2022-09-05 21:40:49

by andrey.konovalov

[permalink] [raw]
Subject: [PATCH mm v3 14/34] kasan: only define kasan_metadata_size for Generic mode

From: Andrey Konovalov <[email protected]>

KASAN provides a helper for calculating the size of per-object metadata
stored in the redzone.

As now only the Generic mode uses per-object metadata, only define
kasan_metadata_size() for this mode.

Reviewed-by: Marco Elver <[email protected]>
Signed-off-by: Andrey Konovalov <[email protected]>
---
include/linux/kasan.h | 17 ++++++++---------
mm/kasan/common.c | 11 -----------
mm/kasan/generic.c | 11 +++++++++++
3 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index b092277bf48d..027df7599573 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -150,14 +150,6 @@ static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
__kasan_cache_create_kmalloc(cache);
}

-size_t __kasan_metadata_size(struct kmem_cache *cache);
-static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache)
-{
- if (kasan_enabled())
- return __kasan_metadata_size(cache);
- return 0;
-}
-
void __kasan_poison_slab(struct slab *slab);
static __always_inline void kasan_poison_slab(struct slab *slab)
{
@@ -282,7 +274,6 @@ static inline void kasan_cache_create(struct kmem_cache *cache,
unsigned int *size,
slab_flags_t *flags) {}
static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
-static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
static inline void kasan_poison_slab(struct slab *slab) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void *object) {}
@@ -333,6 +324,8 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {}

#ifdef CONFIG_KASAN_GENERIC

+size_t kasan_metadata_size(struct kmem_cache *cache);
+
void kasan_cache_shrink(struct kmem_cache *cache);
void kasan_cache_shutdown(struct kmem_cache *cache);
void kasan_record_aux_stack(void *ptr);
@@ -340,6 +333,12 @@ void kasan_record_aux_stack_noalloc(void *ptr);

#else /* CONFIG_KASAN_GENERIC */

+/* Tag-based KASAN modes do not use per-object metadata. */
+static inline size_t kasan_metadata_size(struct kmem_cache *cache)
+{
+ return 0;
+}
+
static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
static inline void kasan_record_aux_stack(void *ptr) {}
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index b6a74fe5e740..7c79c560315d 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -139,17 +139,6 @@ void __kasan_cache_create_kmalloc(struct kmem_cache *cache)
cache->kasan_info.is_kmalloc = true;
}

-size_t __kasan_metadata_size(struct kmem_cache *cache)
-{
- if (!kasan_requires_meta())
- return 0;
- return (cache->kasan_info.alloc_meta_offset ?
- sizeof(struct kasan_alloc_meta) : 0) +
- ((cache->kasan_info.free_meta_offset &&
- cache->kasan_info.free_meta_offset != KASAN_NO_FREE_META) ?
- sizeof(struct kasan_free_meta) : 0);
-}
-
void __kasan_poison_slab(struct slab *slab)
{
struct page *page = slab_page(slab);
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 5125fad76f70..806ab92032c3 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -427,6 +427,17 @@ void kasan_init_object_meta(struct kmem_cache *cache, const void *object)
__memset(alloc_meta, 0, sizeof(*alloc_meta));
}

+size_t kasan_metadata_size(struct kmem_cache *cache)
+{
+ if (!kasan_requires_meta())
+ return 0;
+ return (cache->kasan_info.alloc_meta_offset ?
+ sizeof(struct kasan_alloc_meta) : 0) +
+ ((cache->kasan_info.free_meta_offset &&
+ cache->kasan_info.free_meta_offset != KASAN_NO_FREE_META) ?
+ sizeof(struct kasan_free_meta) : 0);
+}
+
static void __kasan_record_aux_stack(void *addr, bool can_alloc)
{
struct slab *slab = kasan_addr_to_slab(addr);
--
2.25.1