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 *memdup_user_nul(const void __user *, size_t);
  15
  16/*
  17 * Include machine specific inline routines
  18 */
  19#include <asm/string.h>
  20
  21#ifndef __HAVE_ARCH_STRCPY
  22extern char * strcpy(char *,const char *);
  23#endif
  24#ifndef __HAVE_ARCH_STRNCPY
  25extern char * strncpy(char *,const char *, __kernel_size_t);
  26#endif
  27#ifndef __HAVE_ARCH_STRLCPY
  28size_t strlcpy(char *, const char *, size_t);
  29#endif
  30#ifndef __HAVE_ARCH_STRSCPY
  31ssize_t __must_check strscpy(char *, const char *, size_t);
  32#endif
  33#ifndef __HAVE_ARCH_STRCAT
  34extern char * strcat(char *, const char *);
  35#endif
  36#ifndef __HAVE_ARCH_STRNCAT
  37extern char * strncat(char *, const char *, __kernel_size_t);
  38#endif
  39#ifndef __HAVE_ARCH_STRLCAT
  40extern size_t strlcat(char *, const char *, __kernel_size_t);
  41#endif
  42#ifndef __HAVE_ARCH_STRCMP
  43extern int strcmp(const char *,const char *);
  44#endif
  45#ifndef __HAVE_ARCH_STRNCMP
  46extern int strncmp(const char *,const char *,__kernel_size_t);
  47#endif
  48#ifndef __HAVE_ARCH_STRCASECMP
  49extern int strcasecmp(const char *s1, const char *s2);
  50#endif
  51#ifndef __HAVE_ARCH_STRNCASECMP
  52extern int strncasecmp(const char *s1, const char *s2, size_t n);
  53#endif
  54#ifndef __HAVE_ARCH_STRCHR
  55extern char * strchr(const char *,int);
  56#endif
  57#ifndef __HAVE_ARCH_STRCHRNUL
  58extern char * strchrnul(const char *,int);
  59#endif
  60#ifndef __HAVE_ARCH_STRNCHR
  61extern char * strnchr(const char *, size_t, int);
  62#endif
  63#ifndef __HAVE_ARCH_STRRCHR
  64extern char * strrchr(const char *,int);
  65#endif
  66extern char * __must_check skip_spaces(const char *);
  67
  68extern char *strim(char *);
  69
  70static inline __must_check char *strstrip(char *str)
  71{
  72        return strim(str);
  73}
  74
  75#ifndef __HAVE_ARCH_STRSTR
  76extern char * strstr(const char *, const char *);
  77#endif
  78#ifndef __HAVE_ARCH_STRNSTR
  79extern char * strnstr(const char *, const char *, size_t);
  80#endif
  81#ifndef __HAVE_ARCH_STRLEN
  82extern __kernel_size_t strlen(const char *);
  83#endif
  84#ifndef __HAVE_ARCH_STRNLEN
  85extern __kernel_size_t strnlen(const char *,__kernel_size_t);
  86#endif
  87#ifndef __HAVE_ARCH_STRPBRK
  88extern char * strpbrk(const char *,const char *);
  89#endif
  90#ifndef __HAVE_ARCH_STRSEP
  91extern char * strsep(char **,const char *);
  92#endif
  93#ifndef __HAVE_ARCH_STRSPN
  94extern __kernel_size_t strspn(const char *,const char *);
  95#endif
  96#ifndef __HAVE_ARCH_STRCSPN
  97extern __kernel_size_t strcspn(const char *,const char *);
  98#endif
  99
 100#ifndef __HAVE_ARCH_MEMSET
 101extern void * memset(void *,int,__kernel_size_t);
 102#endif
 103
 104#ifndef __HAVE_ARCH_MEMSET16
 105extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
 106#endif
 107
 108#ifndef __HAVE_ARCH_MEMSET32
 109extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
 110#endif
 111
 112#ifndef __HAVE_ARCH_MEMSET64
 113extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
 114#endif
 115
 116static inline void *memset_l(unsigned long *p, unsigned long v,
 117                __kernel_size_t n)
 118{
 119        if (BITS_PER_LONG == 32)
 120                return memset32((uint32_t *)p, v, n);
 121        else
 122                return memset64((uint64_t *)p, v, n);
 123}
 124
 125static inline void *memset_p(void **p, void *v, __kernel_size_t n)
 126{
 127        if (BITS_PER_LONG == 32)
 128                return memset32((uint32_t *)p, (uintptr_t)v, n);
 129        else
 130                return memset64((uint64_t *)p, (uintptr_t)v, n);
 131}
 132
 133#ifndef __HAVE_ARCH_MEMCPY
 134extern void * memcpy(void *,const void *,__kernel_size_t);
 135#endif
 136#ifndef __HAVE_ARCH_MEMMOVE
 137extern void * memmove(void *,const void *,__kernel_size_t);
 138#endif
 139#ifndef __HAVE_ARCH_MEMSCAN
 140extern void * memscan(void *,int,__kernel_size_t);
 141#endif
 142#ifndef __HAVE_ARCH_MEMCMP
 143extern int memcmp(const void *,const void *,__kernel_size_t);
 144#endif
 145#ifndef __HAVE_ARCH_MEMCHR
 146extern void * memchr(const void *,int,__kernel_size_t);
 147#endif
 148#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
 149static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
 150                size_t cnt)
 151{
 152        memcpy(dst, src, cnt);
 153        return 0;
 154}
 155#endif
 156#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
 157static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 158{
 159        memcpy(dst, src, cnt);
 160}
 161#endif
 162void *memchr_inv(const void *s, int c, size_t n);
 163char *strreplace(char *s, char old, char new);
 164
 165extern void kfree_const(const void *x);
 166
 167extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 168extern const char *kstrdup_const(const char *s, gfp_t gfp);
 169extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 170extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 171extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
