[PATCH v2 04/12] kasan: clean up setting free info in kasan_slab_free

Andrey Konovalov andreyknvl at google.com
Fri Feb 5 10:39:05 EST 2021

Put kasan_stack_collection_enabled() check and kasan_set_free_info()
calls next to each other.

The way this was previously implemented was a minor optimization that
relied of the the fact that kasan_stack_collection_enabled() is always
true for generic KASAN. The confusion that this brings outweights saving
a few instructions.

Reviewed-by: Marco Elver <elver at google.com>
Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
 mm/kasan/common.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index f2a6bae13053..da24b144d46c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -350,13 +350,11 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
 	kasan_poison(object, cache->object_size, KASAN_KMALLOC_FREE);
-	if (!kasan_stack_collection_enabled())
-		return false;
 	if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine))
 		return false;
-	kasan_set_free_info(cache, object, tag);
+	if (kasan_stack_collection_enabled())
+		kasan_set_free_info(cache, object, tag);
 	return kasan_quarantine_put(cache, object);

More information about the linux-arm-kernel mailing list