linux/drivers/cpufreq
Sudeep Holla 6941051d30 cpufreq: Cancel policy update work scheduled before freeing
Scheduled policy update work may end up racing with the freeing of the
policy and unregistering the driver.

One possible race is as below, where the cpufreq_driver is unregistered,
but the scheduled work gets executed at later stage when, cpufreq_driver
is NULL (i.e. after freeing the policy and driver).

Unable to handle kernel NULL pointer dereference at virtual address 0000001c
pgd = (ptrval)
[0000001c] *pgd=80000080204003, *pmd=00000000
Internal error: Oops: 206 [#1] SMP THUMB2
Modules linked in:
CPU: 0 PID: 34 Comm: kworker/0:1 Not tainted 5.4.0-rc3-00006-g67f5a8081a4b #86
Hardware name: ARM-Versatile Express
Workqueue: events handle_update
PC is at cpufreq_set_policy+0x58/0x228
LR is at dev_pm_qos_read_value+0x77/0xac
Control: 70c5387d  Table: 80203000  DAC: fffffffd
Process kworker/0:1 (pid: 34, stack limit = 0x(ptrval))
	(cpufreq_set_policy) from (refresh_frequency_limits.part.24+0x37/0x48)
	(refresh_frequency_limits.part.24) from (handle_update+0x2f/0x38)
	(handle_update) from (process_one_work+0x16d/0x3cc)
	(process_one_work) from (worker_thread+0xff/0x414)
	(worker_thread) from (kthread+0xff/0x100)
	(kthread) from (ret_from_fork+0x11/0x28)

Fixes: 67d874c3b2 ("cpufreq: Register notifiers with the PM QoS framework")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[ rjw: Cancel the work before dropping the QoS requests ]
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-22 18:07:30 +02:00
..
acpi-cpufreq.c
amd_freq_sensitivity.c
arm_big_little.c
arm_big_little.h
armada-8k-cpufreq.c cpufreq: ap806: Add NULL check after kcalloc 2019-07-22 11:12:15 +05:30
armada-37xx-cpufreq.c
bmips-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
brcmstb-avs-cpufreq.c
cppc_cpufreq.c
cpufreq-dt-platdev.c Merge branch 'cpufreq/qcom-updates' into cpufreq/arm/linux-next 2019-09-03 07:55:22 +05:30
cpufreq-dt.c
cpufreq-dt.h
cpufreq-nforce2.c
cpufreq.c cpufreq: Cancel policy update work scheduled before freeing 2019-10-22 18:07:30 +02:00
cpufreq_conservative.c
cpufreq_governor.c
cpufreq_governor.h
cpufreq_governor_attr_set.c
cpufreq_ondemand.c
cpufreq_ondemand.h
cpufreq_performance.c
cpufreq_powersave.c
cpufreq_stats.c
cpufreq_userspace.c
davinci-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
e_powersaver.c
elanfreq.c
freq_table.c
gx-suspmod.c
highbank-cpufreq.c
ia64-acpi-cpufreq.c
imx-cpufreq-dt.c cpufreq: imx-cpufreq-dt: Add i.MX8MN support 2019-08-22 11:31:04 +05:30
imx6q-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
intel_pstate.c cpufreq: Use per-policy frequency QoS 2019-10-21 02:05:21 +02:00
Kconfig
Kconfig.arm Merge branch 'cpufreq/qcom-updates' into cpufreq/arm/linux-next 2019-09-03 07:55:22 +05:30
Kconfig.powerpc
Kconfig.x86
kirkwood-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
longhaul.c
longhaul.h
longrun.c
loongson1-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
loongson2_cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
Makefile Merge branch 'cpufreq/qcom-updates' into cpufreq/arm/linux-next 2019-09-03 07:55:22 +05:30
maple-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
mediatek-cpufreq.c cpufreq: mediatek: Add support for mt8183 2019-08-22 11:31:04 +05:30
mvebu-cpufreq.c
omap-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
p4-clockmod.c
pasemi-cpufreq.c cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init() 2019-07-23 09:49:10 +02:00
pcc-cpufreq.c
pmac32-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
pmac64-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
powernow-k6.c
powernow-k7.c
powernow-k7.h
powernow-k8.c
powernow-k8.h
powernv-cpufreq.c
ppc_cbe_cpufreq.c cpufreq: powerpc_cbe: Switch to QoS requests for freq limits 2019-08-26 10:02:01 +02:00
ppc_cbe_cpufreq.h cpufreq: powerpc_cbe: Switch to QoS requests for freq limits 2019-08-26 10:02:01 +02:00
ppc_cbe_cpufreq_pervasive.c
ppc_cbe_cpufreq_pmi.c cpufreq: Use per-policy frequency QoS 2019-10-21 02:05:21 +02:00
pxa2xx-cpufreq.c
pxa3xx-cpufreq.c
qcom-cpufreq-hw.c cpufreq: qcom-hw: invoke frequency-invariance setter function 2019-08-22 11:31:04 +05:30
qcom-cpufreq-nvmem.c cpufreq: qcom: Add support for qcs404 on nvmem driver 2019-09-03 07:55:00 +05:30
qoriq-cpufreq.c
raspberrypi-cpufreq.c
s3c24xx-cpufreq-debugfs.c
s3c24xx-cpufreq.c
s3c64xx-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
s3c2410-cpufreq.c
s3c2412-cpufreq.c
s3c2416-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
s3c2440-cpufreq.c
s5pv210-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
sa1100-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
sa1110-cpufreq.c Merge branch 'pm-cpufreq' 2019-07-18 09:49:30 +02:00
sc520_freq.c
scmi-cpufreq.c
scpi-cpufreq.c
sfi-cpufreq.c
sh-cpufreq.c
sparc-us2e-cpufreq.c
sparc-us3-cpufreq.c
spear-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
speedstep-centrino.c
speedstep-ich.c
speedstep-lib.c
speedstep-lib.h
speedstep-smi.c
sti-cpufreq.c
sun50i-cpufreq-nvmem.c cpufreq: Add sun50i nvmem based CPU scaling driver 2019-07-22 11:10:51 +05:30
tango-cpufreq.c
tegra20-cpufreq.c cpufreq: Make cpufreq_generic_init() return void 2019-07-16 10:20:11 +02:00
tegra124-cpufreq.c
tegra186-cpufreq.c
ti-cpufreq.c cpufreq: ti-cpufreq: Mark expected switch fall-through 2019-07-30 08:10:45 +05:30
unicore2-cpufreq.c
vexpress-spc-cpufreq.c