kasan: don't use __builtin_return_address(1)

__builtin_return_address(1) is unreliable without frame pointers.
With defconfig on kmalloc_pagealloc_invalid_free test I am getting:

BUG: KASAN: double-free or invalid-free in           (null)

Pass caller PC from callers explicitly.

Link: http://lkml.kernel.org/r/9b01bc2d237a4df74ff8472a3bf6b7635908de01.1514378558.git.dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>a
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 fc9e642..f0d13c3 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -56,14 +56,14 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object);
 void kasan_init_slab_obj(struct kmem_cache *cache, const void *object);
 
 void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags);
-void kasan_kfree_large(void *ptr);
+void kasan_kfree_large(void *ptr, unsigned long ip);
 void kasan_poison_kfree(void *ptr);
 void kasan_kmalloc(struct kmem_cache *s, const void *object, size_t size,
                  gfp_t flags);
 void kasan_krealloc(const void *object, size_t new_size, gfp_t flags);
 
 void kasan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags);
-bool kasan_slab_free(struct kmem_cache *s, void *object);
+bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
 
 struct kasan_cache {
        int alloc_meta_offset;
@@ -108,7 +108,7 @@ static inline void kasan_init_slab_obj(struct kmem_cache *cache,
                                const void *object) {}
 
 static inline void kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags) {}
-static inline void kasan_kfree_large(void *ptr) {}
+static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
 static inline void kasan_poison_kfree(void *ptr) {}
 static inline void kasan_kmalloc(struct kmem_cache *s, const void *object,
                                size_t size, gfp_t flags) {}
@@ -117,7 +117,8 @@ static inline void kasan_krealloc(const void *object, size_t new_size,
 
 static inline void kasan_slab_alloc(struct kmem_cache *s, void *object,
                                   gfp_t flags) {}
-static inline bool kasan_slab_free(struct kmem_cache *s, void *object)
+static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
+                                  unsigned long ip)
 {
        return false;
 }

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index ecb64fd..32f555d 100644 (file)
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -501,7 +501,7 @@ static void kasan_poison_slab_free(struct kmem_cache *cache, void *object)
        kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
 }
 
-bool kasan_slab_free(struct kmem_cache *cache, void *object)
+bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip)
 {
        s8 shadow_byte;
 
@@ -511,7 +511,7 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object)
 
        shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object));
        if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) {
-               kasan_report_invalid_free(object, __builtin_return_address(1));
+               kasan_report_invalid_free(object, ip);
                return true;
        }
 
@@ -601,10 +601,10 @@ void kasan_poison_kfree(void *ptr)
                kasan_poison_slab_free(page->slab_cache, ptr);
 }
 
-void kasan_kfree_large(void *ptr)
+void kasan_kfree_large(void *ptr, unsigned long ip)
 {
        if (ptr != page_address(virt_to_head_page(ptr)))
-               kasan_report_invalid_free(ptr, __builtin_return_address(1));
+               kasan_report_invalid_free(ptr, ip);
        /* The object will be poisoned by page_alloc. */
 }
 

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index bf353a1..c12dcfd 100644 (file)
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -107,7 +107,7 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 
 void kasan_report(unsigned long addr, size_t size,
                bool is_write, unsigned long ip);
-void kasan_report_invalid_free(void *object, void *ip);
+void kasan_report_invalid_free(void *object, unsigned long ip);
 
 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB)
 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 55916ad..7520699 100644 (file)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -326,12 +326,12 @@ static void print_shadow_for_address(const void *addr)
        }
 }
 
-void kasan_report_invalid_free(void *object, void *ip)
+void kasan_report_invalid_free(void *object, unsigned long ip)
 {
        unsigned long flags;
 
        kasan_start_report(&flags);
-       pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", ip);
+       pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
        pr_err("\n");
        print_address_description(object);
        pr_err("\n");

diff --git a/mm/slab.c b/mm/slab.c
index cd86f15..3244466 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3478,11 +3478,11 @@ free_done:
  * Release an obj back to its cache. If the obj has a constructed state, it must
  * be in this state _before_ it is released.  Called with disabled ints.
  */
-static inline void __cache_free(struct kmem_cache *cachep, void *objp,
-                               unsigned long caller)
+static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp,
+                                        unsigned long caller)
 {
        /* Put the object into the quarantine, don't touch it for now. */
-       if (kasan_slab_free(cachep, objp))
+       if (kasan_slab_free(cachep, objp, _RET_IP_))
                return;
 
        ___cache_free(cachep, objp, caller);

diff --git a/mm/slub.c b/mm/slub.c
index b54f878..e381728 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1356,13 +1356,13 @@ static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
        kasan_kmalloc_large(ptr, size, flags);
 }
 
-static inline void kfree_hook(void *x)
+static __always_inline void kfree_hook(void *x)
 {
        kmemleak_free(x);
-       kasan_kfree_large(x);
+       kasan_kfree_large(x, _RET_IP_);
 }
 
-static inline void *slab_free_hook(struct kmem_cache *s, void *x)
+static __always_inline void *slab_free_hook(struct kmem_cache *s, void *x)
 {
        void *freeptr;
 
@@ -1390,7 +1390,7 @@ static inline void *slab_free_hook(struct kmem_cache *s, void *x)
         * kasan_slab_free() may put x into memory quarantine, delaying its
         * reuse. In this case the object's freelist pointer is changed.
         */
-       kasan_slab_free(s, x);
+       kasan_slab_free(s, x, _RET_IP_);
        return freeptr;
 }