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
12 extern char *strndup_user(const char __user *, long);
13 extern void *memdup_user(const void __user *, size_t);
14 extern void *memdup_user_nul(const void __user *, size_t);
15
16 /*
17 * Include machine specific inline routines
18 */
19 #include <asm/string.h>
20
21 #ifndef __HAVE_ARCH_STRCPY
22 extern char * strcpy(char *,const char *);
23 #endif
24 #ifndef __HAVE_ARCH_STRNCPY
25 extern char * strncpy(char *,const char *, __kernel_size_t);
26 #endif
27 #ifndef __HAVE_ARCH_STRLCPY
28 size_t strlcpy(char *, const char *, size_t);
29 #endif
30 #ifndef __HAVE_ARCH_STRSCPY
31 ssize_t strscpy(char *, const char *, size_t);
32 #endif
33 #ifndef __HAVE_ARCH_STRCAT
34 extern char * strcat(char *, const char *);
35 #endif
36 #ifndef __HAVE_ARCH_STRNCAT
37 extern char * strncat(char *, const char *, __kernel_size_t);
38 #endif
39 #ifndef __HAVE_ARCH_STRLCAT
40 extern size_t strlcat(char *, const char *, __kernel_size_t);
41 #endif
42 #ifndef __HAVE_ARCH_STRCMP
43 extern int strcmp(const char *,const char *);
44 #endif
45 #ifndef __HAVE_ARCH_STRNCMP
46 extern int strncmp(const char *,const char *,__kernel_size_t);
47 #endif
48 #ifndef __HAVE_ARCH_STRCASECMP
49 extern int strcasecmp(const char *s1, const char *s2);
50 #endif
51 #ifndef __HAVE_ARCH_STRNCASECMP
52 extern int strncasecmp(const char *s1, const char *s2, size_t n);
53 #endif
54 #ifndef __HAVE_ARCH_STRCHR
55 extern char * strchr(const char *,int);
56 #endif
57 #ifndef __HAVE_ARCH_STRCHRNUL
58 extern char * strchrnul(const char *,int);
59 #endif
60 #ifndef __HAVE_ARCH_STRNCHR
61 extern char * strnchr(const char *, size_t, int);
62 #endif
63 #ifndef __HAVE_ARCH_STRRCHR
64 extern char * strrchr(const char *,int);
65 #endif
66 extern char * __must_check skip_spaces(const char *);
67
68 extern char *strim(char *);
69
strstrip(char * str)70 static inline __must_check char *strstrip(char *str)
71 {
72 return strim(str);
73 }
74
75 #ifndef __HAVE_ARCH_STRSTR
76 extern char * strstr(const char *, const char *);
77 #endif
78 #ifndef __HAVE_ARCH_STRNSTR
79 extern char * strnstr(const char *, const char *, size_t);
80 #endif
81 #ifndef __HAVE_ARCH_STRLEN
82 extern __kernel_size_t strlen(const char *);
83 #endif
84 #ifndef __HAVE_ARCH_STRNLEN
85 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
86 #endif
87 #ifndef __HAVE_ARCH_STRPBRK
88 extern char * strpbrk(const char *,const char *);
89 #endif
90 #ifndef __HAVE_ARCH_STRSEP
91 extern char * strsep(char **,const char *);
92 #endif
93 #ifndef __HAVE_ARCH_STRSPN
94 extern __kernel_size_t strspn(const char *,const char *);
95 #endif
96 #ifndef __HAVE_ARCH_STRCSPN
97 extern __kernel_size_t strcspn(const char *,const char *);
98 #endif
99
100 #ifndef __HAVE_ARCH_MEMSET
101 extern void * memset(void *,int,__kernel_size_t);
102 #endif
103
104 #ifndef __HAVE_ARCH_MEMSET16
105 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
106 #endif
107
108 #ifndef __HAVE_ARCH_MEMSET32
109 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
110 #endif
111
112 #ifndef __HAVE_ARCH_MEMSET64
113 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
114 #endif
115
memset_l(unsigned long * p,unsigned long v,__kernel_size_t n)116 static inline void *memset_l(unsigned long *p, unsigned long v,
117 __kernel_size_t n)
118 {
119 if (BITS_PER_LONG == 32)
120 return memset32((uint32_t *)p, v, n);
121 else
122 return memset64((uint64_t *)p, v, n);
123 }
124
memset_p(void ** p,void * v,__kernel_size_t n)125 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
126 {
127 if (BITS_PER_LONG == 32)
128 return memset32((uint32_t *)p, (uintptr_t)v, n);
129 else
130 return memset64((uint64_t *)p, (uintptr_t)v, n);
131 }
132
133 #ifndef __HAVE_ARCH_MEMCPY
134 extern void * memcpy(void *,const void *,__kernel_size_t);
135 #endif
136 #ifndef __HAVE_ARCH_MEMMOVE
137 extern void * memmove(void *,const void *,__kernel_size_t);
138 #endif
139 #ifndef __HAVE_ARCH_MEMSCAN
140 extern void * memscan(void *,int,__kernel_size_t);
141 #endif
142 #ifndef __HAVE_ARCH_MEMCMP
143 extern int memcmp(const void *,const void *,__kernel_size_t);
144 #endif
145 #ifndef __HAVE_ARCH_BCMP
146 extern int bcmp(const void *,const void *,__kernel_size_t);
147 #endif
148 #ifndef __HAVE_ARCH_MEMCHR
149 extern void * memchr(const void *,int,__kernel_size_t);
150 #endif
151 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
memcpy_mcsafe(void * dst,const void * src,size_t cnt)152 static inline __must_check int memcpy_mcsafe(void *dst, const void *src,
153 size_t cnt)
154 {
155 memcpy(dst, src, cnt);
156 return 0;
157 }
158 #endif
159 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
