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

[Nirmoy Das <nirmoy.das@xxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx> # 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@xxxxxxxxxxxxxxx>
> > > Cc: Shawn Lee <shawn.c.lee@xxxxxxxxx>
> > > Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
> > > ---
> > >   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;
> > >   }