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 35 /* Wraps calls to strscpy()/memset(), no arch specific code required */ 36 ssize_t strscpy_pad(char *dest, const char *src, size_t count); 37 38 #ifndef __HAVE_ARCH_STRCAT 39 extern char * strcat(char *, const char *); 40 #endif 41 #ifndef __HAVE_ARCH_STRNCAT 42 extern char * strncat(char *, const char *, __kernel_size_t); 43 #endif 44 #ifndef __HAVE_ARCH_STRLCAT 45 extern size_t strlcat(char *, const char *, __kernel_size_t); 46 #endif 47 #ifndef __HAVE_ARCH_STRCMP 48 extern int strcmp(const char *,const char *); 49 #endif 50 #ifndef __HAVE_ARCH_STRNCMP 51 extern int strncmp(const char *,const char *,__kernel_size_t); 52 #endif 53 #ifndef __HAVE_ARCH_STRCASECMP 54 extern int strcasecmp(const char *s1, const char *s2); 55 #endif 56 #ifndef __HAVE_ARCH_STRNCASECMP 57 extern int strncasecmp(const char *s1, const char *s2, size_t n); 58 #endif 59 #ifndef __HAVE_ARCH_STRCHR 60 extern char * strchr(const char *,int); 61 #endif 62 #ifndef __HAVE_ARCH_STRCHRNUL 63 extern char * strchrnul(const char *,int); 64 #endif 65 #ifndef __HAVE_ARCH_STRNCHR 66 extern char * strnchr(const char *, size_t, int); 67 #endif 68 #ifndef __HAVE_ARCH_STRRCHR 69 extern char * strrchr(const char *,int); 70 #endif 71 extern char * __must_check skip_spaces(const char *); 72 73 extern char *strim(char *); 74 75 static inline __must_check char *strstrip(char *str) 76 { 77 return strim(str); 78 } 79 80 #ifndef __HAVE_ARCH_STRSTR 81 extern char * strstr(const char *, const char *); 82 #endif 83 #ifndef __HAVE_ARCH_STRNSTR 84 extern char * strnstr(const char *, const char *, size_t); 85 #endif 86 #ifndef __HAVE_ARCH_STRLEN 87 extern __kernel_size_t strlen(const char *); 88 #endif 89 #ifndef __HAVE_ARCH_STRNLEN 90 extern __kernel_size_t strnlen(const char *,__kernel_size_t); 91 #endif 92 #ifndef __HAVE_ARCH_STRPBRK 93 extern char * strpbrk(const char *,const char *); 94 #endif 95 #ifndef __HAVE_ARCH_STRSEP 96 extern char * strsep(char **,const char *); 97 #endif 98 #ifndef __HAVE_ARCH_STRSPN 99 extern __kernel_size_t strspn(const char *,const char *); 100 #endif 101 #ifndef __HAVE_ARCH_STRCSPN 102 extern __kernel_size_t strcspn(const char *,const char *); 103 #endif 104 105 #ifndef __HAVE_ARCH_MEMSET 106 extern void * memset(void *,int,__kernel_size_t); 107 #endif 108 109 #ifndef __HAVE_ARCH_MEMSET16 110 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); 111 #endif 112 113 #ifndef __HAVE_ARCH_MEMSET32 114 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); 115 #endif 116 117 #ifndef __HAVE_ARCH_MEMSET64 118 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); 119 #endif 120 121 static inline void *memset_l(unsigned long *p, unsigned long v, 122 __kernel_size_t n) 123 { 124 if (BITS_PER_LONG == 32) 125 return memset32((uint32_t *)p, v, n); 126 else 127 return memset64((uint64_t *)p, v, n); 128 } 129 130 static inline void *memset_p(void **p, void *v, __kernel_size_t n) 131 { 132 if (BITS_PER_LONG == 32) 133 return memset32((uint32_t *)p, (uintptr_t)v, n); 134 else 135 return memset64((uint64_t *)p, (uintptr_t)v, n); 136 } 137 138 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)); \ 143 }) 144 145 #ifndef __HAVE_ARCH_MEMCPY 146 extern void * memcpy(void *,const void *,__kernel_size_t); 147 #endif 148 #ifndef __HAVE_ARCH_MEMMOVE 149 extern void * memmove(void *,const void *,__kernel_size_t); 150 #endif 151 #ifndef __HAVE_ARCH_MEMSCAN 152 extern void * memscan(void *,int,__kernel_size_t); 153 #endif 154 #ifndef __HAVE_ARCH_MEMCMP 155 extern int memcmp(const void *,const void *,__kernel_size_t); 156 #endif 157 #ifndef __HAVE_ARCH_BCMP 158 extern int bcmp(const void *,const void *,__kernel_size_t); 159 #endif 160 #ifndef __HAVE_ARCH_MEMCHR 161 extern void * memchr(const void *,int,__kernel_size_t); 162 #endif 163 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE 164 static inline __must_check unsigned long memcpy_mcsafe(void *dst, 165 const void *src, size_t cnt) 166 { 167 memcpy(dst, src, cnt); 168 return 0; 169 } 170 #endif 171 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 172 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 173 { 174 memcpy(dst, src, cnt); 175 } 176 #endif 177 void *memchr_inv(const void *s, int c, size_t n); 178 char *strreplace(char *s, char old, char new); 179 180 extern void kfree_const(const void *x); 181 182 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); 187 188 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 189 extern void