[PATCH -next 2/2] mm/kasan: simplify is_kmalloc check

From: Feng Tang
Date: Mon Nov 21 2022 - 08:53:37 EST


Use new is_kmalloc_cache() to simplify the code of checking whether
a kmem_cache is a kmalloc cache.

Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
---
include/linux/kasan.h | 9 ---------
mm/kasan/common.c | 9 ++-------
mm/slab_common.c | 1 -
3 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index dff604912687..fc46f5d6f404 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -102,7 +102,6 @@ struct kasan_cache {
int alloc_meta_offset;
int free_meta_offset;
#endif
- bool is_kmalloc;
};

void __kasan_unpoison_range(const void *addr, size_t size);
@@ -129,13 +128,6 @@ 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)
{
@@ -252,7 +244,6 @@ static inline void kasan_poison_pages(struct page *page, unsigned int order,
bool init) {}
static inline bool kasan_unpoison_pages(struct page *page, unsigned int order,
bool init) { 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) {}
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 1f30080a7a4c..f7e0e5067e7a 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -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(). */
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8276022f0da4..a5480d67f391 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -663,7 +663,6 @@ 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;
--
2.34.1