Re: Oops (NULL pointer dereference) in radeon_fence_ref in 3.14.63

On 08.03.2016 11:54, Nicolai Hähnle wrote:

On 05.03.2016 16:24, Christian König wrote:

...

just an educated guess, but I think the problem is simply that kernel 3.14 doesn't yet contain the code so that radeon_fence_get() can safely called with a NULL pointer.

So the backport of Nicolai's patch needs and extra check for the case when the fence is NULL.

Oops indeed. Only the ref call should need the guard, the unref has always had a NULL pointer test as far as I can see.

Lutz, could you please test whether the attached patch on top of 3.14.63 fixes the problem?

Nicolai, if you haven't already, please send this patch to stable@vger.kernel.org with an explicit explanation of which stable branches need it.