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Commit a28a6e86 authored by Francis Laniel's avatar Francis Laniel Committed by Linus Torvalds
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string.h: move fortified functions definitions in a dedicated header. 

This patch adds fortify-string.h to contain fortified functions
definitions.  Thus, the code is more separated and compile time is
approximately 1% faster for people who do not set CONFIG_FORTIFY_SOURCE.

Link: https://lkml.kernel.org/r/20210111092141.22946-1-laniel_francis@privacyrequired.com
Link: https://lkml.kernel.org/r/20210111092141.22946-2-laniel_francis@privacyrequired.comSigned-off-by: default avatarFrancis Laniel <laniel_francis@privacyrequired.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0e24465d
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Inline Side-by-side
Showing with 303 additions and 281 deletions
include/linux/fortify-string.h 0 → 100644
View file @ a28a6e86
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FORTIFY_STRING_H_
#define _LINUX_FORTIFY_STRING_H_
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove);
extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset);
extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat);
extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy);
extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
#else
#define __underlying_memchr __builtin_memchr
#define __underlying_memcmp __builtin_memcmp
#define __underlying_memcpy __builtin_memcpy
#define __underlying_memmove __builtin_memmove
#define __underlying_memset __builtin_memset
#define __underlying_strcat __builtin_strcat
#define __underlying_strcpy __builtin_strcpy
#define __underlying_strlen __builtin_strlen
#define __underlying_strncat __builtin_strncat
#define __underlying_strncpy __builtin_strncpy
#endif
__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 1);
if (__builtin_constant_p(size) && p_size < size)
__write_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_strncpy(p, q, size);
}
__FORTIFY_INLINE char *strcat(char *p, const char *q)
{
size_t p_size = __builtin_object_size(p, 1);
if (p_size == (size_t)-1)
return __underlying_strcat(p, q);
if (strlcat(p, q, p_size) >= p_size)
fortify_panic(__func__);
return p;
}
__FORTIFY_INLINE __kernel_size_t strlen(const char *p)
{
__kernel_size_t ret;
size_t p_size = __builtin_object_size(p, 1);
/* Work around gcc excess stack consumption issue */
if (p_size == (size_t)-1 ||
(__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
return __underlying_strlen(p);
ret = strnlen(p, p_size);
if (p_size <= ret)
fortify_panic(__func__);
return ret;
}
extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
{
size_t p_size = __builtin_object_size(p, 1);
__kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
if (p_size <= ret && maxlen != ret)
fortify_panic(__func__);
return ret;
}
/* defined after fortified strlen to reuse it */
extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
{
size_t ret;
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __real_strlcpy(p, q, size);
ret = strlen(q);
if (size) {
size_t len = (ret >= size) ? size - 1 : ret;
if (__builtin_constant_p(len) && len >= p_size)
__write_overflow();
if (len >= p_size)
fortify_panic(__func__);
__underlying_memcpy(p, q, len);
p[len] = '\0';
}
return ret;
}
/* defined after fortified strnlen to reuse it */
extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy);
__FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size)
{
size_t len;
/* Use string size rather than possible enclosing struct size. */
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
/* If we cannot get size of p and q default to call strscpy. */
if (p_size == (size_t) -1 && q_size == (size_t) -1)
return __real_strscpy(p, q, size);
/*
* If size can be known at compile time and is greater than
* p_size, generate a compile time write overflow error.
*/
if (__builtin_constant_p(size) && size > p_size)
__write_overflow();
/*
* This call protects from read overflow, because len will default to q
* length if it smaller than size.
*/
len = strnlen(q, size);
/*
* If len equals size, we will copy only size bytes which leads to
* -E2BIG being returned.
* Otherwise we will copy len + 1 because of the final '\O'.
*/
len = len == size ? size : len + 1;
/*
* Generate a runtime write overflow error if len is greater than
* p_size.
*/
if (len > p_size)
fortify_panic(__func__);
/*
* We can now safely call vanilla strscpy because we are protected from:
* 1. Read overflow thanks to call to strnlen().
* 2. Write overflow thanks to above ifs.
