On Tue, Mar 29, 2022 at 10:48:10AM +0200, Daniel Vetter wrote:
> On Tue, Mar 29, 2022 at 09:00:01AM +0200, Christian König wrote:
> > A bug inside the new sync-file merge code created empty dma_fence_array
> > instances.
> >
> > Warn about that and handle those without crashing.
> >
> > Signed-off-by: Christian König <christian.koe...@amd.com>
>
> > ---
> > drivers/dma-buf/dma-fence-array.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/dma-buf/dma-fence-array.c
> > b/drivers/dma-buf/dma-fence-array.c
> > index 52b85d292383..5c8a7084577b 100644
> > --- a/drivers/dma-buf/dma-fence-array.c
> > +++ b/drivers/dma-buf/dma-fence-array.c
> > @@ -159,6 +159,8 @@ struct dma_fence_array *dma_fence_array_create(int
> > num_fences,
> > struct dma_fence_array *array;
> > size_t size = sizeof(*array);
> >
> > + WARN_ON(!num_fences || !fences);
>
> WARN_ON and then dying randomly is kinda not nice, I'd wrap this in an
>
> if (WARN_ON)
> return NULL;
>
> with that: Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
Uh strike that, you handle it gracefully with the check below.
>
> > +
> > /* Allocate the callback structures behind the array. */
> > size += num_fences * sizeof(struct dma_fence_array_cb);
> > array = kzalloc(size, GFP_KERNEL);
> > @@ -231,6 +233,9 @@ struct dma_fence *dma_fence_array_first(struct
> > dma_fence *head)
> > if (!array)
> > return head;
> >
Maybe add a comment here that this is just defensive programming, like
/* No fences isn't allowed and splats in create, but be defensive */
Either way Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch> I guess,
coffee not quite yet working.
-Daniel
> > + if (!array->num_fences)
> > + return NULL;
> > +
> > return array->fences[0];
> > }
> > EXPORT_SYMBOL(dma_fence_array_first);
> > --
> > 2.25.1
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
