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

[Nirmoy Das <nirmoy.das@linux.intel.com>]

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@vger.kernel.org> # v5.13+
>
> ?
>
Yes. Sorry, I missed that. Can we still the tag ?


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@linux.intel.com>
>>> Cc: Shawn Lee <shawn.c.lee@intel.com>
>>> Signed-off-by: Nirmoy Das <nirmoy.das@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;
>>>   }