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author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2018-10-26 15:02:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-26 16:25:18 -0700 |
commit | 19a2ca0fb560fd7be7b5293c6b652c6d6078dcde (patch) | |
tree | c4ed897c25ef86a5b04565027e6f7e65ff3d7f45 /arch/arm64/include/asm/string.h | |
parent | 74f213ea25b99fddcf34cbe07dabdb01136bcd86 (diff) | |
download | lwn-19a2ca0fb560fd7be7b5293c6b652c6d6078dcde.tar.gz lwn-19a2ca0fb560fd7be7b5293c6b652c6d6078dcde.zip |
arm64: lib: use C string functions with KASAN enabled
ARM64 has asm implementation of memchr(), memcmp(), str[r]chr(),
str[n]cmp(), str[n]len(). KASAN don't see memory accesses in asm code,
thus it can potentially miss many bugs.
Ifdef out __HAVE_ARCH_* defines of these functions when KASAN is enabled,
so the generic implementations from lib/string.c will be used.
We can't just remove the asm functions because efistub uses them. And we
can't have two non-weak functions either, so declare the asm functions as
weak.
Link: http://lkml.kernel.org/r/20180920135631.23833-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@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/include/asm/string.h')
-rw-r--r-- | arch/arm64/include/asm/string.h | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h index dd95d33a5bd5..03a6c256b7ec 100644 --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -16,6 +16,7 @@ #ifndef __ASM_STRING_H #define __ASM_STRING_H +#ifndef CONFIG_KASAN #define __HAVE_ARCH_STRRCHR extern char *strrchr(const char *, int c); @@ -34,6 +35,13 @@ extern __kernel_size_t strlen(const char *); #define __HAVE_ARCH_STRNLEN extern __kernel_size_t strnlen(const char *, __kernel_size_t); +#define __HAVE_ARCH_MEMCMP +extern int memcmp(const void *, const void *, size_t); + +#define __HAVE_ARCH_MEMCHR +extern void *memchr(const void *, int, __kernel_size_t); +#endif + #define __HAVE_ARCH_MEMCPY extern void *memcpy(void *, const void *, __kernel_size_t); extern void *__memcpy(void *, const void *, __kernel_size_t); @@ -42,16 +50,10 @@ extern void *__memcpy(void *, const void *, __kernel_size_t); extern void *memmove(void *, const void *, __kernel_size_t); extern void *__memmove(void *, const void *, __kernel_size_t); -#define __HAVE_ARCH_MEMCHR -extern void *memchr(const void *, int, __kernel_size_t); - #define __HAVE_ARCH_MEMSET extern void *memset(void *, int, __kernel_size_t); extern void *__memset(void *, int, __kernel_size_t); -#define __HAVE_ARCH_MEMCMP -extern int memcmp(const void *, const void *, size_t); - #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE #define __HAVE_ARCH_MEMCPY_FLUSHCACHE void memcpy_flushcache(void *dst, const void *src, size_t cnt); |