diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2016-11-30 15:54:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-11-30 16:32:52 -0800 |
| commit | 828347f8f9a558cf1af2faa46387a26564f2ac3e (patch) | |
| tree | 4acb63366cc89b3e87e85805530911300dd4ab19 /mm/kasan/kasan.c | |
| parent | 045d599a286bc01daa3510d59272440a17b23c2e (diff) | |
kasan: support use-after-scope detection
Gcc revision 241896 implements use-after-scope detection. Will be
available in gcc 7. Support it in KASAN.
Gcc emits 2 new callbacks to poison/unpoison large stack objects when
they go in/out of scope. Implement the callbacks and add a test.
[dvyukov@google.com: v3]
Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com
Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org> [4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/kasan.c')
| -rw-r--r-- | mm/kasan/kasan.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 70c009741aab..0e9505f66ec1 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -764,6 +764,25 @@ EXPORT_SYMBOL(__asan_storeN_noabort); void __asan_handle_no_return(void) {} EXPORT_SYMBOL(__asan_handle_no_return); +/* Emitted by compiler to poison large objects when they go out of scope. */ +void __asan_poison_stack_memory(const void *addr, size_t size) +{ + /* + * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded + * by redzones, so we simply round up size to simplify logic. + */ + kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), + KASAN_USE_AFTER_SCOPE); +} +EXPORT_SYMBOL(__asan_poison_stack_memory); + +/* Emitted by compiler to unpoison large objects when they go into scope. */ +void __asan_unpoison_stack_memory(const void *addr, size_t size) +{ + kasan_unpoison_shadow(addr, size); +} +EXPORT_SYMBOL(__asan_unpoison_stack_memory); + #ifdef CONFIG_MEMORY_HOTPLUG static int kasan_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) |