include/linux/string.h

   1 #ifndef _LINUX_STRING_H_
   2 #define _LINUX_STRING_H_
   3
   4
   5 #include <linux/compiler.h>     /* for inline */
   6 #include <linux/types.h>        /* for size_t */
   7 #include <linux/stddef.h>       /* for NULL */
   8 #include <stdarg.h>
   9 #include <uapi/linux/string.h>
  10
  11 extern char *strndup_user(const char __user *, long);
  12 extern void *memdup_user(const void __user *, size_t);
  13 extern void *memdup_user_nul(const void __user *, size_t);
  14
  15 /*
  16  * Include machine specific inline routines
  17  */
  18 #include <asm/string.h>
  19
  20 #ifndef __HAVE_ARCH_STRCPY
  21 extern char * strcpy(char *,const char *);
  22 #endif
  23 #ifndef __HAVE_ARCH_STRNCPY
  24 extern char * strncpy(char *,const char *, __kernel_size_t);
  25 #endif
  26 #ifndef __HAVE_ARCH_STRLCPY
  27 size_t strlcpy(char *, const char *, size_t);
  28 #endif
  29 #ifndef __HAVE_ARCH_STRSCPY
  30 ssize_t __must_check strscpy(char *, const char *, size_t);
  31 #endif
  32 #ifndef __HAVE_ARCH_STRCAT
  33 extern char * strcat(char *, const char *);
  34 #endif
  35 #ifndef __HAVE_ARCH_STRNCAT
  36 extern char * strncat(char *, const char *, __kernel_size_t);
  37 #endif
  38 #ifndef __HAVE_ARCH_STRLCAT
  39 extern size_t strlcat(char *, const char *, __kernel_size_t);
  40 #endif
  41 #ifndef __HAVE_ARCH_STRCMP
  42 extern int strcmp(const char *,const char *);
  43 #endif
  44 #ifndef __HAVE_ARCH_STRNCMP
  45 extern int strncmp(const char *,const char *,__kernel_size_t);
  46 #endif
  47 #ifndef __HAVE_ARCH_STRCASECMP
  48 extern int strcasecmp(const char *s1, const char *s2);
  49 #endif
  50 #ifndef __HAVE_ARCH_STRNCASECMP
  51 extern int strncasecmp(const char *s1, const char *s2, size_t n);
  52 #endif
  53 #ifndef __HAVE_ARCH_STRCHR
  54 extern char * strchr(const char *,int);
  55 #endif
  56 #ifndef __HAVE_ARCH_STRCHRNUL
  57 extern char * strchrnul(const char *,int);
  58 #endif
  59 #ifndef __HAVE_ARCH_STRNCHR
  60 extern char * strnchr(const char *, size_t, int);
  61 #endif
  62 #ifndef __HAVE_ARCH_STRRCHR
  63 extern char * strrchr(const char *,int);
  64 #endif
  65 extern char * __must_check skip_spaces(const char *);
  66
  67 extern char *strim(char *);
  68
  69 static inline __must_check char *strstrip(char *str)
  70 {
  71         return strim(str);
  72 }
  73
  74 #ifndef __HAVE_ARCH_STRSTR
  75 extern char * strstr(const char *, const char *);
  76 #endif
  77 #ifndef __HAVE_ARCH_STRNSTR
  78 extern char * strnstr(const char *, const char *, size_t);
  79 #endif
  80 #ifndef __HAVE_ARCH_STRLEN
  81 extern __kernel_size_t strlen(const char *);
  82 #endif
  83 #ifndef __HAVE_ARCH_STRNLEN
  84 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
  85 #endif
  86 #ifndef __HAVE_ARCH_STRPBRK
  87 extern char * strpbrk(const char *,const char *);
  88 #endif
  89 #ifndef __HAVE_ARCH_STRSEP
  90 extern char * strsep(char **,const char *);
  91 #endif
  92 #ifndef __HAVE_ARCH_STRSPN
  93 extern __kernel_size_t strspn(const char *,const char *);
  94 #endif
  95 #ifndef __HAVE_ARCH_STRCSPN
  96 extern __kernel_size_t strcspn(const char *,const char *);
  97 #endif
  98
  99 #ifndef __HAVE_ARCH_MEMSET
 100 extern void * memset(void *,int,__kernel_size_t);
 101 #endif
 102
 103 #ifndef __HAVE_ARCH_MEMSET16
 104 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
 105 #endif
 106
 107 #ifndef __HAVE_ARCH_MEMSET32
 108 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
 109 #endif
 110
 111 #ifndef __HAVE_ARCH_MEMSET64
 112 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
 113 #endif