 172
 173extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 174extern void argv_free(char **argv);
 175
 176extern bool sysfs_streq(const char *s1, const char *s2);
 177extern int kstrtobool(const char *s, bool *res);
 178static inline int strtobool(const char *s, bool *res)
 179{
 180        return kstrtobool(s, res);
 181}
 182
 183int match_string(const char * const *array, size_t n, const char *string);
 184int __sysfs_match_string(const char * const *array, size_t n, const char *s);
 185
 186/**
 187 * sysfs_match_string - matches given string in an array
 188 * @_a: array of strings
 189 * @_s: string to match with
 190 *
 191 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
 192 */
 193#define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 194
 195#ifdef CONFIG_BINARY_PRINTF
 196int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 197int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
 198int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 199#endif
 200
 201extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 202                                       const void *from, size_t available);
 203
 204/**
 205 * strstarts - does @str start with @prefix?
 206 * @str: string to examine
 207 * @prefix: prefix to look for.
 208 */
 209static inline bool strstarts(const char *str, const char *prefix)
 210{
 211        return strncmp(str, prefix, strlen(prefix)) == 0;
 212}
 213
 214size_t memweight(const void *ptr, size_t bytes);
 215void memzero_explicit(void *s, size_t count);
 216
 217/**
 218 * kbasename - return the last part of a pathname.
 219 *
 220 * @path: path to extract the filename from.
 221 */
 222static inline const char *kbasename(const char *path)
 223{
 224        const char *tail = strrchr(path, '/');
 225        return tail ? tail + 1 : path;
 226}
 227
 228#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
 229#define __RENAME(x) __asm__(#x)
 230
 231void fortify_panic(const char *name) __noreturn __cold;
 232void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
 233void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
 234void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
 235void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
 236
 237#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 238__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
 239{
 240        size_t p_size = __builtin_object_size(p, 0);
 241        if (__builtin_constant_p(size) && p_size < size)
 242                __write_overflow();
 243        if (p_size < size)
 244                fortify_panic(__func__);
 245        return __builtin_strncpy(p, q, size);
 246}
 247
 248__FORTIFY_INLINE char *strcat(char *p, const char *q)
 249{
 250        size_t p_size = __builtin_object_size(p, 0);
 251        if (p_size == (size_t)-1)
 252                return __builtin_strcat(p, q);
 253        if (strlcat(p, q, p_size) >= p_size)
 254                fortify_panic(__func__);
 255        return p;
 256}
 257
 258__FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 259{
 260        __kernel_size_t ret;
 261        size_t p_size = __builtin_object_size(p, 0);
 262
 263        /* Work around gcc excess stack consumption issue */
 264        if (p_size == (size_t)-1 ||
 265            (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
 266                return __builtin_strlen(p);
 267        ret = strnlen(p, p_size);
 268        if (p_size <= ret)
 269                fortify_panic(__func__);
 270        return ret;
 271}
 272
 273extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
 274__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
 275{
 276        size_t p_size = __builtin_object_size(p, 0);
 277        __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
 278        if (p_size <= ret && maxlen != ret)
 279                fortify_panic(__func__);
 280        return ret;
 281}
 282
 283/* defined after fortified strlen to reuse it */
 284extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 285__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 286{
 287        size_t ret;
 288        size_t p_size = __builtin_object_size(p, 0);
 289        size_t q_size = __builtin_object_size(q, 0);
 290        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 291                return __real_strlcpy(p, q, size);
 292        ret = strlen(q);
 293        if (size) {
 294                size_t len = (ret >= size) ? size - 1 : ret;
 295                if (__builtin_constant_p(len) && len >= p_size)
 296                        __write_overflow();
 297                if (len >= p_size)
 298                        fortify_panic(__func__);
 299                __builtin_memcpy(p, q, len);
 300                p[len] = '\0';
 301        }
 302        return ret;
 303}
 304
 305/* defined after fortified strlen and strnlen to reuse them */
 306__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
 307{
 308        size_t p_len, copy_len;
 309        size_t p_size = __builtin_object_size(p, 0);
