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| author | Andrey Konovalov <andreyknvl@google.com> | 2018-12-28 09:30:16 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-28 21:11:43 +0100 |
| commit | 3c9e3aa11094e821aff4a8f6812a6e032293dbc0 (patch) | |
| tree | 6d4b0baeb13a2f51dc3b5dd2019b0133b0456ca2 /mm/kasan/kasan.h | |
| parent | arm64: move untagged_addr macro from uaccess.h to memory.h (diff) | |
| download | linux-3c9e3aa11094e821aff4a8f6812a6e032293dbc0.tar.xz linux-3c9e3aa11094e821aff4a8f6812a6e032293dbc0.zip | |
kasan: add tag related helper functions
This commit adds a few helper functions, that are meant to be used to work
with tags embedded in the top byte of kernel pointers: to set, to get or
to reset the top byte.
Link: http://lkml.kernel.org/r/f6c6437bb8e143bc44f42c3c259c62e734be7935.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.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>
Diffstat (limited to 'mm/kasan/kasan.h')
| -rw-r--r-- | mm/kasan/kasan.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 19b950eaccff..b080b8d92812 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -8,6 +8,10 @@ #define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) #define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1) +#define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ +#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ +#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ + #define KASAN_FREE_PAGE 0xFF /* page was freed */ #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ #define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */ @@ -126,6 +130,33 @@ static inline void quarantine_reduce(void) { } static inline void quarantine_remove_cache(struct kmem_cache *cache) { } #endif +#ifdef CONFIG_KASAN_SW_TAGS + +u8 random_tag(void); + +#else + +static inline u8 random_tag(void) +{ + return 0; +} + +#endif + +#ifndef arch_kasan_set_tag +#define arch_kasan_set_tag(addr, tag) ((void *)(addr)) +#endif +#ifndef arch_kasan_reset_tag +#define arch_kasan_reset_tag(addr) ((void *)(addr)) +#endif +#ifndef arch_kasan_get_tag +#define arch_kasan_get_tag(addr) 0 +#endif + +#define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag))) +#define reset_tag(addr) ((void *)arch_kasan_reset_tag(addr)) +#define get_tag(addr) arch_kasan_get_tag(addr) + /* * Exported functions for interfaces called from assembly or from generated * code. Declarations here to avoid warning about missing declarations. |