Re: [PATCH] kasan: test: prevent cache merging in kmem_cache_double_destroy
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From: Marco Elver <elver@google.com>
Date: 2022-02-08 18:43:32
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On Tue, 8 Feb 2022 at 19:37, [off-list ref] wrote:
From: Andrey Konovalov <redacted> With HW_TAGS KASAN and kasan.stacktrace=off, the cache created in the kmem_cache_double_destroy() test might get merged with an existing one. Thus, the first kmem_cache_destroy() call won't actually destroy it but will only descrease the refcount. This causes the test to fail.
s/descrease/decrease/
Provide an empty contructor for the created cache to prevent the cache
s/contructor/constructor/
from getting merged.
Fixes: f98f966cd750 ("kasan: test: add test case for double-kmem_cache_destroy()")
Signed-off-by: Andrey Konovalov <redacted>Reviewed-by: Marco Elver <elver@google.com>
quoted hunk ↗ jump to hunk
--- lib/test_kasan.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 26a5c9007653..3b413f8c8a71 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c@@ -869,11 +869,14 @@ static void kmem_cache_invalid_free(struct kunit *test) kmem_cache_destroy(cache); } +static void empty_cache_ctor(void *object) { } + static void kmem_cache_double_destroy(struct kunit *test) { struct kmem_cache *cache; - cache = kmem_cache_create("test_cache", 200, 0, 0, NULL); + /* Provide a constructor to prevent cache merging. */ + cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); kmem_cache_destroy(cache); KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache)); --2.25.1