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 <linux/errno.h> /* for E2BIG */ 10 #include <stdarg.h> 11 #include <uapi/linux/string.h> 12 13 extern char *strndup_user(const char __user *, long); 14 extern void *memdup_user(const void __user *, size_t); 15 extern void *vmemdup_user(const void __user *, size_t); 16 extern void *memdup_user_nul(const void __user *, size_t); 17 18 /* 19 * Include machine specific inline routines 20 */ 21 #include <asm/string.h> 22 23 #ifndef __HAVE_ARCH_STRCPY 24 extern char * strcpy(char *,const char *); 25 #endif 26 #ifndef __HAVE_ARCH_STRNCPY 27 extern char * strncpy(char *,const char *, __kernel_size_t); 28 #endif 29 #ifndef __HAVE_ARCH_STRLCPY 30 size_t strlcpy(char *, const char *, size_t); 31 #endif 32 #ifndef __HAVE_ARCH_STRSCPY 33 ssize_t strscpy(char *, const char *, size_t); 34 #endif 35 36 /* Wraps calls to strscpy()/memset(), no arch specific code required */ 37 ssize_t strscpy_pad(char *dest, const char *src, size_t count); 38 39 #ifndef __HAVE_ARCH_STRCAT 40 extern char * strcat(char *, const char *); 41 #endif 42 #ifndef __HAVE_ARCH_STRNCAT 43 extern char * strncat(char *, const char *, __kernel_size_t); 44 #endif 45 #ifndef __HAVE_ARCH_STRLCAT 46 extern size_t strlcat(char *, const char *, __kernel_size_t); 47 #endif 48 #ifndef __HAVE_ARCH_STRCMP 49 extern int strcmp(const char *,const char *); 50 #endif 51 #ifndef __HAVE_ARCH_STRNCMP 52 extern int strncmp(const char *,const char *,__kernel_size_t); 53 #endif 54 #ifndef __HAVE_ARCH_STRCASECMP 55 extern int strcasecmp(const char *s1, const char *s2); 56 #endif 57 #ifndef __HAVE_ARCH_STRNCASECMP 58 extern int strncasecmp(const char *s1, const char *s2, size_t n); 59 #endif 60 #ifndef __HAVE_ARCH_STRCHR 61 extern char * strchr(const char *,int); 62 #endif 63 #ifndef __HAVE_ARCH_STRCHRNUL 64 extern char * strchrnul(const char *,int); 65 #endif 66 extern char * strnchrnul(const char *, size_t, int); 67 #ifndef __HAVE_ARCH_STRNCHR 68 extern char * strnchr(const char *, size_t, int); 69 #endif 70 #ifndef __HAVE_ARCH_STRRCHR 71 extern char * strrchr(const char *,int); 72 #endif 73 extern char * __must_check skip_spaces(const char *); 74 75 extern char *strim(char *); 76 77 static inline __must_check char *strstrip(char *str) 78 { 79 return strim(str); 80 } 81 82 #ifndef __HAVE_ARCH_STRSTR 83 extern char * strstr(const char *, const char *); 84 #endif 85 #ifndef __HAVE_ARCH_STRNSTR 86 extern char * strnstr(const char *, const char *, size_t); 87 #endif 88 #ifndef __HAVE_ARCH_STRLEN 89 extern __kernel_size_t strlen(const char *); 90 #endif 91 #ifndef __HAVE_ARCH_STRNLEN 92 extern __kernel_size_t strnlen(const char *,__kernel_size_t); 93 #endif 94 #ifndef __HAVE_ARCH_STRPBRK 95 extern char * strpbrk(const char *,const char *); 96 #endif 97 #ifndef __HAVE_ARCH_STRSEP 98 extern char * strsep(char **,const char *); 99 #endif 100 #ifndef __HAVE_ARCH_STRSPN 101 extern __kernel_size_t strspn(const char *,const char *); 102 #endif 103 #ifndef __HAVE_ARCH_STRCSPN 104 extern __kernel_size_t strcspn(const char *,const char *); 105 #endif 106 107 #ifndef __HAVE_ARCH_MEMSET 108 extern void * memset(void *,int,__kernel_size_t); 109 #endif 110 111 #ifndef __HAVE_ARCH_MEMSET16 112 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); 113 #endif 114 115 #ifndef __HAVE_ARCH_MEMSET32 116 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); 117 #endif 118 119 #ifndef __HAVE_ARCH_MEMSET64 120 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); 121 #endif 122 123 static inline void *memset_l(unsigned long *p, unsigned long v, 124 __kernel_size_t n) 125 { 126 if (BITS_PER_LONG == 32) 127 return memset32((uint32_t *)p, v, n); 128 else 129 return memset64((uint64_t *)p, v, n); 130 } 131 132 static inline void *memset_p(void **p, void *v, __kernel_size_t n) 133 { 134 if (BITS_PER_LONG == 32) 135 return memset32((uint32_t *)p, (uintptr_t)v, n); 136 else 137 return memset64((uint64_t *)p, (uintptr_t)v, n); 138 } 139 140 extern void **__memcat_p(void **a, void **b); 141 #define memcat_p(a, b) ({ \ 142 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \ 143 "type mismatch in memcat_p()"); \ 144 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \ 145 }) 146 147 #ifndef __HAVE_ARCH_MEMCPY 148 extern void * memcpy(void *,const void *,__kernel_size_t); 149 #endif 150 #ifndef __HAVE_ARCH_MEMMOVE 151 extern void * memmove(void *,const void *,__kernel_size_t); 152 #endif 153 #ifndef __HAVE_ARCH_MEMSCAN 154 extern void * memscan(void *,int,__kernel_size_t); 155 #endif 156 #ifndef __HAVE_ARCH_MEMCMP 157 extern int memcmp(const void *,const void *,__kernel_size_t); 158 #endif 159 #ifndef __HAVE_ARCH_BCMP 160 extern int bcmp(const void *,const void *,__kernel_size_t); 161 #endif 162 #ifndef __HAVE_ARCH_MEMCHR 163 extern void * memchr(const void *,int,__kernel_size_t); 164 #endif 165 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 