string.h 13 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _LINUX_STRING_H_
  3. #define _LINUX_STRING_H_
  4. #include <linux/compiler.h> /* for inline */
  5. #include <linux/types.h> /* for size_t */
  6. #include <linux/stddef.h> /* for NULL */
  7. #include <stdarg.h>
  8. #include <uapi/linux/string.h>
  9. extern char *strndup_user(const char __user *, long);
  10. extern void *memdup_user(const void __user *, size_t);
  11. extern void *memdup_user_nul(const void __user *, size_t);
  12. /*
  13. * Include machine specific inline routines
  14. */
  15. #include <asm/string.h>
  16. #ifndef __HAVE_ARCH_STRCPY
  17. extern char * strcpy(char *,const char *);
  18. #endif
  19. #ifndef __HAVE_ARCH_STRNCPY
  20. extern char * strncpy(char *,const char *, __kernel_size_t);
  21. #endif
  22. #ifndef __HAVE_ARCH_STRLCPY
  23. size_t strlcpy(char *, const char *, size_t);
  24. #endif
  25. #ifndef __HAVE_ARCH_STRSCPY
  26. ssize_t __must_check strscpy(char *, const char *, size_t);
  27. #endif
  28. #ifndef __HAVE_ARCH_STRCAT
  29. extern char * strcat(char *, const char *);
  30. #endif
  31. #ifndef __HAVE_ARCH_STRNCAT
  32. extern char * strncat(char *, const char *, __kernel_size_t);
  33. #endif
  34. #ifndef __HAVE_ARCH_STRLCAT
  35. extern size_t strlcat(char *, const char *, __kernel_size_t);
  36. #endif
  37. #ifndef __HAVE_ARCH_STRCMP
  38. extern int strcmp(const char *,const char *);
  39. #endif
  40. #ifndef __HAVE_ARCH_STRNCMP
  41. extern int strncmp(const char *,const char *,__kernel_size_t);
  42. #endif
  43. #ifndef __HAVE_ARCH_STRCASECMP
  44. extern int strcasecmp(const char *s1, const char *s2);
  45. #endif
  46. #ifndef __HAVE_ARCH_STRNCASECMP
  47. extern int strncasecmp(const char *s1, const char *s2, size_t n);
  48. #endif
  49. #ifndef __HAVE_ARCH_STRCHR
  50. extern char * strchr(const char *,int);
  51. #endif
  52. #ifndef __HAVE_ARCH_STRCHRNUL
  53. extern char * strchrnul(const char *,int);
  54. #endif
  55. #ifndef __HAVE_ARCH_STRNCHR
  56. extern char * strnchr(const char *, size_t, int);
  57. #endif
  58. #ifndef __HAVE_ARCH_STRRCHR
  59. extern char * strrchr(const char *,int);
  60. #endif
  61. extern char * __must_check skip_spaces(const char *);
  62. extern char *strim(char *);
  63. static inline __must_check char *strstrip(char *str)
  64. {
  65. return strim(str);
  66. }
  67. #ifndef __HAVE_ARCH_STRSTR
  68. extern char * strstr(const char *, const char *);
  69. #endif
  70. #ifndef __HAVE_ARCH_STRNSTR
  71. extern char * strnstr(const char *, const char *, size_t);
  72. #endif
  73. #ifndef __HAVE_ARCH_STRLEN
  74. extern __kernel_size_t strlen(const char *);
  75. #endif
  76. #ifndef __HAVE_ARCH_STRNLEN
  77. extern __kernel_size_t strnlen(const char *,__kernel_size_t);
  78. #endif
  79. #ifndef __HAVE_ARCH_STRPBRK
  80. extern char * strpbrk(const char *,const char *);
  81. #endif
  82. #ifndef __HAVE_ARCH_STRSEP
  83. extern char * strsep(char **,const char *);
  84. #endif
  85. #ifndef __HAVE_ARCH_STRSPN
  86. extern __kernel_size_t strspn(const char *,const char *);
  87. #endif
  88. #ifndef __HAVE_ARCH_STRCSPN
  89. extern __kernel_size_t strcspn(const char *,const char *);
  90. #endif
  91. #ifndef __HAVE_ARCH_MEMSET
  92. extern void * memset(void *,int,__kernel_size_t);
  93. #endif
  94. #ifndef __HAVE_ARCH_MEMSET16
  95. extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
  96. #endif
  97. #ifndef __HAVE_ARCH_MEMSET32
  98. extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
  99. #endif
  100. #ifndef __HAVE_ARCH_MEMSET64
  101. extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