memcpy_flushcache(void * dst,const void * src,size_t cnt)160 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
161 {
162 memcpy(dst, src, cnt);
163 }
164 #endif
165 void *memchr_inv(const void *s, int c, size_t n);
166 char *strreplace(char *s, char old, char new);
167
168 extern void kfree_const(const void *x);
169
170 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
171 extern const char *kstrdup_const(const char *s, gfp_t gfp);
172 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
173 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
174 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
175
176 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
177 extern void argv_free(char **argv);
178
179 extern bool sysfs_streq(const char *s1, const char *s2);
180 extern int kstrtobool(const char *s, bool *res);
strtobool(const char * s,bool * res)181 static inline int strtobool(const char *s, bool *res)
182 {
183 return kstrtobool(s, res);
184 }
185
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 /**
208 * strstarts - does @str start with @prefix?
209 * @str: string to examine
210 * @prefix: prefix to look for.
211 */
strstarts(const char * str,const char * prefix)212 static inline bool strstarts(const char *str, const char *prefix)
213 {
214 return strncmp(str, prefix, strlen(prefix)) == 0;
215 }
216
217 size_t memweight(const void *ptr, size_t bytes);
218 void memzero_explicit(void *s, size_t count);
219
220 /**
221 * kbasename - return the last part of a pathname.
222 *
223 * @path: path to extract the filename from.
224 */
kbasename(const char * path)225 static inline const char *kbasename(const char *path)
226 {
227 const char *tail = strrchr(path, '/');
228 return tail ? tail + 1 : path;
229 }
230
231 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
232 #define __RENAME(x) __asm__(#x)
233
234 void fortify_panic(const char *name) __noreturn __cold;
235 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
236 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
237 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
238 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
239
240 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
strncpy(char * p,const char * q,__kernel_size_t size)241 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
242 {
243 size_t p_size = __builtin_object_size(p, 0);
244 if (__builtin_constant_p(size) && p_size < size)
245 __write_overflow();
246 if (p_size < size)
247 fortify_panic(__func__);
248 return __builtin_strncpy(p, q, size);
249 }
250
strcat(char * p,const char * q)251 __FORTIFY_INLINE char *strcat(char *p, const char *q)
252 {
253 size_t p_size = __builtin_object_size(p, 0);
254 if (p_size == (size_t)-1)
255 return __builtin_strcat(p, q);
256 if (strlcat(p, q, p_size) >= p_size)
257 fortify_panic(__func__);
258 return p;
259 }
260
strlen(const char * p)261 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
262 {
263 __kernel_size_t ret;
264 size_t p_size = __builtin_object_size(p, 0);
265
266 /* Work around gcc excess stack consumption issue */
267 if (p_size == (size_t)-1 ||
268 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
269 return __builtin_strlen(p);
270 ret = strnlen(p, p_size);
271 if (p_size <= ret)
272 fortify_panic(__func__);
273 return ret;
274 }
275
276 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
strnlen(const char * p,__kernel_size_t maxlen)277 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
278 {
279 size_t p_size = __builtin_object_size(p, 0);
280 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
281 if (p_size <= ret && maxlen != ret)
282 fortify_panic(__func__);
283 return ret;
284 }
285
286 /* defined after fortified strlen to reuse it */
287 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
strlcpy(char * p,const char * q,size_t size)288 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
289 {
290 size_t ret;
291 size_t p_size = __builtin_object_size(p, 0);
292 size_t q_size = __builtin_object_size(q, 0);
293 if (p_size == (size_t)-1 && q_size == (size_t)-1)
294 return __real_strlcpy(p, q, size);
295 ret = strlen(q);
296 if (size) {
297 size_t len = (ret >= size) ? size - 1 : ret;
298 if (__builtin_constant_p(len) && len >= p_size)
299 __write_overflow();
300 if (len >= p_size)
301 fortify_panic(__func__);
302 __builtin_memcpy(p, q, len);
303 p[len] = '\0';
304 }
305 return ret;
306 }
307
308 /* defined after fortified strlen and strnlen to reuse them */
strncat(char * p,const char * q,__kernel_size_t count)309 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
310 {
311 size_t p_len, copy_len;
312 size_t p_size = __builtin_object_size(p, 0);
313 size_t q_size = __builtin_object_size(q, 0);
314 if (p_size == (size_t)-1 && q_size == (size_t)-1)
