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 #ifndef __HAVE_ARCH_MEMCPY
 103 extern void * memcpy(void *,const void *,__kernel_size_t);
 104 #endif
 105 #ifndef __HAVE_ARCH_MEMMOVE
 106 extern void * memmove(void *,const void *,__kernel_size_t);
 107 #endif
 108 #ifndef __HAVE_ARCH_MEMSCAN
 109 extern void * memscan(void *,int,__kernel_size_t);
 110 #endif
 111 #ifndef __HAVE_ARCH_MEMCMP
 112 extern int memcmp(const void *,const void *,__kernel_size_t);
 113 #endif
 114 #ifndef __HAVE_ARCH_MEMCHR
 115 extern void * memchr(const void *,int,__kernel_size_t);
 116 #endif
 117 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
 118 static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
 119                 size_t cnt)
 120 {
 121         memcpy(dst, src, cnt);
 122         return 0;
 123 }
 124 #endif
 125 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
 126 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 127 {
 128         memcpy(dst, src, cnt);
 129 }
 130 #endif
 131 void *memchr_inv(const void *s, int c, size_t n);
 132 char *strreplace(char *s, char old, char new);
 133
 134 extern void kfree_const(const void *x);
 135
 136 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 137 extern const char *kstrdup_const(const char *s, gfp_t gfp);
 138 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 139 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 140
 141 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 142 extern void argv_free(char **argv);
 143
 144 extern bool sysfs_streq(const char *s1, const char *s2);
 145 extern int kstrtobool(const char *s, bool *res);
 146 static inline int strtobool(const char *s, bool *res)
 147 {
 148         return kstrtobool(s, res);
 149 }
 150
 151 int match_string(const char * const *array, size_t n, const char *string);
 152 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
 153
 154 /**
 155  * sysfs_match_string - matches given string in an array
 156  * @_a: array of strings
 157  * @_s: string to match with
 158  *
 159  * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
 160  */
 161 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 162
 163 #ifdef CONFIG_BINARY_PRINTF
 164 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 165 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
 166 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 167 #endif
 168
 169 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 170                                        const void *from, size_t available);
 171
 172 /**
 173  * strstarts - does @str start with @prefix?
 174  * @str: string to examine
 175  * @prefix: prefix to look for.
 176  */
 177 static inline bool strstarts(const char *str, const char *prefix)
 178 {
 179         return strncmp(str, prefix, strlen(prefix)) == 0;
 180 }
 181
 182 size_t memweight(const void *ptr, size_t bytes);
 183 void memzero_explicit(void *s, size_t count);
 184
 185 /**
 186  * kbasename - return the last part of a pathname.
 187  *
 188  * @path: path to extract the filename from.
 189  */
 190 static inline const char *kbasename(const char *path)
 191 {
 192         const char *tail = strrchr(path, '/');
 193         return tail ? tail + 1 : path;
 194 }
 195
 196 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
 197 #define __RENAME(x) __asm__(#x)
 198
 199 void fortify_panic(const char *name) __noreturn __cold;
 200 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
 201 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
 202 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
 203
 204 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 205 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
 206 {
 207         size_t p_size = __builtin_object_size(p, 0);
 208         size_t q_size = __builtin_object_size(q, 0);
 209         if (p_size == (size_t)-1 && q_size == (size_t)-1)
 210                 return __builtin_strcpy(p, q);
 211         if (strscpy(p, q, p_size < q_size ? p_size : q_size) < 0)
 212                 fortify_panic(__func__);
 213         return p;
 214 }
 215
 216 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
 217 {
 218         size_t p_size = __builtin_object_size(p, 0);
 219         if (__builtin_constant_p(size) && p_size < size)
 220                 __write_overflow();
 221         if (p_size < size)
 222                 fortify_panic(__func__);
 223         return __builtin_strncpy(p, q, size);
 224 }
 225
 226 __FORTIFY_INLINE char *strcat(char *p, const char *q)
 227 {
 228         size_t p_size = __builtin_object_size(p, 0);
 229         if (p_size == (size_t)-1)
 230                 return __builtin_strcat(p, q);
 231         if (strlcat(p, q, p_size) >= p_size)
 232                 fortify_panic(__func__);
 233         return p;
 234 }
 235
 236 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 237 {
 238         __kernel_size_t ret;
 239         size_t p_size = __builtin_object_size(p, 0);
 240         if (p_size == (size_t)-1)
 241                 return __builtin_strlen(p);
 242         ret = strnlen(p, p_size);
 243         if (p_size <= ret)