 114
 115 static inline void *memset_l(unsigned long *p, unsigned long v,
 116                 __kernel_size_t n)
 117 {
 118         if (BITS_PER_LONG == 32)
 119                 return memset32((uint32_t *)p, v, n);
 120         else
 121                 return memset64((uint64_t *)p, v, n);
 122 }
 123
 124 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
 125 {
 126         if (BITS_PER_LONG == 32)
 127                 return memset32((uint32_t *)p, (uintptr_t)v, n);
 128         else
 129                 return memset64((uint64_t *)p, (uintptr_t)v, n);
 130 }
 131
 132 #ifndef __HAVE_ARCH_MEMCPY
 133 extern void * memcpy(void *,const void *,__kernel_size_t);
 134 #endif
 135 #ifndef __HAVE_ARCH_MEMMOVE
 136 extern void * memmove(void *,const void *,__kernel_size_t);
 137 #endif
 138 #ifndef __HAVE_ARCH_MEMSCAN
 139 extern void * memscan(void *,int,__kernel_size_t);
 140 #endif
 141 #ifndef __HAVE_ARCH_MEMCMP
 142 extern int memcmp(const void *,const void *,__kernel_size_t);
 143 #endif
 144 #ifndef __HAVE_ARCH_MEMCHR
 145 extern void * memchr(const void *,int,__kernel_size_t);
 146 #endif
 147 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
 148 static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
 149                 size_t cnt)
 150 {
 151         memcpy(dst, src, cnt);
 152         return 0;
 153 }
 154 #endif
 155 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
 156 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 157 {
 158         memcpy(dst, src, cnt);
 159 }
 160 #endif
 161 void *memchr_inv(const void *s, int c, size_t n);
 162 char *strreplace(char *s, char old, char new);
 163
 164 extern void kfree_const(const void *x);
 165
 166 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 167 extern const char *kstrdup_const(const char *s, gfp_t gfp);
 168 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 169 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 170 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
 171
 172 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 173 extern void argv_free(char **argv);
 174
 175 extern bool sysfs_streq(const char *s1, const char *s2);
 176 extern int kstrtobool(const char *s, bool *res);
 177 static inline int strtobool(const char *s, bool *res)
 178 {
 179         return kstrtobool(s, res);
 180 }
 181
 182 int match_string(const char * const *array, size_t n, const char *string);
 183 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
 184
 185 /**
 186  * sysfs_match_string - matches given string in an array
 187  * @_a: array of strings
 188  * @_s: string to match with
 189  *
 190  * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
 191  */
 192 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 193
 194 #ifdef CONFIG_BINARY_PRINTF
 195 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 196 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
 197 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 198 #endif
 199
 200 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 201                                        const void *from, size_t available);
 202
 203 /**
 204  * strstarts - does @str start with @prefix?
 205  * @str: string to examine
 206  * @prefix: prefix to look for.
 207  */
 208 static inline bool strstarts(const char *str, const char *prefix)
 209 {
 210         return strncmp(str, prefix, strlen(prefix)) == 0;
 211 }
 212
 213 size_t memweight(const void *ptr, size_t bytes);
 214 void memzero_explicit(void *s, size_t count);
 215
 216 /**
 217  * kbasename - return the last part of a pathname.
