diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2022-09-06 00:05:30 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-04 00:02:58 +0300 |
| commit | 3b7f8813e9ecf7fe91f2f8dc3b581a111cd374a5 (patch) | |
| tree | 5cebe42b30879ee83ee7a7f8ef8cda292ff064ef | |
| parent | f372bde922e2ced8e0b5a928887b4cf587cc4453 (diff) | |
| download | linux-3b7f8813e9ecf7fe91f2f8dc3b581a111cd374a5.tar.xz | |
kasan: only define kasan_never_merge for Generic mode
KASAN prevents merging of slab caches whose objects have per-object
metadata stored in redzones.
As now only the Generic mode uses per-object metadata, define
kasan_never_merge() only for this mode.
Link: https://lkml.kernel.org/r/81ed01f29ff3443580b7e2fe362a8b47b1e8006d.1662411799.git.andreyknvl@google.com
Signed-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>
| -rw-r--r-- | include/linux/kasan.h | 18 | ||||
| -rw-r--r-- | mm/kasan/common.c | 8 | ||||
| -rw-r--r-- | mm/kasan/generic.c | 8 |
3 files changed, 14 insertions, 20 deletions
diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 027df7599573..9743d4b3a918 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -103,14 +103,6 @@ struct kasan_cache { bool is_kmalloc; }; -slab_flags_t __kasan_never_merge(void); -static __always_inline slab_flags_t kasan_never_merge(void) -{ - if (kasan_enabled()) - return __kasan_never_merge(); - return 0; -} - void __kasan_unpoison_range(const void *addr, size_t size); static __always_inline void kasan_unpoison_range(const void *addr, size_t size) { @@ -261,10 +253,6 @@ static __always_inline bool kasan_check_byte(const void *addr) #else /* CONFIG_KASAN */ -static inline slab_flags_t kasan_never_merge(void) -{ - return 0; -} static inline void kasan_unpoison_range(const void *address, size_t size) {} static inline void kasan_poison_pages(struct page *page, unsigned int order, bool init) {} @@ -325,6 +313,7 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {} #ifdef CONFIG_KASAN_GENERIC size_t kasan_metadata_size(struct kmem_cache *cache); +slab_flags_t kasan_never_merge(void); void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); @@ -338,6 +327,11 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } +/* And thus nothing prevents cache merging. */ +static inline slab_flags_t kasan_never_merge(void) +{ + return 0; +} static inline void kasan_cache_shrink(struct kmem_cache *cache) {} static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 7c79c560315d..c2690e938030 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -88,14 +88,6 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) } #endif /* CONFIG_KASAN_STACK */ -/* Only allow cache merging when no per-object metadata is present. */ -slab_flags_t __kasan_never_merge(void) -{ - if (kasan_requires_meta()) - return SLAB_KASAN; - return 0; -} - void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init) { u8 tag; diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 806ab92032c3..25333bf3c99f 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -328,6 +328,14 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); +/* Only allow cache merging when no per-object metadata is present. */ +slab_flags_t kasan_never_merge(void) +{ + if (!kasan_requires_meta()) + return 0; + return SLAB_KASAN; +} + /* * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. * For larger allocations larger redzones are used. |