*/
return __real_strscpy(p, q, len);
}
/* defined after fortified strlen and strnlen to reuse them */
__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
{
size_t p_len, copy_len;
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __underlying_strncat(p, q, count);
p_len = strlen(p);
copy_len = strnlen(q, count);
if (p_size < p_len + copy_len + 1)
fortify_panic(__func__);
__underlying_memcpy(p + p_len, q, copy_len);
p[p_len + copy_len] = '\0';
return p;
}
__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__write_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_memset(p, c, size);
}
__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__write_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memcpy(p, q, size);
}
__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__write_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memmove(p, q, size);
}
extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
__FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_memscan(p, c, size);
}
__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__read_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memcmp(p, q, size);
}
__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_memchr(p, c, size);
}
void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_memchr_inv(p, c, size);
}
extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
__FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_kmemdup(p, size, gfp);
}
/* defined after fortified strlen and memcpy to reuse them */
__FORTIFY_INLINE char *strcpy(char *p, const char *q)
{
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
size_t size;
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __underlying_strcpy(p, q);
size = strlen(q) + 1;
/* test here to use the more stringent object size */
if (p_size < size)
fortify_panic(__func__);
memcpy(p, q, size);
return p;
}
/* Don't use these outside the FORITFY_SOURCE implementation */
#undef __underlying_memchr
#undef __underlying_memcmp
#undef __underlying_memcpy
#undef __underlying_memmove
#undef __underlying_memset
#undef __underlying_strcat
#undef __underlying_strcpy
#undef __underlying_strlen
#undef __underlying_strncat
#undef __underlying_strncpy
#endif /* _LINUX_FORTIFY_STRING_H_ */
include/linux/string.h
View file @ a28a6e86
......@@ -266,287 +266,7 @@ void __read_overflow3(void) __compiletime_error("detected read beyond size of ob
void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove);
extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset);
extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat);
extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy);
extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
#else
#define __underlying_memchr __builtin_memchr
#define __underlying_memcmp __builtin_memcmp
#define __underlying_memcpy __builtin_memcpy
#define __underlying_memmove __builtin_memmove
#define __underlying_memset __builtin_memset
#define __underlying_strcat __builtin_strcat
#define __underlying_strcpy __builtin_strcpy
#define __underlying_strlen __builtin_strlen
#define __underlying_strncat __builtin_strncat
#define __underlying_strncpy __builtin_strncpy
#endif
__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 1);
if (__builtin_constant_p(size) && p_size < size)
__write_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_strncpy(p, q, size);
}
__FORTIFY_INLINE char *strcat(char *p, const char *q)
{
size_t p_size = __builtin_object_size(p, 1);
if (p_size == (size_t)-1)
return __underlying_strcat(p, q);
if (strlcat(p, q, p_size) >= p_size)
fortify_panic(__func__);
return p;
}
__FORTIFY_INLINE __kernel_size_t strlen(const char *p)
{
__kernel_size_t ret;
size_t p_size = __builtin_object_size(p, 1);
/* Work around gcc excess stack consumption issue */
if (p_size == (size_t)-1 ||
(__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
return __underlying_strlen(p);
ret = strnlen(p, p_size);
if (p_size <= ret)
fortify_panic(__func__);
return ret;
}
extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
{
size_t p_size = __builtin_object_size(p, 1);
__kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
if (p_size <= ret && maxlen != ret)
fortify_panic(__func__);
return ret;
}
/* defined after fortified strlen to reuse it */
extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
{
size_t ret;
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __real_strlcpy(p, q, size);
ret = strlen(q);
if (size) {
size_t len = (ret >= size) ? size - 1 : ret;
if (__builtin_constant_p(len) && len >= p_size)
__write_overflow();
if (len >= p_size)
fortify_panic(__func__);
__underlying_memcpy(p, q, len);
p[len] = '\0';
}
return ret;
}
/* defined after fortified strnlen to reuse it */
extern ssize_t __real_strscpy(char *, const char *, size_t) __RENAME(strscpy);
__FORTIFY_INLINE ssize_t strscpy(char *p, const char *q, size_t size)
{
size_t len;
/* Use string size rather than possible enclosing struct size. */
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
/* If we cannot get size of p and q default to call strscpy. */
if (p_size == (size_t) -1 && q_size == (size_t) -1)
return __real_strscpy(p, q, size);
/*
* If size can be known at compile time and is greater than
* p_size, generate a compile time write overflow error.
*/
if (__builtin_constant_p(size) && size > p_size)
__write_overflow();
/*
* This call protects from read overflow, because len will default to q
* length if it smaller than size.
*/
len = strnlen(q, size);
/*
* If len equals size, we will copy only size bytes which leads to
* -E2BIG being returned.
* Otherwise we will copy len + 1 because of the final '\O'.
*/
len = len == size ? size : len + 1;
/*
* Generate a runtime write overflow error if len is greater than
* p_size.
*/
if (len > p_size)
fortify_panic(__func__);
/*
* We can now safely call vanilla strscpy because we are protected from:
* 1. Read overflow thanks to call to strnlen().
* 2. Write overflow thanks to above ifs.
*/
return __real_strscpy(p, q, len);
}
/* defined after fortified strlen and strnlen to reuse them */
__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
{
size_t p_len, copy_len;
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __underlying_strncat(p, q, count);
p_len = strlen(p);
copy_len = strnlen(q, count);
if (p_size < p_len + copy_len + 1)
fortify_panic(__func__);
__underlying_memcpy(p + p_len, q, copy_len);
p[p_len + copy_len] = '\0';
return p;
}
__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__write_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_memset(p, c, size);
}
__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__write_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memcpy(p, q, size);
}
__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__write_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memmove(p, q, size);
}
extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
__FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_memscan(p, c, size);
}
__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
size_t q_size = __builtin_object_size(q, 0);
if (__builtin_constant_p(size)) {
if (p_size < size)
__read_overflow();
if (q_size < size)
__read_overflow2();
}
if (p_size < size || q_size < size)
fortify_panic(__func__);
return __underlying_memcmp(p, q, size);
}
__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __underlying_memchr(p, c, size);
}
void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_memchr_inv(p, c, size);
}
extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
__FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
{
size_t p_size = __builtin_object_size(p, 0);
if (__builtin_constant_p(size) && p_size < size)
__read_overflow();
if (p_size < size)
fortify_panic(__func__);
return __real_kmemdup(p, size, gfp);
}
/* defined after fortified strlen and memcpy to reuse them */
__FORTIFY_INLINE char *strcpy(char *p, const char *q)
{
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
size_t size;
if (p_size == (size_t)-1 && q_size == (size_t)-1)
return __underlying_strcpy(p, q);
size = strlen(q) + 1;
/* test here to use the more stringent object size */
if (p_size < size)
fortify_panic(__func__);
memcpy(p, q, size);
return p;
}
/* Don't use these outside the FORITFY_SOURCE implementation */
#undef __underlying_memchr
#undef __underlying_memcmp
#undef __underlying_memcpy
#undef __underlying_memmove
#undef __underlying_memset
#undef __underlying_strcat
#undef __underlying_strcpy
#undef __underlying_strlen
#undef __underlying_strncat
#undef __underlying_strncpy
#include <linux/fortify-string.h>
#endif
/**
......
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