 218  *
 219  * @path: path to extract the filename from.
 220  */
 221 static inline const char *kbasename(const char *path)
 222 {
 223         const char *tail = strrchr(path, '/');
 224         return tail ? tail + 1 : path;
 225 }
 226
 227 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
 228 #define __RENAME(x) __asm__(#x)
 229
 230 void fortify_panic(const char *name) __noreturn __cold;
 231 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
 232 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
 233 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
 234 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
 235
 236 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 237 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
 238 {
 239         size_t p_size = __builtin_object_size(p, 0);
 240         if (__builtin_constant_p(size) && p_size < size)
 241                 __write_overflow();
 242         if (p_size < size)
 243                 fortify_panic(__func__);
 244         return __builtin_strncpy(p, q, size);
 245 }
 246
 247 __FORTIFY_INLINE char *strcat(char *p, const char *q)
 248 {
 249         size_t p_size = __builtin_object_size(p, 0);
 250         if (p_size == (size_t)-1)
 251                 return __builtin_strcat(p, q);
 252         if (strlcat(p, q, p_size) >= p_size)
 253                 fortify_panic(__func__);
 254         return p;
 255 }
 256
 257 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 258 {
 259         __kernel_size_t ret;
 260         size_t p_size = __builtin_object_size(p, 0);
 261         if (p_size == (size_t)-1)
 262                 return __builtin_strlen(p);
 263         ret = strnlen(p, p_size);
 264         if (p_size <= ret)
 265                 fortify_panic(__func__);
 266         return ret;
 267 }
 268
 269 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
 270 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
 271 {
 272         size_t p_size = __builtin_object_size(p, 0);
 273         __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
 274         if (p_size <= ret && maxlen != ret)
 275                 fortify_panic(__func__);
 276         return ret;
 277 }
 278
 279 /* defined after fortified strlen to reuse it */
 280 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 281 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 282 {
 283         size_t ret;
 284         size_t p_size = __builtin_object_size(p, 0);
 285         size_t q_size = __builtin_object_size(q, 0);
 286         if (p_size == (size_t)-1 && q_size == (size_t)-1)
 287                 return __real_strlcpy(p, q, size);
 288         ret = strlen(q);
 289         if (size) {
 290                 size_t len = (ret >= size) ? size - 1 : ret;
 291                 if (__builtin_constant_p(len) && len >= p_size)
 292                         __write_overflow();
 293                 if (len >= p_size)
 294                         fortify_panic(__func__);
 295                 __builtin_memcpy(p, q, len);
 296                 p[len] = '\0';
 297         }
 298         return ret;
 299 }
 300
 301 /* defined after fortified strlen and strnlen to reuse them */
 302 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
 303 {
 304         size_t p_len, copy_len;
 305         size_t p_size = __builtin_object_size(p, 0);
 306         size_t q_size = __builtin_object_size(q, 0);
 307         if (p_size == (size_t)-1 && q_size == (size_t)-1)
 308                 return __builtin_strncat(p, q, count);
 309         p_len = strlen(p);
 310         copy_len = strnlen(q, count);
 311         if (p_size < p_len + copy_len + 1)
 312                 fortify_panic(__func__);
 313         __builtin_memcpy(p + p_len, q, copy_len);
 314         p[p_len + copy_len] = '\0';
 315         return p;
 316 }
 317
 318 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
 319 {
 320         size_t p_size = __builtin_object_size(p, 0);
 321         if (__builtin_constant_p(size) && p_size < size)
 322                 __write_overflow();
 323         if (p_size < size)
 324                 fortify_panic(__func__);
 325         return __builtin_memset(p, c, size);
 326 }
 327
 328 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
 329 {
 330         size_t p_size = __builtin_object_size(p, 0);
 331         size_t q_size = __builtin_object_size(q, 0);
 332         if (__builtin_constant_p(size)) {
