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Subject[PATCH 2/3] venus: core: cancel pending work items in workqueue
Date
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@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);
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
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