315 return __builtin_strncat(p, q, count);
316 p_len = strlen(p);
317 copy_len = strnlen(q, count);
318 if (p_size < p_len + copy_len + 1)
319 fortify_panic(__func__);
320 __builtin_memcpy(p + p_len, q, copy_len);
321 p[p_len + copy_len] = '\0';
322 return p;
323 }
324
memset(void * p,int c,__kernel_size_t size)325 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
326 {
327 size_t p_size = __builtin_object_size(p, 0);
328 if (__builtin_constant_p(size) && p_size < size)
329 __write_overflow();
330 if (p_size < size)
331 fortify_panic(__func__);
332 return __builtin_memset(p, c, size);
333 }
334
memcpy(void * p,const void * q,__kernel_size_t size)335 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
336 {
337 size_t p_size = __builtin_object_size(p, 0);
338 size_t q_size = __builtin_object_size(q, 0);
339 if (__builtin_constant_p(size)) {
340 if (p_size < size)
341 __write_overflow();
342 if (q_size < size)
343 __read_overflow2();
344 }
345 if (p_size < size || q_size < size)
346 fortify_panic(__func__);
347 return __builtin_memcpy(p, q, size);
348 }
349
memmove(void * p,const void * q,__kernel_size_t size)350 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
351 {
352 size_t p_size = __builtin_object_size(p, 0);
353 size_t q_size = __builtin_object_size(q, 0);
354 if (__builtin_constant_p(size)) {
355 if (p_size < size)
356 __write_overflow();
357 if (q_size < size)
358 __read_overflow2();
359 }
360 if (p_size < size || q_size < size)
361 fortify_panic(__func__);
362 return __builtin_memmove(p, q, size);
363 }
364
365 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
memscan(void * p,int c,__kernel_size_t size)366 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
367 {
368 size_t p_size = __builtin_object_size(p, 0);
369 if (__builtin_constant_p(size) && p_size < size)
370 __read_overflow();
371 if (p_size < size)
372 fortify_panic(__func__);
373 return __real_memscan(p, c, size);
374 }
375
memcmp(const void * p,const void * q,__kernel_size_t size)376 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
377 {
378 size_t p_size = __builtin_object_size(p, 0);
379 size_t q_size = __builtin_object_size(q, 0);
380 if (__builtin_constant_p(size)) {
381 if (p_size < size)
382 __read_overflow();
383 if (q_size < size)
384 __read_overflow2();
385 }
386 if (p_size < size || q_size < size)
387 fortify_panic(__func__);
388 return __builtin_memcmp(p, q, size);
389 }
390
memchr(const void * p,int c,__kernel_size_t size)391 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
392 {
393 size_t p_size = __builtin_object_size(p, 0);
394 if (__builtin_constant_p(size) && p_size < size)
395 __read_overflow();
396 if (p_size < size)
397 fortify_panic(__func__);
398 return __builtin_memchr(p, c, size);
399 }
400
401 void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
memchr_inv(const void * p,int c,size_t size)402 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
403 {
404 size_t p_size = __builtin_object_size(p, 0);
405 if (__builtin_constant_p(size) && p_size < size)
406 __read_overflow();
407 if (p_size < size)
408 fortify_panic(__func__);
409 return __real_memchr_inv(p, c, size);
410 }
411
412 extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
kmemdup(const void * p,size_t size,gfp_t gfp)413 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
414 {
415 size_t p_size = __builtin_object_size(p, 0);
416 if (__builtin_constant_p(size) && p_size < size)
417 __read_overflow();
418 if (p_size < size)
419 fortify_panic(__func__);
420 return __real_kmemdup(p, size, gfp);
421 }
422
423 /* defined after fortified strlen and memcpy to reuse them */
strcpy(char * p,const char * q)424 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
425 {
426 size_t p_size = __builtin_object_size(p, 0);
427 size_t q_size = __builtin_object_size(q, 0);
428 if (p_size == (size_t)-1 && q_size == (size_t)-1)
429 return __builtin_strcpy(p, q);
430 memcpy(p, q, strlen(q) + 1);
431 return p;
432 }
433
434 #endif
435
436 /**
437 * memcpy_and_pad - Copy one buffer to another with padding
438 * @dest: Where to copy to
439 * @dest_len: The destination buffer size
440 * @src: Where to copy from
441 * @count: The number of bytes to copy
442 * @pad: Character to use for padding if space is left in destination.
443 */
memcpy_and_pad(void * dest,size_t dest_len,const void * src,size_t count,int pad)444 static inline void memcpy_and_pad(void *dest, size_t dest_len,
445 const void *src, size_t count, int pad)
446 {
447 if (dest_len > count) {
448 memcpy(dest, src, count);
449 memset(dest + count, pad, dest_len - count);
450 } else
451 memcpy(dest, src, dest_len);
452 }
453
454 #endif /* _LINUX_STRING_H_ */
455