1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_STRING_H_ 3 #define _LINUX_STRING_H_ 4 5 6 #include <linux/compiler.h> /* for inline */ 7 #include <linux/types.h> /* for size_t */ 8 #include <linux/stddef.h> /* for NULL */ 9 #include <stdarg.h> 10 #include <uapi/linux/string.h> 11 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); 16 17 /* 18 * Include machine specific inline routines 19 */ 20 #include <asm/string.h> 21 22 #ifndef __HAVE_ARCH_STRCPY 23 extern char * strcpy(char *,const char *); 24 #endif 25 #ifndef __HAVE_ARCH_STRNCPY 26 extern char * strncpy(char *,const char *, __kernel_size_t); 27 #endif 28 #ifndef __HAVE_ARCH_STRLCPY 29 size_t strlcpy(char *, const char *, size_t); 30 #endif 31 #ifndef __HAVE_ARCH_STRSCPY 32 ssize_t strscpy(char *, const char *, size_t); 33 #endif 34 #ifndef __HAVE_ARCH_STRCAT 35 extern char * strcat(char *, const char *); 36 #endif 37 #ifndef __HAVE_ARCH_STRNCAT 38 extern char * strncat(char *, const char *, __kernel_size_t); 39 #endif 40 #ifndef __HAVE_ARCH_STRLCAT 41 extern size_t strlcat(char *, const char *, __kernel_size_t); 42 #endif 43 #ifndef __HAVE_ARCH_STRCMP 44 extern int strcmp(const char *,const char *); 45 #endif 46 #ifndef __HAVE_ARCH_STRNCMP 47 extern int strncmp(const char *,const char *,__kernel_size_t); 48 #endif 49 #ifndef __HAVE_ARCH_STRCASECMP 50 extern int strcasecmp(const char *s1, const char *s2); 51 #endif 52 #ifndef __HAVE_ARCH_STRNCASECMP 53 extern int strncasecmp(const char *s1, const char *s2, size_t n); 54 #endif 55 #ifndef __HAVE_ARCH_STRCHR 56 extern char * strchr(const char *,int); 57 #endif 58 #ifndef __HAVE_ARCH_STRCHRNUL 59 extern char * strchrnul(const char *,int); 60 #endif 61 #ifndef __HAVE_ARCH_STRNCHR 62 extern char * strnchr(const char *, size_t, int); 63 #endif 64 #ifndef __HAVE_ARCH_STRRCHR 65 extern char * strrchr(const char *,int); 66 #endif 67 extern char * __must_check skip_spaces(const char *); 68 69 extern char *strim(char *); 70 71 static inline __must_check char *strstrip(char *str) 72 { 73 return strim(str); 74 } 75 76 #ifndef __HAVE_ARCH_STRSTR 77 extern char * strstr(const char *, const char *); 78 #endif 79 #ifndef __HAVE_ARCH_STRNSTR 80 extern char * strnstr(const char *, const char *, size_t); 81 #endif 82 #ifndef __HAVE_ARCH_STRLEN 83 extern __kernel_size_t strlen(const char *); 84 #endif 85 #ifndef __HAVE_ARCH_STRNLEN 86 extern __kernel_size_t strnlen(const char *,__kernel_size_t); 87 #endif 88 #ifndef __HAVE_ARCH_STRPBRK 89 extern char * strpbrk(const char *,const char *); 90 #endif 91 #ifndef __HAVE_ARCH_STRSEP 92 extern char * strsep(char **,const char *); 93 #endif 94 #ifndef __HAVE_ARCH_STRSPN 95 extern __kernel_size_t strspn(const char *,const char *); 96 #endif 97 #ifndef __HAVE_ARCH_STRCSPN 98 extern __kernel_size_t strcspn(const char *,const char *); 99 #endif 100 101 #ifndef __HAVE_ARCH_MEMSET 102 extern void * memset(void *,int,__kernel_size_t); 103 #endif 104 105 #ifndef __HAVE_ARCH_MEMSET16 106 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); 107 #endif 108 109 #ifndef __HAVE_ARCH_MEMSET32 110 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); 111 #endif 112 113 #ifndef __HAVE_ARCH_MEMSET64 114 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); 115 #endif 116 117 static inline void *memset_l(unsigned long *p, unsigned long v, 118 __kernel_size_t n) 119 { 120 if (BITS_PER_LONG == 32) 121 return memset32((uint32_t *)p, v, n); 122 else 123 return memset64((uint64_t *)p, v, n); 124 } 125 126 static inline void *memset_p(void **p, void *v, __kernel_size_t n) 127 { 128 if (BITS_PER_LONG == 32) 129 return memset32((uint32_t *)p, (uintptr_t)v, n); 130 else 131 return memset64((uint64_t *)p, (uintptr_t)v, n); 132 } 133 134 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)); \ 139 }) 140 141 #ifndef __HAVE_ARCH_MEMCPY 142 extern void * memcpy(void *,const void *,__kernel_size_t); 143 #endif 144 #ifndef __HAVE_ARCH_MEMMOVE 145 extern void * memmove(void *,const void *,__kernel_size_t); 146 #endif 147 #ifndef __HAVE_ARCH_MEMSCAN 148 extern void * memscan(void *,int,__kernel_size_t); 149 #endif 150 #ifndef __HAVE_ARCH_MEMCMP 151 extern int memcmp(const void *,const void *,__kernel_size_t); 152 #endif 153 #ifndef __HAVE_ARCH_MEMCHR 154 extern void * memchr(const void *,int,__kernel_size_t); 155 #endif 156 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE 157 static inline __must_check unsigned long memcpy_mcsafe(void *dst, 158 const void *src, size_t cnt) 159 { 160 memcpy(dst, src, cnt); 161 return 0; 162 } 163 #endif 164 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 165 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 166 { 167 memcpy(dst, src, cnt); 168 } 169 #endif 170 void *memchr_inv(const void *s, int c, size_t n); 171 char *strreplace(char *s, char old, char new); 172 173 extern void kfree_const(const void *x); 174 175 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); 180 181 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 182 extern void argv_free(char **argv); 183 184 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) 187 { 188 return kstrtobool(s, res); 189 } 190 191 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); 193 194 /** 195 * sysfs_match_string - matches given string in an array 196 * @_a: array of strings 197 * @_s: string to match with 198 * 199 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 200 */ 201 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 202 203 #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); 207 #endif 208 209 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 210 const void *from, size_t available); 211 212 /** 213 * strstarts - does @str start with @prefix? 214 * @str: string to examine 215 * @prefix: prefix to look for. 216 */ 217 static inline bool strstarts(const char *str, const char *prefix) 218 { 219 return strncmp(str, prefix, strlen(prefix)) == 0; 220 } 221 222 size_t memweight(const void *ptr, size_t bytes); 223 void memzero_explicit(void *s, size_t count); 224 225 /** 226 * kbasename - return the last part of a pathname. 227 * 228 * @path: path to extract the filename from. 229 */ 230 static inline const char *kbasename(const char *path) 231 { 232 const char *tail = strrchr(path, '/'); 233 return tail ? tail + 1 : path; 234 } 235 236 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) 237 #define __RENAME(x) __asm__(#x) 238 239 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"); 244 245 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 246 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) 247 { 248 size_t p_size = __builtin_object_size(p, 0); 249 if (__builtin_constant_p(size) && p_size < size) 250 __write_overflow(); 251 if (p_size < size) 252 fortify_panic(__func__); 253 return __builtin_strncpy(p, q, size); 254 } 255 256 __FORTIFY_INLINE char *strcat(char *p, const char *q) 257 { 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__); 263 return p; 264 } 265 266 __FORTIFY_INLINE __kernel_size_t strlen(const char *p) 267 { 268 __kernel_size_t ret; 269 size_t p_size = __builtin_object_size(p, 0); 270 271 /* 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); 276 if (p_size <= ret) 277 fortify_panic(__func__); 278 return ret; 279 } 280 281 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) 283 { 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__); 288 return ret; 289 } 290 291 /* 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) 294 { 295 size_t ret; 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); 300 ret = strlen(q); 301 if (size) { 302 size_t len = (ret >= size) ? size - 1 : ret; 303 if (__builtin_constant_p(len) && len >= p_size) 304 __write_overflow(); 305 if (len >= p_size) 306 fortify_panic(__func__); 307 __builtin_memcpy(p, q, len); 308 p[len] = '\0'; 309 } 310 return ret; 311 } 312 313 /* defined after fortified strlen and strnlen to reuse them */ 