 244                 fortify_panic(__func__);
 245         return ret;
 246 }
 247
 248 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
 249 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
 250 {
 251         size_t p_size = __builtin_object_size(p, 0);
 252         __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
 253         if (p_size <= ret && maxlen != ret)
 254                 fortify_panic(__func__);
 255         return ret;
 256 }
 257
 258 /* defined after fortified strlen to reuse it */
 259 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 260 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 261 {
 262         size_t ret;
 263         size_t p_size = __builtin_object_size(p, 0);
 264         size_t q_size = __builtin_object_size(q, 0);
 265         if (p_size == (size_t)-1 && q_size == (size_t)-1)
 266                 return __real_strlcpy(p, q, size);
 267         ret = strlen(q);
 268         if (size) {
 269                 size_t len = (ret >= size) ? size - 1 : ret;
 270                 if (__builtin_constant_p(len) && len >= p_size)
 271                         __write_overflow();
 272                 if (len >= p_size)
 273                         fortify_panic(__func__);
 274                 __builtin_memcpy(p, q, len);
 275                 p[len] = '\0';
 276         }
 277         return ret;
 278 }
 279
 280 /* defined after fortified strlen and strnlen to reuse them */
 281 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
 282 {
 283         size_t p_len, copy_len;
 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 __builtin_strncat(p, q, count);
 288         p_len = strlen(p);
 289         copy_len = strnlen(q, count);
 290         if (p_size < p_len + copy_len + 1)
 291                 fortify_panic(__func__);
 292         __builtin_memcpy(p + p_len, q, copy_len);
 293         p[p_len + copy_len] = '\0';
 294         return p;
 295 }
 296
 297 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
 298 {
 299         size_t p_size = __builtin_object_size(p, 0);
 300         if (__builtin_constant_p(size) && p_size < size)
 301                 __write_overflow();
 302         if (p_size < size)
 303                 fortify_panic(__func__);
 304         return __builtin_memset(p, c, size);
 305 }
 306
 307 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
 308 {
 309         size_t p_size = __builtin_object_size(p, 0);
 310         size_t q_size = __builtin_object_size(q, 0);
 311         if (__builtin_constant_p(size)) {
 312                 if (p_size < size)
 313                         __write_overflow();
 314                 if (q_size < size)
 315                         __read_overflow2();
 316         }
 317         if (p_size < size || q_size < size)
 318                 fortify_panic(__func__);
 319         return __builtin_memcpy(p, q, size);
 320 }
 321
 322 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
 323 {
 324         size_t p_size = __builtin_object_size(p, 0);
 325         size_t q_size = __builtin_object_size(q, 0);
 326         if (__builtin_constant_p(size)) {
 327                 if (p_size < size)
 328                         __write_overflow();
 329                 if (q_size < size)
 330                         __read_overflow2();
 331         }
 332         if (p_size < size || q_size < size)
 333                 fortify_panic(__func__);
 334         return __builtin_memmove(p, q, size);
 335 }
 336
 337 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
 338 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
 339 {
 340         size_t p_size = __builtin_object_size(p, 0);
 341         if (__builtin_constant_p(size) && p_size < size)
 342                 __read_overflow();
 343         if (p_size < size)
 344                 fortify_panic(__func__);
 345         return __real_memscan(p, c, size);
 346 }
 347
 348 __FORTIFY_INLINE int memcmp(const 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                         __read_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_memcmp(p, q, size);
 361 }
 362
 363 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
 364 {
 365         size_t p_size = __builtin_object_size(p, 0);
 366         if (__builtin_constant_p(size) && p_size < size)
 367                 __read_overflow();
 368         if (p_size < size)
 369                 fortify_panic(__func__);
 370         return __builtin_memchr(p, c, size);
 371 }
 372
 373 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
 374 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, 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_memchr_inv(p, c, size);
 382 }
 383
 384 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
 385 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 386 {
 387         size_t p_size = __builtin_object_size(p, 0);
 388         if (__builtin_constant_p(size) && p_size < size)
 389                 __read_overflow();
 390         if (p_size < size)
 391                 fortify_panic(__func__);
 392         return __real_kmemdup(p, size, gfp);
 393 }
 394 #endif
 395
 396 #endif /* _LINUX_STRING_H_ */