[AMD Official Use Only - AMD Internal Distribution Only] Hi Christian Thanks for your comments. I miss the before logic has limited the generated pointer. Regards, Bob -----Original Message----- From: Koenig, Christian <Christian.Koenig@xxxxxxx> Sent: 2024年7月3日 17:26 To: Zhou, Bob <Bob.Zhou@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Huang, Tim <Tim.Huang@xxxxxxx>; Zhang, Jesse(Jie) <Jesse.Zhang@xxxxxxx> Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx> Subject: Re: [PATCH] drm/amdgpu: : Fix the null pointer dereference for amdgpu_device_switch_gang Am 03.07.24 um 11:01 schrieb Bob Zhou: > To avoid null pointer dereference reported by Coverity, so add null > pointer check for the return of amdgpu_device_get_gang(). NAK, that's complete nonsense in the first place. The pointer is guaranteed to be never NULL or otherwise the logic would have crashed long before. Regards, Christian. > > Signed-off-by: Bob Zhou <bob.zhou@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > index bcacf2e35eba..c1d82c346daa 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -6569,7 +6569,7 @@ struct dma_fence *amdgpu_device_switch_gang(struct amdgpu_device *adev, > if (old == gang) > break; > > - if (!dma_fence_is_signaled(old)) > + if (!old || !dma_fence_is_signaled(old)) > return old; > > } while (cmpxchg((struct dma_fence __force **)&adev->gang_submit,
