1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_STRING_H_
3 #define _LINUX_STRING_H_
6 #include <linux/compiler.h> /* for inline */
7 #include <linux/types.h> /* for size_t */
8 #include <linux/stddef.h> /* for NULL */
10 #include <uapi/linux/string.h>
12 extern char *strndup_user(const char __user
*, long);
13 extern void *memdup_user(const void __user
*, size_t);
14 extern void *vmemdup_user(const void __user
*, size_t);
15 extern void *memdup_user_nul(const void __user
*, size_t);
18 * Include machine specific inline routines
20 #include <asm/string.h>
22 #ifndef __HAVE_ARCH_STRCPY
23 extern char * strcpy(char *,const char *);
25 #ifndef __HAVE_ARCH_STRNCPY
26 extern char * strncpy(char *,const char *, __kernel_size_t
);
28 #ifndef __HAVE_ARCH_STRLCPY
29 size_t strlcpy(char *, const char *, size_t);
31 #ifndef __HAVE_ARCH_STRSCPY
32 ssize_t
strscpy(char *, const char *, size_t);
35 /* Wraps calls to strscpy()/memset(), no arch specific code required */
36 ssize_t
strscpy_pad(char *dest
, const char *src
, size_t count
);
38 #ifndef __HAVE_ARCH_STRCAT
39 extern char * strcat(char *, const char *);
41 #ifndef __HAVE_ARCH_STRNCAT
42 extern char * strncat(char *, const char *, __kernel_size_t
);
44 #ifndef __HAVE_ARCH_STRLCAT
45 extern size_t strlcat(char *, const char *, __kernel_size_t
);
47 #ifndef __HAVE_ARCH_STRCMP
48 extern int strcmp(const char *,const char *);
50 #ifndef __HAVE_ARCH_STRNCMP
51 extern int strncmp(const char *,const char *,__kernel_size_t
);
53 #ifndef __HAVE_ARCH_STRCASECMP
54 extern int strcasecmp(const char *s1
, const char *s2
);
56 #ifndef __HAVE_ARCH_STRNCASECMP
57 extern int strncasecmp(const char *s1
, const char *s2
, size_t n
);
59 #ifndef __HAVE_ARCH_STRCHR
60 extern char * strchr(const char *,int);
62 #ifndef __HAVE_ARCH_STRCHRNUL
63 extern char * strchrnul(const char *,int);
65 extern char * strnchrnul(const char *, size_t, int);
66 #ifndef __HAVE_ARCH_STRNCHR
67 extern char * strnchr(const char *, size_t, int);
69 #ifndef __HAVE_ARCH_STRRCHR
70 extern char * strrchr(const char *,int);
72 extern char * __must_check
skip_spaces(const char *);
74 extern char *strim(char *);
76 static inline __must_check
char *strstrip(char *str
)
81 #ifndef __HAVE_ARCH_STRSTR
82 extern char * strstr(const char *, const char *);
84 #ifndef __HAVE_ARCH_STRNSTR
85 extern char * strnstr(const char *, const char *, size_t);
87 #ifndef __HAVE_ARCH_STRLEN
88 extern __kernel_size_t
strlen(const char *);
90 #ifndef __HAVE_ARCH_STRNLEN
91 extern __kernel_size_t
strnlen(const char *,__kernel_size_t
);
93 #ifndef __HAVE_ARCH_STRPBRK
94 extern char * strpbrk(const char *,const char *);
96 #ifndef __HAVE_ARCH_STRSEP
97 extern char * strsep(char **,const char *);
99 #ifndef __HAVE_ARCH_STRSPN
100 extern __kernel_size_t
strspn(const char *,const char *);
102 #ifndef __HAVE_ARCH_STRCSPN
103 extern __kernel_size_t
strcspn(const char *,const char *);
106 #ifndef __HAVE_ARCH_MEMSET
107 extern void * memset(void *,int,__kernel_size_t
);
110 #ifndef __HAVE_ARCH_MEMSET16
111 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t
);
114 #ifndef __HAVE_ARCH_MEMSET32
115 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t
);
118 #ifndef __HAVE_ARCH_MEMSET64
119 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t
);
