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From:   Rolf Eike Beer <eb@emlix.com>
To:     Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: mm: use mmap_assert_write_locked() instead of open coding it
Date:   Mon, 28 Mar 2022 10:24:51 +0200
Message-ID: <5827758.TJ1SttVevJ@mobilepool36.emlix.com>
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In case the lock is actually not held at this point this also avoids a
stale lock reference if built with NDEBUG.

Signed-off-by: Rolf Eike Beer <eb@emlix.com>
---
 mm/mmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 3aa839f81e63..d62598dc2fdd 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3561,7 +3561,7 @@ int mm_take_all_locks(struct mm_struct *mm)
 	struct vm_area_struct *vma;
 	struct anon_vma_chain *avc;
 
-	BUG_ON(mmap_read_trylock(mm));
+	mmap_assert_write_locked(mm);
 
 	mutex_lock(&mm_all_locks_mutex);
 
@@ -3641,7 +3641,7 @@ void mm_drop_all_locks(struct mm_struct *mm)
 	struct vm_area_struct *vma;
 	struct anon_vma_chain *avc;
 
-	BUG_ON(mmap_read_trylock(mm));
+	mmap_assert_write_locked(mm);
 	BUG_ON(!mutex_is_locked(&mm_all_locks_mutex));
 
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-- 
2.35.1


-- 
Rolf Eike Beer, emlix GmbH, https://www.emlix.com
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