diff mbox series

[mm,v3,12/19] kasan, mm: check kasan_enabled in annotations

Message ID 68b9e818c971a28c4b8082d6dbac52967553bd73.1605305978.git.andreyknvl@google.com (mailing list archive)
State New
Headers show
Series kasan: boot parameters for hardware tag-based mode | expand

Commit Message

Andrey Konovalov Nov. 13, 2020, 10:20 p.m. UTC
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@arm.com>
Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e
---
 include/linux/kasan.h | 213 ++++++++++++++++++++++++++++++++----------
 include/linux/mm.h    |  22 +++--
 mm/kasan/common.c     |  56 +++++------
 3 files changed, 210 insertions(+), 81 deletions(-)

Comments

Marco Elver Nov. 16, 2020, 3:26 p.m. UTC | #1
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@arm.com>
> Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e

Reviewed-by: Marco Elver <elver@google.com>

> ---
>  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
>
Dmitry Vyukov Nov. 17, 2020, 11:12 a.m. UTC | #2
On Mon, Nov 16, 2020 at 4:26 PM Marco Elver <elver@google.com> wrote:
>
> 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@arm.com>
> > Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > Link: https://linux-review.googlesource.com/id/I2589451d3c96c97abbcbf714baabe6161c6f153e
>
> Reviewed-by: Marco Elver <elver@google.com>

Also much nicer with kasan_enabled() now.

Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

> > ---
> >  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
> >
diff mbox series

Patch

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);