122 static inline void *memset_l(unsigned long *p
, unsigned long v
,
125 if (BITS_PER_LONG
== 32)
126 return memset32((uint32_t *)p
, v
, n
);
128 return memset64((uint64_t *)p
, v
, n
);
131 static inline void *memset_p(void **p
, void *v
, __kernel_size_t n
)
133 if (BITS_PER_LONG
== 32)
134 return memset32((uint32_t *)p
, (uintptr_t)v
, n
);
136 return memset64((uint64_t *)p
, (uintptr_t)v
, n
);
139 extern void **__memcat_p(void **a
, void **b
);
140 #define memcat_p(a, b) ({ \
141 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \
142 "type mismatch in memcat_p()"); \
143 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \
146 #ifndef __HAVE_ARCH_MEMCPY
147 extern void * memcpy(void *,const void *,__kernel_size_t
);
149 #ifndef __HAVE_ARCH_MEMMOVE
150 extern void * memmove(void *,const void *,__kernel_size_t
);
152 #ifndef __HAVE_ARCH_MEMSCAN
153 extern void * memscan(void *,int,__kernel_size_t
);
155 #ifndef __HAVE_ARCH_MEMCMP
156 extern int memcmp(const void *,const void *,__kernel_size_t
);
158 #ifndef __HAVE_ARCH_BCMP
159 extern int bcmp(const void *,const void *,__kernel_size_t
);
161 #ifndef __HAVE_ARCH_MEMCHR
162 extern void * memchr(const void *,int,__kernel_size_t
);
164 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
165 static inline __must_check
unsigned long memcpy_mcsafe(void *dst
,
166 const void *src
, size_t cnt
)
168 memcpy(dst
, src
, cnt
);
172 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
173 static inline void memcpy_flushcache(void *dst
, const void *src
, size_t cnt
)
175 memcpy(dst
, src
, cnt
);
178 void *memchr_inv(const void *s
, int c
, size_t n
);
179 char *strreplace(char *s
, char old
, char new);
181 extern void kfree_const(const void *x
);
183 extern char *kstrdup(const char *s
, gfp_t gfp
) __malloc
;
184 extern const char *kstrdup_const(const char *s
, gfp_t gfp
);
185 extern char *kstrndup(const char *s
, size_t len
, gfp_t gfp
);
186 extern void *kmemdup(const void *src
, size_t len
, gfp_t gfp
);
187 extern char *kmemdup_nul(const char *s
, size_t len
, gfp_t gfp
);
189 extern char **argv_split(gfp_t gfp
, const char *str
, int *argcp
);
190 extern void argv_free(char **argv
);
192 extern bool sysfs_streq(const char *s1
, const char *s2
);
193 extern int kstrtobool(const char *s
, bool *res
);
194 static inline int strtobool(const char *s
, bool *res
)
196 return kstrtobool(s
, res
);
199 int match_string(const char * const *array
, size_t n
, const char *string
);
200 int __sysfs_match_string(const char * const *array
, size_t n
, const char *s
);
203 * sysfs_match_string - matches given string in an array
204 * @_a: array of strings
205 * @_s: string to match with
207 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
209 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
211 #ifdef CONFIG_BINARY_PRINTF
212 int vbin_printf(u32
*bin_buf
, size_t size
, const char *fmt
, va_list args
);
213 int bstr_printf(char *buf
, size_t size
, const char *fmt
, const u32
*bin_buf
);
214 int bprintf(u32
*bin_buf
, size_t size
, const char *fmt
, ...) __printf(3, 4);
217 extern ssize_t
memory_read_from_buffer(void *to
, size_t count
, loff_t
*ppos
,
218 const void *from
, size_t available
);
220 int ptr_to_hashval(const void *ptr
, unsigned long *hashval_out
);
223 * strstarts - does @str start with @prefix?
