1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_STRING_H_ 3 #define _LINUX_STRING_H_ 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 <linux/errno.h> /* for E2BIG */ 9 #include <linux/stdarg.h> 10 #include <uapi/linux/string.h> 11 12 extern char *strndup_user(const char __user *, long); 13 extern void *memdup_user(const void __user *, size_t); 14 extern void *vmemdup_user(const void __user *, size_t); 15 extern 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 23 extern char * strcpy(char *,const char *); 24 #endif 25 #ifndef __HAVE_ARCH_STRNCPY 26 extern char * strncpy(char *,const char *, __kernel_size_t); 27 #endif 28 #ifndef __HAVE_ARCH_STRLCPY 29 size_t strlcpy(char *, const char *, size_t); 30 #endif 31 #ifndef __HAVE_ARCH_STRSCPY 32 ssize_t strscpy(char *, const char *, size_t); 33 #endif 34 35 /* Wraps calls to strscpy()/memset(), no arch specific code required */ 36 ssize_t strscpy_pad(char *dest, const char *src, size_t count); 37 38 #ifndef __HAVE_ARCH_STRCAT 39 extern char * strcat(char *, const char *); 40 #endif 41 #ifndef __HAVE_ARCH_STRNCAT 42 extern char * strncat(char *, const char *, __kernel_size_t); 43 #endif 44 #ifndef __HAVE_ARCH_STRLCAT 45 extern size_t strlcat(char *, const char *, __kernel_size_t); 46 #endif 47 #ifndef __HAVE_ARCH_STRCMP 48 extern int strcmp(const char *,const char *); 49 #endif 50 #ifndef __HAVE_ARCH_STRNCMP 51 extern int strncmp(const char *,const char *,__kernel_size_t); 52 #endif 53 #ifndef __HAVE_ARCH_STRCASECMP 54 extern int strcasecmp(const char *s1, const char *s2); 55 #endif 56 #ifndef __HAVE_ARCH_STRNCASECMP 57 extern int strncasecmp(const char *s1, const char *s2, size_t n); 58 #endif 59 #ifndef __HAVE_ARCH_STRCHR 60 extern char * strchr(const char *,int); 61 #endif 62 #ifndef __HAVE_ARCH_STRCHRNUL 63 extern char * strchrnul(const char *,int); 64 #endif 65 extern char * strnchrnul(const char *, size_t, int); 66 #ifndef __HAVE_ARCH_STRNCHR 67 extern char * strnchr(const char *, size_t, int); 68 #endif 69 #ifndef __HAVE_ARCH_STRRCHR 70 extern char * strrchr(const char *,int); 71 #endif 72 extern char * __must_check skip_spaces(const char *); 73 74 extern char *strim(char *); 75 76 static inline __must_check char *strstrip(char *str) 77 { 78 return strim(str); 79 } 80 81 #ifndef __HAVE_ARCH_STRSTR 82 extern char * strstr(const char *, const char *); 83 #endif 84 #ifndef __HAVE_ARCH_STRNSTR 85 extern char * strnstr(const char *, const char *, size_t); 86 #endif 87 #ifndef __HAVE_ARCH_STRLEN 88 extern __kernel_size_t strlen(const char *); 89 #endif 90 #ifndef __HAVE_ARCH_STRNLEN 91 extern __kernel_size_t strnlen(const char *,__kernel_size_t); 92 #endif 93 #ifndef __HAVE_ARCH_STRPBRK 94 extern char * strpbrk(const char *,const char *); 95 #endif 96 #ifndef __HAVE_ARCH_STRSEP 97 extern char * strsep(char **,const char *); 98 #endif 99 #ifndef __HAVE_ARCH_STRSPN 100 extern __kernel_size_t strspn(const char *,const char *); 101 #endif 102 #ifndef __HAVE_ARCH_STRCSPN 103 extern __kernel_size_t strcspn(const char *,const char *); 104 #endif 105 106 #ifndef __HAVE_ARCH_MEMSET 107 extern void * memset(void *,int,__kernel_size_t); 108 #endif 109 110 #ifndef __HAVE_ARCH_MEMSET16 111 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t); 112 #endif 113 114 #ifndef __HAVE_ARCH_MEMSET32 115 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t); 116 #endif 117 118 #ifndef __HAVE_ARCH_MEMSET64 119 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t); 120 #endif 121 122 static inline void *memset_l(unsigned long *p, unsigned long v, 123 __kernel_size_t n) 124 { 125 if (BITS_PER_LONG == 32) 126 return memset32((uint32_t *)p, v, n); 127 else 128 return memset64((uint64_t *)p, v, n); 129 } 130 131 static inline void *memset_p(void **p, void *v, __kernel_size_t n) 132 { 133 if (BITS_PER_LONG == 32) 134 return memset32((uint32_t *)p, (uintptr_t)v, n); 135 else 136 return memset64((uint64_t *)p, (uintptr_t)v, n); 137 } 138 139 extern void **__memcat_p(void **a, void **b); 140 #define memcat_p(a, b) ({ \ 141 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \ 142 "type mismatch in memcat_p()"); \ 143 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \ 144 }) 145 146 #ifndef __HAVE_ARCH_MEMCPY 147 extern void * memcpy(void *,const void *,__kernel_size_t); 148 #endif 149 #ifndef __HAVE_ARCH_MEMMOVE 150 extern void * memmove(void *,const void *,__kernel_size_t); 151 #endif 152 #ifndef __HAVE_ARCH_MEMSCAN 153 extern void * memscan(void *,int,__kernel_size_t); 154 #endif 155 #ifndef __HAVE_ARCH_MEMCMP 156 extern int memcmp(const void *,const void *,__kernel_size_t); 157 #endif 158 #ifndef __HAVE_ARCH_BCMP 159 extern int bcmp(const void *,const void *,__kernel_size_t); 160 #endif 161 #ifndef __HAVE_ARCH_MEMCHR 162 extern void * memchr(const void *,int,__kernel_size_t); 163 #endif 164 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE 165 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt) 166 { 167 memcpy(dst, src, cnt); 168 } 169 #endif 170 171 void *memchr_inv(const void *s, int c, size_t n); 172 char *strreplace(char *s, char old, char new); 173 174 extern void kfree_const(const void *x); 175 176 extern char *kstrdup(const char *s, gfp_t gfp) __malloc; 177 extern const char *kstrdup_const(const char *s, gfp_t gfp); 178 extern char *kstrndup(const char *s, size_t len, gfp_t gfp); 179 extern void *kmemdup(const void *src, size_t len, gfp_t gfp); 180 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp); 181 182 extern char **argv_split(gfp_t gfp, const char *str, int *argcp); 183 extern void argv_free(char **argv); 184 185 extern bool sysfs_streq(const char *s1, const char *s2); 186 int match_string(const char * const *array, size_t n, const char *string); 187 int __sysfs_match_string(const char * const *array, size_t n, const char *s); 188 189 /** 190 * sysfs_match_string - matches given string in an array 191 * @_a: array of strings 192 * @_s: string to match with 193 * 194 * Helper for __sysfs_match_string(). Calculates the size of @a automatically. 195 */ 196 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s) 197 198 #ifdef CONFIG_BINARY_PRINTF 199 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); 200 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf); 201 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); 202 #endif 203 204 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, 205 const void *from, size_t available); 206 207 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out); 208 209 /** 210 * strstarts - does @str start with @prefix? 211 * @str: string to examine 212 * @prefix: prefix to look for. 213 */ 214 static inline bool strstarts(const char *str, const char *prefix) 215 { 216 return strncmp(str, prefix, strlen(prefix)) == 0; 217 } 218 219 size_t memweight(const void *ptr, size_t bytes); 220 221 /** 222 * memzero_explicit - Fill a region of memory (e.g. sensitive 223 * keying data) with 0s. 224 * @s: Pointer to the start of the area. 225 * @count: The size of the area. 226 * 227 * Note: usually using memset() is just fine (!), but in cases 228 * where clearing out _local_ data at the end of a scope is 229 * necessary, memzero_explicit() should be used instead in 230 * order to prevent the compiler from optimising away zeroing. 231 * 232 * memzero_explicit() doesn't need an arch-specific version as 233 * it just invokes the one of memset() implicitly. 234 */ 235 static inline void memzero_explicit(void *s, size_t count) 236 { 237 memset(s, 0, count); 238 barrier_data(s); 239 } 240 241 /** 242 * kbasename - return the last part of a pathname. 243 * 244 * @path: path to extract the filename from. 245 */ 246 static inline const char *kbasename(const char *path) 247 { 248 const char *tail = strrchr(path, '/'); 249 return tail ? tail + 1 : path; 250 } 251 252 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE) 253 #include <linux/fortify-string.h> 254 #endif 255 256 void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, 257 int pad); 258 259 /** 260 * memset_after - Set a value after a struct member to the end of a struct 261 * 262 * @obj: Address of target struct instance 263 * @v: Byte value to repeatedly write 264 * @member: after which struct member to start writing bytes 265 * 266 * This is good for clearing padding following the given member. 267 */ 268 #define memset_after(obj, v, member) \ 269 ({ \ 270 u8 *__ptr = (u8 *)(obj); \ 271 typeof(v) __val = (v); \ 272 memset(__ptr + offsetofend(typeof(*(obj)), member), __val, \ 273 sizeof(*(obj)) - offsetofend(typeof(*(obj)), member)); \ 274 }) 275 276 /** 277 * memset_startat - Set a value starting at a member to the end of a struct 278 * 279 * @obj: Address of target struct instance 280 * @v: Byte value to repeatedly write 281 * @member: struct member to start writing at 282 * 283 * Note that if there is padding between the prior member and the target 284 * member, memset_after() should be used to clear the prior padding. 285 */ 286 #define memset_startat(obj, v, member) \ 287 ({ \ 288 u8 *__ptr = (u8 *)(obj); \ 289 typeof(v) __val = (v); \ 290 memset(__ptr + offsetof(typeof(*(obj)), member), __val, \ 291 sizeof(*(obj)) - offsetof(typeof(*(obj)), member)); \ 292 }) 293 294 /** 295 * str_has_prefix - Test if a string has a given prefix 296 * @str: The string to test 297 * @prefix: The string to see if @str starts with 298 * 299 * A common way to test a prefix of a string is to do: 300 * strncmp(str, prefix, sizeof(prefix) - 1) 301 * 302 * But this can lead to bugs due to typos, or if prefix is a pointer 303 * and not a constant. Instead use str_has_prefix(). 304 * 305 * Returns: 306 * * strlen(@prefix) if @str starts with @prefix 307 * * 0 if @str does not start with @prefix 308 */ 309 static __always_inline size_t str_has_prefix(const char *str, const char *prefix) 310 { 311 size_t len = strlen(prefix); 312 return strncmp(str, prefix, len) == 0 ? len : 0; 313 } 314 315 #endif /* _LINUX_STRING_H_ */ 316