Hi,

On 17/05/2022 17:56, Yongzhi Liu wrote:

if drm_syncobj_fence_get return null, we will get a null pointer. Fix this by adding the null pointer check on fence.

Signed-off-by: Yongzhi Liu lyz_cs@pku.edu.cn

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index fd0e15d..3a82a62 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -3184,6 +3184,10 @@ eb_fences_add(struct i915_execbuffer *eb, struct i915_request *rq, struct dma_fence *fence;

fence = drm_syncobj_fence_get(eb->gem_context->syncobj);

• if (!fence) {
  

• 	DRM_DEBUG("Syncobj has no fence\n");
  

• 	return ERR_PTR(-EINVAL);
  

Lookup can't fail here since reference to context is held and syncobj can't get replaced during that time. You could make it a single GEM_BUG_ON(!fence) instead if you really wanted but I am not convinced it would be useful.

Regards,

Tvrtko

• }
  

  err = i915_request_await_dma_fence(rq, fence); dma_fence_put(fence); if (err)