224 * @str: string to examine
225 * @prefix: prefix to look for.
227 static inline bool strstarts(const char *str
, const char *prefix
)
229 return strncmp(str
, prefix
, strlen(prefix
)) == 0;
232 size_t memweight(const void *ptr
, size_t bytes
);
235 * memzero_explicit - Fill a region of memory (e.g. sensitive
236 * keying data) with 0s.
237 * @s: Pointer to the start of the area.
238 * @count: The size of the area.
240 * Note: usually using memset() is just fine (!), but in cases
241 * where clearing out _local_ data at the end of a scope is
242 * necessary, memzero_explicit() should be used instead in
243 * order to prevent the compiler from optimising away zeroing.
245 * memzero_explicit() doesn't need an arch-specific version as
246 * it just invokes the one of memset() implicitly.
248 static inline void memzero_explicit(void *s
, size_t count
)
255 * kbasename - return the last part of a pathname.
257 * @path: path to extract the filename from.
259 static inline const char *kbasename(const char *path
)
261 const char *tail
= strrchr(path
, '/');
262 return tail
? tail
+ 1 : path
;
265 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
266 #define __RENAME(x) __asm__(#x)
268 void fortify_panic(const char *name
) __noreturn __cold
;
269 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
270 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
271 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
272 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
274 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
277 extern void *__underlying_memchr(const void *p
, int c
, __kernel_size_t size
) __RENAME(memchr
);
278 extern int __underlying_memcmp(const void *p
, const void *q
, __kernel_size_t size
) __RENAME(memcmp
);
279 extern void *__underlying_memcpy(void *p
, const void *q
, __kernel_size_t size
) __RENAME(memcpy
);
280 extern void *__underlying_memmove(void *p
, const void *q
, __kernel_size_t size
) __RENAME(memmove
);
281 extern void *__underlying_memset(void *p
, int c
, __kernel_size_t size
) __RENAME(memset
);
282 extern char *__underlying_strcat(char *p
, const char *q
) __RENAME(strcat
);
283 extern char *__underlying_strcpy(char *p
, const char *q
) __RENAME(strcpy
);
284 extern __kernel_size_t
__underlying_strlen(const char *p
) __RENAME(strlen
);
285 extern char *__underlying_strncat(char *p
, const char *q
, __kernel_size_t count
) __RENAME(strncat
);
286 extern char *__underlying_strncpy(char *p
, const char *q
, __kernel_size_t size
) __RENAME(strncpy
);
288 #define __underlying_memchr __builtin_memchr
289 #define __underlying_memcmp __builtin_memcmp
290 #define __underlying_memcpy __builtin_memcpy
291 #define __underlying_memmove __builtin_memmove
292 #define __underlying_memset __builtin_memset
293 #define __underlying_strcat __builtin_strcat
294 #define __underlying_strcpy __builtin_strcpy
295 #define __underlying_strlen __builtin_strlen
296 #define __underlying_strncat __builtin_strncat
297 #define __underlying_strncpy __builtin_strncpy
300 __FORTIFY_INLINE
char *strncpy(char *p
, const char *q
, __kernel_size_t size
)
302 size_t p_size
= __builtin_object_size(p
, 0);
303 if (__builtin_constant_p(size
) && p_size
< size
)
306 fortify_panic(__func__
);
307 return __underlying_strncpy(p
, q
, size
);
310 __FORTIFY_INLINE
char *strcat(char *p
