Declare the kasan_enabled static key in include/linux/kasan.h and in include/linux/mm.h and check it in all kasan annotations. This allows to avoid any slowdown caused by function calls when kasan_enabled is disabled.
Signed-off-by: Andrey Konovalov <andreyk...@google.com> Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e --- include/linux/kasan.h | 220 ++++++++++++++++++++++++++++++++---------- include/linux/mm.h | 22 +++-- mm/kasan/common.c | 60 ++++++------ 3 files changed, 216 insertions(+), 86 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 34236f134472..ae1046fc74e5 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -2,6 +2,7 @@ #ifndef _LINUX_KASAN_H #define _LINUX_KASAN_H +#include <linux/jump_label.h> #include <linux/types.h> struct kmem_cache; @@ -72,56 +73,179 @@ static inline void kasan_disable_current(void) {} #ifdef CONFIG_KASAN -void kasan_alloc_pages(struct page *page, unsigned int order); -void kasan_free_pages(struct page *page, unsigned int order); +struct kasan_cache { + int alloc_meta_offset; + int free_meta_offset; +}; -void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, - slab_flags_t *flags); +#ifdef CONFIG_KASAN_HW_TAGS +DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled); +static inline kasan_enabled(void) +{ + return static_branch_likely(&kasan_flag_enabled); +} +#else +static inline kasan_enabled(void) +{ + return true; +} +#endif -void kasan_unpoison_data(const void *address, size_t size); -void kasan_unpoison_slab(const void *ptr); +void __kasan_alloc_pages(struct page *page, unsigned int order); +static inline void kasan_alloc_pages(struct page *page, unsigned int order) +{ + if (kasan_enabled()) + __kasan_alloc_pages(page, order); +} -void kasan_poison_slab(struct page *page); -void kasan_unpoison_object_data(struct kmem_cache *cache, void *object); -void kasan_poison_object_data(struct kmem_cache *cache, void *object); -void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, - const void *object); +void __kasan_free_pages(struct page *page, unsigned int order); +static inline void kasan_free_pages(struct page *page, unsigned int order) +{ + if (kasan_enabled()) + __kasan_free_pages(page, order); +} -void * __must_check kasan_kmalloc_large(const void *ptr, size_t size, - gfp_t flags); -void kasan_kfree_large(void *ptr, unsigned long ip); -void kasan_poison_kfree(void *ptr, unsigned long ip); -void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object, - size_t size, gfp_t flags); -void * __must_check kasan_krealloc(const void *object, size_t new_size, - gfp_t flags); +void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags); +static inline void kasan_cache_create(struct kmem_cache *cache, + unsigned int *size, slab_flags_t *flags) +{ + if (kasan_enabled()) + __kasan_cache_create(cache, size, flags); +} -void * __must_check kasan_slab_alloc(struct kmem_cache *s, void *object, - gfp_t flags); -bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip); +size_t __kasan_metadata_size(struct kmem_cache *cache); +static inline size_t kasan_metadata_size(struct kmem_cache *cache) +{ + if (kasan_enabled()) + return __kasan_metadata_size(cache); + return 0; +} -struct kasan_cache { - int alloc_meta_offset; - int free_meta_offset; -}; +void __kasan_unpoison_data(const void *addr, size_t size); +static inline void kasan_unpoison_data(const void *addr, size_t size) +{ + if (kasan_enabled()) + __kasan_unpoison_data(addr, size); +} + +void __kasan_unpoison_slab(const void *ptr); +static inline void kasan_unpoison_slab(const void *ptr) +{ + if (kasan_enabled()) + __kasan_unpoison_slab(ptr); +} + +void __kasan_poison_slab(struct page *page); +static inline void kasan_poison_slab(struct page *page) +{ + if (kasan_enabled()) + return __kasan_poison_slab(page); +} + +void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object); +static inline void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) +{ + if (kasan_enabled()) + return __kasan_unpoison_object_data(cache, object); +} + +void __kasan_poison_object_data(struct kmem_cache *cache, void *object); +static inline void kasan_poison_object_data(struct kmem_cache *cache, void *object) +{ + if (kasan_enabled()) + __kasan_poison_object_data(cache, object); +} + +void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache, + const void *object); +static inline void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, + const void *object) +{ + if (kasan_enabled()) + return __kasan_init_slab_obj(cache, object); + return (void *)object; +} + +bool __kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip); +static inline bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip) +{ + if (kasan_enabled()) + return __kasan_slab_free(s, object, ip); + return false; +} + +void * __must_check __kasan_slab_alloc(struct kmem_cache *s, + void *object, gfp_t flags); +static inline void * __must_check kasan_slab_alloc(struct kmem_cache *s, + void *object, gfp_t flags) +{ + if (kasan_enabled()) + return __kasan_slab_alloc(s, object, flags); + return object; +} -size_t kasan_metadata_size(struct kmem_cache *cache); +void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object, + size_t size, gfp_t flags); +static inline void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object, + size_t size, gfp_t flags) +{ + if (kasan_enabled()) + return __kasan_kmalloc(s, object, size, flags); + return (void *)object; +} + +void * __must_check __kasan_kmalloc_large(const void *ptr, + size_t size, gfp_t flags); +static inline void * __must_check kasan_kmalloc_large(const void *ptr, + size_t size, gfp_t flags) +{ + if (kasan_enabled()) + return __kasan_kmalloc_large(ptr, size, flags); + return (void *)ptr; +} + +void * __must_check __kasan_krealloc(const void *object, + size_t new_size, gfp_t flags); +static inline void * __must_check kasan_krealloc(const void *object, + size_t new_size, gfp_t flags) +{ + if (kasan_enabled()) + return __kasan_krealloc(object, new_size, flags); + return (void *)object; +} + +void __kasan_poison_kfree(void *ptr, unsigned long ip); +static inline void kasan_poison_kfree(void *ptr, unsigned long ip) +{ + if (kasan_enabled()) + __kasan_poison_kfree(ptr, ip); +} + +void __kasan_kfree_large(void *ptr, unsigned long ip); +static inline void kasan_kfree_large(void *ptr, unsigned long ip) +{ + if (kasan_enabled()) + __kasan_kfree_large(ptr, ip); +} bool kasan_save_enable_multi_shot(void); void kasan_restore_multi_shot(bool enabled); #else /* CONFIG_KASAN */ +static inline kasan_enabled(void) +{ + return false; +} static inline void kasan_alloc_pages(struct page *page, unsigned int order) {} static inline void kasan_free_pages(struct page *page, unsigned int order) {} - static inline void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags) {} - -static inline void kasan_unpoison_data(const void *address, size_t size) { } -static inline void kasan_unpoison_slab(const void *ptr) { } - +static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } +static inline void kasan_unpoison_data(const void *address, size_t size) {} +static inline void kasan_unpoison_slab(const void *ptr) {} static inline void kasan_poison_slab(struct page *page) {} static inline void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) {} @@ -132,36 +256,32 @@ static inline void *kasan_init_slab_obj(struct kmem_cache *cache, { return (void *)object; } - -static inline void *kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags) +static inline bool kasan_slab_free(struct kmem_cache *s, void *object, + unsigned long ip) { - return ptr; + return false; +} +static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object, + gfp_t flags) +{ + return object; } -static inline void kasan_kfree_large(void *ptr, unsigned long ip) {} -static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {} static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size, gfp_t flags) { return (void *)object; } +static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) +{ + return (void *)ptr; +} static inline void *kasan_krealloc(const void *object, size_t new_size, gfp_t flags) { return (void *)object; } - -static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object, - gfp_t flags) -{ - return object; -} -static inline bool kasan_slab_free(struct kmem_cache *s, void *object, - unsigned long ip) -{ - return false; -} - -static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } +static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {} +static inline void kasan_kfree_large(void *ptr, unsigned long ip) {} #endif /* CONFIG_KASAN */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 0793d03a4183..8d84a6b2fa3c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -31,6 +31,7 @@ #include <linux/sizes.h> #include <linux/sched.h> #include <linux/pgtable.h> +#include <linux/kasan.h> struct mempolicy; struct anon_vma; @@ -1414,22 +1415,30 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid) #endif /* CONFIG_NUMA_BALANCING */ #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) + static inline u8 page_kasan_tag(const struct page *page) { - return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK; + if (kasan_enabled()) + return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK; + return 0xff; } static inline void page_kasan_tag_set(struct page *page, u8 tag) { - page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT); - page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT; + if (kasan_enabled()) { + page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT); + page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT; + } } static inline void page_kasan_tag_reset(struct page *page) { - page_kasan_tag_set(page, 0xff); + if (kasan_enabled()) + page_kasan_tag_set(page, 0xff); } -#else + +#else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ + static inline u8 page_kasan_tag(const struct page *page) { return 0xff; @@ -1437,7 +1446,8 @@ static inline u8 page_kasan_tag(const struct page *page) static inline void page_kasan_tag_set(struct page *page, u8 tag) { } static inline void page_kasan_tag_reset(struct page *page) { } -#endif + +#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */ static inline struct zone *page_zone(const struct page *page) { diff --git a/mm/kasan/common.c b/mm/kasan/common.c index efad5ed6a3bd..385863eaec2c 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -81,7 +81,7 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) } #endif /* CONFIG_KASAN_STACK */ -void kasan_alloc_pages(struct page *page, unsigned int order) +void __kasan_alloc_pages(struct page *page, unsigned int order) { u8 tag; unsigned long i; @@ -95,7 +95,7 @@ void kasan_alloc_pages(struct page *page, unsigned int order) kasan_unpoison_memory(page_address(page), PAGE_SIZE << order); } -void kasan_free_pages(struct page *page, unsigned int order) +void __kasan_free_pages(struct page *page, unsigned int order) { if (likely(!PageHighMem(page))) kasan_poison_memory(page_address(page), @@ -122,8 +122,8 @@ static inline unsigned int optimal_redzone(unsigned int object_size) object_size <= (1 << 16) - 1024 ? 