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 #ifndef __HAVE_ARCH_MEMCPY 135 extern void * memcpy(void *,const void *,__kernel_size_t); 136 #endif 137 #ifndef __HAVE_ARCH_MEMMOVE 138 extern void * memmove(void *,const void *,__kernel_size_t); 139 #endif 140 #ifndef __HAVE_ARCH_MEMSCAN 141 extern void * memscan(void *,int,__kernel_size_t); 142 #endif 143 #ifndef __HAVE_ARCH_MEMCMP 144 extern int memcmp(const void *,const void *,__kernel_size_t); 145 #endif 146 #ifndef __HAVE_ARCH_MEMCHR 147 extern void * memchr(const void *,int,__kernel_size_t); 148 #endif 149 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE 150 static inline __must_check unsigned long memcpy_mcsafe(void *dst, 151 const void *src, size_t cnt) 152 { 153 memcpy(dst, src, cnt); 154 return 0; 155 } 156 #endif 157 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 158 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 159 { 160 memcpy(dst, src, cnt); 161 } 162 #endif 163 void *memchr_inv(const void *s, int c, size_t n); 164 char *strreplace(char *s, char old, char new); 165 166 extern void kfree_const(const void *x); 167 168 extern char *kstrdup(const char *s, gfp_t gfp) __malloc; 169 extern const char *kstrdup_const(const char *s, gfp_t gfp); 170 extern char *kstrndup(const char *s, size_t len, gfp_t gfp); 171 extern void *kmemdup(const void *src, size_t len, gfp_t gfp); 172 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); 173 174 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 175 extern void argv_free(char **argv); 176 177 extern bool sysfs_streq(const char *s1, const char *s2); 178 extern int kstrtobool(const char *s, bool *res); 179 static inline int strtobool(const char *s, bool *res) 180 { 181 return kstrtobool(s, res); 182 } 183 184 int match_string(const char * const *array, size_t n, const char *string); 185 int __sysfs_match_string(const char * const *array, size_t n, const char *s); 186 187 /** 188 * sysfs_match_string - matches given string in an array 189 * @_a: array of strings 190 * @_s: string to match with 191 * 192 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 193 */ 194 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 195 196 #ifdef CONFIG_BINARY_PRINTF 197 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); 198 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); 199 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); 200 #endif 201 202 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 203 const void *from, size_t available); 204 205 /** 206 * strstarts - does @str start with @prefix? 207 * @str: string to examine 208 * @prefix: prefix to look for. 209 */ 210 static inline bool strstarts(const char *str, const char *prefix) 211 { 212 return strncmp(str, prefix, strlen(prefix)) == 0; 213 } 214 215 size_t memweight(const void *ptr, size_t bytes); 216 void memzero_explicit(void *s, size_t count); 217 218 /** 219 * kbasename - return the last part of a pathname. 220 * 221 * @path: path to extract the filename from. 222 */ 223 static inline const char *kbasename(const char *path) 224 { 225 const char *tail = strrchr(path, '/'); 226 return tail ? tail + 1 : path; 227 } 228 229 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) 230 #define __RENAME(x) __asm__(#x) 231 232 void fortify_panic(const char *name) __noreturn __cold; 233 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); 234 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); 235 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter"); 236 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); 237 238 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 239 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size) 240 { 241 size_t p_size = __builtin_object_size(p, 0); 242 if (__builtin_constant_p(size) && p_size < size) 243 __write_overflow(); 244 if (p_size < size) 245 fortify_panic(__func__); 246 return __builtin_strncpy(p, q, size); 247 } 248 249 __FORTIFY_INLINE char *strcat(char *p, const char *q) 250 { 251 size_t p_size = __builtin_object_size(p, 0); 252 if (p_size == (size_t)-1) 253 return __builtin_strcat(p, q); 254 if (strlcat(p, q, p_size) >= p_size) 255 fortify_panic(__func__); 256 return p; 257 } 258 259 __FORTIFY_INLINE __kernel_size_t strlen(const char *p) 260 { 261 __kernel_size_t ret; 262 size_t p_size = __builtin_object_size(p, 0); 263 264 /* Work around gcc excess stack consumption issue */ 265 if (p_size == (size_t)-1 || 266 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0')) 267 return __builtin_strlen(p); 268 ret = strnlen(p, p_size); 269 if (p_size <= ret) 270 fortify_panic(__func__); 271 return ret; 272 } 273 274 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen); 275 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen) 276 { 277 size_t p_size = __builtin_object_size(p, 0); 278 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size); 279 if (p_size <= ret && maxlen != ret) 280 fortify_panic(__func__); 281 return ret; 282 } 283 