, const char *q
)
312 size_t p_size
= __builtin_object_size(p
, 0);
313 if (p_size
== (size_t)-1)
314 return __underlying_strcat(p
, q
);
315 if (strlcat(p
, q
, p_size
) >= p_size
)
316 fortify_panic(__func__
);
320 __FORTIFY_INLINE __kernel_size_t
strlen(const char *p
)
323 size_t p_size
= __builtin_object_size(p
, 0);
325 /* Work around gcc excess stack consumption issue */
326 if (p_size
== (size_t)-1 ||
327 (__builtin_constant_p(p
[p_size
- 1]) && p
[p_size
- 1] == '\0'))
328 return __underlying_strlen(p
);
329 ret
= strnlen(p
, p_size
);
331 fortify_panic(__func__
);
335 extern __kernel_size_t
__real_strnlen(const char *, __kernel_size_t
) __RENAME(strnlen
);
336 __FORTIFY_INLINE __kernel_size_t
strnlen(const char *p
, __kernel_size_t maxlen
)
338 size_t p_size
= __builtin_object_size(p
, 0);
339 __kernel_size_t ret
= __real_strnlen(p
, maxlen
< p_size
? maxlen
: p_size
);
340 if (p_size
<= ret
&& maxlen
!= ret
)
341 fortify_panic(__func__
);
345 /* defined after fortified strlen to reuse it */
346 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy
);
347 __FORTIFY_INLINE
size_t strlcpy(char *p
, const char *q
, size_t size
)
350 size_t p_size
= __builtin_object_size(p
, 0);
351 size_t q_size
= __builtin_object_size(q
, 0);
352 if (p_size
== (size_t)-1 && q_size
== (size_t)-1)
353 return __real_strlcpy(p
, q
, size
);
356 size_t len
= (ret
>= size
) ? size
- 1 : ret
;
357 if (__builtin_constant_p(len
) && len
>= p_size
)
360 fortify_panic(__func__
);
361 __underlying_memcpy(p
, q
, len
);
367 /* defined after fortified strlen and strnlen to reuse them */
368 __FORTIFY_INLINE
char *strncat(char *p
, const char *q
, __kernel_size_t count
)
370 size_t p_len
, copy_len
;
371 size_t p_size
= __builtin_object_size(p
, 0);
372 size_t q_size
= __builtin_object_size(q
, 0);
373 if (p_size
== (size_t)-1 && q_size
== (size_t)-1)
374 return __underlying_strncat(p
, q
, count
);
376 copy_len
= strnlen(q
, count
);
377 if (p_size
< p_len
+ copy_len
+ 1)
378 fortify_panic(__func__
);
379 __underlying_memcpy(p
+ p_len
, q
, copy_len
);
380 p
[p_len
+ copy_len
] = '\0';
384 __FORTIFY_INLINE
void *memset(void *p
, int c
, __kernel_size_t size
)
386 size_t p_size
= __builtin_object_size(p
, 0);
387 if (__builtin_constant_p(size
) && p_size
< size
)
390 fortify_panic(__func__
);
391 return __underlying_memset(p
, c
, size
);
394 __FORTIFY_INLINE
void *memcpy(void *p
, const void *q
, __kernel_size_t size
)
396 size_t p_size
= __builtin_object_size(p
, 0);
397 size_t q_size
= __builtin_object_size(q
, 0);
398 if (__builtin_constant_p(size
)) {
404 if (p_size
< size
|| q_size
< size
)
405 fortify_panic(__func__
);
406 return __underlying_memcpy(p
, q
, size
);
409 __FORTIFY_INLINE
void *memmove(void *p
, const void *q
, __kernel_size_t size
)
411 size_t p_size
= __builtin_object_size(p
, 0);
412 size_t q_size
= __builtin_object_size(q
, 0);
413 if (__builtin_constant_p(size
)) {
419 if (p_size
< size
|| q_size
< size
)
420 fortify_panic(__func__
);
421 return __underlying_memmove(p
, q
, size
);
424 extern void *__real_memscan(void *, int, __kernel_size_t
) __RENAME(memscan
);
425 __FORTIFY_INLINE
void *memscan(void *p
, int c
, __kernel_size_t size
)
427 size_t p_size
= __builtin_object_size(p
, 0);
428 if (__builtin_constant_p(size
) && p_size
< size
)
431 fortify_panic(__func__
