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/err.h> /* for ERR_PTR() */
9 #include <linux/errno.h> /* for E2BIG */
10 #include <linux/overflow.h> /* for check_mul_overflow() */
11 #include <linux/stdarg.h>
12 #include <uapi/linux/string.h>
13
14 extern char *strndup_user(const char __user *, long);
15 extern void *memdup_user(const void __user *, size_t);
16 extern void *vmemdup_user(const void __user *, size_t);
17 extern void *memdup_user_nul(const void __user *, size_t);
18
19 /**
20 * memdup_array_user - duplicate array from user space
21 * @src: source address in user space
22 * @n: number of array members to copy
23 * @size: size of one array member
24 *
25 * Return: an ERR_PTR() on failure. Result is physically
26 * contiguous, to be freed by kfree().
27 */
memdup_array_user(const void __user * src,size_t n,size_t size)28 static inline void *memdup_array_user(const void __user *src, size_t n, size_t size)
29 {
30 size_t nbytes;
31
32 if (check_mul_overflow(n, size, &nbytes))
33 return ERR_PTR(-EOVERFLOW);
34
35 return memdup_user(src, nbytes);
36 }
37
38 /**
39 * vmemdup_array_user - duplicate array from user space
40 * @src: source address in user space
41 * @n: number of array members to copy
42 * @size: size of one array member
43 *
44 * Return: an ERR_PTR() on failure. Result may be not
45 * physically contiguous. Use kvfree() to free.
46 */
vmemdup_array_user(const void __user * src,size_t n,size_t size)47 static inline void *vmemdup_array_user(const void __user *src, size_t n, size_t size)
48 {
49 size_t nbytes;
50
51 if (check_mul_overflow(n, size, &nbytes))
52 return ERR_PTR(-EOVERFLOW);
53
54 return vmemdup_user(src, nbytes);
55 }
56
57 /*
58 * Include machine specific inline routines
59 */
60 #include <asm/string.h>
61
62 #ifndef __HAVE_ARCH_STRCPY
63 extern char * strcpy(char *,const char *);
64 #endif
65 #ifndef __HAVE_ARCH_STRNCPY
66 extern char * strncpy(char *,const char *, __kernel_size_t);
67 #endif
68 #ifndef __HAVE_ARCH_STRLCPY
69 size_t strlcpy(char *, const char *, size_t);
70 #endif
71 #ifndef __HAVE_ARCH_STRSCPY
72 ssize_t strscpy(char *, const char *, size_t);
73 #endif
74
75 /* Wraps calls to strscpy()/memset(), no arch specific code required */
76 ssize_t strscpy_pad(char *dest, const char *src, size_t count);
77
78 #ifndef __HAVE_ARCH_STRCAT
79 extern char * strcat(char *, const char *);
80 #endif
81 #ifndef __HAVE_ARCH_STRNCAT
82 extern char * strncat(char *, const char *, __kernel_size_t);
83 #endif
84 #ifndef __HAVE_ARCH_STRLCAT
85 extern size_t strlcat(char *, const char *, __kernel_size_t);
86 #endif
87 #ifndef __HAVE_ARCH_STRCMP
88 extern int strcmp(const char *,const char *);
89 #endif
90 #ifndef __HAVE_ARCH_STRNCMP
91 extern int strncmp(const char *,const char *,__kernel_size_t);
92 #endif
93 #ifndef __HAVE_ARCH_STRCASECMP
94 extern int strcasecmp(const char *s1, const char *s2);
95 #endif
96 #ifndef __HAVE_ARCH_STRNCASECMP
97 extern int strncasecmp(const char *s1, const char *s2, size_t n);
98 #endif
99 #ifndef __HAVE_ARCH_STRCHR
100 extern char * strchr(const char *,int);
101 #endif
102 #ifndef __HAVE_ARCH_STRCHRNUL
103 extern char * strchrnul(const char *,int);
104 #endif
105 extern char * strnchrnul(const char *, size_t, int);
106 #ifndef __HAVE_ARCH_STRNCHR
107 extern char * strnchr(const char *, size_t, int);
108 #endif
109 #ifndef __HAVE_ARCH_STRRCHR
110 extern char * strrchr(const char *,int);
111 #endif
112 extern char * __must_check skip_spaces(const char *);
113
114 extern char *strim(char *);
115
strstrip(char * str)116 static inline __must_check char *strstrip(char *str)
117 {
118 return strim(str);
119 }
120
121 #ifndef __HAVE_ARCH_STRSTR
122 extern char * strstr(const char *, const char *);
123 #endif
124 #ifndef __HAVE_ARCH_STRNSTR
125 extern char * strnstr(const char *, const char *, size_t);
126 #endif
127 #ifndef __HAVE_ARCH_STRLEN
128 extern __kernel_size_t strlen(const char *);
129 #endif
130 #ifndef __HAVE_ARCH_STRNLEN
131 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
132 #endif
133 #ifndef __HAVE_ARCH_STRPBRK
134 extern char * strpbrk(const char *,const char *);
135 #endif
136 #ifndef __HAVE_ARCH_STRSEP
137 extern char * strsep(char **,const char *);
138 #endif
139 #ifndef __HAVE_ARCH_STRSPN
140 extern __kernel_size_t strspn(const char *,const char *);
141 #endif
142 #ifndef __HAVE_ARCH_STRCSPN
143 extern __kernel_size_t strcspn(const char *,const char *);
144 #endif
145
146 #ifndef __HAVE_ARCH_MEMSET
147 extern void * memset(void *,int,__kernel_size_t);
148 #endif
149
150 #ifndef __HAVE_ARCH_MEMSET16
151 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
152 #endif
153
154 #ifndef __HAVE_ARCH_MEMSET32
155 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
156 #endif
157
158 #ifndef __HAVE_ARCH_MEMSET64
159 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
160 #endif
161
memset_l(unsigned long * p,unsigned long v,__kernel_size_t n)162 static inline void *memset_l(unsigned long *p, unsigned long v,
163 __kernel_size_t n)
164 {
165 if (BITS_PER_LONG == 32)
166 return memset32((uint32_t *)p, v, n);
167 else
168 return memset64((uint64_t *)p, v, n);
169 }
170
memset_p(void ** p,void * v,__kernel_size_t n)171 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
172 {
173 if (BITS_PER_LONG == 32)
174 return memset32((uint32_t *)p, (uintptr_t)v, n);
175 else
