[PATCH] drm/i915: check before removing mm notifier

[Tvrtko Ursulin]

On 27/02/2024 09:26, Nirmoy Das wrote:
> Hi Tvrtko,
> 
> On 2/27/2024 10:04 AM, Tvrtko Ursulin wrote:
>>
>> On 21/02/2024 11:52, Nirmoy Das wrote:
>>> Merged it to drm-intel-gt-next with s/check/Check
>>
>> Shouldn't this have had:
>>
>> Fixes: ed29c2691188 ("drm/i915: Fix userptr so we do not have to worry 
>> about obj->mm.lock, v7.")
>> Cc: <stable at vger.kernel.org> # v5.13+
>>
>> ?
>>
> Yes. Sorry, I missed that. Can we still the tag ?

I've added them and force pushed the branch since commit was still at 
the top.

FYI + Jani, Joonas and Rodrigo

Regards,

Tvrtko

> 
> 
> Thanks,
> 
> Nirmoy
> 
>> Regards,
>>
>> Tvrtko
>>
>>> On 2/19/2024 1:50 PM, Nirmoy Das wrote:
>>>> Error in mmu_interval_notifier_insert() can leave a NULL
>>>> notifier.mm pointer. Catch that and return early.
>>>>
>>>> Cc: Andi Shyti <andi.shyti at linux.intel.com>
>>>> Cc: Shawn Lee <shawn.c.lee at intel.com>
>>>> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
>>>> ---
>>>>   drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 3 +++
>>>>   1 file changed, 3 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c 
>>>> b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>>>> index 0e21ce9d3e5a..61abfb505766 100644
>>>> --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>>>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>>>> @@ -349,6 +349,9 @@ i915_gem_userptr_release(struct 
>>>> drm_i915_gem_object *obj)
>>>>   {
>>>>       GEM_WARN_ON(obj->userptr.page_ref);
>>>> +    if (!obj->userptr.notifier.mm)
>>>> +        return;
>>>> +
>>>> mmu_interval_notifier_remove(&obj->userptr.notifier);
>>>>       obj->userptr.notifier.mm = NULL;
>>>>   }