kasan, mm: rename kasan_poison_kfree

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.

Link: https://lkml.kernel.org/r/141675fb493555e984c5dca555e9d9f768c7bbaa.1606162397.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/I5026f87364e556b506ef1baee725144bb04b8810
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 9176849c49349df2fb7fe04b1029bc7bcee69d4e..6f0c5d9aa43f246a735e2938966a910bd1203103 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -176,6 +176,13 @@ 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(
@@ -216,13 +223,6 @@ 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)
 {
@@ -261,6 +261,7 @@ 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)
 {
@@ -280,7 +281,6 @@ 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 ae0130cf9de3d9fa14363e4079a32516b86b27f5..d0f8d7a955cd95d86713c81fa376d84f40446d07 100644 (file)
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -331,6 +331,29 @@ 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);
@@ -422,23 +445,6 @@ 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 583a9865b181863e15b20769418b88ea4eeef8c7..624ed51b060f0549c398b659b1cc66d26e7ede5f 100644 (file)
--- 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);
 }