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| author | Nicolai Hähnle <Nicolai.Haehnle@amd.com> | 2015-12-02 17:35:12 +0100 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2015-12-02 15:04:04 -0500 |
| commit | 07df04dfcfe51a45239d056d43cbc09702262c82 (patch) | |
| tree | cd4cd9b9a9d38c1dd16ea31b11a4e87766b641b9 /drivers/gpu | |
| parent | e2f784fa8a3b1fbf6999ba44f7327bd9d29f2c5b (diff) | |
| download | linux-07df04dfcfe51a45239d056d43cbc09702262c82.tar.bz2 | |
drm/amdgpu: fix race condition in amd_sched_entity_push_job
As soon as we leave the spinlock after the job has been added to the job
queue, we can no longer rely on the job's data to be available.
I have seen a null-pointer dereference due to sched == NULL in
amd_sched_wakeup via amd_sched_entity_push_job and
amd_sched_ib_submit_kernel_helper. Since the latter initializes
sched_job->sched with the address of the ring scheduler, which is
guaranteed to be non-NULL, this race appears to be a likely culprit.
Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Bugzilla: https://bugs.freedesktop.org/attachment.cgi?bugid=93079
Reviewed-by: Christian König <christian.koenig@amd.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/scheduler/gpu_scheduler.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c index 651129f2ec1d..3a4820e863ec 100644 --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c @@ -288,6 +288,7 @@ amd_sched_entity_pop_job(struct amd_sched_entity *entity) */ static bool amd_sched_entity_in(struct amd_sched_job *sched_job) { + struct amd_gpu_scheduler *sched = sched_job->sched; struct amd_sched_entity *entity = sched_job->s_entity; bool added, first = false; @@ -302,7 +303,7 @@ static bool amd_sched_entity_in(struct amd_sched_job *sched_job) /* first job wakes up scheduler */ if (first) - amd_sched_wakeup(sched_job->sched); + amd_sched_wakeup(sched); return added; } @@ -318,9 +319,9 @@ void amd_sched_entity_push_job(struct amd_sched_job *sched_job) { struct amd_sched_entity *entity = sched_job->s_entity; + trace_amd_sched_job(sched_job); wait_event(entity->sched->job_scheduled, amd_sched_entity_in(sched_job)); - trace_amd_sched_job(sched_job); } /** |