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/arm/include/asm/string.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/arch/arm/include/asm/string.h b/arch/arm/include/asm/string.h index cf4f3aa..3cbe47f 100644 --- a/arch/arm/include/asm/string.h +++ b/arch/arm/include/asm/string.h @@ -38,4 +38,34 @@ extern void __memzero(void *ptr, __kernel_size_t n); (__p); \ }) + +#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 case if any of mem*() fucntions are written in C we use our instrumented + * functions for perfomance reasons. It's should be faster to check whole + * accessed memory range at once, then do a lot of checks at each memory access. + * + * In rare circumstances you may need to use the original functions, + * in such case #undef KASAN_HOOKS before includes. + */ +#undef memset + +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 -- 1.8.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>