  102. #endif
  103. static inline void *memset_l(unsigned long *p, unsigned long v,
  104. __kernel_size_t n)
  105. {
  106. if (BITS_PER_LONG == 32)
  107. return memset32((uint32_t *)p, v, n);
  108. else
  109. return memset64((uint64_t *)p, v, n);
  110. }
  111. static inline void *memset_p(void **p, void *v, __kernel_size_t n)
  112. {
  113. if (BITS_PER_LONG == 32)
  114. return memset32((uint32_t *)p, (uintptr_t)v, n);
  115. else
  116. return memset64((uint64_t *)p, (uintptr_t)v, n);
  117. }
  118. #ifndef __HAVE_ARCH_MEMCPY
  119. extern void * memcpy(void *,const void *,__kernel_size_t);
  120. #endif
  121. #ifndef __HAVE_ARCH_MEMMOVE
  122. extern void * memmove(void *,const void *,__kernel_size_t);
  123. #endif
  124. #ifndef __HAVE_ARCH_MEMSCAN
  125. extern void * memscan(void *,int,__kernel_size_t);
  126. #endif
  127. #ifndef __HAVE_ARCH_MEMCMP
  128. extern int memcmp(const void *,const void *,__kernel_size_t);
  129. #endif
  130. #ifndef __HAVE_ARCH_MEMCHR
  131. extern void * memchr(const void *,int,__kernel_size_t);
  132. #endif
  133. #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
  134. static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
  135. size_t cnt)
  136. {
  137. memcpy(dst, src, cnt);
  138. return 0;
  139. }
  140. #endif
  141. #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
  142. static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
  143. {
  144. memcpy(dst, src, cnt);
  145. }
  146. #endif
  147. void *memchr_inv(const void *s, int c, size_t n);
  148. char *strreplace(char *s, char old, char new);
  149. extern void kfree_const(const void *x);
  150. extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
  151. extern const char *kstrdup_const(const char *s, gfp_t gfp);
  152. extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
  153. extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
  154. extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
  155. extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
  156. extern void argv_free(char **argv);
  157. extern bool sysfs_streq(const char *s1, const char *s2);
  158. extern int kstrtobool(const char *s, bool *res);
  159. static inline int strtobool(const char *s, bool *res)
  160. {
  161. return kstrtobool(s, res);
  162. }
  163. int match_string(const char * const *array, size_t n, const char *string);
  164. int __sysfs_match_string(const char * const *array, size_t n, const char *s);
  165. /**
  166. * sysfs_match_string - matches given string in an array
  167. * @_a: array of strings
  168. * @_s: string to match with
  169. *
  170. * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
  171. */
  172. #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
  173. #ifdef CONFIG_BINARY_PRINTF
  174. int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
  175. int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
  176. int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
  177. #endif
  178. extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
  179. const void *from, size_t available);
  180. /**
  181. * strstarts - does @str start with @prefix?
  182. * @str: string to examine
  183. * @prefix: prefix to look for.
  184. */
  185. static inline bool strstarts(const char *str, const char *prefix)
  186. {
  187. return strncmp(str, prefix, strlen(prefix)) == 0;
  188. }
  189. size_t memweight(const void *ptr, size_t bytes);
  190. void memzero_explicit(void *s, size_t count);
  191. /**
  192. * kbasename - return the last part of a pathname.
