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

[Tvrtko Ursulin]

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+

?

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;
>>   }