kasan: rename and document kasan_(un)poison_object_data

Rename kasan_unpoison_object_data to kasan_unpoison_new_object and add a
documentation comment.  Do the same for kasan_poison_object_data.

The new names and the comments should suggest the users that these hooks
are intended for internal use by the slab allocator.

The following patch will remove non-slab-internal uses of these hooks.

No functional changes.

[andreyknvl@google.com: update references to renamed functions in comments]
  Link: https://lkml.kernel.org/r/20231221180637.105098-1-andrey.konovalov@linux.dev
Link: https://lkml.kernel.org/r/eab156ebbd635f9635ef67d1a4271f716994e628.1703024586.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2023-12-19 23:29:03 +01:00 committed by Andrew Morton
parent 86b1596983
commit 1ce9a05239
6 changed files with 41 additions and 24 deletions

View file

@ -129,20 +129,39 @@ static __always_inline void kasan_poison_slab(struct slab *slab)
__kasan_poison_slab(slab);
}
void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
static __always_inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void __kasan_unpoison_new_object(struct kmem_cache *cache, void *object);
/**
* kasan_unpoison_new_object - Temporarily unpoison a new slab object.
* @cache: Cache the object belong to.
* @object: Pointer to the object.
*
* This function is intended for the slab allocator's internal use. It
* temporarily unpoisons an object from a newly allocated slab without doing
* anything else. The object must later be repoisoned by
* kasan_poison_new_object().
*/
static __always_inline void kasan_unpoison_new_object(struct kmem_cache *cache,
void *object)
{
if (kasan_enabled())
__kasan_unpoison_object_data(cache, object);
__kasan_unpoison_new_object(cache, object);
}
void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
static __always_inline void kasan_poison_object_data(struct kmem_cache *cache,
void __kasan_poison_new_object(struct kmem_cache *cache, void *object);
/**
* kasan_unpoison_new_object - Repoison a new slab object.
* @cache: Cache the object belong to.
* @object: Pointer to the object.
*
* This function is intended for the slab allocator's internal use. It
* repoisons an object that was previously unpoisoned by
* kasan_unpoison_new_object() without doing anything else.
*/
static __always_inline void kasan_poison_new_object(struct kmem_cache *cache,
void *object)
{
if (kasan_enabled())
__kasan_poison_object_data(cache, object);
__kasan_poison_new_object(cache, object);
}
void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
@ -342,9 +361,9 @@ static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
return false;
}
static inline void kasan_poison_slab(struct slab *slab) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
static inline void kasan_unpoison_new_object(struct kmem_cache *cache,
void *object) {}
static inline void kasan_poison_object_data(struct kmem_cache *cache,
static inline void kasan_poison_new_object(struct kmem_cache *cache,
void *object) {}
static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
const void *object)

View file

@ -143,12 +143,12 @@ void __kasan_poison_slab(struct slab *slab)
KASAN_SLAB_REDZONE, false);
}
void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
void __kasan_unpoison_new_object(struct kmem_cache *cache, void *object)
{
kasan_unpoison(object, cache->object_size, false);
}
void __kasan_poison_object_data(struct kmem_cache *cache, void *object)
void __kasan_poison_new_object(struct kmem_cache *cache, void *object)
{
kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE),
KASAN_SLAB_REDZONE, false);

View file

@ -130,7 +130,7 @@ void kasan_poison(const void *addr, size_t size, u8 value, bool init)
/*
* Perform shadow offset calculation based on untagged address, as
* some of the callers (e.g. kasan_poison_object_data) pass tagged
* some of the callers (e.g. kasan_poison_new_object) pass tagged
* addresses to this function.
*/
addr = kasan_reset_tag(addr);
@ -170,7 +170,7 @@ void kasan_unpoison(const void *addr, size_t size, bool init)
/*
* Perform shadow offset calculation based on untagged address, as
* some of the callers (e.g. kasan_unpoison_object_data) pass tagged
* some of the callers (e.g. kasan_unpoison_new_object) pass tagged
* addresses to this function.
*/
addr = kasan_reset_tag(addr);

View file

@ -2327,11 +2327,9 @@ static void cache_init_objs_debug(struct kmem_cache *cachep, struct slab *slab)
* They must also be threaded.
*/
if (cachep->ctor && !(cachep->flags & SLAB_POISON)) {
kasan_unpoison_object_data(cachep,
objp + obj_offset(cachep));
kasan_unpoison_new_object(cachep, objp + obj_offset(cachep));
cachep->ctor(objp + obj_offset(cachep));
kasan_poison_object_data(
cachep, objp + obj_offset(cachep));
kasan_poison_new_object(cachep, objp + obj_offset(cachep));
}
if (cachep->flags & SLAB_RED_ZONE) {
@ -2472,9 +2470,9 @@ static void cache_init_objs(struct kmem_cache *cachep,
/* constructor could break poison info */
if (DEBUG == 0 && cachep->ctor) {
kasan_unpoison_object_data(cachep, objp);
kasan_unpoison_new_object(cachep, objp);
cachep->ctor(objp);
kasan_poison_object_data(cachep, objp);
kasan_poison_new_object(cachep, objp);
}
if (!shuffled)

View file

@ -1860,9 +1860,9 @@ static void *setup_object(struct kmem_cache *s, void *object)
setup_object_debug(s, object);
object = kasan_init_slab_obj(s, object);
if (unlikely(s->ctor)) {
kasan_unpoison_object_data(s, object);
kasan_unpoison_new_object(s, object);
s->ctor(object);
kasan_poison_object_data(s, object);
kasan_poison_new_object(s, object);
}
return object;
}

View file

@ -337,7 +337,7 @@ static struct sk_buff *napi_skb_cache_get(void)
}
skb = nc->skb_cache[--nc->skb_count];
kasan_unpoison_object_data(skbuff_cache, skb);
kasan_unpoison_new_object(skbuff_cache, skb);
return skb;
}
@ -1309,13 +1309,13 @@ static void napi_skb_cache_put(struct sk_buff *skb)
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
u32 i;
kasan_poison_object_data(skbuff_cache, skb);
kasan_poison_new_object(skbuff_cache, skb);
nc->skb_cache[nc->skb_count++] = skb;
if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) {
for (i = NAPI_SKB_CACHE_HALF; i < NAPI_SKB_CACHE_SIZE; i++)
kasan_unpoison_object_data(skbuff_cache,
nc->skb_cache[i]);
kasan_unpoison_new_object(skbuff_cache,
nc->skb_cache[i]);
kmem_cache_free_bulk(skbuff_cache, NAPI_SKB_CACHE_HALF,
nc->skb_cache + NAPI_SKB_CACHE_HALF);