  193. *
  194. * @path: path to extract the filename from.
  195. */
  196. static inline const char *kbasename(const char *path)
  197. {
  198. const char *tail = strrchr(path, '/');
  199. return tail ? tail + 1 : path;
  200. }
  201. #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
  202. #define __RENAME(x) __asm__(#x)
  203. void fortify_panic(const char *name) __noreturn __cold;
  204. void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
  205. void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
  206. void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
  207. void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
  208. #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
  209. __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
  210. {
  211. size_t p_size = __builtin_object_size(p, 0);
  212. if (__builtin_constant_p(size) && p_size < size)
  213. __write_overflow();
  214. if (p_size < size)
  215. fortify_panic(__func__);
  216. return __builtin_strncpy(p, q, size);
  217. }
  218. __FORTIFY_INLINE char *strcat(char *p, const char *q)
  219. {
  220. size_t p_size = __builtin_object_size(p, 0);
  221. if (p_size == (size_t)-1)
  222. return __builtin_strcat(p, q);
  223. if (strlcat(p, q, p_size) >= p_size)
  224. fortify_panic(__func__);
  225. return p;
  226. }
  227. __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
  228. {
  229. __kernel_size_t ret;
  230. size_t p_size = __builtin_object_size(p, 0);
  231. /* Work around gcc excess stack consumption issue */
  232. if (p_size == (size_t)-1 ||
  233. (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
  234. return __builtin_strlen(p);
  235. ret = strnlen(p, p_size);
  236. if (p_size <= ret)
  237. fortify_panic(__func__);
  238. return ret;
  239. }
  240. extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
  241. __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
  242. {
  243. size_t p_size = __builtin_object_size(p, 0);
  244. __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
  245. if (p_size <= ret && maxlen != ret)
  246. fortify_panic(__func__);
  247. return ret;
  248. }
  249. /* defined after fortified strlen to reuse it */
  250. extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
  251. __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
  252. {
  253. size_t ret;
  254. size_t p_size = __builtin_object_size(p, 0);
  255. size_t q_size = __builtin_object_size(q, 0);
  256. if (p_size == (size_t)-1 && q_size == (size_t)-1)
  257. return __real_strlcpy(p, q, size);
  258. ret = strlen(q);
  259. if (size) {
  260. size_t len = (ret >= size) ? size - 1 : ret;
  261. if (__builtin_constant_p(len) && len >= p_size)
  262. __write_overflow();
  263. if (len >= p_size)
  264. fortify_panic(__func__);
  265. __builtin_memcpy(p, q, len);
  266. p[len] = '\0';
  267. }
  268. return ret;
  269. }
  270. /* defined after fortified strlen and strnlen to reuse them */
  271. __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
  272. {
  273. size_t p_len, copy_len;
  274. size_t p_size = __builtin_object_size(p, 0);
  275. size_t q_size = __builtin_object_size(q, 0);
  276. if (p_size == (size_t)-1 && q_size == (size_t)-1)
  277. return __builtin_strncat(p, q, count);
  278. p_len = strlen(p);
  279. copy_len = strnlen(q, count);
  280. if (p_size < p_len + copy_len + 1)
  281. fortify_panic(__func__);
  282. __builtin_memcpy(p + p_len, q, copy_len);
  283. p[p_len + copy_len] = '\0';
  284. return p;
  285. }
  286. __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
  287. {
  288. size_t p_size = __builtin_object_size(p, 0);
  289. if (__builtin_constant_p(size) && p_size < size)
  290. __write_overflow();
  291. if (p_size < size)
  292. fortify_panic(__func__);
  293. return __builtin_memset(p, c, size);
  294. }
  295. __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
