On 2/26/26 16:49, Tvrtko Ursulin wrote:
> LKP reports two suspicious NULL pointer checks, triggered by
> 4ca06f6fb45d ("drm/amdgpu/userq: Use drm_gem_objects_lookup in
> amdgpu_userq_signal_ioctl")
> but these checks were redundant even before. Remove them.
>
> Signed-off-by: Tvrtko Ursulin <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> Closes: https://lore.kernel.org/r/[email protected]/
> Cc: Alex Deucher <[email protected]>
> Cc: Christian König <[email protected]>
> Cc: Sunil Khatri <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> index ba128b2a2d49..0f941021fcf4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> @@ -548,7 +548,7 @@ int amdgpu_userq_signal_ioctl(struct drm_device *dev,
> void *data,
> }
>
> for (i = 0; i < num_read_bo_handles; i++) {
> - if (!gobj_read || !gobj_read[i]->resv)
> + if (!gobj_read[i]->resv)
> continue;
The test for resv not NULL is also completely superfluous here.
We would have crashed much earlier with a NULL pointer dereference if the GEM
object would be mangled like that.
Regards,
Christian.
>
> dma_resv_add_fence(gobj_read[i]->resv, fence,
> @@ -556,7 +556,7 @@ int amdgpu_userq_signal_ioctl(struct drm_device *dev,
> void *data,
> }
>
> for (i = 0; i < num_write_bo_handles; i++) {
> - if (!gobj_write || !gobj_write[i]->resv)
> + if (!gobj_write[i]->resv)
> continue;
>
> dma_resv_add_fence(gobj_write[i]->resv, fence,
