[PATCH] dma_fence_array: Fix PENDING_ERROR leak in dma_fence_array_signaled()

[Thomas Hellström]

Hi, Christian,

On Mon, 2021-11-29 at 09:21 +0100, Christian König wrote:
> Am 29.11.21 um 08:35 schrieb Thomas Hellström:
> > If a dma_fence_array is reported signaled by a call to
> > dma_fence_is_signaled(), it may leak the PENDING_ERROR status.
> > 
> > Fix this by clearing the PENDING_ERROR status if we return true in
> > dma_fence_array_signaled().
> > 
> > Fixes: 1f70b8b812f3 ("dma-fence: Propagate errors to dma-fence-
> > array container")
> > Cc: linaro-mm-sig at lists.linaro.org
> > Cc: Christian König <ckoenig.leichtzumerken at gmail.com>
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> 
> Reviewed-by: Christian König <christian.koenig at amd.com>

How are the dma-buf / dma-fence patches typically merged? If i915 is
the only fence->error user, could we take this through drm-intel to
avoid a backmerge for upcoming i915 work?

/Thomas


> 
> > ---
> >   drivers/dma-buf/dma-fence-array.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-
> > buf/dma-fence-array.c
> > index d3fbd950be94..3e07f961e2f3 100644
> > --- a/drivers/dma-buf/dma-fence-array.c
> > +++ b/drivers/dma-buf/dma-fence-array.c
> > @@ -104,7 +104,11 @@ static bool dma_fence_array_signaled(struct
> > dma_fence *fence)
> >   {
> >         struct dma_fence_array *array = to_dma_fence_array(fence);
> >   
> > -       return atomic_read(&array->num_pending) <= 0;
> > +       if (atomic_read(&array->num_pending) > 0)
> > +               return false;
> > +
> > +       dma_fence_array_clear_pending_error(array);
> > +       return true;
> >   }
> >   
> >   static void dma_fence_array_release(struct dma_fence *fence)
>