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);
34 #ifndef __HAVE_ARCH_STRCAT
35 extern char * strcat(char *, const char *);
37 #ifndef __HAVE_ARCH_STRNCAT
38 extern char * strncat(char *, const char *, __kernel_size_t);
40 #ifndef __HAVE_ARCH_STRLCAT
41 extern size_t strlcat(char *, const char *, __kernel_size_t);
43 #ifndef __HAVE_ARCH_STRCMP
44 extern int strcmp(const char *,const char *);
46 #ifndef __HAVE_ARCH_STRNCMP
47 extern int strncmp(const char *,const char *,__kernel_size_t);
49 #ifndef __HAVE_ARCH_STRCASECMP
50 extern int strcasecmp(const char *s1, const char *s2);
52 #ifndef __HAVE_ARCH_STRNCASECMP
53 extern int strncasecmp(const char *s1, const char *s2, size_t n);
55 #ifndef __HAVE_ARCH_STRCHR
56 extern char * strchr(const char *,int);
58 #ifndef __HAVE_ARCH_STRCHRNUL
59 extern char * strchrnul(const char *,int);
61 #ifndef __HAVE_ARCH_STRNCHR
62 extern char * strnchr(const char *, size_t, int);
64 #ifndef __HAVE_ARCH_STRRCHR
65 extern char * strrchr(const char *,int);
67 extern char * __must_check skip_spaces(const char *);
69 extern char *strim(char *);
71 static inline __must_check char *strstrip(char *str)
76 #ifndef __HAVE_ARCH_STRSTR
77 extern char * strstr(const char *, const char *);
79 #ifndef __HAVE_ARCH_STRNSTR
80 extern char * strnstr(const char *, const char *, size_t);
82 #ifndef __HAVE_ARCH_STRLEN
83 extern __kernel_size_t strlen(const char *);
85 #ifndef __HAVE_ARCH_STRNLEN
86 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
88 #ifndef __HAVE_ARCH_STRPBRK
89 extern char * strpbrk(const char *,const char *);
91 #ifndef __HAVE_ARCH_STRSEP
92 extern char * strsep(char **,const char *);
94 #ifndef __HAVE_ARCH_STRSPN
95 extern __kernel_size_t strspn(const char *,const char *);
97 #ifndef __HAVE_ARCH_STRCSPN
98 extern __kernel_size_t strcspn(const char *,const char *);
101 #ifndef __HAVE_ARCH_MEMSET
102 extern void * memset(void *,int,__kernel_size_t);
105 #ifndef __HAVE_ARCH_MEMSET16
106 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
109 #ifndef __HAVE_ARCH_MEMSET32
110 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
113 #ifndef __HAVE_ARCH_MEMSET64
114 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
117 static inline void *memset_l(unsigned long *p, unsigned long v,
120 if (BITS_PER_LONG == 32)
121 return memset32((uint32_t *)p, v, n);
123 return memset64((uint64_t *)p, v, n);
126 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
128 if (BITS_PER_LONG == 32)
129 return memset32((uint32_t *)p, (uintptr_t)v, n);
131 return memset64((uint64_t *)p, (uintptr_t)v, n);
134 extern void **__memcat_p(void **a, void **b);
135 #define memcat_p(a, b) ({ \
136 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \
137 "type mismatch in memcat_p()"); \
138 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \
141 #ifndef __HAVE_ARCH_MEMCPY
142 extern void * memcpy(void *,const void *,__kernel_size_t);
144 #ifndef __HAVE_ARCH_MEMMOVE
145 extern void * memmove(void *,const void *,__kernel_size_t);
147 #ifndef __HAVE_ARCH_MEMSCAN
148 extern void * memscan(void *,int,__kernel_size_t);
150 #ifndef __HAVE_ARCH_MEMCMP
151 extern int memcmp(const void *,const void *,__kernel_size_t);
153 #ifndef __HAVE_ARCH_MEMCHR
154 extern void * memchr(const void *,int,__kernel_size_t);
156 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
157 static inline __must_check unsigned long memcpy_mcsafe(void *dst,
158 const void *src, size_t cnt)
160 memcpy(dst, src, cnt);
164 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
165 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
167 memcpy(dst, src, cnt);
170 void *memchr_inv(const void *s, int c, size_t n);
171 char *strreplace(char *s, char old, char new);
173 extern void kfree_const(const void *x);
175 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
176 extern const char *kstrdup_const(const char *s, gfp_t gfp);
177 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
178 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
