On Wed, Nov 23, 2022 at 1:35 PM Feng Tang <feng.tang@xxxxxxxxx> wrote:
>
> 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.
>
> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
> ---
> Changlog:
>
> Since v1
> * Use CONFIG_KASAN_GENERIC instead of CONFIG_KASAN for 'kasan_cache',
> as suggested by Andrey Konovalov
>
> include/linux/kasan.h | 22 +++++-----------------
> include/linux/slab_def.h | 2 +-
> include/linux/slub_def.h | 2 +-
> mm/kasan/common.c | 9 ++-------
> mm/slab_common.c | 1 -
> 5 files changed, 9 insertions(+), 27 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index dff604912687..0ff382f79f80 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -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)
> {
> @@ -252,7 +236,6 @@ 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) {}
> @@ -303,6 +286,11 @@ 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,
> diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
> index f0ffad6a3365..39f7f1f95de2 100644
> --- a/include/linux/slab_def.h
> +++ b/include/linux/slab_def.h
> @@ -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
>
> diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
> index f9c68a9dac04..4e7cdada4bbb 100644
> --- a/include/linux/slub_def.h
> +++ b/include/linux/slub_def.h
> @@ -132,7 +132,7 @@ struct kmem_cache {
> unsigned int *random_seq;
> #endif
>
> -#ifdef CONFIG_KASAN
> +#ifdef CONFIG_KASAN_GENERIC
> struct kasan_cache kasan_info;
> #endif
>
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 1f30080a7a4c..6e265beefc27 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
>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Thanks!