166 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 167 { 168 memcpy(dst, src, cnt); 169 } 170 #endif 171 172 void *memchr_inv(const void *s, int c, size_t n); 173 char *strreplace(char *s, char old, char new); 174 175 extern void kfree_const(const void *x); 176 177 extern char *kstrdup(const char *s, gfp_t gfp) __malloc; 178 extern const char *kstrdup_const(const char *s, gfp_t gfp); 179 extern char *kstrndup(const char *s, size_t len, gfp_t gfp); 180 extern void *kmemdup(const void *src, size_t len, gfp_t gfp); 181 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); 182 183 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 184 extern void argv_free(char **argv); 185 186 extern bool sysfs_streq(const char *s1, const char *s2); 187 extern int kstrtobool(const char *s, bool *res); 188 static inline int strtobool(const char *s, bool *res) 189 { 190 return kstrtobool(s, res); 191 } 192 193 int match_string(const char * const *array, size_t n, const char *string); 194 int __sysfs_match_string(const char * const *array, size_t n, const char *s); 195 196 /** 197 * sysfs_match_string - matches given string in an array 198 * @_a: array of strings 199 * @_s: string to match with 200 * 201 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 202 */ 203 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 204 205 #ifdef CONFIG_BINARY_PRINTF 206 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); 207 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); 208 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); 209 #endif 210 211 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 212 const void *from, size_t available); 213 214 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); 215 216 /** 217 * strstarts - does @str start with @prefix? 218 * @str: string to examine 219 * @prefix: prefix to look for. 220 */ 221 static inline bool strstarts(const char *str, const char *prefix) 222 { 223 return strncmp(str, prefix, strlen(prefix)) == 0; 224 } 225 226 size_t memweight(const void *ptr, size_t bytes); 227 228 /** 229 * memzero_explicit - Fill a region of memory (e.g. sensitive 230 * keying data) with 0s. 231 * @s: Pointer to the start of the area. 232 * @count: The size of the area. 233 * 234 * Note: usually using memset() is just fine (!), but in cases 235 * where clearing out _local_ data at the end of a scope is 236 * necessary, memzero_explicit() should be used instead in 237 * order to prevent the compiler from optimising away zeroing. 238 * 239 * memzero_explicit() doesn't need an arch-specific version as 240 * it just invokes the one of memset() implicitly. 241 */ 242 static inline void memzero_explicit(void *s, size_t count) 243 { 244 memset(s, 0, count); 245 barrier_data(s); 246 } 247 248 /** 249 * kbasename - return the last part of a pathname. 250 * 251 * @path: path to extract the filename from. 252 */ 253 static inline const char *kbasename(const char *path) 254 { 255 const char *tail = strrchr(path, '/'); 256 return tail ? tail + 1 : path; 257 } 258 259 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline)) 260 #define __RENAME(x) __asm__(#x) 261 262 void fortify_panic(const char *name) __noreturn __cold; 263 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter"); 264 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter"); 265 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter"); 266 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter"); 267 268 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 269 #include <linux/fortify-string.h> 270 #endif 271 272 /** 273 * memcpy_and_pad - Copy one buffer to another with padding 274 * @dest: Where to copy to 275 * @dest_len: The destination buffer size 276 * @src: Where to copy from 277 * @count: The number of bytes to copy 278 * @pad: Character to use for padding if space is left in destination. 279 */ 280 static inline void memcpy_and_pad(void *dest, size_t dest_len, 281 const void *src, size_t count, int pad) 282 { 283 if (dest_len > count) { 284 memcpy(dest, src, count); 285 memset(dest + count, pad, dest_len - count); 286 } else 287 memcpy(dest, src, dest_len); 288 } 289 290 /** 291 * str_has_prefix - Test if a string has a given prefix 292 * @str: The string to test 293 * @prefix: The string to see if @str starts with 294 * 295 * A common way to test a prefix of a string is to do: 296 * strncmp(str, prefix, sizeof(prefix) - 1) 297 * 298 * But this can lead to bugs due to typos, or if prefix is a pointer 299 * and not a constant. Instead use str_has_prefix(). 300 * 301 * Returns: 302 * * strlen(@prefix) if @str starts with @prefix 303 * * 0 if @str does not start with @prefix 304 */ 305 static __always_inline size_t str_has_prefix(const char *str, const char *prefix) 306 { 307 size_t len = strlen(prefix); 308 return strncmp(str, prefix, len) == 0 ? len : 0; 309 } 310 311 #endif /* _LINUX_STRING_H_ */ 312