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Message-Id: <20220614020707.1099487-5-sashal@kernel.org>
Date: Mon, 13 Jun 2022 22:06:30 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Philip Yang <Philip.Yang@....com>,
Felix Kuehling <Felix.Kuehling@....com>,
Alex Deucher <alexander.deucher@....com>,
Sasha Levin <sashal@...nel.org>, oded.gabbay@...il.com,
christian.koenig@....com, airlied@...ux.ie,
dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.15 05/41] drm/amdkfd: Use mmget_not_zero in MMU notifier
From: Philip Yang <Philip.Yang@....com>
[ Upstream commit fa582c6f3684ac0098a9d02ddf0ed52a02b37127 ]
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 <Philip.Yang@....com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 830809b694dd..74e6f613be02 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2181,6 +2181,8 @@ 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;
@@ -2207,6 +2209,7 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
}
svm_range_unlock(prange);
+ mmput(mni->mm);
return true;
}
--
2.35.1
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