| Message ID | 1514287346-6224-1-git-send-email-yizeng@asrmicro.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Zhang Rui |
| Headers | show |
On Tue, 2017-12-26 at 19:22 +0800, Yi Zeng wrote: > When invoking allow_maximum_power and traverse tz->thermal_instances, > we should grab thermal_zone_device->lock to avoid race condition. For > example, during the system reboot, if the mali GPU device implements > device shutdown callback and unregister GPU devfreq cooling device, > the deleted list head may be accessed to cause panic, as the > following > log shows: > > [ 33.551070] c3 25 (kworker/3:0) Unable to handle kernel paging > request at virtual address dead000000000070 > [ 33.566708] c3 25 (kworker/3:0) pgd = ffffffc0ed290000 > [ 33.572071] c3 25 (kworker/3:0) [dead000000000070] > *pgd=00000001ed292003, *pud=00000001ed292003, *pmd=0000000000000000 > [ 33.581515] c3 25 (kworker/3:0) Internal error: Oops: 96000004 > [#1] PREEMPT SMP > [ 33.599761] c3 25 (kworker/3:0) CPU: 3 PID: 25 Comm: kworker/3:0 > Not tainted 4.4.35+ #912 > [ 33.614137] c3 25 (kworker/3:0) Workqueue: events_freezable > thermal_zone_device_check > [ 33.620245] c3 25 (kworker/3:0) task: ffffffc0f32e4200 ti: > ffffffc0f32f0000 task.ti: ffffffc0f32f0000 > [ 33.629466] c3 25 (kworker/3:0) PC is at > power_allocator_throttle+0x7c8/0x8a4 > [ 33.636609] c3 25 (kworker/3:0) LR is at > power_allocator_throttle+0x808/0x8a4 > [ 33.643742] c3 25 (kworker/3:0) pc : [<ffffff8008683dd0>] lr : > [<ffffff8008683e10>] pstate: 20000145 > [ 33.652874] c3 25 (kworker/3:0) sp : ffffffc0f32f3bb0 > [ 34.468519] c3 25 (kworker/3:0) Process kworker/3:0 (pid: 25, > stack limit = 0xffffffc0f32f0020) > [ 34.477220] c3 25 (kworker/3:0) Stack: (0xffffffc0f32f3bb0 to > 0xffffffc0f32f4000) > [ 34.819822] c3 25 (kworker/3:0) Call trace: > [ 34.824021] c3 25 (kworker/3:0) Exception stack(0xffffffc0f32f39c0 > to 0xffffffc0f32f3af0) > [ 34.924993] c3 25 (kworker/3:0) [<ffffff8008683dd0>] > power_allocator_throttle+0x7c8/0x8a4 > [ 34.933184] c3 25 (kworker/3:0) [<ffffff80086807f4>] > handle_thermal_trip.part.25+0x70/0x224 > [ 34.941545] c3 25 (kworker/3:0) [<ffffff8008680a68>] > thermal_zone_device_update+0xc0/0x20c > [ 34.949818] c3 25 (kworker/3:0) [<ffffff8008680bd4>] > thermal_zone_device_check+0x20/0x2c > [ 34.957924] c3 25 (kworker/3:0) [<ffffff80080b93a4>] > process_one_work+0x168/0x458 > [ 34.965414] c3 25 (kworker/3:0) [<ffffff80080ba068>] > worker_thread+0x13c/0x4b4 > [ 34.972650] c3 25 (kworker/3:0) [<ffffff80080c0a4c>] > kthread+0xe8/0xfc > [ 34.979187] c3 25 (kworker/3:0) [<ffffff8008084e90>] > ret_from_fork+0x10/0x40 > [ 34.986244] c3 25 (kworker/3:0) Code: f9405e73 eb1302bf d102e273 > 54ffc460 (b9402a61) > [ 34.994339] c3 25 (kworker/3:0) ---[ end trace 32057901e3b7e1db ]- > -- > > Signed-off-by: Yi Zeng <yizeng@asrmicro.com> applied. thanks, rui > --- > drivers/thermal/power_allocator.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/thermal/power_allocator.c > b/drivers/thermal/power_allocator.c > index b4d3116..3055f9a 100644 > --- a/drivers/thermal/power_allocator.c > +++ b/drivers/thermal/power_allocator.c > @@ -523,6 +523,7 @@ static void allow_maximum_power(struct > thermal_zone_device *tz) > struct thermal_instance *instance; > struct power_allocator_params *params = tz->governor_data; > > + mutex_lock(&tz->lock); > list_for_each_entry(instance, &tz->thermal_instances, > tz_node) { > if ((instance->trip != params- > >trip_max_desired_temperature) || > (!cdev_is_power_actor(instance->cdev))) > @@ -534,6 +535,7 @@ static void allow_maximum_power(struct > thermal_zone_device *tz) > mutex_unlock(&instance->cdev->lock); > thermal_cdev_update(instance->cdev); > } > + mutex_unlock(&tz->lock); > } > > /**