 310        size_t q_size = __builtin_object_size(q, 0);
 311        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 312                return __builtin_strncat(p, q, count);
 313        p_len = strlen(p);
 314        copy_len = strnlen(q, count);
 315        if (p_size < p_len + copy_len + 1)
 316                fortify_panic(__func__);
 317        __builtin_memcpy(p + p_len, q, copy_len);
 318        p[p_len + copy_len] = '\0';
 319        return p;
 320}
 321
 322__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
 323{
 324        size_t p_size = __builtin_object_size(p, 0);
 325        if (__builtin_constant_p(size) && p_size < size)
 326                __write_overflow();
 327        if (p_size < size)
 328                fortify_panic(__func__);
 329        return __builtin_memset(p, c, size);
 330}
 331
 332__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
 333{
 334        size_t p_size = __builtin_object_size(p, 0);
 335        size_t q_size = __builtin_object_size(q, 0);
 336        if (__builtin_constant_p(size)) {
 337                if (p_size < size)
 338                        __write_overflow();
 339                if (q_size < size)
 340                        __read_overflow2();
 341        }
 342        if (p_size < size || q_size < size)
 343                fortify_panic(__func__);
 344        return __builtin_memcpy(p, q, size);
 345}
 346
 347__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
 348{
 349        size_t p_size = __builtin_object_size(p, 0);
 350        size_t q_size = __builtin_object_size(q, 0);
 351        if (__builtin_constant_p(size)) {
 352                if (p_size < size)
 353                        __write_overflow();
 354                if (q_size < size)
 355                        __read_overflow2();
 356        }
 357        if (p_size < size || q_size < size)
 358                fortify_panic(__func__);
 359        return __builtin_memmove(p, q, size);
 360}
 361
 362extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
 363__FORTIFY_INLINE void *memscan(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 __real_memscan(p, c, size);
 371}
 372
 373__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
 374{
 375        size_t p_size = __builtin_object_size(p, 0);
 376        size_t q_size = __builtin_object_size(q, 0);
 377        if (__builtin_constant_p(size)) {
 378                if (p_size < size)
 379                        __read_overflow();
 380                if (q_size < size)
 381                        __read_overflow2();
 382        }
 383        if (p_size < size || q_size < size)
 384                fortify_panic(__func__);
 385        return __builtin_memcmp(p, q, size);
 386}
 387
 388__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
 389{
 390        size_t p_size = __builtin_object_size(p, 0);
 391        if (__builtin_constant_p(size) && p_size < size)
 392                __read_overflow();
 393        if (p_size < size)
 394                fortify_panic(__func__);
 395        return __builtin_memchr(p, c, size);
 396}
 397
 398void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
 399__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
 400{
 401        size_t p_size = __builtin_object_size(p, 0);
 402        if (__builtin_constant_p(size) && p_size < size)
 403                __read_overflow();
 404        if (p_size < size)
 405                fortify_panic(__func__);
 406        return __real_memchr_inv(p, c, size);
 407}
 408
 409extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
 410__FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 411{
 412        size_t p_size = __builtin_object_size(p, 0);
 413        if (__builtin_constant_p(size) && p_size < size)
 414                __read_overflow();
 415        if (p_size < size)
 416                fortify_panic(__func__);
 417        return __real_kmemdup(p, size, gfp);
 418}
 419
 420/* defined after fortified strlen and memcpy to reuse them */
 421__FORTIFY_INLINE char *strcpy(char *p, const char *q)
 422{
 423        size_t p_size = __builtin_object_size(p, 0);
 424        size_t q_size = __builtin_object_size(q, 0);
 425        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 426                return __builtin_strcpy(p, q);
 427        memcpy(p, q, strlen(q) + 1);
 428        return p;
 429}
 430
 431#endif
 432
 433/**
 434 * memcpy_and_pad - Copy one buffer to another with padding
 435 * @dest: Where to copy to
 436 * @dest_len: The destination buffer size
 437 * @src: Where to copy from
 438 * @count: The number of bytes to copy
 439 * @pad: Character to use for padding if space is left in destination.
 440 */
 441static inline void memcpy_and_pad(void *dest, size_t dest_len,
 442                                  const void *src, size_t count, int pad)
 443{
 444        if (dest_len > count) {
 445                memcpy(dest, src, count);
 446                memset(dest + count, pad,  dest_len - count);
 447        } else
 448                memcpy(dest, src, dest_len);
 449}
 450
 451#endif /* _LINUX_STRING_H_ */
 452