amdgpu_benchmark_do_move() can exit the loop early if
amdgpu_copy_buffer() or dma_fence_wait() fails.
In the error path, the function jumps to the exit label
without releasing adev->mman.default_entity.lock, which
leaves the mutex held and results in a lock imbalance.
This can block subsequent users of default_entity and
potentially cause deadlocks.
Move the mutex_unlock() to the common exit path so the
lock is released on both success and error returns.
This fixes:
drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c:57 amdgpu_benchmark_do_move()
warn: inconsistent returns '&adev->mman.default_entity.lock'.
v2:
- Drop unrelated initialization of 'r'
- Keep the change focused on the mutex imbalance fix (Pierre).
Fixes: 64c9e5ec16fa ("drm/amdgpu: add missing lock in amdgpu_benchmark_do_move")
Reported-by: Dan Carpenter <[email protected]>
Cc: Pierre-Eric Pelloux-Prayer <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
index 98ccd7ab9e9a..f7cee5ce854e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
@@ -48,9 +48,10 @@ static int amdgpu_benchmark_do_move(struct amdgpu_device
*adev, unsigned size,
if (r)
goto exit_do_move;
}
- mutex_unlock(&adev->mman.default_entity.lock);
+
exit_do_move:
+ mutex_unlock(&adev->mman.default_entity.lock);
etime = ktime_get();
*time_ms = ktime_ms_delta(etime, stime);
--
2.34.1
