mirror_ubuntu-kernels/drivers/cpufreq
Fabio Baltieri 3e33ee9e08 cpufreq: ondemand: update sampling rate only on right CPUs
Fix cpufreq_gov_ondemand to skip CPU where another governor is used.

The bug present itself as NULL pointer access on the mutex_lock() call,
an can be reproduced on an SMP machine by setting the default governor
to anything other than ondemand, setting a single CPU's governor to
ondemand, then changing the sample rate by writing on:

> /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate

Backtrace:

Nov 26 17:36:54 balto kernel: [  839.585241] BUG: unable to handle kernel NULL pointer dereference at           (null)
Nov 26 17:36:54 balto kernel: [  839.585311] IP: [<ffffffff8174e082>] __mutex_lock_slowpath+0xb2/0x170
[snip]
Nov 26 17:36:54 balto kernel: [  839.587005] Call Trace:
Nov 26 17:36:54 balto kernel: [  839.587030]  [<ffffffff8174da82>] mutex_lock+0x22/0x40
Nov 26 17:36:54 balto kernel: [  839.587067]  [<ffffffff81610b8f>] store_sampling_rate+0xbf/0x150
Nov 26 17:36:54 balto kernel: [  839.587110]  [<ffffffff81031e9c>] ?  __do_page_fault+0x1cc/0x4c0
Nov 26 17:36:54 balto kernel: [  839.587153]  [<ffffffff813309bf>] kobj_attr_store+0xf/0x20
Nov 26 17:36:54 balto kernel: [  839.587192]  [<ffffffff811bb62d>] sysfs_write_file+0xcd/0x140
Nov 26 17:36:54 balto kernel: [  839.587234]  [<ffffffff8114c12c>] vfs_write+0xac/0x180
Nov 26 17:36:54 balto kernel: [  839.587271]  [<ffffffff8114c472>] sys_write+0x52/0xa0
Nov 26 17:36:54 balto kernel: [  839.587306]  [<ffffffff810321ce>] ?  do_page_fault+0xe/0x10
Nov 26 17:36:54 balto kernel: [  839.587345]  [<ffffffff81751202>] system_call_fastpath+0x16/0x1b

Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-27 14:11:19 +01:00
..
acpi-cpufreq.c acpi-cpufreq: Add compatibility for legacy AMD cpb sysfs knob 2012-09-09 22:05:20 +02:00
cpufreq_conservative.c cpufreq: governors: remove redundant code 2012-11-15 00:33:07 +01:00
cpufreq_governor.c cpufreq: governors: Fix jiffies/cputime mixup (revisited) 2012-11-24 10:08:47 +01:00
cpufreq_governor.h cpufreq: Fix sparse warnings by updating cputime64_t to u64 2012-11-15 00:33:08 +01:00
cpufreq_ondemand.c cpufreq: ondemand: update sampling rate only on right CPUs 2012-11-27 14:11:19 +01:00
cpufreq_performance.c cpufreq: Improve debug prints 2012-11-15 00:33:06 +01:00
cpufreq_powersave.c cpufreq: Improve debug prints 2012-11-15 00:33:06 +01:00
cpufreq_stats.c cpufreq: Fix sparse warnings by updating cputime64_t to u64 2012-11-15 00:33:08 +01:00
cpufreq_userspace.c cpufreq: Improve debug prints 2012-11-15 00:33:06 +01:00
cpufreq-cpu0.c cpufreq: remove use of __devinit 2012-11-21 01:18:40 +01:00
cpufreq-nforce2.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
cpufreq.c cpufreq: Remove unnecessary initialization of a local variable 2012-11-15 00:33:09 +01:00
db8500-cpufreq.c ARM: ux500: core U9540 support 2012-05-02 00:25:13 +02:00
e_powersaver.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
elanfreq.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
exynos4x12-cpufreq.c EXYNOS4X12: Add support cpufreq for EXYNOS4X12 2012-03-14 14:39:47 -04:00
exynos4210-cpufreq.c [CPUFREQ] EXYNOS4210: update the name of EXYNOS clock register 2012-02-29 22:24:38 -05:00
exynos5250-cpufreq.c [CPUFREQ] EXYNOS5250: Add support max 1.7GHz for EXYNOS5250 2012-07-19 13:20:25 +09:00
exynos-cpufreq.c cpufreq: exynos: Use static for functions used in only this file 2012-11-22 00:19:25 +01:00
freq_table.c cpufreq: Improve debug prints 2012-11-15 00:33:06 +01:00
gx-suspmod.c cpufreq/gx: Fix the compile error 2012-02-02 15:32:12 -08:00
Kconfig cpufreq: Add a generic cpufreq-cpu0 driver 2012-09-09 22:06:34 +02:00
Kconfig.arm cpufreq: SPEAr: Add CPUFreq driver 2012-11-27 14:05:26 +01:00
Kconfig.powerpc powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards 2011-07-19 15:13:04 +10:00
Kconfig.x86 acpi-cpufreq: Add compatibility for legacy AMD cpb sysfs knob 2012-09-09 22:05:20 +02:00
longhaul.c cpufreq: remove use of __devexit 2012-11-21 01:18:49 +01:00
longhaul.h sections: fix section conflicts in drivers/cpufreq 2012-09-14 21:10:46 +02:00
longrun.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
Makefile cpufreq: SPEAr: Add CPUFreq driver 2012-11-27 14:05:26 +01:00
maple-cpufreq.c powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards 2011-07-19 15:13:04 +10:00
mperf.c [CPUFREQ] Move x86 drivers to drivers/cpufreq/ 2011-05-19 18:51:07 -04:00
mperf.h [CPUFREQ] Move x86 drivers to drivers/cpufreq/ 2011-05-19 18:51:07 -04:00
omap-cpufreq.c cpufreq: OMAP: use get_cpu_device() instead of omap_device API 2012-10-08 14:58:56 -07:00
p4-clockmod.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
pcc-cpufreq.c drivers/cpufreq/pcc-cpufreq.c: fix error return code 2012-08-08 20:49:25 +02:00
powernow-k6.c powernow-k6: Really enable auto-loading 2012-02-13 15:26:03 -08:00
powernow-k7.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
powernow-k7.h [CPUFREQ] Move x86 drivers to drivers/cpufreq/ 2011-05-19 18:51:07 -04:00
powernow-k8.c cpufreq: remove use of __devexit 2012-11-21 01:18:49 +01:00
powernow-k8.h cpufreq: Remove support for hardware P-state chips from powernow-k8 2012-09-09 22:05:30 +02:00
s3c64xx-cpufreq.c [CPUFREQ] s3c64xx: Fix mis-cherry pick of VDDINT 2012-02-29 22:24:38 -05:00
s3c2416-cpufreq.c cpufreq: Fix typo in cpufreq driver 2012-07-20 10:37:40 +02:00
s5pv210-cpufreq.c [CPUFREQ] s5pv210: make needlessly global symbols static 2011-07-13 18:30:00 -04:00
sc520_freq.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
spear-cpufreq.c cpufreq: SPEAr: Add CPUFreq driver 2012-11-27 14:05:26 +01:00
speedstep-centrino.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
speedstep-ich.c cpufreq: Fix typo in cpufreq driver 2012-07-20 10:37:40 +02:00
speedstep-lib.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00
speedstep-lib.h [CPUFREQ] Move x86 drivers to drivers/cpufreq/ 2011-05-19 18:51:07 -04:00
speedstep-smi.c cpufreq: Add support for x86 cpuinfo auto loading v4 2012-01-26 16:49:06 -08:00