diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2018-12-28 00:30:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-28 12:11:43 -0800 |
| commit | 3c9e3aa11094e821aff4a8f6812a6e032293dbc0 (patch) | |
| tree | 6d4b0baeb13a2f51dc3b5dd2019b0133b0456ca2 /arch/arm64 | |
| parent | 9c23f84723d2bb5611a973f56f0952fa74f048f3 (diff) | |
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 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/kasan.h | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 12 | ||||
| -rw-r--r-- | arch/arm64/mm/kasan_init.c | 2 |
3 files changed, 20 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kasan.h b/arch/arm64/include/asm/kasan.h index 8758bb008436..b52aacd2c526 100644 --- a/arch/arm64/include/asm/kasan.h +++ b/arch/arm64/include/asm/kasan.h @@ -4,12 +4,16 @@ #ifndef __ASSEMBLY__ -#ifdef CONFIG_KASAN - #include <linux/linkage.h> #include <asm/memory.h> #include <asm/pgtable-types.h> +#define arch_kasan_set_tag(addr, tag) __tag_set(addr, tag) +#define arch_kasan_reset_tag(addr) __tag_reset(addr) +#define arch_kasan_get_tag(addr) __tag_get(addr) + +#ifdef CONFIG_KASAN + /* * KASAN_SHADOW_START: beginning of the kernel virtual addresses. * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses, diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index e73bb89d6141..25b46f88726c 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -226,6 +226,18 @@ extern u64 vabits_user; #define untagged_addr(addr) \ ((__typeof__(addr))sign_extend64((u64)(addr), 55)) +#ifdef CONFIG_KASAN_SW_TAGS +#define __tag_shifted(tag) ((u64)(tag) << 56) +#define __tag_set(addr, tag) (__typeof__(addr))( \ + ((u64)(addr) & ~__tag_shifted(0xff)) | __tag_shifted(tag)) +#define __tag_reset(addr) untagged_addr(addr) +#define __tag_get(addr) (__u8)((u64)(addr) >> 56) +#else +#define __tag_set(addr, tag) (addr) +#define __tag_reset(addr) (addr) +#define __tag_get(addr) 0 +#endif + /* * Physical vs virtual RAM address space conversion. These are * private definitions which should NOT be used outside memory.h diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 38fa4bba9279..3e142add890b 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -252,6 +252,8 @@ void __init kasan_init(void) memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); + kasan_init_tags(); + /* At this point kasan is fully initialized. Enable error messages */ init_task.kasan_depth = 0; pr_info("KernelAddressSanitizer initialized\n"); |