kasan: move is_kmalloc check out of save_alloc_info

Move kasan_info.is_kmalloc check out of save_alloc_info().

This is a preparatory change that simplifies the following patches in this
series.

Link: https://lkml.kernel.org/r/df89f1915b788f9a10319905af6d0202a3b30c30.1662411799.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 +424,10 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
 	}
 }
 
-static void save_alloc_info(struct kmem_cache *cache, void *object,
-				gfp_t flags, bool is_kmalloc)
+static void save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
 {
 	struct kasan_alloc_meta *alloc_meta;
 
-	/* Don't save alloc info for kmalloc caches in kasan_slab_alloc(). */
-	if (cache->kasan_info.is_kmalloc && !is_kmalloc)
-		return;
-
 	alloc_meta = kasan_get_alloc_meta(cache, object);
 	if (alloc_meta)
 		kasan_set_track(&alloc_meta->alloc_track, flags);
@@ -467,8 +462,8 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache,
 	kasan_unpoison(tagged_object, cache->object_size, init);
 
 	/* Save alloc info (if possible) for non-kmalloc() allocations. */
-	if (kasan_stack_collection_enabled())
-		save_alloc_info(cache, (void *)object, flags, false);
+	if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)
+		save_alloc_info(cache, (void *)object, flags);
 
 	return tagged_object;
 }
@@ -513,8 +508,8 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache,
 	 * Save alloc info (if possible) for kmalloc() allocations.
 	 * This also rewrites the alloc info when called from kasan_krealloc().
 	 */
-	if (kasan_stack_collection_enabled())
-		save_alloc_info(cache, (void *)object, flags, true);
+	if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)
+		save_alloc_info(cache, (void *)object, flags);
 
 	/* Keep the tag that was set by kasan_slab_alloc(). */
 	return (void *)object;