  296. {
  297. size_t p_size = __builtin_object_size(p, 0);
  298. size_t q_size = __builtin_object_size(q, 0);
  299. if (__builtin_constant_p(size)) {
  300. if (p_size < size)
  301. __write_overflow();
  302. if (q_size < size)
  303. __read_overflow2();
  304. }
  305. if (p_size < size || q_size < size)
  306. fortify_panic(__func__);
  307. return __builtin_memcpy(p, q, size);
  308. }
  309. __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
  310. {
  311. size_t p_size = __builtin_object_size(p, 0);
  312. size_t q_size = __builtin_object_size(q, 0);
  313. if (__builtin_constant_p(size)) {
  314. if (p_size < size)
  315. __write_overflow();
  316. if (q_size < size)
  317. __read_overflow2();
  318. }
  319. if (p_size < size || q_size < size)
  320. fortify_panic(__func__);
  321. return __builtin_memmove(p, q, size);
  322. }
  323. extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
  324. __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
  325. {
  326. size_t p_size = __builtin_object_size(p, 0);
  327. if (__builtin_constant_p(size) && p_size < size)
  328. __read_overflow();
  329. if (p_size < size)
  330. fortify_panic(__func__);
  331. return __real_memscan(p, c, size);
  332. }
  333. __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
  334. {
  335. size_t p_size = __builtin_object_size(p, 0);
  336. size_t q_size = __builtin_object_size(q, 0);
  337. if (__builtin_constant_p(size)) {
  338. if (p_size < size)
  339. __read_overflow();
  340. if (q_size < size)
  341. __read_overflow2();
  342. }
  343. if (p_size < size || q_size < size)
  344. fortify_panic(__func__);
  345. return __builtin_memcmp(p, q, size);
  346. }
  347. __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
  348. {
  349. size_t p_size = __builtin_object_size(p, 0);
  350. if (__builtin_constant_p(size) && p_size < size)
  351. __read_overflow();
  352. if (p_size < size)
  353. fortify_panic(__func__);
  354. return __builtin_memchr(p, c, size);
  355. }
  356. void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
  357. __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
  358. {
  359. size_t p_size = __builtin_object_size(p, 0);
  360. if (__builtin_constant_p(size) && p_size < size)
  361. __read_overflow();
  362. if (p_size < size)
  363. fortify_panic(__func__);
  364. return __real_memchr_inv(p, c, size);
  365. }
  366. extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
  367. __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
  368. {
  369. size_t p_size = __builtin_object_size(p, 0);
  370. if (__builtin_constant_p(size) && p_size < size)
  371. __read_overflow();
  372. if (p_size < size)
  373. fortify_panic(__func__);
  374. return __real_kmemdup(p, size, gfp);
  375. }
  376. /* defined after fortified strlen and memcpy to reuse them */
  377. __FORTIFY_INLINE char *strcpy(char *p, const char *q)
  378. {
  379. size_t p_size = __builtin_object_size(p, 0);
  380. size_t q_size = __builtin_object_size(q, 0);
  381. if (p_size == (size_t)-1 && q_size == (size_t)-1)
  382. return __builtin_strcpy(p, q);
  383. memcpy(p, q, strlen(q) + 1);
  384. return p;
  385. }
  386. #endif
  387. /**
  388. * memcpy_and_pad - Copy one buffer to another with padding
  389. * @dest: Where to copy to
  390. * @dest_len: The destination buffer size
  391. * @src: Where to copy from
  392. * @count: The number of bytes to copy
  393. * @pad: Character to use for padding if space is left in destination.
  394. */
  395. static inline void memcpy_and_pad(void *dest, size_t dest_len,
  396. const void *src, size_t count, int pad)
  397. {
  398. if (dest_len > count) {
  399. memcpy(dest, src, count);
  400. memset(dest + count, pad, dest_len - count);
  401. } else
  402. memcpy(dest, src, dest_len);
  403. }
  404. #endif /* _LINUX_STRING_H_ */