Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
13extern char *strndup_user(const char __user *, long);
14extern void *memdup_user(const void __user *, size_t);
15extern void *vmemdup_user(const void __user *, size_t);
16extern 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
24extern char * strcpy(char *,const char *);
25#endif
26#ifndef __HAVE_ARCH_STRNCPY
27extern char * strncpy(char *,const char *, __kernel_size_t);
28#endif
29#ifndef __HAVE_ARCH_STRLCPY
30size_t strlcpy(char *, const char *, size_t);
31#endif
32#ifndef __HAVE_ARCH_STRSCPY
33ssize_t strscpy(char *, const char *, size_t);
34#endif
35
36/* Wraps calls to strscpy()/memset(), no arch specific code required */
37ssize_t strscpy_pad(char *dest, const char *src, size_t count);
38
39#ifndef __HAVE_ARCH_STRCAT
40extern char * strcat(char *, const char *);
41#endif
42#ifndef __HAVE_ARCH_STRNCAT
43extern char * strncat(char *, const char *, __kernel_size_t);
44#endif
45#ifndef __HAVE_ARCH_STRLCAT
46extern size_t strlcat(char *, const char *, __kernel_size_t);
47#endif
48#ifndef __HAVE_ARCH_STRCMP
49extern int strcmp(const char *,const char *);
50#endif
51#ifndef __HAVE_ARCH_STRNCMP
52extern int strncmp(const char *,const char *,__kernel_size_t);
53#endif
54#ifndef __HAVE_ARCH_STRCASECMP
55extern int strcasecmp(const char *s1, const char *s2);
56#endif
57#ifndef __HAVE_ARCH_STRNCASECMP
58extern int strncasecmp(const char *s1, const char *s2, size_t n);
59#endif
60#ifndef __HAVE_ARCH_STRCHR
61extern char * strchr(const char *,int);
62#endif
63#ifndef __HAVE_ARCH_STRCHRNUL
64extern char * strchrnul(const char *,int);
65#endif
66extern char * strnchrnul(const char *, size_t, int);
67#ifndef __HAVE_ARCH_STRNCHR
68extern char * strnchr(const char *, size_t, int);
69#endif
70#ifndef __HAVE_ARCH_STRRCHR
71extern char * strrchr(const char *,int);
72#endif
73extern char * __must_check skip_spaces(const char *);
74
75extern char *strim(char *);
76
77static inline __must_check char *strstrip(char *str)
78{
79 return strim(str);
80}
81
82#ifndef __HAVE_ARCH_STRSTR
83extern char * strstr(const char *, const char *);
84#endif
85#ifndef __HAVE_ARCH_STRNSTR
86extern char * strnstr(const char *, const char *, size_t);
87#endif
88#ifndef __HAVE_ARCH_STRLEN
89extern __kernel_size_t strlen(const char *);
90#endif
91#ifndef __HAVE_ARCH_STRNLEN
92extern __kernel_size_t strnlen(const char *,__kernel_size_t);
93#endif
94#ifndef __HAVE_ARCH_STRPBRK
95extern char * strpbrk(const char *,const char *);
96#endif
97#ifndef __HAVE_ARCH_STRSEP
98extern char * strsep(char **,const char *);
99#endif
100#ifndef __HAVE_ARCH_STRSPN
101extern __kernel_size_t strspn(const char *,const char *);
102#endif
103#ifndef __HAVE_ARCH_STRCSPN
104extern __kernel_size_t strcspn(const char *,const char *);
105#endif
106
107#ifndef __HAVE_ARCH_MEMSET
108extern void * memset(void *,int,__kernel_size_t);
109#endif
110
111#ifndef __HAVE_ARCH_MEMSET16
112extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
113#endif
114
115#ifndef __HAVE_ARCH_MEMSET32
116extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
117#endif
118
119#ifndef __HAVE_ARCH_MEMSET64
120extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
121#endif
122
123static 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
132static 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
140extern 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
148extern void * memcpy(void *,const void *,__kernel_size_t);
149#endif
150#ifndef __HAVE_ARCH_MEMMOVE
151extern void * memmove(void *,const void *,__kernel_size_t);
152#endif
153#ifndef __HAVE_ARCH_MEMSCAN
154extern void * memscan(void *,int,__kernel_size_t);
155#endif
156#ifndef __HAVE_ARCH_MEMCMP
157extern int memcmp(const void *,const void *,__kernel_size_t);
158#endif
159#ifndef __HAVE_ARCH_BCMP
160extern int bcmp(const void *,const void *,__kernel_size_t);
161#endif
162#ifndef __HAVE_ARCH_MEMCHR
163extern void * memchr(const void *,int,__kernel_size_t);
164#endif
165#ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
166static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
167{
168 memcpy(dst, src, cnt);
169}
170#endif
171
172void *memchr_inv(const void *s, int c, size_t n);
173char *strreplace(char *s, char old, char new);
174
175extern void kfree_const(const void *x);
176
177extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
178extern const char *kstrdup_const(const char *s, gfp_t gfp);
179extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
180extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
181extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
182
183extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
184extern void argv_free(char **argv);
185
186extern bool sysfs_streq(const char *s1, const char *s2);
187extern int kstrtobool(const char *s, bool *res);
188static inline int strtobool(const char *s, bool *res)
189{
190 return kstrtobool(s, res);
191}
192
193int match_string(const char * const *array, size_t n, const char *string);
194int __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
206int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
207int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
208int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
209#endif
210
211extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
212 const void *from, size_t available);
213
214int 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 */
221static inline bool strstarts(const char *str, const char *prefix)
222{
223 return strncmp(str, prefix, strlen(prefix)) == 0;
224}
225
226size_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 */
242static 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 */
253static 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
262void fortify_panic(const char *name) __noreturn __cold;
263void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
264void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
265void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
266void __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 */
280static 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 */
305static __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_ */