Commit bbc61844 authored by Feng Tang's avatar Feng Tang Committed by Andrew Morton
Browse files

mm/kasan: simplify and refine kasan_cache code 

struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host
kmem_cache is a kmalloc cache.  With newly introduced is_kmalloc_cache()
helper, 'is_kmalloc' and its related function can be replaced and removed.

Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW
tag modes, so refine its protection macro accordingly, suggested by Andrey
Konoval.

Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com


Signed-off-by: default avatarFeng Tang <feng.tang@intel.com>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent bb944290

include/linux/kasan.h

+5 −17
Original line number Diff line number Diff line
@@ -96,15 +96,6 @@ static inline bool kasan_has_integrated_init(void) 
}



#ifdef CONFIG_KASAN



struct kasan_cache {

#ifdef CONFIG_KASAN_GENERIC

	int alloc_meta_offset;

	int free_meta_offset;

#endif

	bool is_kmalloc;

};



void __kasan_unpoison_range(const void *addr, size_t size);

static __always_inline void kasan_unpoison_range(const void *addr, size_t size)

{
@@ -129,13 +120,6 @@ static __always_inline bool kasan_unpoison_pages(struct page *page, 
	return false;

}



void __kasan_cache_create_kmalloc(struct kmem_cache *cache);

static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)

{

	if (kasan_enabled())

		__kasan_cache_create_kmalloc(cache);

}



void __kasan_poison_slab(struct slab *slab);

static __always_inline void kasan_poison_slab(struct slab *slab)

{
@@ -255,7 +239,6 @@ static inline bool kasan_unpoison_pages(struct page *page, unsigned int order, 
{

	return false;

}

static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}

static inline void kasan_poison_slab(struct slab *slab) {}

static inline void kasan_unpoison_object_data(struct kmem_cache *cache,

					void *object) {}
@@ -306,6 +289,11 @@ static inline void kasan_unpoison_task_stack(struct task_struct *task) {} 


#ifdef CONFIG_KASAN_GENERIC



struct kasan_cache {

	int alloc_meta_offset;

	int free_meta_offset;

};



size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object);

slab_flags_t kasan_never_merge(void);

void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,

include/linux/slab_def.h

+1 −1
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ struct kmem_cache { 
	int obj_offset;

#endif /* CONFIG_DEBUG_SLAB */



#ifdef CONFIG_KASAN

#ifdef CONFIG_KASAN_GENERIC

	struct kasan_cache kasan_info;

#endif

include/linux/slub_def.h

+1 −1
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ struct kmem_cache { 
	unsigned int *random_seq;

#endif



#ifdef CONFIG_KASAN

#ifdef CONFIG_KASAN_GENERIC

	struct kasan_cache kasan_info;

#endif

mm/kasan/common.c

+2 −7
Original line number Diff line number Diff line
@@ -122,11 +122,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init) 
			     KASAN_PAGE_FREE, init);

}



void __kasan_cache_create_kmalloc(struct kmem_cache *cache)

{

	cache->kasan_info.is_kmalloc = true;

}



void __kasan_poison_slab(struct slab *slab)

{

	struct page *page = slab_page(slab);
@@ -326,7 +321,7 @@ void * __must_check __kasan_slab_alloc(struct kmem_cache *cache, 
	kasan_unpoison(tagged_object, cache->object_size, init);



	/* Save alloc info (if possible) for non-kmalloc() allocations. */

	if (kasan_stack_collection_enabled() && !cache->kasan_info.is_kmalloc)

	if (kasan_stack_collection_enabled() && !is_kmalloc_cache(cache))

		kasan_save_alloc_info(cache, tagged_object, flags);



	return tagged_object;
@@ -372,7 +367,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache, 
	 * Save alloc info (if possible) for kmalloc() allocations.

	 * This also rewrites the alloc info when called from kasan_krealloc().

	 */

	if (kasan_stack_collection_enabled() && cache->kasan_info.is_kmalloc)

	if (kasan_stack_collection_enabled() && is_kmalloc_cache(cache))

		kasan_save_alloc_info(cache, (void *)object, flags);



	/* Keep the tag that was set by kasan_slab_alloc(). */

mm/slab_common.c

+0 −1
Original line number Diff line number Diff line
@@ -670,7 +670,6 @@ struct kmem_cache *__init create_kmalloc_cache(const char *name, 


	create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset,

								usersize);

	kasan_cache_create_kmalloc(s);

	list_add(&s->list, &slab_caches);

	s->refcount = 1;

	return s;