1024 : 2048; } -void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, - slab_flags_t *flags) +void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags) { unsigned int orig_size = *size; unsigned int redzone_size; @@ -168,7 +168,7 @@ void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, *flags |= SLAB_KASAN; } -size_t kasan_metadata_size(struct kmem_cache *cache) +size_t __kasan_metadata_size(struct kmem_cache *cache) { if (!kasan_stack_collection_enabled()) return 0; @@ -191,17 +191,17 @@ struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, return kasan_reset_tag(object) + cache->kasan_info.free_meta_offset; } -void kasan_unpoison_data(const void *address, size_t size) +void __kasan_unpoison_data(const void *addr, size_t size) { - kasan_unpoison_memory(address, size); + kasan_unpoison_memory(addr, size); } -void kasan_unpoison_slab(const void *ptr) +void __kasan_unpoison_slab(const void *ptr) { kasan_unpoison_memory(ptr, __ksize(ptr)); } -void kasan_poison_slab(struct page *page) +void __kasan_poison_slab(struct page *page) { unsigned long i; @@ -211,12 +211,12 @@ void kasan_poison_slab(struct page *page) KASAN_KMALLOC_REDZONE); } -void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) +void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object) { kasan_unpoison_memory(object, cache->object_size); } -void kasan_poison_object_data(struct kmem_cache *cache, void *object) +void __kasan_poison_object_data(struct kmem_cache *cache, void *object) { kasan_poison_memory(object, round_up(cache->object_size, KASAN_GRANULE_SIZE), @@ -269,7 +269,7 @@ static u8 assign_tag(struct kmem_cache *cache, const void *object, #endif } -void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, +void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache, const void *object) { struct kasan_alloc_meta *alloc_meta; @@ -288,7 +288,7 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, return (void *)object; } -static bool __kasan_slab_free(struct kmem_cache *cache, void *object, +static bool ____kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip, bool quarantine) { u8 tag; @@ -331,9 +331,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object, return IS_ENABLED(CONFIG_KASAN_GENERIC); } -bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) +bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) { - return __kasan_slab_free(cache, object, ip, true); + return ____kasan_slab_free(cache, object, ip, true); } static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) @@ -341,7 +341,7 @@ static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) kasan_set_track(&kasan_get_alloc_meta(cache, object)->alloc_track, flags); } -static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, +static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags, bool keep_tag) { unsigned long redzone_start; @@ -373,20 +373,20 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, return set_tag(object, tag); } -void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object, - gfp_t flags) +void * __must_check __kasan_slab_alloc(struct kmem_cache *cache, + void *object, gfp_t flags) { - return __kasan_kmalloc(cache, object, cache->object_size, flags, false); + return ____kasan_kmalloc(cache, object, cache->object_size, flags, false); } -void * __must_check kasan_kmalloc(struct kmem_cache *cache, const void *object, - size_t size, gfp_t flags) +void * __must_check __kasan_kmalloc(struct kmem_cache *cache, const void *object, + size_t size, gfp_t flags) { - return __kasan_kmalloc(cache, object, size, flags, true); + return ____kasan_kmalloc(cache, object, size, flags, true); } -EXPORT_SYMBOL(kasan_kmalloc); +EXPORT_SYMBOL(__kasan_kmalloc); -void * __must_check kasan_kmalloc_large(const void *ptr, size_t size, +void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) { struct page *page; @@ -411,7 +411,7 @@ void * __must_check kasan_kmalloc_large(const void *ptr, size_t size, return (void *)ptr; } -void * __must_check kasan_krealloc(const void *object, size_t size, gfp_t flags) +void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flags) { struct page *page; @@ -421,13 +421,13 @@ void * __must_check kasan_krealloc(const void *object, size_t size, gfp_t flags) page = virt_to_head_page(object); if (unlikely(!PageSlab(page))) - return kasan_kmalloc_large(object, size, flags); + return __kasan_kmalloc_large(object, size, flags); else - return __kasan_kmalloc(page->slab_cache, object, size, + return ____kasan_kmalloc(page->slab_cache, object, size, flags, true); } -void kasan_poison_kfree(void *ptr, unsigned long ip) +void __kasan_poison_kfree(void *ptr, unsigned long ip) { struct page *page; @@ -440,11 +440,11 @@ void kasan_poison_kfree(void *ptr, unsigned long ip) } kasan_poison_memory(ptr, page_size(page), KASAN_FREE_PAGE); } else { - __kasan_slab_free(page->slab_cache, ptr, ip, false); + ____kasan_slab_free(page->slab_cache, ptr, ip, false); } } -void kasan_kfree_large(void *ptr, unsigned long ip) +void __kasan_kfree_large(void *ptr, unsigned long ip) { if (ptr != page_address(virt_to_head_page(ptr))) kasan_report_invalid_free(ptr, ip); -- 2.29.1.341.ge80a0c044ae-goog
