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author | 2022-09-05 23:05:26 +0200 | |
---|---|---|
committer | 2022-10-03 14:02:58 -0700 | |
commit | 284f8590a1dfbe1c33b50bf6e8f8dc714e61bfd3 (patch) | |
tree | 74be3b66761d656f58efbd6625d158adce0973b7 /mm/kasan | |
parent | kasan: move kasan_get_*_meta to generic.c (diff) | |
download | linux-284f8590a1dfbe1c33b50bf6e8f8dc714e61bfd3.tar.gz linux-284f8590a1dfbe1c33b50bf6e8f8dc714e61bfd3.tar.bz2 linux-284f8590a1dfbe1c33b50bf6e8f8dc714e61bfd3.zip |
kasan: introduce kasan_requires_meta
Add a kasan_requires_meta() helper that indicates whether the enabled
KASAN mode requires per-object metadata and use this helper in the common
code.
Also hide kasan_init_object_meta() under CONFIG_KASAN_GENERIC ifdef check,
as Generic is the only mode that uses per-object metadata.
To allow for a potential future change that makes Generic KASAN support
the kasan.stacktrace command-line parameter, let kasan_requires_meta()
return kasan_stack_collection_enabled() instead of simply returning true.
Link: https://lkml.kernel.org/r/cf837e9996246aaaeebf704ccf8ec26a34fcf64f.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>
Diffstat (limited to 'mm/kasan')
-rw-r--r-- | mm/kasan/common.c | 13 | ||||
-rw-r--r-- | mm/kasan/kasan.h | 33 | ||||
-rw-r--r-- | mm/kasan/tags.c | 4 |
3 files changed, 34 insertions, 16 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 19ddc0ed0e7b..d0300954d76b 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -88,13 +88,10 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) } #endif /* CONFIG_KASAN_STACK */ -/* - * Only allow cache merging when stack collection is disabled and no metadata - * is present. - */ +/* Only allow cache merging when no per-object metadata is present. */ slab_flags_t __kasan_never_merge(void) { - if (kasan_stack_collection_enabled()) + if (kasan_requires_meta()) return SLAB_KASAN; return 0; } @@ -152,7 +149,7 @@ void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, */ *flags |= SLAB_KASAN; - if (!kasan_stack_collection_enabled()) + if (!kasan_requires_meta()) return; ok_size = *size; @@ -220,7 +217,7 @@ void __kasan_cache_create_kmalloc(struct kmem_cache *cache) size_t __kasan_metadata_size(struct kmem_cache *cache) { - if (!kasan_stack_collection_enabled()) + if (!kasan_requires_meta()) return 0; return (cache->kasan_info.alloc_meta_offset ? sizeof(struct kasan_alloc_meta) : 0) + @@ -295,7 +292,7 @@ void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache, const void *object) { /* Initialize per-object metadata if it is present. */ - if (kasan_stack_collection_enabled()) + if (kasan_requires_meta()) kasan_init_object_meta(cache, object); /* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */ diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index fdd577f3eb9d..1736abd661b6 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -43,7 +43,7 @@ static inline bool kasan_sync_fault_possible(void) return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM; } -#else +#else /* CONFIG_KASAN_HW_TAGS */ static inline bool kasan_stack_collection_enabled(void) { @@ -60,7 +60,31 @@ static inline bool kasan_sync_fault_possible(void) return true; } -#endif +#endif /* CONFIG_KASAN_HW_TAGS */ + +#ifdef CONFIG_KASAN_GENERIC + +/* Generic KASAN uses per-object metadata to store stack traces. */ +static inline bool kasan_requires_meta(void) +{ + /* + * Technically, Generic KASAN always collects stack traces right now. + * However, let's use kasan_stack_collection_enabled() in case the + * kasan.stacktrace command-line argument is changed to affect + * Generic KASAN. + */ + return kasan_stack_collection_enabled(); +} + +#else /* CONFIG_KASAN_GENERIC */ + +/* Tag-based KASAN modes do not use per-object metadata. */ +static inline bool kasan_requires_meta(void) +{ + return false; +} + +#endif /* CONFIG_KASAN_GENERIC */ #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) @@ -272,13 +296,14 @@ void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report struct page *kasan_addr_to_page(const void *addr); struct slab *kasan_addr_to_slab(const void *addr); -void kasan_init_object_meta(struct kmem_cache *cache, const void *object); - #ifdef CONFIG_KASAN_GENERIC +void kasan_init_object_meta(struct kmem_cache *cache, const void *object); struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache, const void *object); struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, const void *object); +#else +static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { } #endif depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc); diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index f11c89505c77..4f24669085e9 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -17,10 +17,6 @@ #include "kasan.h" -void kasan_init_object_meta(struct kmem_cache *cache, const void *object) -{ -} - void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) { } |