include/linux/string.h

   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 int memcpy_mcsafe(void *dst, const void *src,
 151                 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_ */