linux/drivers/cpufreq
Ethan Zhao cb57720bf7 cpufreq: fix a NULL pointer dereference in __cpufreq_governor()
If ACPI _PPC changed notification happens before governor was initiated
while kernel is booting, a NULL pointer dereference will be triggered:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
 IP: [<ffffffff81470453>] __cpufreq_governor+0x23/0x1e0
 PGD 0
 Oops: 0000 [#1] SMP
 ... ...
 RIP: 0010:[<ffffffff81470453>]  [<ffffffff81470453>]
 __cpufreq_governor+0x23/0x1e0
 RSP: 0018:ffff881fcfbcfbb8  EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff881fd11b3980 RCX: ffff88407fc20000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff881fd11b3980
 RBP: ffff881fcfbcfbd8 R08: 0000000000000000 R09: 000000000000000f
 R10: ffffffff818068d0 R11: 0000000000000043 R12: 0000000000000004
 R13: 0000000000000000 R14: ffffffff8196cae0 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff881fffc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000030 CR3: 00000000018ae000 CR4: 00000000000407f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process kworker/0:3 (pid: 750, threadinfo ffff881fcfbce000, task
 ffff881fcf556400)
 Stack:
  ffff881fffc17d00 ffff881fcfbcfc18 ffff881fd11b3980 0000000000000000
  ffff881fcfbcfc08 ffffffff81470d08 ffff881fd11b3980 0000000000000007
  ffff881fcfbcfc18 ffff881fffc17d00 ffff881fcfbcfd28 ffffffff81472e9a
 Call Trace:
  [<ffffffff81470d08>] __cpufreq_set_policy+0x1b8/0x2e0
  [<ffffffff81472e9a>] cpufreq_update_policy+0xca/0x150
  [<ffffffff81472f20>] ? cpufreq_update_policy+0x150/0x150
  [<ffffffff81324a96>] acpi_processor_ppc_has_changed+0x71/0x7b
  [<ffffffff81320bcd>] acpi_processor_notify+0x55/0x115
  [<ffffffff812f9c29>] acpi_device_notify+0x19/0x1b
  [<ffffffff813084ca>] acpi_ev_notify_dispatch+0x41/0x5f
  [<ffffffff812f64a4>] acpi_os_execute_deferred+0x27/0x34

The root cause is a race conditon -- cpufreq core and acpi-cpufreq driver
were initiated, but cpufreq_governor wasn't and _PPC changed notification
happened, __cpufreq_governor() was called within acpi_os_execute_deferred
kernel thread context.

To fix this panic issue, add pointer checking code in __cpufreq_governor()
before pointer policy->governor is to be dereferenced.