284 /* defined after fortified strlen to reuse it */ 285 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy); 286 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size) 287 { 288 size_t ret; 289 size_t p_size = __builtin_object_size(p, 0); 290 size_t q_size = __builtin_object_size(q, 0); 291 if (p_size == (size_t)-1 && q_size == (size_t)-1) 292 return __real_strlcpy(p, q, size); 293 ret = strlen(q); 294 if (size) { 295 size_t len = (ret >= size) ? size - 1 : ret; 296 if (__builtin_constant_p(len) && len >= p_size) 297 __write_overflow(); 298 if (len >= p_size) 299 fortify_panic(__func__); 300 __builtin_memcpy(p, q, len); 301 p[len] = '\0'; 302 } 303 return ret; 304 } 305 306 /* defined after fortified strlen and strnlen to reuse them */ 307 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count) 308 { 309 size_t p_len, copy_len; 310 size_t p_size = __builtin_object_size(p, 0); 311 size_t q_size = __builtin_object_size(q, 0); 312 if (p_size == (size_t)-1 && q_size == (size_t)-1) 313 return __builtin_strncat(p, q, count); 314 p_len = strlen(p); 315 copy_len = strnlen(q, count); 316 if (p_size < p_len + copy_len + 1) 317 fortify_panic(__func__); 318 __builtin_memcpy(p + p_len, q, copy_len); 319 p[p_len + copy_len] = '\0'; 320 return p; 321 } 322 323 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size) 324 { 325 size_t p_size = __builtin_object_size(p, 0); 326 if (__builtin_constant_p(size) && p_size < size) 327 __write_overflow(); 328 if (p_size < size) 329 fortify_panic(__func__); 330 return __builtin_memset(p, c, size); 331 } 332 333 __FORTIFY_INLINE void *memcpy(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 __write_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_memcpy(p, q, size); 346 } 347 348 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size) 349 { 350 size_t p_size = __builtin_object_size(p, 0); 351 size_t q_size = __builtin_object_size(q, 0); 352 if (__builtin_constant_p(size)) { 353 if (p_size < size) 354 __write_overflow(); 355 if (q_size < size) 356 __read_overflow2(); 357 } 358 if (p_size < size || q_size < size) 359 fortify_panic(__func__); 360 return __builtin_memmove(p, q, size); 361 } 362 363 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan); 364 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size) 365 { 366 size_t p_size = __builtin_object_size(p, 0); 367 if (__builtin_constant_p(size) && p_size < size) 368 __read_overflow(); 369 if (p_size < size) 370 fortify_panic(__func__); 371 return __real_memscan(p, c, size); 372 } 373 374 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size) 375 { 376 size_t p_size = __builtin_object_size(p, 0); 377 size_t q_size = __builtin_object_size(q, 0); 378 if (__builtin_constant_p(size)) { 379 if (p_size < size) 380 __read_overflow(); 381 if (q_size < size) 382 __read_overflow2(); 383 } 384 if (p_size < size || q_size < size) 385 fortify_panic(__func__); 386 return __builtin_memcmp(p, q, size); 387 } 388 389 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size) 390 { 391 size_t p_size = __builtin_object_size(p, 0); 392 if (__builtin_constant_p(size) && p_size < size) 393 __read_overflow(); 394 if (p_size < size) 395 fortify_panic(__func__); 396 return __builtin_memchr(p, c, size); 397 } 398 399 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv); 400 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size) 401 { 402 size_t p_size = __builtin_object_size(p, 0); 403 if (__builtin_constant_p(size) && p_size < size) 404 __read_overflow(); 405 if (p_size < size) 406 fortify_panic(__func__); 407 return __real_memchr_inv(p, c, size); 408 } 409 410 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup); 411 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp) 412 { 413 size_t p_size = __builtin_object_size(p, 0); 414 if (__builtin_constant_p(size) && p_size < size) 415 __read_overflow(); 416 if (p_size < size) 417 fortify_panic(__func__); 418 return __real_kmemdup(p, size, gfp); 419 } 420 421 /* defined after fortified strlen and memcpy to reuse them */ 422 __FORTIFY_INLINE char *strcpy(char *p, const char *q) 423 { 424 size_t p_size = __builtin_object_size(p, 0); 425 size_t q_size = __builtin_object_size(q, 0); 426 if (p_size == (size_t)-1 && q_size == (size_t)-1) 427 return __builtin_strcpy(p, q); 428 memcpy(p, q, strlen(q) + 1); 429 return p; 430 } 431 432 #endif 433 434 /** 435 * memcpy_and_pad - Copy one buffer to another with padding 436 * @dest: Where to copy to 437 * @dest_len: The destination buffer size 438 * @src: Where to copy from 439 * @count: The number of bytes to copy 440 * @pad: Character to use for padding if space is left in destination. 441 */ 442 static inline void memcpy_and_pad(void *dest, size_t dest_len, 443 const void *src, size_t count, int pad) 444 { 445 if (dest_len > count) { 446 memcpy(dest, src, count); 447 memset(dest + count, pad, dest_len - count); 448 } else 449 memcpy(dest, src, dest_len); 450 } 451 452 #endif /* _LINUX_STRING_H_ */ 453