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c index b4d3116..3055f9a 100644 --- a/drivers/thermal/power_allocator.c +++ b/drivers/thermal/power_allocator.c @@ -523,6 +523,7 @@ static void allow_maximum_power(struct thermal_zone_device *tz) struct thermal_instance *instance; struct power_allocator_params *params = tz->governor_data; + mutex_lock(&tz->lock); list_for_each_entry(instance, &tz->thermal_instances, tz_node) { if ((instance->trip != params->trip_max_desired_temperature) || (!cdev_is_power_actor(instance->cdev))) @@ -534,6 +535,7 @@ static void allow_maximum_power(struct thermal_zone_device *tz) mutex_unlock(&instance->cdev->lock); thermal_cdev_update(instance->cdev); } + mutex_unlock(&tz->lock); } /**
When invoking allow_maximum_power and traverse tz->thermal_instances, we should grab thermal_zone_device->lock to avoid race condition. For example, during the system reboot, if the mali GPU device implements device shutdown callback and unregister GPU devfreq cooling device, the deleted list head may be accessed to cause panic, as the following log shows: [ 33.551070] c3 25 (kworker/3:0) Unable to handle kernel paging request at virtual address dead000000000070 [ 33.566708] c3 25 (kworker/3:0) pgd = ffffffc0ed290000 [ 33.572071] c3 25 (kworker/3:0) [dead000000000070] *pgd=00000001ed292003, *pud=00000001ed292003, *pmd=0000000000000000 [ 33.581515] c3 25 (kworker/3:0) Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 33.599761] c3 25 (kworker/3:0) CPU: 3 PID: 25 Comm: kworker/3:0 Not tainted 4.4.35+ #912 [ 33.614137] c3 25 (kworker/3:0) Workqueue: events_freezable thermal_zone_device_check [ 33.620245] c3 25 (kworker/3:0) task: ffffffc0f32e4200 ti: ffffffc0f32f0000 task.ti: ffffffc0f32f0000 [ 33.629466] c3 25 (kworker/3:0) PC is at power_allocator_throttle+0x7c8/0x8a4 [ 33.636609] c3 25 (kworker/3:0) LR is at power_allocator_throttle+0x808/0x8a4 [ 33.643742] c3 25 (kworker/3:0) pc : [<ffffff8008683dd0>] lr : [<ffffff8008683e10>] pstate: 20000145 [ 33.652874] c3 25 (kworker/3:0) sp : ffffffc0f32f3bb0 [ 34.468519] c3 25 (kworker/3:0) Process kworker/3:0 (pid: 25, stack limit = 0xffffffc0f32f0020) [ 34.477220] c3 25 (kworker/3:0) Stack: (0xffffffc0f32f3bb0 to 0xffffffc0f32f4000) [ 34.819822] c3 25 (kworker/3:0) Call trace: [ 34.824021] c3 25 (kworker/3:0) Exception stack(0xffffffc0f32f39c0 to 0xffffffc0f32f3af0) [ 34.924993] c3 25 (kworker/3:0) [<ffffff8008683dd0>] power_allocator_throttle+0x7c8/0x8a4 [ 34.933184] c3 25 (kworker/3:0) [<ffffff80086807f4>] handle_thermal_trip.part.25+0x70/0x224 [ 34.941545] c3 25 (kworker/3:0) [<ffffff8008680a68>] thermal_zone_device_update+0xc0/0x20c [ 34.949818] c3 25 (kworker/3:0) [<ffffff8008680bd4>] thermal_zone_device_check+0x20/0x2c [ 34.957924] c3 25 (kworker/3:0) [<ffffff80080b93a4>] process_one_work+0x168/0x458 [ 34.965414] c3 25 (kworker/3:0) [<ffffff80080ba068>] worker_thread+0x13c/0x4b4 [ 34.972650] c3 25 (kworker/3:0) [<ffffff80080c0a4c>] kthread+0xe8/0xfc [ 34.979187] c3 25 (kworker/3:0) [<ffffff8008084e90>] ret_from_fork+0x10/0x40 [ 34.986244] c3 25 (kworker/3:0) Code: f9405e73 eb1302bf d102e273 54ffc460 (b9402a61) [ 34.994339] c3 25 (kworker/3:0) ---[ end trace 32057901e3b7e1db ]--- Signed-off-by: Yi Zeng <yizeng@asrmicro.com> --- drivers/thermal/power_allocator.c | 2 ++ 1 file changed, 2 insertions(+)