[PATCH] drm/syncobj: Fix oops on drm_syncobj_find_fence(file_priv, 0, ...).

[Daniel Vetter]

On Tue, Nov 06, 2018 at 09:10:55AM +0000, Koenig, Christian wrote:
> Acked-by: Christian König <christian.koenig at amd.com>
> 
> Should I push it to drm-misc-next?

Yeah.

This should have broken an igt somewhere ... would be good to double check
whether that's true and why it wasn't caught. From a quick look i915
doesn't use this interface (it uses drm_syncobj_find, which isn't broken
like this), only amdgpu and v3d use this.

I guess an in-kernel unit test for these driver interfaces is what we need
here.
-Daniel

> 
> Christian.
> 
> Am 06.11.18 um 03:18 schrieb Zhou, David(ChunMing):
> > Reviewed-by: Chunming Zhou <david1.zhou at amd.com>
> >
> >> -----Original Message-----
> >> From: Eric Anholt <eric at anholt.net>
> >> Sent: Tuesday, November 06, 2018 7:01 AM
> >> To: dri-devel at lists.freedesktop.org
> >> Cc: linux-kernel at vger.kernel.org; Eric Anholt <eric at anholt.net>; Zhou,
> >> David(ChunMing) <David1.Zhou at amd.com>; Koenig, Christian
> >> <Christian.Koenig at amd.com>
> >> Subject: [PATCH] drm/syncobj: Fix oops on
> >> drm_syncobj_find_fence(file_priv, 0, ...).
> >>
> >> This broke rendering on V3D, where we almost always have a 0 in-syncobj.
> >>
> >> Signed-off-by: Eric Anholt <eric at anholt.net>
> >> Fixes: 48197bc564c7 ("drm: add syncobj timeline support v9")
> >> Cc: Chunming Zhou <david1.zhou at amd.com>
> >> Cc: Christian König <christian.koenig at amd.com>
> >> ---
> >>   drivers/gpu/drm/drm_syncobj.c | 3 ++-
> >>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/drm_syncobj.c
> >> b/drivers/gpu/drm/drm_syncobj.c index 4dca5f7e8c4b..da8175d9c6ff 100644
> >> --- a/drivers/gpu/drm/drm_syncobj.c
> >> +++ b/drivers/gpu/drm/drm_syncobj.c
> >> @@ -443,7 +443,8 @@ int drm_syncobj_find_fence(struct drm_file
> >> *file_private,
> >>   	int ret;
> >>
> >>   	ret = drm_syncobj_search_fence(syncobj, point, flags, fence);
> >> -	drm_syncobj_put(syncobj);
> >> +	if (syncobj)
> >> +		drm_syncobj_put(syncobj);
> >>   	return ret;
> >>   }
> >>   EXPORT_SYMBOL(drm_syncobj_find_fence);
> >> --
> >> 2.19.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch