[PATCH] drm/amd: fix memory leak in amdgpu_cs_sync_rings

[Alex Deucher]

On Thu, Feb 2, 2023 at 1:05 PM Bert Karwatzki <spasswolf at web.de> wrote:
>
> amdgpu_sync_get_fence deletes the returned fence from the syncobj, so
> the refcount of fence needs to lowered to avoid a memory leak:
> https://gitlab.freedesktop.org/drm/amd/-/issues/2360

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2360

Please send a proper patch using git-format-patch.  Also, please add
your Signed-off-by line.

With those fixed, the patch is:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 0f4cb41078c1..08eced097bd8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -1222,10 +1222,13 @@ static int amdgpu_cs_sync_rings(struct
> amdgpu_cs_parser *p)
>                  * next job actually sees the results from the previous
> one
>                  * before we start executing on the same scheduler
> ring.
>                  */
> -               if (!s_fence || s_fence->sched != sched)
> +               if (!s_fence || s_fence->sched != sched) {
> +                       dma_fence_put(fence);
>                         continue;
> +               }
>
>                 r = amdgpu_sync_fence(&p->gang_leader->explicit_sync,
> fence);
> +               dma_fence_put(fence);
>                 if (r)
>                         return r;
>         }
>
>
> Bert Karwatzki