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
 134extern void **__memcat_p(void **a, void **b);
 135#define memcat_p(a, b) ({                                       \
 136        BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)),              \
 137                         "type mismatch in memcat_p()");        \
 138        (typeof(*a) *)__memcat_p((void **)(a), (void **)(b));   \
 139})
 140
 141#ifndef __HAVE_ARCH_MEMCPY
 142extern void * memcpy(void *,const void *,__kernel_size_t);
 143#endif
 144#ifndef __HAVE_ARCH_MEMMOVE
 145extern void * memmove(void *,const void *,__kernel_size_t);
 146#endif
 147#ifndef __HAVE_ARCH_MEMSCAN
 148extern void * memscan(void *,int,__kernel_size_t);
 149#endif
 150#ifndef __HAVE_ARCH_MEMCMP
 151extern int memcmp(const void *,const void *,__kernel_size_t);
 152#endif
 153#ifndef __HAVE_ARCH_MEMCHR
 154extern void * memchr(const void *,int,__kernel_size_t);
 155#endif
 156#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
 157static inline __must_check unsigned long memcpy_mcsafe(void *dst,
 158                const void *src, size_t cnt)
 159{
 160        memcpy(dst, src, cnt);
 161        return 0;
 162}
 163#endif
 164#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
 165static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 166{
 167        memcpy(dst, src, cnt);
 168}
 169#endif
 170void *memchr_inv(const void *s, int c, size_t n);
 171char *strreplace(char *s, char old, char new);
 172
 173extern void kfree_const(const void *x);
 174
 175extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 176extern const char *kstrdup_const(const char *s, gfp_t gfp);
 177extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 178extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
 179extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
 180
 181extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 182extern void argv_free(char **argv);
 183
 184extern bool sysfs_streq(const char *s1, const char *s2);
 185extern int kstrtobool(const char *s, bool *res);
 186static inline int strtobool(const char *s, bool *res)
 187{
 188        return kstrtobool(s, res);
 189}
 190
 191int match_string(const char * const *array, size_t n, const char *string);
 192int __sysfs_match_string(const char * const *array, size_t n, const char *s);
 193
 194/**
 195 * sysfs_match_string - matches given string in an array
 196 * @_a: array of strings
 197 * @_s: string to match with
 198 *
 199 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
 200 */
 201#define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 202
 203#ifdef CONFIG_BINARY_PRINTF
 204int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
 205int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
 206int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
 207#endif
 208
 209extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
 210                                       const void *from, size_t available);
 211
 212/**
 213 * strstarts - does @str start with @prefix?
 214 * @str: string to examine
 215 * @prefix: prefix to look for.
 216 */
 217static inline bool strstarts(const char *str, const char *prefix)
 218{
 219        return strncmp(str, prefix, strlen(prefix)) == 0;
 220}
 221
 222size_t memweight(const void *ptr, size_t bytes);
 223void memzero_explicit(void *s, size_t count);
 224
 225/**
 226 * kbasename - return the last part of a pathname.
 227 *
 228 * @path: path to extract the filename from.
 229 */
 230static inline const char *kbasename(const char *path)
 231{
 232        const char *tail = strrchr(path, '/');
 233        return tail ? tail + 1 : path;
 234}
 235
 236#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
 237#define __RENAME(x) __asm__(#x)
 238
 239void fortify_panic(const char *name) __noreturn __cold;
 240void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
 241void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
 242void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
 243void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
 244
 245#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 246__FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
 247{
 248        size_t p_size = __builtin_object_size(p, 0);
 249        if (__builtin_constant_p(size) && p_size < size)
 250                __write_overflow();
 251        if (p_size < size)
 252                fortify_panic(__func__);
 253        return __builtin_strncpy(p, q, size);
 254}
 255
 256__FORTIFY_INLINE char *strcat(char *p, const char *q)
 257{
 258        size_t p_size = __builtin_object_size(p, 0);
 259        if (p_size == (size_t)-1)
 260                return __builtin_strcat(p, q);
 261        if (strlcat(p, q, p_size) >= p_size)
 262                fortify_panic(__func__);
 263        return p;
 264}
 265
 266__FORTIFY_INLINE __kernel_size_t strlen(const char *p)
 267{
 268        __kernel_size_t ret;
 269        size_t p_size = __builtin_object_size(p, 0);
 270
 271        /* Work around gcc excess stack consumption issue */
 272        if (p_size == (size_t)-1 ||
 273            (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
 274                return __builtin_strlen(p);
 275        ret = strnlen(p, p_size);
 276        if (p_size <= ret)
 277                fortify_panic(__func__);
 278        return ret;
 279}
 280
 281extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
 282__FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
 283{
 284        size_t p_size = __builtin_object_size(p, 0);
 285        __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
 286        if (p_size <= ret && maxlen != ret)
 287                fortify_panic(__func__);
 288        return ret;
 289}
 290
 291/* defined after fortified strlen to reuse it */
 292extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
 293__FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
 294{
 295        size_t ret;
 296        size_t p_size = __builtin_object_size(p, 0);
 297        size_t q_size = __builtin_object_size(q, 0);
