From fa582c6f3684ac0098a9d02ddf0ed52a02b37127 Mon Sep 17 00:00:00 2001 From: Philip Yang Date: Thu, 26 May 2022 16:15:38 -0400 Subject: drm/amdkfd: Use mmget_not_zero in MMU notifier MMU notifier callback may pass in mm with mm->mm_users==0 when process is exiting, use mmget_no_zero to avoid accessing invalid mm in deferred list work after mm is gone. Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpu/drm/amd') diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 2ebf0132c25b..3bd0f1a670bb 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2307,6 +2307,8 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, if (range->event == MMU_NOTIFY_RELEASE) return true; + if (!mmget_not_zero(mni->mm)) + return true; start = mni->interval_tree.start; last = mni->interval_tree.last; @@ -2333,6 +2335,7 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, } svm_range_unlock(prange); + mmput(mni->mm); return true; } -- cgit v1.2.3-58-ga151