From 19a2ca0fb560fd7be7b5293c6b652c6d6078dcde Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Fri, 26 Oct 2018 15:02:30 -0700 Subject: 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 Reported-by: Kyeongdon Kim Cc: Alexander Potapenko Cc: Ard Biesheuvel Cc: Dmitry Vyukov Cc: Mark Rutland Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm64/include/asm/string.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'arch/arm64/include/asm/string.h') 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); -- cgit