179 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
181 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
182 extern void argv_free(char **argv);
184 extern bool sysfs_streq(const char *s1, const char *s2);
185 extern int kstrtobool(const char *s, bool *res);
186 static inline int strtobool(const char *s, bool *res)
188 return kstrtobool(s, res);
191 int match_string(const char * const *array, size_t n, const char *string);
192 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
195 * sysfs_match_string - matches given string in an array
196 * @_a: array of strings
197 * @_s: string to match with
199 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
201 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
203 #ifdef CONFIG_BINARY_PRINTF
204 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
205 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
206 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
209 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
210 const void *from, size_t available);
213 * strstarts - does @str start with @prefix?
214 * @str: string to examine
215 * @prefix: prefix to look for.
217 static inline bool strstarts(const char *str, const char *prefix)
219 return strncmp(str, prefix, strlen(prefix)) == 0;
222 size_t memweight(const void *ptr, size_t bytes);
223 void memzero_explicit(void *s, size_t count);
226 * kbasename - return the last part of a pathname.
228 * @path: path to extract the filename from.
230 static inline const char *kbasename(const char *path)
232 const char *tail = strrchr(path, '/');
233 return tail ? tail + 1 : path;
236 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
237 #define __RENAME(x) __asm__(#x)
239 void fortify_panic(const char *name) __noreturn __cold;
240 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
241 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
242 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
243 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
245 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
246 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
248 size_t p_size = __builtin_object_size(p, 0);
249 if (__builtin_constant_p(size) && p_size < size)
252 fortify_panic(__func__);
253 return __builtin_strncpy(p, q, size);
256 __FORTIFY_INLINE char *strcat(char *p, const char *q)
258 size_t p_size = __builtin_object_size(p, 0);
259 if (p_size == (size_t)-1)
260 return __builtin_strcat(p, q);
261 if (strlcat(p, q, p_size) >= p_size)
262 fortify_panic(__func__);
266 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
269 size_t p_size = __builtin_object_size(p, 0);
271 /* Work around gcc excess stack consumption issue */
272 if (p_size == (size_t)-1 ||
273 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
274 return __builtin_strlen(p);
275 ret = strnlen(p, p_size);
277 fortify_panic(__func__);
281 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
282 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
284 size_t p_size = __builtin_object_size(p, 0);
285 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
286 if (p_size <= ret && maxlen != ret)
287 fortify_panic(__func__);
291 /* defined after fortified strlen to reuse it */
292 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
293 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
296 size_t p_size = __builtin_object_size(p, 0);
297 size_t q_size = __builtin_object_size(q, 0);
298 if (p_size == (size_t)-1 && q_size == (size_t)-1)
299 return __real_strlcpy(p, q, size);
302 size_t len = (ret >= size) ? size - 1 : ret;
303 if (__builtin_constant_p(len) && len >= p_size)
306 fortify_panic(__func__);
307 __builtin_memcpy(p, q, len);
313 /* defined after fortified strlen and strnlen to reuse them */
314 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
316 size_t p_len, copy_len;
317 size_t p_size = __builtin_object_size(p, 0);
318 size_t q_size = __builtin_object_size(q, 0);
319 if (p_size == (size_t)-1 && q_size == (size_t)-1)
