diff options
author | Walter Wu <walter-zh.wu@mediatek.com> | 2020-08-06 23:24:39 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 11:33:28 -0700 |
commit | e4b7818b9aa8fa8dfd5fc7bb98f0d4c16b50fd8b (patch) | |
tree | ca2fdf671e3f54c67c5a86efe5a3f81603d36370 /mm/kasan/tags.c | |
parent | 26e760c9a7c8ec31fa1a6bfbbce3f63f189ccef0 (diff) | |
download | linux-stable-e4b7818b9aa8fa8dfd5fc7bb98f0d4c16b50fd8b.tar.gz linux-stable-e4b7818b9aa8fa8dfd5fc7bb98f0d4c16b50fd8b.tar.bz2 linux-stable-e4b7818b9aa8fa8dfd5fc7bb98f0d4c16b50fd8b.zip |
kasan: record and print the free track
Move free track from kasan_alloc_meta to kasan_free_meta in order to make
struct kasan_alloc_meta and kasan_free_meta size are both 16 bytes. It is
a good size because it is the minimal redzone size and a good number of
alignment.
For free track, we make some modifications as shown below:
1) Remove the free_track from struct kasan_alloc_meta.
2) Add the free_track into struct kasan_free_meta.
3) Add a macro KASAN_KMALLOC_FREETRACK in order to check whether
it can print free stack in KASAN report.
[1]https://bugzilla.kernel.org/show_bug.cgi?id=198437
[walter-zh.wu@mediatek.com: build fix]
Link: http://lkml.kernel.org/r/20200710162440.23887-1-walter-zh.wu@mediatek.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Co-developed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Link: http://lkml.kernel.org/r/20200601051022.1230-1-walter-zh.wu@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/tags.c')
-rw-r--r-- | mm/kasan/tags.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 8a959fdd30e3..e02a36a51f42 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -161,3 +161,40 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size) kasan_poison_shadow((void *)addr, size, tag); } EXPORT_SYMBOL(__hwasan_tag_memory); + +void kasan_set_free_info(struct kmem_cache *cache, + void *object, u8 tag) +{ + struct kasan_alloc_meta *alloc_meta; + u8 idx = 0; + + alloc_meta = get_alloc_info(cache, object); + +#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY + idx = alloc_meta->free_track_idx; + alloc_meta->free_pointer_tag[idx] = tag; + alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS; +#endif + + kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT); +} + +struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, + void *object, u8 tag) +{ + struct kasan_alloc_meta *alloc_meta; + int i = 0; + + alloc_meta = get_alloc_info(cache, object); + +#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY + for (i = 0; i < KASAN_NR_FREE_STACKS; i++) { + if (alloc_meta->free_pointer_tag[i] == tag) + break; + } + if (i == KASAN_NR_FREE_STACKS) + i = alloc_meta->free_track_idx; +#endif + + return &alloc_meta->free_track[i]; +} |