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_BCMP 154 extern int bcmp(const void *,const void *,__kernel_size_t); 155 #endif 156 #ifndef __HAVE_ARCH_MEMCHR 157 extern void * memchr(const void *,int,__kernel_size_t); 158 #endif 159 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE 160 static inline __must_check unsigned long memcpy_mcsafe(void *dst, 161 const void *src, size_t cnt) 162 { 163 memcpy(dst, src, cnt); 164 return 0; 165 } 166 #endif 167 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 168 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 169 { 170 memcpy(dst, src, cnt); 171 } 172 #endif 173 void *memchr_inv(const void *s, int c, size_t n); 174 char *strreplace(char *s, char old, char new); 175 176 extern void kfree_const(const void *x); 177 178 extern char *kstrdup(const char *s, gfp_t gfp) __malloc; 179 extern const char *kstrdup_const(const char *s, gfp_t gfp); 180 extern char *kstrndup(const char *s, size_t len, gfp_t gfp); 181 extern void *kmemdup(const void *src, size_t len, gfp_t gfp); 182 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); 183 184 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 185 extern void argv_free(char **argv); 186 187 extern bool sysfs_streq(const char *s1, const char *s2); 188 extern int kstrtobool(const char *s, bool *res); 189 static inline int strtobool(const char *s, bool *res) 190 { 191 return kstrtobool(s, res); 192 } 193 194 int match_string(const char * const *array, size_t n, const char *string); 195 int __sysfs_match_string(const char * const *array, size_t n, const char *s); 196 197 /** 198 * sysfs_match_string - matches given string in an array 199 * @_a: array of strings 200 * @_s: string to match with 201 * 202 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 203 */ 204 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 205 206 #ifdef CONFIG_BINARY_PRINTF 207 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); 208 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); 209 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); 210 #endif 211 212 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 213 const void *from, size_t available); 214 215 /** 216 * strstarts - does @str start with @prefix? 217 * @str: string to examine 218 * @prefix: prefix to look for. 219 */ 220 static inline bool strstarts(const char *str, const char *prefix) 221 { 222 return strncmp(str, prefix, strlen(prefix)) == 0; 223 } 224 225 size_t memweight(const void *ptr, size_t bytes); 226 void memzero_explicit(void *s, size_t count); 227 228 /** 229 * kbasename - return the last part of a pathname. 230 * 231 * @path: path to extract the filename from. 232 */ 233 static inline const char *kbasename(const char *path) 234 { 235 const char *tail = strrchr(path, '/'); 236 return tail ? tail + 1 : path; 237 } 238 239 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) 240 #define __RENAME(x) __asm__(#x) 241 242 void fortify_panic(const char *name) __noreturn __cold; 243 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); 244 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); 245 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter"); 246 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); 247 248 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 249 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) 250 { 251 size_t p_size = __builtin_object_size(p, 0); 252 if (__builtin_constant_p(size) && p_size < size) 253 __write_overflow(); 254 if (p_size < size) 255 fortify_panic(__func__); 256 return __builtin_strncpy(p, q, size); 257 } 258 259 __FORTIFY_INLINE char *strcat(char *p, const char *q) 260 { 261 size_t p_size = __builtin_object_size(p, 0); 262 if (p_size == (size_t)-1) 263 return __builtin_strcat(p, q); 264 if (strlcat(p, q, p_size) >= p_size) 265 fortify_panic(__func__); 266 return p; 267 } 268 269 __FORTIFY_INLINE __kernel_size_t strlen(const char *p) 270 { 271 __kernel_size_t ret; 272 size_t p_size = __builtin_object_size(p, 0); 273 274 /* Work around gcc excess stack consumption issue */ 275 if (p_size == (size_t)-1 || 276 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0')) 277 return __builtin_strlen(p); 278 ret = strnlen(p, p_size); 279 if (p_size <= ret) 280 fortify_panic(__func__); 281 return ret; 282 } 283 284 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen); 285 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen) 286 { 287 size_t p_size = __builtin_object_size(p, 0); 288 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size); 289 if (p_size <= ret && maxlen != ret) 290 fortify_panic(__func__); 291 return ret; 292 } 293 294 /* defined after fortified strlen to reuse it */ 295 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); 296 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size) 297 { 298 size_t ret; 299 size_t p_size = __builtin_object_size(p, 0); 300 size_t q_size = __builtin_object_size(q, 0); 301 if (p_size == (size_t)-1 && q_size == (size_t)-1) 302 return __real_strlcpy(p, q, size); 303 ret = strlen(q); 304 if (size) { 305 size_t len = (ret >= size) ? size - 1 : ret; 306 if (__builtin_constant_p(len) && len >= p_size) 307 __write_overflow(); 308 if (len >= p_size) 309 fortify_panic(__func__); 