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)
275 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
277 size_t p_size = __builtin_object_size(p, 0);
278 if (__builtin_constant_p(size) && p_size < size)
281 fortify_panic(__func__);
282 return __builtin_strncpy(p, q, size);
285 __FORTIFY_INLINE char *strcat(char *p, const char *q)
287 size_t p_size = __builtin_object_size(p, 0);
288 if (p_size == (size_t)-1)
289 return __builtin_strcat(p, q);
290 if (strlcat(p, q, p_size) >= p_size)
291 fortify_panic(__func__);
295 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
298 size_t p_size = __builtin_object_size(p, 0);
300 /* Work around gcc excess stack consumption issue */
301 if (p_size == (size_t)-1 ||
302 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
303 return __builtin_strlen(p);
304 ret = strnlen(p, p_size);
306 fortify_panic(__func__);
310 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
311 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
313 size_t p_size = __builtin_object_size(p, 0);
314 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
315 if (p_size <= ret && maxlen != ret)
316 fortify_panic(__func__);
320 /* defined after fortified strlen to reuse it */
321 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
322 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
325 size_t p_size = __builtin_object_size(p, 0);
326 size_t q_size = __builtin_object_size(q, 0);
327 if (p_size == (size_t)-1 && q_size == (size_t)-1)
328 return __real_strlcpy(p, q, size);
331 size_t len = (ret >= size) ? size - 1 : ret;
332 if (__builtin_constant_p(len) && len >= p_size)
335 fortify_panic(__func__);
336 __builtin_memcpy(p, q, len);
342 /* defined after fortified strlen and strnlen to reuse them */
343 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
345 size_t p_len, copy_len;
346 size_t p_size = __builtin_object_size(p, 0);
347 size_t q_size = __builtin_object_size(q, 0);
348 if (p_size == (size_t)-1 && q_size == (size_t)-1)
349 return __builtin_strncat(p, q, count);
351 copy_len = strnlen(q, count);
352 if (p_size < p_len + copy_len + 1)
353 fortify_panic(__func__);
354 __builtin_memcpy(p + p_len, q, copy_len);
355 p[p_len + copy_len] = '\0';
359 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
361 size_t p_size = __builtin_object_size(p, 0);
362 if (__builtin_constant_p(size) && p_size < size)
365 fortify_panic(__func__);
366 return __builtin_memset(p, c, size);
369 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
371 size_t p_size = __builtin_object_size(p, 0);
372 size_t q_size = __builtin_object_size(q, 0);
373 if (__builtin_constant_p(size)) {
379 if (p_size < size || q_size < size)
380 fortify_panic(__func__);
381 return __builtin_memcpy(p, q, size);
384 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
386 size_t p_size = __builtin_object_size(p, 0);
387 size_t q_size = __builtin_object_size(q, 0);
388 if (__builtin_constant_p(size)) {
394 if (p_size < size || q_size < size)
395 fortify_panic(__func__);
396 return __builtin_memmove(p, q, size);
399 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
400 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
402 size_t p_size = __builtin_object_size(p, 0);
403 if (__builtin_constant_p(size) && p_size < size)
406 fortify_panic(__func__);
407 return __real_memscan(p, c, size);
410 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
412 size_t p_size = __builtin_object_size(p, 0);
413 size_t q_size = __builtin_object_size(q, 0);
414 if (__builtin_constant_p(size)) {
420 if (p_size < size || q_size < size)
421 fortify_panic(__func__);
422 return __builtin_memcmp(p, q, size);
425 __FORTIFY_INLINE void *memchr(const 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 __builtin_memchr(p, c, size);
435 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
436 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
438 size_t p_size = __builtin_object_size(p, 0);
439 if (__builtin_constant_p(size) && p_size < size)
442 fortify_panic(__func__);
443 return __real_memchr_inv(p, c, size);
446 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
447 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
449 size_t p_size = __builtin_object_size(p, 0);
450 if (__builtin_constant_p(size) && p_size < size)
453 fortify_panic(__func__);
454 return __real_kmemdup(p, size, gfp);
457 /* defined after fortified strlen and memcpy to reuse them */
458 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
460 size_t p_size = __builtin_object_size(p, 0);
461 size_t q_size = __builtin_object_size(q, 0);
462 if (p_size == (size_t)-1 && q_size == (size_t)-1)
463 return __builtin_strcpy(p, q);
464 memcpy(p, q, strlen(q) + 1);
471 * memcpy_and_pad - Copy one buffer to another with padding
472 * @dest: Where to copy to
473 * @dest_len: The destination buffer size
474 * @src: Where to copy from
475 * @count: The number of bytes to copy
476 * @pad: Character to use for padding if space is left in destination.
478 static inline void memcpy_and_pad(void *dest, size_t dest_len,
479 const void *src, size_t count, int pad)
481 if (dest_len > count) {
482 memcpy(dest, src, count);
483 memset(dest + count, pad, dest_len - count);
485 memcpy(dest, src, dest_len);
489 * str_has_prefix - Test if a string has a given prefix
490 * @str: The string to test
491 * @prefix: The string to see if @str starts with
493 * A common way to test a prefix of a string is to do:
494 * strncmp(str, prefix, sizeof(prefix) - 1)
496 * But this can lead to bugs due to typos, or if prefix is a pointer
497 * and not a constant. Instead use str_has_prefix().
500 * * strlen(@prefix) if @str starts with @prefix
501 * * 0 if @str does not start with @prefix
503 static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
505 size_t len = strlen(prefix);
506 return strncmp(str, prefix, len) == 0 ? len : 0;
509 #endif /* _LINUX_STRING_H_ */