kasan: move kasan_get_*_meta to generic.c

Move the implementations of kasan_get_alloc/free_meta() to generic.c, as
the common KASAN code does not use these functions anymore.

Also drop kasan_reset_tag() from the implementation, as the Generic mode
does not tag pointers.

Link: https://lkml.kernel.org/r/ffcfc0ad654d78a2ef4ca054c943ddb4e5ca477b.1662411799.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/kasan/common.c

@@ -229,25 +229,6 @@ size_t __kasan_metadata_size(struct kmem_cache *cache)
 		 sizeof(struct kasan_free_meta) : 0);
 }
 
-struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
-					      const void *object)
-{
-	if (!cache->kasan_info.alloc_meta_offset)
-		return NULL;
-	return kasan_reset_tag(object) + cache->kasan_info.alloc_meta_offset;
-}
-
-#ifdef CONFIG_KASAN_GENERIC
-struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
-					    const void *object)
-{
-	BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
-	if (cache->kasan_info.free_meta_offset == KASAN_NO_FREE_META)
-		return NULL;
-	return kasan_reset_tag(object) + cache->kasan_info.free_meta_offset;
-}
-#endif
-
 void __kasan_poison_slab(struct slab *slab)
 {
 	struct page *page = slab_page(slab);

mm/kasan/generic.c

@@ -328,6 +328,23 @@ DEFINE_ASAN_SET_SHADOW(f3);
 DEFINE_ASAN_SET_SHADOW(f5);
 DEFINE_ASAN_SET_SHADOW(f8);
 
+struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
+					      const void *object)
+{
+	if (!cache->kasan_info.alloc_meta_offset)
+		return NULL;
+	return (void *)object + cache->kasan_info.alloc_meta_offset;
+}
+
+struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
+					    const void *object)
+{
+	BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
+	if (cache->kasan_info.free_meta_offset == KASAN_NO_FREE_META)
+		return NULL;
+	return (void *)object + cache->kasan_info.free_meta_offset;
+}
+
 void kasan_init_object_meta(struct kmem_cache *cache, const void *object)
 {
 	struct kasan_alloc_meta *alloc_meta;

mm/kasan/kasan.h

@@ -209,13 +209,6 @@ struct kunit_kasan_status {
 };
 #endif
 
-struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
-						const void *object);
-#ifdef CONFIG_KASAN_GENERIC
-struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
-						const void *object);
-#endif
-
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 
 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
@@ -281,6 +274,13 @@ struct slab *kasan_addr_to_slab(const void *addr);
 
 void kasan_init_object_meta(struct kmem_cache *cache, const void *object);
 
+#ifdef CONFIG_KASAN_GENERIC
+struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
+						const void *object);
+struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
+						const void *object);
+#endif
+
 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
 void kasan_set_track(struct kasan_track *track, gfp_t flags);
 void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);