drm/amd/amdgpu: fix bad job hw_fence use after free in advance tdr

[Why]
In advance tdr mode, the real bad job will be resubmitted twice, while
in drm_sched_resubmit_jobs_ext, there's a dma_fence_put, so the bad job
is put one more time than other jobs.

[How]
Adding dma_fence_get before resbumit job in
amdgpu_device_recheck_guilty_jobs and put the fence for normal jobs

Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 6e40cc1bc6dcf914106fe3d746172dbf03b8cda9..7c3f6ee148534d362b971c5e926a212c9118d44c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4850,6 +4850,9 @@ static void amdgpu_device_recheck_guilty_jobs(
 
                /* clear job's guilty and depend the folowing step to decide the real one */
                drm_sched_reset_karma(s_job);
+               /* for the real bad job, it will be resubmitted twice, adding a dma_fence_get
+                * to make sure fence is balanced */
+               dma_fence_get(s_job->s_fence->parent);
                drm_sched_resubmit_jobs_ext(&ring->sched, 1);
 
                ret = dma_fence_wait_timeout(s_job->s_fence->parent, false, ring->sched.timeout);
@@ -4885,6 +4888,7 @@ retry:
 
                /* got the hw fence, signal finished fence */
                atomic_dec(ring->sched.score);
+               dma_fence_put(s_job->s_fence->parent);
                dma_fence_get(&s_job->s_fence->finished);
                dma_fence_signal(&s_job->s_fence->finished);
                dma_fence_put(&s_job->s_fence->finished);