015-02-11T07:00:56+00:00

commit 2d926c15d629a13914ce3e5f26354f6a0ac99e70 upstream.

I noticed some CLOCK_TAI timer test failures on one of my
less-frequently used configurations. And after digging in I
found in 76f4108892d9 (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 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1423097126-10236-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()

2015-02-11T07:00:56+00:00

commit 4bee96860a65c3a62d332edac331b3cf936ba3ad upstream.

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 
Cc: Thomas Gleixner 
Cc: Rusty Russell 
Cc: Peter Zijlstra 
Cc: Srivatsa S. Bhat 
Cc: David Rientjes 
Link: http://lkml.kernel.org/r/1406777421-12830-1-git-send-email-laijs@cn.fujitsu.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86, microcode: Return error from driver init code when loader is disabled

2015-02-11T07:00:56+00:00

commit da63865a01c6384d459464e5165d95d4f04878d8 upstream.

Commits 65cef1311d5d ("x86, microcode: Add a disable chicken bit") and
a18a0f6850d4 ("x86, microcode: Don't initialize microcode code on
paravirt") allow microcode driver skip initialization when microcode
loading is not permitted.

However, they don't prevent the driver from being loaded since the
init code returns 0. If at some point later the driver gets unloaded
this will result in an oops while trying to deregister the (never
registered) device.

To avoid this, make init code return an error on paravirt or when
microcode loading is disabled. The driver will then never be loaded.

Signed-off-by: Boris Ostrovsky 
Link: http://lkml.kernel.org/r/1422411669-25147-1-git-send-email-boris.ostrovsky@oracle.com
Reported-by: James Digwall 
Signed-off-by: Borislav Petkov 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: Fix I2S1, I2S2 compatible for exynos4 SoCs

2015-02-11T07:00:56+00:00

commit fddcd300732dad5b822d27de7aa78998dca43162 upstream.

I2S1, I2S2 on Exynos4 SoC series have limited functionality compared
to I2S0, "samsung,s3c6410-i2s" compatible should be used for them.

Signed-off-by: Sylwester Nawrocki 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

ALSA: ak411x: Fix stall in work callback

2015-02-11T07:00:55+00:00

commit 4161b4505f1690358ac0a9ee59845a7887336b21 upstream.

When ak4114 work calls its callback and the callback invokes
ak4114_reinit(), it stalls due to flush_delayed_work().  For avoiding
this, control the reentrance by introducing a refcount.  Also
flush_delayed_work() is replaced with cancel_delayed_work_sync().

The exactly same bug is present in ak4113.c and fixed as well.

Reported-by: Pavel Hofman 
Acked-by: Jaroslav Kysela 
Tested-by: Pavel Hofman 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ASoC: sgtl5000: add delay before first I2C access

2015-02-11T07:00:55+00:00

commit 58cc9c9a175885bbf6bae3acf18233d0a8229a84 upstream.

To quote from section 1.3.1 of the data sheet:
	The SGTL5000 has an internal reset that is deasserted
	8 SYS_MCLK cycles after all power rails have been brought
	up. After this time, communication can start

	...
	1.0us represents 8 SYS_MCLK cycles at the minimum 8.0 MHz SYS_MCLK.

Signed-off-by: Eric Nelson 
Reviewed-by: Fabio Estevam 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman