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 #ifndef __HAVE_ARCH_STRNCHR
66 extern char * strnchr(const char *, size_t, int);
68 #ifndef __HAVE_ARCH_STRRCHR
69 extern char * strrchr(const char *,int);
71 extern char * __must_check skip_spaces(const char *);
73 extern char *strim(char *);
75 static inline __must_check char *strstrip(char *str)
80 #ifndef __HAVE_ARCH_STRSTR
81 extern char * strstr(const char *, const char *);
83 #ifndef __HAVE_ARCH_STRNSTR
84 extern char * strnstr(const char *, const char *, size_t);
86 #ifndef __HAVE_ARCH_STRLEN
87 extern __kernel_size_t strlen(const char *);
89 #ifndef __HAVE_ARCH_STRNLEN
90 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
92 #ifndef __HAVE_ARCH_STRPBRK
93 extern char * strpbrk(const char *,const char *);
95 #ifndef __HAVE_ARCH_STRSEP
96 extern char * strsep(char **,const char *);
98 #ifndef __HAVE_ARCH_STRSPN
99 extern __kernel_size_t strspn(const char *,const char *);
101 #ifndef __HAVE_ARCH_STRCSPN
102 extern __kernel_size_t strcspn(const char *,const char *);
105 #ifndef __HAVE_ARCH_MEMSET
106 extern void * memset(void *,int,__kernel_size_t);
109 #ifndef __HAVE_ARCH_MEMSET16
110 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
113 #ifndef __HAVE_ARCH_MEMSET32
114 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
117 #ifndef __HAVE_ARCH_MEMSET64
118 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
121 static inline void *memset_l(unsigned long *p, unsigned long v,
124 if (BITS_PER_LONG == 32)
125 return memset32((uint32_t *)p, v, n);
127 return memset64((uint64_t *)p, v, n);
130 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
132 if (BITS_PER_LONG == 32)
133 return memset32((uint32_t *)p, (uintptr_t)v, n);
135 return memset64((uint64_t *)p, (uintptr_t)v, n);
138 extern void **__memcat_p(void **a, void **b);
139 #define memcat_p(a, b) ({ \
140 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \
141 "type mismatch in memcat_p()"); \
142 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \
145 #ifndef __HAVE_ARCH_MEMCPY
146 extern void * memcpy(void *,const void *,__kernel_size_t);
148 #ifndef __HAVE_ARCH_MEMMOVE
149 extern void * memmove(void *,const void *,__kernel_size_t);
151 #ifndef __HAVE_ARCH_MEMSCAN
152 extern void * memscan(void *,int,__kernel_size_t);
154 #ifndef __HAVE_ARCH_MEMCMP
155 extern int memcmp(const void *,const void *,__kernel_size_t);
157 #ifndef __HAVE_ARCH_BCMP
158 extern int bcmp(const void *,const void *,__kernel_size_t);
160 #ifndef __HAVE_ARCH_MEMCHR
161 extern void * memchr(const void *,int,__kernel_size_t);
163 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
164 static inline __must_check unsigned long memcpy_mcsafe(void *dst,
165 const void *src, size_t cnt)
167 memcpy(dst, src, cnt);
171 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
172 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
174 memcpy(dst, src, cnt);
177 void *memchr_inv(const void *s, int c, size_t n);
178 char *strreplace(char *s, char old, char new);
180 extern void kfree_const(const void *x);
182 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
183 extern const char *kstrdup_const(const char *s, gfp_t gfp);
184 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
185 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
186 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
188 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
189 extern void argv_free(char **argv);
191 extern bool sysfs_streq(const char *s1, const char *s2);
192 extern int kstrtobool(const char *s, bool *res);
193 static inline int strtobool(const char *s, bool *res)
195 return kstrtobool(s, res);
198 int match_string(const char * const *array, size_t n, const char *string);
199 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
202 * sysfs_match_string - matches given string in an array
203 * @_a: array of strings
204 * @_s: string to match with
206 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
208 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
210 #ifdef CONFIG_BINARY_PRINTF
211 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
212 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
213 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
216 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
217 const void *from, size_t available);
220 * strstarts - does @str start with @prefix?
221 * @str: string to examine
222 * @prefix: prefix to look for.
224 static inline bool strstarts(const char *str, const char *prefix)
226 return strncmp(str, prefix, strlen(prefix)) == 0;
229 size_t memweight(const void *ptr, size_t bytes);
232 * memzero_explicit - Fill a region of memory (e.g. sensitive
233 * keying data) with 0s.
234 * @s: Pointer to the start of the area.
235 * @count: The size of the area.
237 * Note: usually using memset() is just fine (!), but in cases
238 * where clearing out _local_ data at the end of a scope is
239 * necessary, memzero_explicit() should be used instead in
240 * order to prevent the compiler from optimising away zeroing.
242 * memzero_explicit() doesn't need an arch-specific version as
243 * it just invokes the one of memset() implicitly.
245 static inline void memzero_explicit(void *s, size_t count)
252 * kbasename - return the last part of a pathname.
254 * @path: path to extract the filename from.
256 static inline const char *kbasename(const char *path)
258 const char *tail = strrchr(path, '/');
259 return tail ? tail + 1 : path;
262 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
263 #define __RENAME(x) __asm__(#x)
265 void fortify_panic(const char *name) __noreturn __cold;
266 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
267 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
268 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
269 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
271 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
272 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
274 size_t p_size = __builtin_object_size(p, 0);
275 if (__builtin_constant_p(size) && p_size < size)
278 fortify_panic(__func__);
279 return __builtin_strncpy(p, q, size);
282 __FORTIFY_INLINE char *strcat(char *p, const char *q)
284 size_t p_size = __builtin_object_size(p, 0);
285 if (p_size == (size_t)-1)
286 return __builtin_strcat(p, q);
287 if (strlcat(p, q, p_size) >= p_size)
288 fortify_panic(__func__);
292 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
295 size_t p_size = __builtin_object_size(p, 0);
297 /* Work around gcc excess stack consumption issue */
298 if (p_size == (size_t)-1 ||
299 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
300 return __builtin_strlen(p);
301 ret = strnlen(p, p_size);
303 fortify_panic(__func__);
307 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
308 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
310 size_t p_size = __builtin_object_size(p, 0);
311 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
312 if (p_size <= ret && maxlen != ret)
313 fortify_panic(__func__);
317 /* defined after fortified strlen to reuse it */
318 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
319 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
322 size_t p_size = __builtin_object_size(p, 0);
323 size_t q_size = __builtin_object_size(q, 0);
324 if (p_size == (size_t)-1 && q_size == (size_t)-1)
325 return __real_strlcpy(p, q, size);
328 size_t len = (ret >= size) ? size - 1 : ret;
329 if (__builtin_constant_p(len) && len >= p_size)
332 fortify_panic(__func__);
333 __builtin_memcpy(p, q, len);
339 /* defined after fortified strlen and strnlen to reuse them */
340 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
342 size_t p_len, copy_len;
343 size_t p_size = __builtin_object_size(p, 0);
344 size_t q_size = __builtin_object_size(q, 0);
345 if (p_size == (size_t)-1 && q_size == (size_t)-1)
346 return __builtin_strncat(p, q, count);
348 copy_len = strnlen(q, count);
349 if (p_size < p_len + copy_len + 1)
350 fortify_panic(__func__);
351 __builtin_memcpy(p + p_len, q, copy_len);
352 p[p_len + copy_len] = '\0';
356 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
358 size_t p_size = __builtin_object_size(p, 0);
359 if (__builtin_constant_p(size) && p_size < size)
362 fortify_panic(__func__);
363 return __builtin_memset(p, c, size);
366 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
368 size_t p_size = __builtin_object_size(p, 0);
369 size_t q_size = __builtin_object_size(q, 0);
370 if (__builtin_constant_p(size)) {
376 if (p_size < size || q_size < size)
377 fortify_panic(__func__);
378 return __builtin_memcpy(p, q, size);
381 __FORTIFY_INLINE void *memmove(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_memmove(p, q, size);
396 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
397 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
399 size_t p_size = __builtin_object_size(p, 0);
400 if (__builtin_constant_p(size) && p_size < size)
403 fortify_panic(__func__);
404 return __real_memscan(p, c, size);
407 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
409 size_t p_size = __builtin_object_size(p, 0);
410 size_t q_size = __builtin_object_size(q, 0);
411 if (__builtin_constant_p(size)) {
417 if (p_size < size || q_size < size)
418 fortify_panic(__func__);
419 return __builtin_memcmp(p, q, size);
422 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
424 size_t p_size = __builtin_object_size(p, 0);
425 if (__builtin_constant_p(size) && p_size < size)
428 fortify_panic(__func__);
429 return __builtin_memchr(p, c, size);
432 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
433 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
435 size_t p_size = __builtin_object_size(p, 0);
436 if (__builtin_constant_p(size) && p_size < size)
439 fortify_panic(__func__);
440 return __real_memchr_inv(p, c, size);
443 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
444 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
446 size_t p_size = __builtin_object_size(p, 0);
447 if (__builtin_constant_p(size) && p_size < size)
450 fortify_panic(__func__);
451 return __real_kmemdup(p, size, gfp);
454 /* defined after fortified strlen and memcpy to reuse them */
455 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
457 size_t p_size = __builtin_object_size(p, 0);
458 size_t q_size = __builtin_object_size(q, 0);
459 if (p_size == (size_t)-1 && q_size == (size_t)-1)
460 return __builtin_strcpy(p, q);
461 memcpy(p, q, strlen(q) + 1);
468 * memcpy_and_pad - Copy one buffer to another with padding
469 * @dest: Where to copy to
470 * @dest_len: The destination buffer size
471 * @src: Where to copy from
472 * @count: The number of bytes to copy
473 * @pad: Character to use for padding if space is left in destination.
475 static inline void memcpy_and_pad(void *dest, size_t dest_len,
476 const void *src, size_t count, int pad)
478 if (dest_len > count) {
479 memcpy(dest, src, count);
480 memset(dest + count, pad, dest_len - count);
482 memcpy(dest, src, dest_len);
486 * str_has_prefix - Test if a string has a given prefix
487 * @str: The string to test
488 * @prefix: The string to see if @str starts with
490 * A common way to test a prefix of a string is to do:
491 * strncmp(str, prefix, sizeof(prefix) - 1)
493 * But this can lead to bugs due to typos, or if prefix is a pointer
494 * and not a constant. Instead use str_has_prefix().
497 * * strlen(@prefix) if @str starts with @prefix
498 * * 0 if @str does not start with @prefix
500 static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
502 size_t len = strlen(prefix);
503 return strncmp(str, prefix, len) == 0 ? len : 0;
506 #endif /* _LINUX_STRING_H_ */