kasan: split save_alloc_info implementations

Provide standalone implementations of save_alloc_info() for the Generic
and tag-based modes.

For now, the implementations are the same, but they will diverge later in
the series.

Link: https://lkml.kernel.org/r/77f1a078489c1e859aedb5403f772e5e1f7410a0.1662411799.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

@@ -424,15 +424,6 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
 	}
 }
 
-static void save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
-{
-	struct kasan_alloc_meta *alloc_meta;
-
-	alloc_meta = kasan_get_alloc_meta(cache, object);
-	if (alloc_meta)
-		kasan_set_track(&alloc_meta->alloc_track, flags);
-}
-
 void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
 					void *object, gfp_t flags, bool init)
 {
@@ -463,7 +454,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
 
 	/* Save alloc info (if possible) for non-kmalloc() allocations. */
 	if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
-		save_alloc_info(cache, (void *)object, flags);
+		kasan_save_alloc_info(cache, (void *)object, flags);
 
 	return tagged_object;
 }
@@ -509,7 +500,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
 	 * This also rewrites the alloc info when called from kasan_krealloc().
 	 */
 	if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
-		save_alloc_info(cache, (void *)object, flags);
+		kasan_save_alloc_info(cache, (void *)object, flags);
 
 	/* Keep the tag that was set by kasan_slab_alloc(). */
 	return (void *)object;

mm/kasan/generic.c

@@ -358,6 +358,15 @@ void kasan_record_aux_stack_noalloc(void *addr)
 	return __kasan_record_aux_stack(addr, false);
 }
 
+void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = kasan_get_alloc_meta(cache, object);
+	if (alloc_meta)
+		kasan_set_track(&alloc_meta->alloc_track, flags);
+}
+
 void kasan_save_free_info(struct kmem_cache *cache,
 				void *object, u8 tag)
 {

mm/kasan/kasan.h

@@ -285,6 +285,7 @@ struct slab *kasan_addr_to_slab(const void *addr);
 
 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);
 void kasan_save_free_info(struct kmem_cache *cache, void *object, u8 tag);
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
 				void *object, u8 tag);

mm/kasan/tags.c

@@ -17,6 +17,15 @@
 
 #include "kasan.h"
 
+void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = kasan_get_alloc_meta(cache, object);
+	if (alloc_meta)
+		kasan_set_track(&alloc_meta->alloc_track, flags);
+}
+
 void kasan_save_free_info(struct kmem_cache *cache,
 				void *object, u8 tag)
 {