LXR linux/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
  12extern char *strndup_user(const char __user *, long);
  13extern void *memdup_user(const void __user *, size_t);
  14extern void *vmemdup_user(const void __user *, size_t);
  15extern 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
  23extern char * strcpy(char *,const char *);
  24#endif
  25#ifndef __HAVE_ARCH_STRNCPY
  26extern char * strncpy(char *,const char *, __kernel_size_t);
  27#endif
  28#ifndef __HAVE_ARCH_STRLCPY
  29size_t strlcpy(char *, const char *, size_t);
  30#endif
  31#ifndef __HAVE_ARCH_STRSCPY
  32ssize_t strscpy(char *, const char *, size_t);
  33#endif
  34#ifndef __HAVE_ARCH_STRCAT
  35extern char * strcat(char *, const char *);
  36#endif
  37#ifndef __HAVE_ARCH_STRNCAT
  38extern char * strncat(char *, const char *, __kernel_size_t);
  39#endif
  40#ifndef __HAVE_ARCH_STRLCAT
  41extern size_t strlcat(char *, const char *, __kernel_size_t);
  42#endif
  43#ifndef __HAVE_ARCH_STRCMP
  44extern int strcmp(const char *,const char *);
  45#endif
  46#ifndef __HAVE_ARCH_STRNCMP
  47extern int strncmp(const char *,const char *,__kernel_size_t);
  48#endif
  49#ifndef __HAVE_ARCH_STRCASECMP
  50extern int strcasecmp(const char *s1, const char *s2);
  51#endif
  52#ifndef __HAVE_ARCH_STRNCASECMP
  53extern int strncasecmp(const char *s1, const char *s2, size_t n);
  54#endif
  55#ifndef __HAVE_ARCH_STRCHR
  56extern char * strchr(const char *,int);
  57#endif
  58#ifndef __HAVE_ARCH_STRCHRNUL
  59extern char * strchrnul(const char *,int);
  60#endif
  61#ifndef __HAVE_ARCH_STRNCHR
  62extern char * strnchr(const char *, size_t, int);
  63#endif
  64#ifndef __HAVE_ARCH_STRRCHR
  65extern char * strrchr(const char *,int);
  66#endif
  67extern char * __must_check skip_spaces(const char *);
  68
  69extern char *strim(char *);
  70
  71static inline __must_check char *strstrip(char *str)
  72{
  73        return strim(str);
  74}
  75
  76#ifndef __HAVE_ARCH_STRSTR
  77extern char * strstr(const char *, const char *);
  78#endif
  79#ifndef __HAVE_ARCH_STRNSTR
  80extern char * strnstr(const char *, const char *, size_t);
  81#endif
  82#ifndef __HAVE_ARCH_STRLEN
  83extern __kernel_size_t strlen(const char *);
  84#endif
  85#ifndef __HAVE_ARCH_STRNLEN
  86extern __kernel_size_t strnlen(const char *,__kernel_size_t);
  87#endif
  88#ifndef __HAVE_ARCH_STRPBRK
  89extern char * strpbrk(const char *,const char *);
  90#endif
  91#ifndef __HAVE_ARCH_STRSEP
  92extern char * strsep(char **,const char *);
  93#endif
  94#ifndef __HAVE_ARCH_STRSPN
  95extern __kernel_size_t strspn(const char *,const char *);
  96#endif
  97#ifndef __HAVE_ARCH_STRCSPN
  98extern __kernel_size_t strcspn(const char *,const char *);
  99#endif
 100
 101#ifndef __HAVE_ARCH_MEMSET
 102extern void * memset(void *,int,__kernel_size_t);
 103#endif
 104
 105#ifndef __HAVE_ARCH_MEMSET16
 106extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
 107#endif
 108
 109#ifndef __HAVE_ARCH_MEMSET32
 110extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
 111#endif
 112
 113#ifndef __HAVE_ARCH_MEMSET64
 114extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
 115#endif
 116
 117static 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
 126static 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
 135extern void * memcpy(void *,const void *,__kernel_size_t);
 136#endif
 137#ifndef __HAVE_ARCH_MEMMOVE
 138extern void * memmove(void *,const void *,__kernel_size_t);
 139#endif
 140#ifndef __HAVE_ARCH_MEMSCAN
 141extern void * memscan(void *,int,__kernel_size_t);
 142#endif
 143#ifndef __HAVE_ARCH_MEMCMP
 144extern int memcmp(const void *,const void *,__kernel_size_t);
 145#endif
 146#ifndef __HAVE_ARCH_MEMCHR
 147extern void * memchr(const void *,int,__kernel_size_t);
 148#endif
 149#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
 150static 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
 158static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 159{
 160        memcpy(dst, src, cnt);
 161}
 162#endif
 163void *memchr_inv(const void *s, int c, size_t n);
 164char *strreplace(char *s, char old, char new);
 165
 166extern void kfree_const(const void *x);
 167
 168extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 169extern const char *kstrdup_const(const char *s, gfp_t gfp);
 170extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 171extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 172extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
 173
 174extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 175extern void argv_free(char **argv);
 176
 177extern bool sysfs_streq(const char *s1, const char *s2);
 178extern int kstrtobool(const char *s, bool *res);
 179static inline int strtobool(const char *s, bool *res)
 180{
 181        return kstrtobool(s, res);
 182}
 183
 184int match_string(const char * const *array, size_t n, const char *string);
 185int __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
 197int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 198int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
 199int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 200#endif
 201
 202extern 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 */
 210static inline bool strstarts(const char *str, const char *prefix)
 211{
 212        return strncmp(str, prefix, strlen(prefix)) == 0;
 213}
 214
 215size_t memweight(const void *ptr, size_t bytes);
 216void 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 */
 223static 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
 232void fortify_panic(const char *name) __noreturn __cold;
 233void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
 234void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
 235void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
 236void __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
 274extern __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 */
 285extern 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
 363extern 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
 399void *__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
 410extern 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 */
 442static 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