On Fri, Nov 13, 2020 at 11:20PM +0100, Andrey Konovalov wrote: > 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. > > Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@xxxxxxx> > Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@xxxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > --- > include/linux/kasan.h | 213 ++++++++++++++++++++++++++++++++---------- > include/linux/mm.h | 22 +++-- > mm/kasan/common.c | 56 +++++------ > 3 files changed, 210 insertions(+), 81 deletions(-) > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index 872bf145ddde..6bd95243a583 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/static_key.h> > #include <linux/types.h> > > struct kmem_cache; > @@ -74,54 +75,176 @@ static inline void kasan_disable_current(void) {} > > #ifdef CONFIG_KASAN > > -void kasan_unpoison_range(const void *address, size_t size); > +struct kasan_cache { > + int alloc_meta_offset; > + int free_meta_offset; > +}; > > -void kasan_alloc_pages(struct page *page, unsigned int order); > -void kasan_free_pages(struct page *page, unsigned int order); > +#ifdef CONFIG_KASAN_HW_TAGS > +DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled); > +static __always_inline bool kasan_enabled(void) > +{ > + return static_branch_likely(&kasan_flag_enabled); > +} > +#else > +static inline bool kasan_enabled(void) > +{ > + return true; > +} > +#endif > > -void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > - slab_flags_t *flags); > +void __kasan_unpoison_range(const void *addr, size_t size); > +static __always_inline void kasan_unpoison_range(const void *addr, size_t size) > +{ > + if (kasan_enabled()) > + __kasan_unpoison_range(addr, size); > +} > > -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_alloc_pages(struct page *page, unsigned int order); > +static __always_inline void kasan_alloc_pages(struct page *page, > + unsigned int order) > +{ > + if (kasan_enabled()) > + __kasan_alloc_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_free_pages(struct page *page, unsigned int order); > +static __always_inline void kasan_free_pages(struct page *page, > + unsigned int order) > +{ > + if (kasan_enabled()) > + __kasan_free_pages(page, order); > +} > > -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); > +void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > + slab_flags_t *flags); > +static __always_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); > +} > > -struct kasan_cache { > - int alloc_meta_offset; > - int free_meta_offset; > -}; > +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 page *page); > +static __always_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 __always_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 __always_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 __always_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 __always_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 __always_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; > +} > + > +void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object, > + size_t size, gfp_t flags); > +static __always_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; > +} > > -size_t kasan_metadata_size(struct kmem_cache *cache); > +void * __must_check __kasan_kmalloc_large(const void *ptr, > + size_t size, gfp_t flags); > +static __always_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 __always_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 __always_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 __always_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 bool kasan_enabled(void) > +{ > + return false; > +} > static inline void kasan_unpoison_range(const void *address, size_t size) {} > - > 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 size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } > static inline void kasan_poison_slab(struct page *page) {} > static inline void kasan_unpoison_object_data(struct kmem_cache *cache, > void *object) {} > @@ -132,36 +255,32 @@ 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 947f4f1a6536..24f47e140a4c 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; > @@ -1415,22 +1416,30 @@ 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; > @@ -1438,7 +1447,8 @@ 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 a11e3e75eb08..17918bd20ed9 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -59,7 +59,7 @@ void kasan_disable_current(void) > } > #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ > > -void kasan_unpoison_range(const void *address, size_t size) > +void __kasan_unpoison_range(const void *address, size_t size) > { > unpoison_range(address, size); > } > @@ -87,7 +87,7 @@ 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; > @@ -101,7 +101,7 @@ void kasan_alloc_pages(struct page *page, unsigned int order) > unpoison_range(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))) > poison_range(page_address(page), > @@ -128,8 +128,8 @@ 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; > @@ -174,7 +174,7 @@ 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; > @@ -197,7 +197,7 @@ 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_poison_slab(struct page *page) > +void __kasan_poison_slab(struct page *page) > { > unsigned long i; > > @@ -207,12 +207,12 @@ 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) > { > unpoison_range(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) > { > poison_range(object, > round_up(cache->object_size, KASAN_GRANULE_SIZE), > @@ -265,7 +265,7 @@ 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; > @@ -284,7 +284,7 @@ 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; > @@ -330,9 +330,9 @@ 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) > @@ -340,7 +340,7 @@ 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; > @@ -375,20 +375,20 @@ 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; > @@ -413,7 +413,7 @@ 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; > > @@ -423,13 +423,13 @@ 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; > > @@ -442,11 +442,11 @@ void kasan_poison_kfree(void *ptr, unsigned long ip) > } > poison_range(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); > -- > 2.29.2.299.gdc1121823c-goog >