argv_free(char **argv); 190 191 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) 194 { 195 return kstrtobool(s, res); 196 } 197 198 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); 200 201 /** 202 * sysfs_match_string - matches given string in an array 203 * @_a: array of strings 204 * @_s: string to match with 205 * 206 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 207 */ 208 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 209 210 #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); 214 #endif 215 216 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 217 const void *from, size_t available); 218 219 /** 220 * strstarts - does @str start with @prefix? 221 * @str: string to examine 222 * @prefix: prefix to look for. 223 */ 224 static inline bool strstarts(const char *str, const char *prefix) 225 { 226 return strncmp(str, prefix, strlen(prefix)) == 0; 227 } 228 229 size_t memweight(const void *ptr, size_t bytes); 230 void memzero_explicit(void *s, size_t count); 231 232 /** 233 * kbasename - return the last part of a pathname. 234 * 235 * @path: path to extract the filename from. 236 */ 237 static inline const char *kbasename(const char *path) 238 { 239 const char *tail = strrchr(path, '/'); 240 return tail ? tail + 1 : path; 241 } 242 243 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) 244 #define __RENAME(x) __asm__(#x) 245 246 void fortify_panic(const char *name) __noreturn __cold; 247 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); 248 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); 249 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter"); 250 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); 251 252 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 253 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) 254 { 255 size_t p_size = __builtin_object_size(p, 0); 256 if (__builtin_constant_p(size) && p_size < size) 257 __write_overflow(); 258 if (p_size < size) 259 fortify_panic(__func__); 260 return __builtin_strncpy(p, q, size); 261 } 262 263 __FORTIFY_INLINE char *strcat(char *p, const char *q) 264 { 265 size_t p_size = __builtin_object_size(p, 0); 266 if (p_size == (size_t)-1) 267 return __builtin_strcat(p, q); 268 if (strlcat(p, q, p_size) >= p_size) 269 fortify_panic(__func__); 270 return p; 271 } 272 273 __FORTIFY_INLINE __kernel_size_t strlen(const char *p) 274 { 275 __kernel_size_t ret; 276 size_t p_size = __builtin_object_size(p, 0); 277 278 /* Work around gcc excess stack consumption issue */ 279 if (p_size == (size_t)-1 || 280 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0')) 281 return __builtin_strlen(p); 282 ret = strnlen(p, p_size); 283 if (p_size <= ret) 284 fortify_panic(__func__); 285 return ret; 286 } 287 288 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen); 289 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen) 290 { 291 size_t p_size = __builtin_object_size(p, 0); 292 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size); 293 if (p_size <= ret && maxlen != ret) 294 fortify_panic(__func__); 295 return ret; 296 } 297 298 /* defined after fortified strlen to reuse it */ 299 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); 300 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size) 301 { 302 size_t ret; 303 size_t p_size = __builtin_object_size(p, 0); 304 size_t q_size = __builtin_object_size(q, 0); 305 if (p_size == (size_t)-1 && q_size == (size_t)-1) 306 return __real_strlcpy(p, q, size); 307 ret = strlen(q); 308 if (size) { 309 size_t len = (ret >= size) ? size - 1 : ret; 310 if (__builtin_constant_p(len) && len >= p_size) 311 __write_overflow(); 312 if (len >= p_size) 313 fortify_panic(__func__); 314 __builtin_memcpy(p, q, len); 315 p[len] = '\0'; 316 } 317 return ret; 318 } 319 320 /* defined after fortified strlen and strnlen to reuse them */ 321 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) 322 { 323 size_t p_len, copy_len; 324 size_t p_size = __builtin_object_size(p, 0); 325 size_t q_size = __builtin_object_size(q, 0); 326 if (p_size == (size_t)-1 && q_size == (size_t)-1) 327 return __builtin_strncat(p, q, count); 328 p_len = strlen(p); 329 copy_len = strnlen(q, count); 330 if (p_size < p_len + copy_len + 1) 331 fortify_panic(__func__); 332 __builtin_memcpy(p + p_len, q, copy_len); 333 p[p_len + copy_len] = '\0'; 334 return p; 335 } 336 337 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size) 338 { 339 size_t p_size = __builtin_object_size(p, 0); 340 if (__builtin_constant_p(size) && p_size < size) 341 __write_overflow(); 342 if (p_size < size) 343 fortify_panic(__func__); 344 return __builtin_memset(p, c, size); 345 } 346 347 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size) 348 { 349 size_t p_size = __builtin_object_size(p, 0); 350 size_t q_size = __builtin_object_size(q, 0); 351 if (__builtin_constant_p(size)) { 352 if (p_size < size) 353 __write_overflow(); 354 if (q_size < size) 355 __read_overflow2(); 356 } 357 if (p_size < size || q_size < size) 358 fortify_panic(__func__); 359 return __builtin_memcpy(p, q, size); 360 } 361 362 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size) 363 { 364 size_t p_size = __builtin_object_size(p, 0); 365 size_t q_size = __builtin_object_size(q, 0); 366 if (__builtin_constant_p(size)) { 367 if (p_size < size) 368 __write_overflow(); 369 if (q_size < size) 370 __read_overflow2(); 371 } 372 if (p_size < size || q_size < size) 373 fortify_panic(__func__); 374 return __builtin_memmove(p, q, size); 375 } 376 377 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); 378 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) 379 { 380 size_t p_size = __builtin_object_size(p, 0); 381 if (__builtin_constant_p(size) && p_size < size) 382 __read_overflow(); 383 if (p_size < size) 384 fortify_panic(__func__); 385 return __real_memscan(p, c, size); 386 } 387 388 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) 389 { 390 size_t p_size = __builtin_object_size(p, 0); 391 size_t q_size = __builtin_object_size(q, 0); 392 if (__builtin_constant_p(size)) { 393 if (p_size < size) 394 __read_overflow(); 395 if (q_size < size) 396 __read_overflow2(); 397 } 398 if (p_size < size || q_size < size) 399 fortify_panic(__func__); 400 return __builtin_memcmp(p, q, size); 401 } 402 403 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) 404 { 405 size_t p_size = __builtin_object_size(p, 0); 406 if (__builtin_constant_p(size) && p_size < size) 407 __read_overflow(); 408 if (p_size < size) 409 fortify_panic(__func__); 410 return __builtin_memchr(p, c, size); 411 } 412 413 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv); 414 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size) 415 { 416 size_t p_size = __builtin_object_size(p, 0); 417 if (__builtin_constant_p(size) && p_size < size) 418 __read_overflow(); 419 if (p_size < size) 420 fortify_panic(__func__); 421 return __real_memchr_inv(p, c, size); 422 } 423 424 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup); 425 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp) 426 { 427 size_t p_size = __builtin_object_size(p, 0); 428 if (__builtin_constant_p(size) && p_size < size) 429 __read_overflow(); 430 if (p_size < size) 431 fortify_panic(__func__); 432 return __real_kmemdup(p, size, gfp); 433 } 434 435 /* defined after fortified strlen and memcpy to reuse them */ 436 __FORTIFY_INLINE char *strcpy(char *p, const char *q) 437 { 438 size_t p_size = __builtin_object_size(p, 0); 439 size_t q_size = __builtin_object_size(q, 0); 440 if (p_size == (size_t)-1 && q_size == (size_t)-1) 441 return __builtin_strcpy(p, q); 442 memcpy(p, q, strlen(q) + 1); 443 return p; 444 } 445 446 #endif 447 448 /** 449 * memcpy_and_pad - Copy one buffer to another with padding 450 * @dest: Where to copy to 451 * @dest_len: The destination buffer size 452 * @src: Where to copy from 453 * @count: The number of bytes to copy 454 * @pad: Character to use for padding if space is left in destination. 455 */ 456 static inline void memcpy_and_pad(void *dest, size_t dest_len, 457 const void *src, size_t count, int pad) 458 { 459 if (dest_len > count) { 460 memcpy(dest, src, count); 461 memset(dest + count, pad, dest_len - count); 462 } else 463 memcpy(dest, src, dest_len); 464 } 465 466 /** 467 * str_has_prefix - Test if a string has a given prefix 468 * @str: The string to test 469 * @prefix: The string to see if @str starts with 470 * 471 * A common way to test a prefix of a string is to do: 472 * strncmp(str, prefix, sizeof(prefix) - 1) 473 * 474 * But this can lead to bugs due to typos, or if prefix is a pointer 475 * and not a constant. Instead use str_has_prefix(). 476 * 477 * Returns: 0 if @str does not start with @prefix 478 strlen(@prefix) if @str does start with @prefix 479 */ 480 static __always_inline size_t str_has_prefix(const char *str, const char *prefix) 481 { 482 size_t len = strlen(prefix); 483 return strncmp(str, prefix, len) == 0 ? len : 0; 484 } 485 486 #endif /* _LINUX_STRING_H_ */ 487