In concurrency usecase and reboot scenario we are observing race condition and seeing NULL pointer dereference crash.when workqueue is in progress to handle system recovery and at same when device happends, in bothe paths we are trying to destryo the same mutex hence seeing the crash. So this is hadled by protecting hfi_destroy in remove by mutext variable and cancel a delayed work items before reboot. 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@xxxxxxxxxxxxxx> --- 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); -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
