The patch titled
Subject: kasan: don't use __builtin_return_address(1)
has been added to the -mm tree. Its filename is
kasan-dont-use-__builtin_return_address1.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-dont-use-__builtin_return_address1.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-dont-use-__builtin_return_address1.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>a
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/kasan.h | 9 +++++----
mm/kasan/kasan.c | 8 ++++----
mm/kasan/kasan.h | 2 +-
mm/kasan/report.c | 4 ++--
mm/slab.c | 6 +++---
mm/slub.c | 8 ++++----
6 files changed, 19 insertions(+), 18 deletions(-)
diff -puN include/linux/kasan.h~kasan-dont-use-__builtin_return_address1 include/linux/kasan.h
--- a/include/linux/kasan.h~kasan-dont-use-__builtin_return_address1
+++ a/include/linux/kasan.h
@@ -56,14 +56,14 @@ void kasan_poison_object_data(struct kme
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(s
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
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 -puN mm/kasan/kasan.c~kasan-dont-use-__builtin_return_address1 mm/kasan/kasan.c
--- a/mm/kasan/kasan.c~kasan-dont-use-__builtin_return_address1
+++ a/mm/kasan/kasan.c
@@ -501,7 +501,7 @@ static void kasan_poison_slab_free(struc
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 *
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 -puN mm/kasan/kasan.h~kasan-dont-use-__builtin_return_address1 mm/kasan/kasan.h
--- a/mm/kasan/kasan.h~kasan-dont-use-__builtin_return_address1
+++ a/mm/kasan/kasan.h
@@ -107,7 +107,7 @@ static inline const void *kasan_shadow_t
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 -puN mm/kasan/report.c~kasan-dont-use-__builtin_return_address1 mm/kasan/report.c
--- a/mm/kasan/report.c~kasan-dont-use-__builtin_return_address1
+++ a/mm/kasan/report.c
@@ -326,12 +326,12 @@ static void print_shadow_for_address(con
}
}
-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 -puN mm/slab.c~kasan-dont-use-__builtin_return_address1 mm/slab.c
--- a/mm/slab.c~kasan-dont-use-__builtin_return_address1
+++ a/mm/slab.c
@@ -3477,11 +3477,11 @@ 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 -puN mm/slub.c~kasan-dont-use-__builtin_return_address1 mm/slub.c
--- a/mm/slub.c~kasan-dont-use-__builtin_return_address1
+++ a/mm/slub.c
@@ -1354,13 +1354,13 @@ static inline void kmalloc_large_node_ho
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;
@@ -1388,7 +1388,7 @@ static inline void *slab_free_hook(struc
* 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;
}
_
Patches currently in -mm which might be from dvyukov@xxxxxxxxxx are
kasan-detect-invalid-frees-for-large-objects.patch
kasan-dont-use-__builtin_return_address1.patch
kasan-detect-invalid-frees-for-large-mempool-objects.patch
kasan-unify-code-between-kasan_slab_free-and-kasan_poison_kfree.patch
kasan-detect-invalid-frees.patch
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