RE: [PATCH v2] drm/amdgpu/userq: fix lock missing for userq fence error set

AMD General

Ping..

Regards,
      Prike

> -----Original Message-----
> From: Liang, Prike <[email protected]>
> Sent: Friday, August 14, 2026 11:33 AM
> To: [email protected]
> Cc: Deucher, Alexander <[email protected]>; Koenig, Christian
> <[email protected]>; Liang, Prike <[email protected]>
> Subject: [PATCH v2] drm/amdgpu/userq: fix lock missing for userq fence error set
>
> amdgpu_userq_fence_driver() and amdgpu_userq_fence_driver_destroy()
> don't acquire the dma_fence spinlock, so locking the dma_fence lock before test the
> signaled state and set error state.
>
> Signed-off-by: Prike Liang <[email protected]>
> ---
>  .../gpu/drm/amd/amdgpu/amdgpu_userq_fence.c   | 20 ++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> index 19af1adc2921..09e2079cfdbd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> @@ -191,14 +191,15 @@ void amdgpu_userq_fence_driver_destroy(struct kref
> *ref)
>       struct dma_fence *f;
>
>       spin_lock_irqsave(&fence_drv->fence_list_lock, flags);
> +     lockdep_assert_held(&fence_drv->fence_list_lock);
>       list_for_each_entry_safe(fence, tmp, &fence_drv->fences, link) {
>               f = &fence->base;
> -
> -             if (!dma_fence_is_signaled(f)) {
> +             spin_lock(dma_fence_spinlock(f));
> +             if (!dma_fence_is_signaled_locked(f)) {
>                       dma_fence_set_error(f, -ECANCELED);
> -                     dma_fence_signal(f);
> +                     dma_fence_signal_locked(f);
>               }
> -
> +             spin_unlock(dma_fence_spinlock(f));
>               list_del(&fence->link);
>               dma_fence_put(f);
>       }
> @@ -423,11 +424,16 @@ amdgpu_userq_fence_driver_set_error(struct
> amdgpu_userq_fence *fence,
>       struct dma_fence *f;
>
>       spin_lock_irqsave(&fence_drv->fence_list_lock, flags);
> -
> +     lockdep_assert_held(&fence_drv->fence_list_lock);
>       f = rcu_dereference_protected(&fence->base,
>                                     lockdep_is_held(&fence_drv->fence_list_lock));
> -     if (f && !dma_fence_is_signaled_locked(f))
> -             dma_fence_set_error(f, error);
> +     if (f) {
> +             /* nest f->lock inside fence_list_lock */
> +             spin_lock(dma_fence_spinlock(f));
> +             if (!dma_fence_is_signaled_locked(f))
> +                     dma_fence_set_error(f, error);
> +             spin_unlock(dma_fence_spinlock(f));
> +     }
>       spin_unlock_irqrestore(&fence_drv->fence_list_lock, flags);  }
>
> --
> 2.34.1