310 __builtin_memcpy(p, q, len); 311 p[len] = '\0'; 312 } 313 return ret; 314 } 315 316 /* defined after fortified strlen and strnlen to reuse them */ 317 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) 318 { 319 size_t p_len, copy_len; 320 size_t p_size = __builtin_object_size(p, 0); 321 size_t q_size = __builtin_object_size(q, 0); 322 if (p_size == (size_t)-1 && q_size == (size_t)-1) 323 return __builtin_strncat(p, q, count); 324 p_len = strlen(p); 325 copy_len = strnlen(q, count); 326 if (p_size < p_len + copy_len + 1) 327 fortify_panic(__func__); 328 __builtin_memcpy(p + p_len, q, copy_len); 329 p[p_len + copy_len] = '\0'; 330 return p; 331 } 332 333 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size) 334 { 335 size_t p_size = __builtin_object_size(p, 0); 336 if (__builtin_constant_p(size) && p_size < size) 337 __write_overflow(); 338 if (p_size < size) 339 fortify_panic(__func__); 340 return __builtin_memset(p, c, size); 341 } 342 343 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size) 344 { 345 size_t p_size = __builtin_object_size(p, 0); 346 size_t q_size = __builtin_object_size(q, 0); 347 if (__builtin_constant_p(size)) { 348 if (p_size < size) 349 __write_overflow(); 350 if (q_size < size) 351 __read_overflow2(); 352 } 353 if (p_size < size || q_size < size) 354 fortify_panic(__func__); 355 return __builtin_memcpy(p, q, size); 356 } 357 358 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size) 359 { 360 size_t p_size = __builtin_object_size(p, 0); 361 size_t q_size = __builtin_object_size(q, 0); 362 if (__builtin_constant_p(size)) { 363 if (p_size < size) 364 __write_overflow(); 365 if (q_size < size) 366 __read_overflow2(); 367 } 368 if (p_size < size || q_size < size) 369 fortify_panic(__func__); 370 return __builtin_memmove(p, q, size); 371 } 372 373 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); 374 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) 375 { 376 size_t p_size = __builtin_object_size(p, 0); 377 if (__builtin_constant_p(size) && p_size < size) 378 __read_overflow(); 379 if (p_size < size) 380 fortify_panic(__func__); 381 return __real_memscan(p, c, size); 382 } 383 384 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) 385 { 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)) { 389 if (p_size < size) 390 __read_overflow(); 391 if (q_size < size) 392 __read_overflow2(); 393 } 394 if (p_size < size || q_size < size) 395 fortify_panic(__func__); 396 return __builtin_memcmp(p, q, size); 397 } 398 399 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) 400 { 401 size_t p_size = __builtin_object_size(p, 0); 402 if (__builtin_constant_p(size) && p_size < size) 403 __read_overflow(); 404 if (p_size < size) 405 fortify_panic(__func__); 406 return __builtin_memchr(p, c, size); 407 } 408 409 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv); 410 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size) 411 { 412 size_t p_size = __builtin_object_size(p, 0); 413 if (__builtin_constant_p(size) && p_size < size) 414 __read_overflow(); 415 if (p_size < size) 416 fortify_panic(__func__); 417 return __real_memchr_inv(p, c, size); 418 } 419 420 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup); 421 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp) 422 { 423 size_t p_size = __builtin_object_size(p, 0); 424 if (__builtin_constant_p(size) && p_size < size) 425 __read_overflow(); 426 if (p_size < size) 427 fortify_panic(__func__); 428 return __real_kmemdup(p, size, gfp); 429 } 430 431 /* defined after fortified strlen and memcpy to reuse them */ 432 __FORTIFY_INLINE char *strcpy(char *p, const char *q) 433 { 434 size_t p_size = __builtin_object_size(p, 0); 435 size_t q_size = __builtin_object_size(q, 0); 436 if (p_size == (size_t)-1 && q_size == (size_t)-1) 437 return __builtin_strcpy(p, q); 438 memcpy(p, q, strlen(q) + 1); 439 return p; 440 } 441 442 #endif 443 444 /** 445 * memcpy_and_pad - Copy one buffer to another with padding 446 * @dest: Where to copy to 447 * @dest_len: The destination buffer size 448 * @src: Where to copy from 449 * @count: The number of bytes to copy 450 * @pad: Character to use for padding if space is left in destination. 451 */ 452 static inline void memcpy_and_pad(void *dest, size_t dest_len, 453 const void *src, size_t count, int pad) 454 { 455 if (dest_len > count) { 456 memcpy(dest, src, count); 457 memset(dest + count, pad, dest_len - count); 458 } else 459 memcpy(dest, src, dest_len); 460 } 461 462 /** 463 * str_has_prefix - Test if a string has a given prefix 464 * @str: The string to test 465 * @prefix: The string to see if @str starts with 466 * 467 * A common way to test a prefix of a string is to do: 468 * strncmp(str, prefix, sizeof(prefix) - 1) 469 * 470 * But this can lead to bugs due to typos, or if prefix is a pointer 471 * and not a constant. Instead use str_has_prefix(). 472 * 473 * Returns: 0 if @str does not start with @prefix 474 strlen(@prefix) if @str does start with @prefix 475 */ 476 static __always_inline size_t str_has_prefix(const char *str, const char *prefix) 477 { 478 size_t len = strlen(prefix); 479 return strncmp(str, prefix, len) == 0 ? len : 0; 480 } 481 482 #endif /* _LINUX_STRING_H_ */ 483