[merged mm-stable] mm-kasan-use-slab_no_merge-flag-instead-of-an-empty-constructor.patch removed from -mm tree

[merged mm-stable] mm-kasan-use-slab_no_merge-flag-instead-of-an-empty-constructor.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/kasan: use SLAB_NO_MERGE flag instead of an empty constructor
has been removed from the -mm tree.  Its filename was
     mm-kasan-use-slab_no_merge-flag-instead-of-an-empty-constructor.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Harry Yoo <harry.yoo@oracle.com>
Subject: mm/kasan: use SLAB_NO_MERGE flag instead of an empty constructor
Date: Tue, 18 Mar 2025 10:59:26 +0900

Use SLAB_NO_MERGE flag to prevent merging instead of providing an empty
constructor.  Using an empty constructor in this manner is an abuse of
slab interface.

The SLAB_NO_MERGE flag should be used with caution, but in this case, it
is acceptable as the cache is intended solely for debugging purposes.

No functional changes intended.

Link: https://lkml.kernel.org/r/20250318015926.1629748-1-harry.yoo@oracle.com
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/kasan_test_c.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/mm/kasan/kasan_test_c.c~mm-kasan-use-slab_no_merge-flag-instead-of-an-empty-constructor
+++ a/mm/kasan/kasan_test_c.c
@@ -1073,14 +1073,11 @@ static void kmem_cache_rcu_uaf(struct ku
 	kmem_cache_destroy(cache);
 }
 
-static void empty_cache_ctor(void *object) { }
-
 static void kmem_cache_double_destroy(struct kunit *test)
 {
 	struct kmem_cache *cache;
 
-	/* Provide a constructor to prevent cache merging. */
-	cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
+	cache = kmem_cache_create("test_cache", 200, 0, SLAB_NO_MERGE, NULL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
 	kmem_cache_destroy(cache);
 	KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
_

Patches currently in -mm which might be from harry.yoo@oracle.com are