176 return memset64((uint64_t *)p, (uintptr_t)v, n);
177 }
178
179 extern void **__memcat_p(void **a, void **b);
180 #define memcat_p(a, b) ({ \
181 BUILD_BUG_ON_MSG(!__same_type(*(a), *(b)), \
182 "type mismatch in memcat_p()"); \
183 (typeof(*a) *)__memcat_p((void **)(a), (void **)(b)); \
184 })
185
186 #ifndef __HAVE_ARCH_MEMCPY
187 extern void * memcpy(void *,const void *,__kernel_size_t);
188 #endif
189 #ifndef __HAVE_ARCH_MEMMOVE
190 extern void * memmove(void *,const void *,__kernel_size_t);
191 #endif
192 #ifndef __HAVE_ARCH_MEMSCAN
193 extern void * memscan(void *,int,__kernel_size_t);
194 #endif
195 #ifndef __HAVE_ARCH_MEMCMP
196 extern int memcmp(const void *,const void *,__kernel_size_t);
197 #endif
198 #ifndef __HAVE_ARCH_BCMP
199 extern int bcmp(const void *,const void *,__kernel_size_t);
200 #endif
201 #ifndef __HAVE_ARCH_MEMCHR
202 extern void * memchr(const void *,int,__kernel_size_t);
203 #endif
204 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
memcpy_flushcache(void * dst,const void * src,size_t cnt)205 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
206 {
207 memcpy(dst, src, cnt);
208 }
209 #endif
210
211 void *memchr_inv(const void *s, int c, size_t n);
212 char *strreplace(char *s, char old, char new);
213
214 extern void kfree_const(const void *x);
215
216 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
217 extern const char *kstrdup_const(const char *s, gfp_t gfp);
218 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
219 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
220 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
221
222 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
223 extern void argv_free(char **argv);
224
225 extern bool sysfs_streq(const char *s1, const char *s2);
226 int match_string(const char * const *array, size_t n, const char *string);
227 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
228
229 /**
230 * sysfs_match_string - matches given string in an array
231 * @_a: array of strings
232 * @_s: string to match with
233 *
234 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
235 */
236 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
237
238 #ifdef CONFIG_BINARY_PRINTF
239 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
240 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
241 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
242 #endif
243
244 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
245 const void *from, size_t available);
246
247 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out);
248
249 /**
250 * strstarts - does @str start with @prefix?
251 * @str: string to examine
252 * @prefix: prefix to look for.
253 */
strstarts(const char * str,const char * prefix)254 static inline bool strstarts(const char *str, const char *prefix)
255 {
256 return strncmp(str, prefix, strlen(prefix)) == 0;
257 }
258
259 size_t memweight(const void *ptr, size_t bytes);
260
261 /**
262 * memzero_explicit - Fill a region of memory (e.g. sensitive
263 * keying data) with 0s.
264 * @s: Pointer to the start of the area.
265 * @count: The size of the area.
266 *
267 * Note: usually using memset() is just fine (!), but in cases
268 * where clearing out _local_ data at the end of a scope is
269 * necessary, memzero_explicit() should be used instead in
270 * order to prevent the compiler from optimising away zeroing.
271 *
272 * memzero_explicit() doesn't need an arch-specific version as
273 * it just invokes the one of memset() implicitly.
274 */
memzero_explicit(void * s,size_t count)275 static inline void memzero_explicit(void *s, size_t count)
276 {
277 memset(s, 0, count);
278 barrier_data(s);
279 }
280
281 /**
282 * kbasename - return the last part of a pathname.
283 *
284 * @path: path to extract the filename from.
285 */
kbasename(const char * path)286 static inline const char *kbasename(const char *path)
287 {
288 const char *tail = strrchr(path, '/');
289 return tail ? tail + 1 : path;
290 }
291
292 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
293 #define __RENAME(x) __asm__(#x)
294
295 void fortify_panic(const char *name) __noreturn __cold;
296 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
297 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
298 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
299 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
300
301 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
302 #include <linux/fortify-string.h>
303 #endif
304
305 void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
306 int pad);
307
308 /**
309 * str_has_prefix - Test if a string has a given prefix
310 * @str: The string to test
311 * @prefix: The string to see if @str starts with
312 *
313 * A common way to test a prefix of a string is to do:
314 * strncmp(str, prefix, sizeof(prefix) - 1)
315 *
316 * But this can lead to bugs due to typos, or if prefix is a pointer
317 * and not a constant. Instead use str_has_prefix().
318 *
319 * Returns:
320 * * strlen(@prefix) if @str starts with @prefix
321 * * 0 if @str does not start with @prefix
322 */
str_has_prefix(const char * str,const char * prefix)323 static __always_inline size_t str_has_prefix(const char *str, const char *prefix)
324 {
325 size_t len = strlen(prefix);
326 return strncmp(str, prefix, len) == 0 ? len : 0;
327 }
328
329 #endif /* _LINUX_STRING_H_ */
330