Since functions memset, memmove, memcpy are written in assembly, compiler can't instrument memory accesses inside them. This patch replaces these functions with our own instrumented functions (kasan_mem*) for CONFIG_KASAN = y In rare circumstances you may need to use the original functions, in such case put #undef KASAN_HOOKS before includes. Signed-off-by: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx> --- arch/x86/include/asm/string_32.h | 28 ++++++++++++++++++++++++++++ arch/x86/include/asm/string_64.h | 24 ++++++++++++++++++++++++ arch/x86/lib/Makefile | 2 ++ 3 files changed, 54 insertions(+) diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h index 3d3e835..a86615a 100644 --- a/arch/x86/include/asm/string_32.h +++ b/arch/x86/include/asm/string_32.h @@ -321,6 +321,32 @@ void *__constant_c_and_count_memset(void *s, unsigned long pattern, : __memset_generic((s), (c), (count))) #define __HAVE_ARCH_MEMSET + +#if defined(CONFIG_KASAN) && defined(KASAN_HOOKS) + +/* + * Since some of the following functions (memset, memmove, memcpy) + * are written in assembly, compiler can't instrument memory accesses + * inside them. + * + * To solve this issue we replace these functions with our own instrumented + * functions (kasan_mem*) + * + * In rare circumstances you may need to use the original functions, + * in such case put #undef KASAN_HOOKS before includes. + */ + +#undef memcpy +void *kasan_memset(void *ptr, int val, size_t len); +void *kasan_memcpy(void *dst, const void *src, size_t len); +void *kasan_memmove(void *dst, const void *src, size_t len); + +#define memcpy(dst, src, len) kasan_memcpy((dst), (src), (len)) +#define memset(ptr, val, len) kasan_memset((ptr), (val), (len)) +#define memmove(dst, src, len) kasan_memmove((dst), (src), (len)) + +#else /* CONFIG_KASAN && KASAN_HOOKS */ + #if (__GNUC__ >= 4) #define memset(s, c, count) __builtin_memset(s, c, count) #else @@ -331,6 +357,8 @@ void *__constant_c_and_count_memset(void *s, unsigned long pattern, : __memset((s), (c), (count))) #endif +#endif /* CONFIG_KASAN && KASAN_HOOKS */ + /* * find the first occurrence of byte 'c', or 1 past the area if none */ diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 19e2c46..2af2dbe 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -63,6 +63,30 @@ char *strcpy(char *dest, const char *src); char *strcat(char *dest, const char *src); int strcmp(const char *cs, const char *ct); +#if defined(CONFIG_KASAN) && defined(KASAN_HOOKS) + +/* + * Since some of the following functions (memset, memmove, memcpy) + * are written in assembly, compiler can't instrument memory accesses + * inside them. + * + * To solve this issue we replace these functions with our own instrumented + * functions (kasan_mem*) + * + * In rare circumstances you may need to use the original functions, + * in such case put #undef KASAN_HOOKS before includes. + */ + +void *kasan_memset(void *ptr, int val, size_t len); +void *kasan_memcpy(void *dst, const void *src, size_t len); +void *kasan_memmove(void *dst, const void *src, size_t len); + +#define memcpy(dst, src, len) kasan_memcpy((dst), (src), (len)) +#define memset(ptr, val, len) kasan_memset((ptr), (val), (len)) +#define memmove(dst, src, len) kasan_memmove((dst), (src), (len)) + +#endif /* CONFIG_KASAN && KASAN_HOOKS */ + #endif /* __KERNEL__ */ #endif /* _ASM_X86_STRING_64_H */ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 4d4f96a..d82bc35 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -2,6 +2,8 @@ # Makefile for x86 specific library files. # +KASAN_SANITIZE_memcpy_32.o := n + inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt quiet_cmd_inat_tables = GEN $@ -- 1.8.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
