On Fri, Nov 13, 2020 at 11:20PM +0100, Andrey Konovalov wrote:
> Rename kasan_poison_kfree() to kasan_slab_free_mempool() as it better
> reflects what this annotation does. Also add a comment that explains the
> PageSlab() check.
>
> No functional changes.
>
> Signed-off-by: Andrey Konovalov <andreyk...@google.com>
> Link:
> https://linux-review.googlesource.com/id/I5026f87364e556b506ef1baee725144bb04b8810
Reviewed-by: Marco Elver <el...@google.com>
> ---
> include/linux/kasan.h | 16 ++++++++--------
> mm/kasan/common.c | 40 +++++++++++++++++++++++-----------------
> mm/mempool.c | 2 +-
> 3 files changed, 32 insertions(+), 26 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index 6bd95243a583..16cf53eac29b 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -175,6 +175,13 @@ static __always_inline bool kasan_slab_free(struct
> kmem_cache *s, void *object,
> return false;
> }
>
> +void __kasan_slab_free_mempool(void *ptr, unsigned long ip);
> +static __always_inline void kasan_slab_free_mempool(void *ptr, unsigned long
> ip)
> +{
> + if (kasan_enabled())
> + __kasan_slab_free_mempool(ptr, ip);
> +}
> +
> void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
> void *object, gfp_t flags);
> static __always_inline void * __must_check kasan_slab_alloc(
> @@ -215,13 +222,6 @@ static __always_inline void * __must_check
> kasan_krealloc(const void *object,
> 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)
> {
> @@ -260,6 +260,7 @@ static inline bool kasan_slab_free(struct kmem_cache *s,
> void *object,
> {
> return false;
> }
> +static inline void kasan_slab_free_mempool(void *ptr, unsigned long ip) {}
> static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
> gfp_t flags)
> {
> @@ -279,7 +280,6 @@ static inline void *kasan_krealloc(const void *object,
> size_t new_size,
> {
> return (void *)object;
> }
> -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/mm/kasan/common.c b/mm/kasan/common.c
> index 17918bd20ed9..1205faac90bd 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -335,6 +335,29 @@ bool __kasan_slab_free(struct kmem_cache *cache, void
> *object, unsigned long ip)
> return ____kasan_slab_free(cache, object, ip, true);
> }
>
> +void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
> +{
> + struct page *page;
> +
> + page = virt_to_head_page(ptr);
> +
> + /*
> + * Even though this function is only called for kmem_cache_alloc and
> + * kmalloc backed mempool allocations, those allocations can still be
> + * !PageSlab() when the size provided to kmalloc is larger than
> + * KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc.
> + */
> + if (unlikely(!PageSlab(page))) {
> + if (ptr != page_address(page)) {
> + kasan_report_invalid_free(ptr, ip);
> + return;
> + }
> + poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
> + } else {
> + ____kasan_slab_free(page->slab_cache, ptr, ip, false);
> + }
> +}
> +
> 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);
> @@ -429,23 +452,6 @@ void * __must_check __kasan_krealloc(const void *object,
> size_t size, gfp_t flag
> flags, true);
> }
>
> -void __kasan_poison_kfree(void *ptr, unsigned long ip)
> -{
> - struct page *page;
> -
> - page = virt_to_head_page(ptr);
> -
> - if (unlikely(!PageSlab(page))) {
> - if (ptr != page_address(page)) {
> - kasan_report_invalid_free(ptr, ip);
> - return;
> - }
> - poison_range(ptr, page_size(page), KASAN_FREE_PAGE);
> - } else {
> - ____kasan_slab_free(page->slab_cache, ptr, ip, false);
> - }
> -}
> -
> void __kasan_kfree_large(void *ptr, unsigned long ip)
> {
> if (ptr != page_address(virt_to_head_page(ptr)))
> diff --git a/mm/mempool.c b/mm/mempool.c
> index 583a9865b181..624ed51b060f 100644
> --- a/mm/mempool.c
> +++ b/mm/mempool.c
> @@ -104,7 +104,7 @@ static inline void poison_element(mempool_t *pool, void
> *element)
> static __always_inline void kasan_poison_element(mempool_t *pool, void
> *element)
> {
> if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
> - kasan_poison_kfree(element, _RET_IP_);
> + kasan_slab_free_mempool(element, _RET_IP_);
> else if (pool->alloc == mempool_alloc_pages)
> kasan_free_pages(element, (unsigned long)pool->pool_data);
> }
> --
> 2.29.2.299.gdc1121823c-goog
>
