Re: [PATCH 1/4] dma-buf: Check status of enable-signaling bit on debug

[Yadav, Arvind]

On 9/5/2022 4:51 PM, Christian König wrote:
> Am 05.09.22 um 12:56 schrieb Arvind Yadav:
> > The core DMA-buf framework needs to enable signaling
> > before the fence is signaled. The core DMA-buf framework
> > can forget to enable signaling before the fence is signaled.
> > To avoid this scenario on the debug kernel, check the
> > DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT status bit before checking
> > the signaling bit status to confirm that enable_signaling
> > is enabled.
>
> You might want to put this patch at the end of the series to avoid 
> breaking the kernel in between.
sure, I will add this patch at end.
> > Signed-off-by: Arvind Yadav <Arvind.Yadav@xxxxxxx>
> > ---
> >   include/linux/dma-fence.h | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> > index 775cdc0b4f24..60c0e935c0b5 100644
> > --- a/include/linux/dma-fence.h
> > +++ b/include/linux/dma-fence.h
> > @@ -428,6 +428,11 @@ dma_fence_is_signaled_locked(struct dma_fence 
> > *fence)
> >   static inline bool
> >   dma_fence_is_signaled(struct dma_fence *fence)
> >   {
> > +#ifdef CONFIG_DEBUG_FS
>
> CONFIG_DEBUG_FS is certainly wrong, probably better to check for 
> CONFIG_DEBUG_WW_MUTEX_SLOWPATH here.
>
> Apart from that looks good to me,
> Christian.
I will use CONFIG_DEBUG_WW_MUTEX_SLOWPATH instead of CONFIG_DEBUG_FS

~arvind

> > +    if (!test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags))
> > +        return false;
> > +#endif
> > +
> >       if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
> >           return true;