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-19 22:49:07 +01:00
..
acpi-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
amd_freq_sensitivity.c
arm_big_little_dt.c cpufreq: arm_big_little: free OPP table created during ->init() 2014-12-02 00:01:24 +01:00
arm_big_little.c cpufreq: arm_big_little: free OPP table created during ->init() 2014-12-02 00:01:24 +01:00
arm_big_little.h cpufreq: arm_big_little: free OPP table created during ->init() 2014-12-02 00:01:24 +01:00
at32ap-cpufreq.c cpufreq: at32ap: don't declare local variable as static 2014-04-07 14:31:33 +02:00
blackfin-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
cpufreq_conservative.c
cpufreq_governor.c cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info' 2014-06-09 12:58:21 +02:00
cpufreq_governor.h cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info' 2014-06-09 12:58:21 +02:00
cpufreq_ondemand.c cpufreq: ondemand: Eliminate the deadband effect 2014-07-21 13:43:19 +02:00
cpufreq_opp.c cpufreq / OPP: Fix the order of arguments for kcalloc() 2014-09-08 00:02:58 +02:00
cpufreq_performance.c
cpufreq_powersave.c
cpufreq_stats.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
cpufreq_userspace.c
cpufreq-dt.c cpufreq-dt: defer probing if OPP table is not ready 2014-12-18 01:43:28 +01:00
cpufreq-nforce2.c cpufreq: nforce2: remove DEFINE_PCI_DEVICE_TABLE macro 2014-05-17 01:16:15 +02:00
cpufreq.c cpufreq: fix a NULL pointer dereference in __cpufreq_governor() 2014-12-19 22:49:07 +01:00
cris-artpec3-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
cris-etraxfs-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
davinci-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
dbx500-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
e_powersaver.c
elanfreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
exynos4x12-cpufreq.c cpufreq: cpu0: rename driver and internals to 'cpufreq_dt' 2014-10-03 15:37:54 +02:00
exynos4210-cpufreq.c cpufreq: cpu0: rename driver and internals to 'cpufreq_dt' 2014-10-03 15:37:54 +02:00
exynos5250-cpufreq.c cpufreq: cpu0: rename driver and internals to 'cpufreq_dt' 2014-10-03 15:37:54 +02:00
exynos5440-cpufreq.c exynos5440: free OPP table created during ->init() 2014-12-01 02:49:33 +01:00
exynos-cpufreq.c ACPI and power management updates for 3.16-rc1 2014-06-04 08:57:16 -07:00
exynos-cpufreq.h ACPI and power management updates for 3.16-rc1 2014-06-04 08:57:16 -07:00
freq_table.c cpufreq: Introduce new relation for freq selection 2014-07-21 13:43:19 +02:00
gx-suspmod.c cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end} 2014-03-26 16:41:41 +01:00
highbank-cpufreq.c Merge branch 'mailbox-for-linus' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2014-10-21 11:21:19 -07:00
ia64-acpi-cpufreq.c cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table 2014-04-07 14:43:49 +02:00
imx6q-cpufreq.c imx6q: free OPP table created during ->init() 2014-12-01 02:49:33 +01:00
integrator-cpufreq.c cpufreq: integrator: fix integrator_cpufreq_remove return type 2014-09-29 15:36:03 +02:00
intel_pstate.c intel_pstate: Add a few comments 2014-12-11 00:24:42 +01:00
Kconfig cpufreq: Kconfig: Remove architecture specific menu entries 2014-11-18 02:47:42 +01:00
Kconfig.arm cpufreq: pxa2xx: Add Kconfig entry 2014-11-27 01:53:12 +01:00
Kconfig.powerpc cpufreq: powernv: cpufreq driver for powernv platform 2014-04-07 14:35:27 +02:00
Kconfig.x86 cpufreq: Kconfig: Fix spelling errors 2014-05-01 01:18:19 +02:00
kirkwood-cpufreq.c cpufreq: kirkwood: use the powersave multiplexer 2014-09-02 15:02:54 -07:00
longhaul.c Merge branch 'cpufreq-macros' into pm-cpufreq 2014-05-01 00:50:47 +02:00
longhaul.h
longrun.c
loongson2_cpufreq.c MIPS: Loongson: Modify ChipConfig register definition 2014-07-30 21:46:00 +02:00
ls1x-cpufreq.c cpufreq: Loongson1: Add cpufreq driver for Loongson1B 2014-11-06 01:23:44 +01:00
Makefile cpufreq: pxa2xx: Add Kconfig entry 2014-11-27 01:53:12 +01:00
maple-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
omap-cpufreq.c
p4-clockmod.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
pasemi-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
pcc-cpufreq.c cpufreq: pcc: Enable autoload of pcc-cpufreq for ACPI processors 2014-11-14 00:16:25 +01:00
pmac32-cpufreq.c powerpc: Remove powerpc specific cmd_line 2014-10-02 17:33:55 +10:00
pmac64-cpufreq.c of: Migrate of_find_node_by_name() users to for_each_node_by_name() 2014-06-26 17:12:24 +01:00
powernow-k6.c powernow-k6: support 350MHz CPU 2014-07-21 13:43:19 +02:00
powernow-k7.c cpufreq: powernow-k7: Fix double invocation of cpufreq_freq_transition_begin/end 2014-04-29 01:22:54 +02:00
powernow-k7.h
powernow-k8.c cpufreq: powernow-k8: Suppress checkpatch warnings 2014-05-17 01:27:01 +02:00
powernow-k8.h cpufreq: powernow-k8: Suppress checkpatch warnings 2014-05-17 01:27:01 +02:00
powernv-cpufreq.c cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec 2014-09-29 15:53:04 +02:00
ppc_cbe_cpufreq_pervasive.c
ppc_cbe_cpufreq_pmi.c
ppc_cbe_cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
ppc_cbe_cpufreq.h
ppc-corenet-cpufreq.c cpufreq: ppc-corenet: remove duplicate update of cpu_data 2014-09-30 21:09:40 +02:00
pxa2xx-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
pxa3xx-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
s3c24xx-cpufreq-debugfs.c
s3c24xx-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s3c64xx-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
s3c2410-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s3c2412-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s3c2416-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
s3c2440-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s5pv210-cpufreq.c cpufreq: cpu0: rename driver and internals to 'cpufreq_dt' 2014-10-03 15:37:54 +02:00
sa1100-cpufreq.c
sa1110-cpufreq.c cpufreq: sa1110: set memory type for h3600 2014-07-16 14:30:17 +02:00
sc520_freq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
sh-cpufreq.c cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end} 2014-03-26 16:41:41 +01:00
sparc-us2e-cpufreq.c
sparc-us3-cpufreq.c
spear-cpufreq.c cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table 2014-04-07 14:43:49 +02:00
speedstep-centrino.c cpufreq: Make linux-pm@vger.kernel.org official mailing list 2014-05-01 01:15:32 +02:00
speedstep-ich.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
speedstep-lib.c
speedstep-lib.h
speedstep-smi.c cpufreq: speedstep-smi: fix decimal printf specifiers 2014-08-07 21:21:52 +02:00
tegra-cpufreq.c cpufreq: tegra: update comment for clarity 2014-06-10 22:50:50 +02:00
unicore2-cpufreq.c cpufreq: unicore32: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO 2014-04-21 23:42:27 +02:00
vexpress-spc-cpufreq.c