mm/slab: refactor common ksize KASAN logic into slab_common.c

This refactors common code of ksize() between the various allocators into
slab_common.c: __ksize() is the allocator-specific implementation without
instrumentation, whereas ksize() includes the required KASAN logic.

Link: http://lkml.kernel.org/r/20190626142014.141844-5-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 12 deletions

diff --git a/mm/slub.c b/mm/slub.c
index d46a91759b96..5e217653286c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3895,7 +3895,7 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
 }
 #endif /* CONFIG_HARDENED_USERCOPY */
 
-static size_t __ksize(const void *object)
+size_t __ksize(const void *object)
 {
 	struct page *page;
 
@@ -3911,17 +3911,7 @@ static size_t __ksize(const void *object)
 
 	return slab_ksize(page->slab_cache);
 }
-
-size_t ksize(const void *object)
-{
-	size_t size = __ksize(object);
-	/* We assume that ksize callers could use whole allocated area,
-	 * so we need to unpoison this area.
-	 */
-	kasan_unpoison_shadow(object, size);
-	return size;
-}
-EXPORT_SYMBOL(ksize);
+EXPORT_SYMBOL(__ksize);
 
 void kfree(const void *x)
 {