320 return __builtin_strncat(p, q, count);
322 copy_len = strnlen(q, count);
323 if (p_size < p_len + copy_len + 1)
324 fortify_panic(__func__);
325 __builtin_memcpy(p + p_len, q, copy_len);
326 p[p_len + copy_len] = '\0';
330 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
332 size_t p_size = __builtin_object_size(p, 0);
333 if (__builtin_constant_p(size) && p_size < size)
336 fortify_panic(__func__);
337 return __builtin_memset(p, c, size);
340 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
342 size_t p_size = __builtin_object_size(p, 0);
343 size_t q_size = __builtin_object_size(q, 0);
344 if (__builtin_constant_p(size)) {
350 if (p_size < size || q_size < size)
351 fortify_panic(__func__);
352 return __builtin_memcpy(p, q, size);
355 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
357 size_t p_size = __builtin_object_size(p, 0);
358 size_t q_size = __builtin_object_size(q, 0);
359 if (__builtin_constant_p(size)) {
365 if (p_size < size || q_size < size)
366 fortify_panic(__func__);
367 return __builtin_memmove(p, q, size);
370 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
371 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
373 size_t p_size = __builtin_object_size(p, 0);
374 if (__builtin_constant_p(size) && p_size < size)
377 fortify_panic(__func__);
378 return __real_memscan(p, c, size);
381 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
383 size_t p_size = __builtin_object_size(p, 0);
384 size_t q_size = __builtin_object_size(q, 0);
385 if (__builtin_constant_p(size)) {
391 if (p_size < size || q_size < size)
392 fortify_panic(__func__);
393 return __builtin_memcmp(p, q, size);
396 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
398 size_t p_size = __builtin_object_size(p, 0);
399 if (__builtin_constant_p(size) && p_size < size)
402 fortify_panic(__func__);
403 return __builtin_memchr(p, c, size);
406 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
407 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
409 size_t p_size = __builtin_object_size(p, 0);
410 if (__builtin_constant_p(size) && p_size < size)
413 fortify_panic(__func__);
414 return __real_memchr_inv(p, c, size);
417 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
418 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
420 size_t p_size = __builtin_object_size(p, 0);
421 if (__builtin_constant_p(size) && p_size < size)
424 fortify_panic(__func__);
425 return __real_kmemdup(p, size, gfp);
428 /* defined after fortified strlen and memcpy to reuse them */
429 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
431 size_t p_size = __builtin_object_size(p, 0);
432 size_t q_size = __builtin_object_size(q, 0);
433 if (p_size == (size_t)-1 && q_size == (size_t)-1)
434 return __builtin_strcpy(p, q);
435 memcpy(p, q, strlen(q) + 1);
442 * memcpy_and_pad - Copy one buffer to another with padding
443 * @dest: Where to copy to
444 * @dest_len: The destination buffer size
445 * @src: Where to copy from
446 * @count: The number of bytes to copy
447 * @pad: Character to use for padding if space is left in destination.
449 static inline void memcpy_and_pad(void *dest, size_t dest_len,
450 const void *src, size_t count, int pad)
452 if (dest_len > count) {
453 memcpy(dest, src, count);
454 memset(dest + count, pad, dest_len - count);
456 memcpy(dest, src, dest_len);
460 * str_has_prefix - Test if a string has a given prefix
461 * @str: The string to test
462 * @prefix: The string to see if @str starts with
464 * A common way to test a prefix of a string is to do:
465 * strncmp(str, prefix, sizeof(prefix) - 1)
467 * But this can lead to bugs due to typos, or if prefix is a pointer
468 * and not a constant. Instead use str_has_prefix().
470 * Returns: 0 if @str does not start with @prefix
471 strlen(@prefix) if @str does start with @prefix
473 static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
475 size_t len = strlen(prefix);
476 return strncmp(str, prefix, len) == 0 ? len : 0;
479 #endif /* _LINUX_STRING_H_ */