 298        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 299                return __real_strlcpy(p, q, size);
 300        ret = strlen(q);
 301        if (size) {
 302                size_t len = (ret >= size) ? size - 1 : ret;
 303                if (__builtin_constant_p(len) && len >= p_size)
 304                        __write_overflow();
 305                if (len >= p_size)
 306                        fortify_panic(__func__);
 307                __builtin_memcpy(p, q, len);
 308                p[len] = '\0';
 309        }
 310        return ret;
 311}
 312
 313/* defined after fortified strlen and strnlen to reuse them */
 314__FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
 315{
 316        size_t p_len, copy_len;
 317        size_t p_size = __builtin_object_size(p, 0);
 318        size_t q_size = __builtin_object_size(q, 0);
 319        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 320                return __builtin_strncat(p, q, count);
 321        p_len = strlen(p);
 322        copy_len = strnlen(q, count);
 323        if (p_size < p_len + copy_len + 1)
 324                fortify_panic(__func__);
 325        __builtin_memcpy(p + p_len, q, copy_len);
 326        p[p_len + copy_len] = '\0';
 327        return p;
 328}
 329
 330__FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
 331{
 332        size_t p_size = __builtin_object_size(p, 0);
 333        if (__builtin_constant_p(size) && p_size < size)
 334                __write_overflow();
 335        if (p_size < size)
 336                fortify_panic(__func__);
 337        return __builtin_memset(p, c, size);
 338}
 339
 340__FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
 341{
 342        size_t p_size = __builtin_object_size(p, 0);
 343        size_t q_size = __builtin_object_size(q, 0);
 344        if (__builtin_constant_p(size)) {
 345                if (p_size < size)
 346                        __write_overflow();
 347                if (q_size < size)
 348                        __read_overflow2();
 349        }
 350        if (p_size < size || q_size < size)
 351                fortify_panic(__func__);
 352        return __builtin_memcpy(p, q, size);
 353}
 354
 355__FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
 356{
 357        size_t p_size = __builtin_object_size(p, 0);
 358        size_t q_size = __builtin_object_size(q, 0);
 359        if (__builtin_constant_p(size)) {
 360                if (p_size < size)
 361                        __write_overflow();
 362                if (q_size < size)
 363                        __read_overflow2();
 364        }
 365        if (p_size < size || q_size < size)
 366                fortify_panic(__func__);
 367        return __builtin_memmove(p, q, size);
 368}
 369
 370extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
 371__FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
 372{
 373        size_t p_size = __builtin_object_size(p, 0);
 374        if (__builtin_constant_p(size) && p_size < size)
 375                __read_overflow();
 376        if (p_size < size)
 377                fortify_panic(__func__);
 378        return __real_memscan(p, c, size);
 379}
 380
 381__FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
 382{
 383        size_t p_size = __builtin_object_size(p, 0);
 384        size_t q_size = __builtin_object_size(q, 0);
 385        if (__builtin_constant_p(size)) {
 386                if (p_size < size)
 387                        __read_overflow();
 388                if (q_size < size)
 389                        __read_overflow2();
 390        }
 391        if (p_size < size || q_size < size)
 392                fortify_panic(__func__);
 393        return __builtin_memcmp(p, q, size);
 394}
 395
 396__FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
 397{
 398        size_t p_size = __builtin_object_size(p, 0);
 399        if (__builtin_constant_p(size) && p_size < size)
 400                __read_overflow();
 401        if (p_size < size)
 402                fortify_panic(__func__);
 403        return __builtin_memchr(p, c, size);
 404}
 405
 406void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
 407__FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
 408{
 409        size_t p_size = __builtin_object_size(p, 0);
 410        if (__builtin_constant_p(size) && p_size < size)
 411                __read_overflow();
 412        if (p_size < size)
 413                fortify_panic(__func__);
 414        return __real_memchr_inv(p, c, size);
 415}
 416
 417extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
 418__FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
 419{
 420        size_t p_size = __builtin_object_size(p, 0);
 421        if (__builtin_constant_p(size) && p_size < size)
 422                __read_overflow();
 423        if (p_size < size)
 424                fortify_panic(__func__);
 425        return __real_kmemdup(p, size, gfp);
 426}
 427
 428/* defined after fortified strlen and memcpy to reuse them */
 429__FORTIFY_INLINE char *strcpy(char *p, const char *q)
 430{
 431        size_t p_size = __builtin_object_size(p, 0);
 432        size_t q_size = __builtin_object_size(q, 0);
 433        if (p_size == (size_t)-1 && q_size == (size_t)-1)
 434                return __builtin_strcpy(p, q);
 435        memcpy(p, q, strlen(q) + 1);
 436        return p;
 437}
 438
 439#endif
 440
 441/**
 442 * memcpy_and_pad - Copy one buffer to another with padding
 443 * @dest: Where to copy to
 444 * @dest_len: The destination buffer size
 445 * @src: Where to copy from
 446 * @count: The number of bytes to copy
 447 * @pad: Character to use for padding if space is left in destination.
 448 */
 449static inline void memcpy_and_pad(void *dest, size_t dest_len,
 450                                  const void *src, size_t count, int pad)
 451{
 452        if (dest_len > count) {
 453                memcpy(dest, src, count);
 454                memset(dest + count, pad,  dest_len - count);
 455        } else
 456                memcpy(dest, src, dest_len);
 457}
 458
 459#endif /* _LINUX_STRING_H_ */
 460