[RESEND 2/3] venus: core: cancel pending work items in workqueue

Mansur Alisha Shaik
2020-08-07T06:25:03Z

In concurrency usecase and reboot scenario we are
observing race condition and seeing NULL pointer
dereference crash. In shutdown path and system
recovery path we are destroying the same mutex
hence seeing crash.

This case is handled by mutex protection and
cancel delayed work items in work queue.

Below is the call trace for the crash
Call trace:
venus_remove+0xdc/0xec [venus_core]
venus_core_shutdown+0x1c/0x34 [venus_core]
platform_drv_shutdown+0x28/0x34
device_shutdown+0x154/0x1fc
kernel_restart_prepare+0x40/0x4c
kernel_restart+0x1c/0x64

Call trace:
mutex_lock+0x34/0x60
venus_hfi_destroy+0x28/0x98 [venus_core]
hfi_destroy+0x1c/0x28 [venus_core]
venus_sys_error_handler+0x60/0x14c [venus_core]
process_one_work+0x210/0x3d0
worker_thread+0x248/0x3f4
kthread+0x11c/0x12c
ret_from_fork+0x10/0x18

Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org>
---
drivers/media/platform/qcom/venus/core.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
index fe99c83..41a293e 100644
--- a/drivers/media/platform/qcom/venus/core.c
+++ b/drivers/media/platform/qcom/venus/core.c
@@ -312,6 +312,8 @@ static int venus_remove(struct platform_device *pdev)
struct device *dev = core->dev;
int ret;

+ cancel_delayed_work_sync(&core->work);
+
ret = pm_runtime_get_sync(dev);
WARN_ON(ret < 0);

@@ -329,7 +331,9 @@ static int venus_remove(struct platform_device *pdev)
if (pm_ops->core_put)
pm_ops->core_put(dev);

+ mutex_lock(&core->lock);
hfi_destroy(core);
+ mutex_unlock(&core->lock);

icc_put(core->video_path);
icc_put(core->cpucfg_path);
--
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