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

[Nirmoy Das]

On 2/28/2024 2:24 PM, Tvrtko Ursulin wrote:
>
> 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.

Thanks a lot, Tvrtko!


>
> 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;
>>>>>   }