314 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) 315 { 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); 321 p_len = strlen(p); 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'; 327 return p; 328 } 329 330 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size) 331 { 332 size_t p_size = __builtin_object_size(p, 0); 333 if (__builtin_constant_p(size) && p_size < size) 334 __write_overflow(); 335 if (p_size < size) 336 fortify_panic(__func__); 337 return __builtin_memset(p, c, size); 338 } 339 340 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size) 341 { 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)) { 345 if (p_size < size) 346 __write_overflow(); 347 if (q_size < size) 348 __read_overflow2(); 349 } 350 if (p_size < size || q_size < size) 351 fortify_panic(__func__); 352 return __builtin_memcpy(p, q, size); 353 } 354 355 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size) 356 { 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)) { 360 if (p_size < size) 361 __write_overflow(); 362 if (q_size < size) 363 __read_overflow2(); 364 } 365 if (p_size < size || q_size < size) 366 fortify_panic(__func__); 367 return __builtin_memmove(p, q, size); 368 } 369 370 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); 371 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) 372 { 373 size_t p_size = __builtin_object_size(p, 0); 374 if (__builtin_constant_p(size) && p_size < size) 375 __read_overflow(); 376 if (p_size < size) 377 fortify_panic(__func__); 378 return __real_memscan(p, c, size); 379 } 380 381 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) 382 { 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)) { 386 if (p_size < size) 387 __read_overflow(); 388 if (q_size < size) 389 __read_overflow2(); 390 } 391 if (p_size < size || q_size < size) 392 fortify_panic(__func__); 393 return __builtin_memcmp(p, q, size); 394 } 395 396 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) 397 { 398 size_t p_size = __builtin_object_size(p, 0); 399 if (__builtin_constant_p(size) && p_size < size) 400 __read_overflow(); 401 if (p_size < size) 402 fortify_panic(__func__); 403 return __builtin_memchr(p, c, size); 404 } 405 406 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) 408 { 409 size_t p_size = __builtin_object_size(p, 0); 410 if (__builtin_constant_p(size) && p_size < size) 411 __read_overflow(); 412 if (p_size < size) 413 fortify_panic(__func__); 414 return __real_memchr_inv(p, c, size); 415 } 416 417 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) 419 { 420 size_t p_size = __builtin_object_size(p, 0); 421 if (__builtin_constant_p(size) && p_size < size) 422 __read_overflow(); 423 if (p_size < size) 424 fortify_panic(__func__); 425 return __real_kmemdup(p, size, gfp); 426 } 427 428 /* defined after fortified strlen and memcpy to reuse them */ 429 __FORTIFY_INLINE char *strcpy(char *p, const char *q) 430 { 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); 436 return p; 437 } 438 439 #endif 440 441 /** 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. 448 */ 449 static inline void memcpy_and_pad(void *dest, size_t dest_len, 450 const void *src, size_t count, int pad) 451 { 452 if (dest_len > count) { 453 memcpy(dest, src, count); 454 memset(dest + count, pad, dest_len - count); 455 } else 456 memcpy(dest, src, dest_len); 457 } 458 459 /** 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 463 * 464 * A common way to test a prefix of a string is to do: 465 * strncmp(str, prefix, sizeof(prefix) - 1) 466 * 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(). 469 * 470 * Returns: 0 if @str does not start with @prefix 471 strlen(@prefix) if @str does start with @prefix 472 */ 473 static __always_inline size_t str_has_prefix(const char *str, const char *prefix) 474 { 475 size_t len = strlen(prefix); 476 return strncmp(str, prefix, len) == 0 ? len : 0; 477 } 478 479 #endif /* _LINUX_STRING_H_ */ 480