 333                 if (p_size < size)
 334                         __write_overflow();
 335                 if (q_size < size)
 336                         __read_overflow2();
 337         }
 338         if (p_size < size || q_size < size)
 339                 fortify_panic(__func__);
 340         return __builtin_memcpy(p, q, size);
 341 }
 342
 343 __FORTIFY_INLINE void *memmove(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_memmove(p, q, size);
 356 }
 357
 358 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
 359 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
 360 {
 361         size_t p_size = __builtin_object_size(p, 0);
 362         if (__builtin_constant_p(size) && p_size < size)
 363                 __read_overflow();
 364         if (p_size < size)
 365                 fortify_panic(__func__);
 366         return __real_memscan(p, c, size);
 367 }
 368
 369 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
 370 {
 371         size_t p_size = __builtin_object_size(p, 0);
 372         size_t q_size = __builtin_object_size(q, 0);
 373         if (__builtin_constant_p(size)) {
 374                 if (p_size < size)
 375                         __read_overflow();
 376                 if (q_size < size)
 377                         __read_overflow2();
 378         }
 379         if (p_size < size || q_size < size)
 380                 fortify_panic(__func__);
 381         return __builtin_memcmp(p, q, size);
 382 }
 383
 384 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
 385 {
 386         size_t p_size = __builtin_object_size(p, 0);
 387         if (__builtin_constant_p(size) && p_size < size)
 388                 __read_overflow();
 389         if (p_size < size)
 390                 fortify_panic(__func__);
 391         return __builtin_memchr(p, c, size);
 392 }
 393
 394 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
 395 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
 396 {
 397         size_t p_size = __builtin_object_size(p, 0);
 398         if (__builtin_constant_p(size) && p_size < size)
 399                 __read_overflow();
 400         if (p_size < size)
 401                 fortify_panic(__func__);
 402         return __real_memchr_inv(p, c, size);
 403 }
 404
 405 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
 406 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 407 {
 408         size_t p_size = __builtin_object_size(p, 0);
 409         if (__builtin_constant_p(size) && p_size < size)
 410                 __read_overflow();
 411         if (p_size < size)
 412                 fortify_panic(__func__);
 413         return __real_kmemdup(p, size, gfp);
 414 }
 415
 416 /* defined after fortified strlen and memcpy to reuse them */
 417 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 418 {
 419         size_t p_size = __builtin_object_size(p, 0);
 420         size_t q_size = __builtin_object_size(q, 0);
 421         if (p_size == (size_t)-1 && q_size == (size_t)-1)
 422                 return __builtin_strcpy(p, q);
 423         memcpy(p, q, strlen(q) + 1);
 424         return p;
 425 }
 426
 427 #endif
 428
 429 /**
 430  * memcpy_and_pad - Copy one buffer to another with padding
 431  * @dest: Where to copy to
 432  * @dest_len: The destination buffer size
 433  * @src: Where to copy from
 434  * @count: The number of bytes to copy
 435  * @pad: Character to use for padding if space is left in destination.
 436  */
 437 __FORTIFY_INLINE void memcpy_and_pad(void *dest, size_t dest_len,
 438                                      const void *src, size_t count, int pad)
 439 {
 440         size_t dest_size = __builtin_object_size(dest, 0);
 441         size_t src_size = __builtin_object_size(src, 0);
 442
 443         if (__builtin_constant_p(dest_len) && __builtin_constant_p(count)) {
 444                 if (dest_size < dest_len && dest_size < count)
 445                         __write_overflow();
 446                 else if (src_size < dest_len && src_size < count)
 447                         __read_overflow3();
 448         }
 449         if (dest_size < dest_len)
 450                 fortify_panic(__func__);
 451         if (dest_len > count) {
 452                 memcpy(dest, src, count);
 453                 memset(dest + count, pad,  dest_len - count);
 454         } else
 455                 memcpy(dest, src, dest_len);
 456 }
 457
 458 #endif /* _LINUX_STRING_H_ */