linux/arch/x86/include/asm/string_64.h
Alexander Potapenko 78a498c3a2 x86: fortify: kmsan: fix KMSAN fortify builds
Ensure that KMSAN builds replace memset/memcpy/memmove calls with the
respective __msan_XXX functions, and that none of the macros are redefined
twice.  This should allow building kernel with both CONFIG_KMSAN and
CONFIG_FORTIFY_SOURCE.

Link: https://lkml.kernel.org/r/20221024212144.2852069-5-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:23 -07:00

133 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_STRING_64_H
#define _ASM_X86_STRING_64_H
#ifdef __KERNEL__
#include <linux/jump_label.h>
/* Written 2002 by Andi Kleen */
/* Even with __builtin_ the compiler may decide to use the out of line
function. */
#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
#include <linux/kmsan_string.h>
#endif
#define __HAVE_ARCH_MEMCPY 1
#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
#undef memcpy
#define memcpy __msan_memcpy
#else
extern void *memcpy(void *to, const void *from, size_t len);
#endif
extern void *__memcpy(void *to, const void *from, size_t len);
#define __HAVE_ARCH_MEMSET
#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
extern void *__msan_memset(void *s, int c, size_t n);
#undef memset
#define memset __msan_memset
#else
void *memset(void *s, int c, size_t n);
#endif
void *__memset(void *s, int c, size_t n);
#define __HAVE_ARCH_MEMSET16
static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
{
long d0, d1;
asm volatile("rep\n\t"
"stosw"
: "=&c" (d0), "=&D" (d1)
: "a" (v), "1" (s), "0" (n)
: "memory");
return s;
}
#define __HAVE_ARCH_MEMSET32
static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
{
long d0, d1;
asm volatile("rep\n\t"
"stosl"
: "=&c" (d0), "=&D" (d1)
: "a" (v), "1" (s), "0" (n)
: "memory");
return s;
}
#define __HAVE_ARCH_MEMSET64
static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
{
long d0, d1;
asm volatile("rep\n\t"
"stosq"
: "=&c" (d0), "=&D" (d1)
: "a" (v), "1" (s), "0" (n)
: "memory");
return s;
}
#define __HAVE_ARCH_MEMMOVE
#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
#undef memmove
void *__msan_memmove(void *dest, const void *src, size_t len);
#define memmove __msan_memmove
#else
void *memmove(void *dest, const void *src, size_t count);
#endif
void *__memmove(void *dest, const void *src, size_t count);
int memcmp(const void *cs, const void *ct, size_t count);
size_t strlen(const char *s);
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(__SANITIZE_ADDRESS__))
/*
* For files that not instrumented (e.g. mm/slub.c) we
* should use not instrumented version of mem* functions.
*/
#undef memcpy
#define memcpy(dst, src, len) __memcpy(dst, src, len)
#undef memmove
#define memmove(dst, src, len) __memmove(dst, src, len)
#undef memset
#define memset(s, c, n) __memset(s, c, n)
#ifndef __NO_FORTIFY
#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
#endif
#endif
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
static __always_inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
{
if (__builtin_constant_p(cnt)) {
switch (cnt) {
case 4:
asm ("movntil %1, %0" : "=m"(*(u32 *)dst) : "r"(*(u32 *)src));
return;
case 8:
asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
return;
case 16:
asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
asm ("movntiq %1, %0" : "=m"(*(u64 *)(dst + 8)) : "r"(*(u64 *)(src + 8)));
return;
}
}
__memcpy_flushcache(dst, src, cnt);
}
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_X86_STRING_64_H */