On Mon, Nov 21, 2022 at 2:53 PM Feng Tang <feng.tang@xxxxxxxxx> wrote:
>
> 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>
Hi Feng,
Nice simplification!
> ---
> 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;
> };
We can go even further here, and only define the kasan_cache struct
and add the kasan_info field to kmem_cache when CONFIG_KASAN_GENERIC
is enabled.
>
> 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
>
