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.koenig@xxxxxxx> > > > --- > > 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.vetter@xxxxxxxx> 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.vetter@xxxxxxxx> 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