);
432 return __real_memscan(p
, c
, size
);
435 __FORTIFY_INLINE
int memcmp(const void *p
, const void *q
, __kernel_size_t size
)
437 size_t p_size
= __builtin_object_size(p
, 0);
438 size_t q_size
= __builtin_object_size(q
, 0);
439 if (__builtin_constant_p(size
)) {
445 if (p_size
< size
|| q_size
< size
)
446 fortify_panic(__func__
);
447 return __underlying_memcmp(p
, q
, size
);
450 __FORTIFY_INLINE
void *memchr(const void *p
, int c
, __kernel_size_t size
)
452 size_t p_size
= __builtin_object_size(p
, 0);
453 if (__builtin_constant_p(size
) && p_size
< size
)
456 fortify_panic(__func__
);
457 return __underlying_memchr(p
, c
, size
);
460 void *__real_memchr_inv(const void *s
, int c
, size_t n
) __RENAME(memchr_inv
);
461 __FORTIFY_INLINE
void *memchr_inv(const void *p
, int c
, size_t size
)
463 size_t p_size
= __builtin_object_size(p
, 0);
464 if (__builtin_constant_p(size
) && p_size
< size
)
467 fortify_panic(__func__
);
468 return __real_memchr_inv(p
, c
, size
);
471 extern void *__real_kmemdup(const void *src
, size_t len
, gfp_t gfp
) __RENAME(kmemdup
);
472 __FORTIFY_INLINE
void *kmemdup(const void *p
, size_t size
, gfp_t gfp
)
474 size_t p_size
= __builtin_object_size(p
, 0);
475 if (__builtin_constant_p(size
) && p_size
< size
)
478 fortify_panic(__func__
);
479 return __real_kmemdup(p
, size
, gfp
);
482 /* defined after fortified strlen and memcpy to reuse them */
483 __FORTIFY_INLINE
char *strcpy(char *p
, const char *q
)
485 size_t p_size
= __builtin_object_size(p
, 0);
486 size_t q_size
= __builtin_object_size(q
, 0);
487 if (p_size
== (size_t)-1 && q_size
== (size_t)-1)
488 return __underlying_strcpy(p
, q
);
489 memcpy(p
, q
, strlen(q
) + 1);
493 /* Don't use these outside the FORITFY_SOURCE implementation */
494 #undef __underlying_memchr
495 #undef __underlying_memcmp
496 #undef __underlying_memcpy
497 #undef __underlying_memmove
498 #undef __underlying_memset
499 #undef __underlying_strcat
500 #undef __underlying_strcpy
501 #undef __underlying_strlen
502 #undef __underlying_strncat
503 #undef __underlying_strncpy
507 * memcpy_and_pad - Copy one buffer to another with padding
508 * @dest: Where to copy to
509 * @dest_len: The destination buffer size
510 * @src: Where to copy from
511 * @count: The number of bytes to copy
512 * @pad: Character to use for padding if space is left in destination.
514 static inline void memcpy_and_pad(void *dest
, size_t dest_len
,
515 const void *src
, size_t count
, int pad
)
517 if (dest_len
> count
) {
518 memcpy(dest
, src
, count
);
519 memset(dest
+ count
, pad
, dest_len
- count
);
521 memcpy(dest
, src
, dest_len
);
525 * str_has_prefix - Test if a string has a given prefix
526 * @str: The string to test
527 * @prefix: The string to see if @str starts with
529 * A common way to test a prefix of a string is to do:
530 * strncmp(str, prefix, sizeof(prefix) - 1)
532 * But this can lead to bugs due to typos, or if prefix is a pointer
533 * and not a constant. Instead use str_has_prefix().
536 * * strlen(@prefix) if @str starts with @prefix
537 * * 0 if @str does not start with @prefix
539 static __always_inline
size_t str_has_prefix(const char *str
, const char *prefix
)
541 size_t len
= strlen(prefix
);
542 return strncmp(str
, prefix
, len
) == 0 ? len
: 0;
545 #endif /* _LINUX_STRING_H_ */