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

[Christian König]

Am 29.11.21 um 13:23 schrieb 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?

Well that one here looks like a bugfix to me, so either through 
drm-misc-fixes ore some i915 -fixes branch sounds fine to me.

If you have any new development based on that a backmerge of the -fixes 
into your -next branch is unavoidable anyway.

Regards,
Christian.

>
> /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)
>