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

[Nirmoy Das]

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