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 *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 #ifndef __HAVE_ARCH_STRCAT
35 extern char * strcat(char *, const char *);
36 #endif
37 #ifndef __HAVE_ARCH_STRNCAT
38 extern char * strncat(char *, const char *, __kernel_size_t);
39 #endif
40 #ifndef __HAVE_ARCH_STRLCAT
41 extern size_t strlcat(char *, const char *, __kernel_size_t);
42 #endif
43 #ifndef __HAVE_ARCH_STRCMP
44 extern int strcmp(const char *,const char *);
45 #endif
46 #ifndef __HAVE_ARCH_STRNCMP
47 extern int strncmp(const char *,const char *,__kernel_size_t);
48 #endif
49 #ifndef __HAVE_ARCH_STRCASECMP
50 extern int strcasecmp(const char *s1, const char *s2);
51 #endif
52 #ifndef __HAVE_ARCH_STRNCASECMP
53 extern int strncasecmp(const char *s1, const char *s2, size_t n);
54 #endif
55 #ifndef __HAVE_ARCH_STRCHR
56 extern char * strchr(const char *,int);
57 #endif
58 #ifndef __HAVE_ARCH_STRCHRNUL
59 extern char * strchrnul(const char *,int);
60 #endif
61 #ifndef __HAVE_ARCH_STRNCHR
62 extern char * strnchr(const char *, size_t, int);
63 #endif
64 #ifndef __HAVE_ARCH_STRRCHR
65 extern char * strrchr(const char *,int);
66 #endif
67 extern char * __must_check skip_spaces(const char *);
68
69 extern char *strim(char *);
70
strstrip(char * str)71 static inline __must_check char *strstrip(char *str)
72 {
73 return strim(str);
74 }
75
76 #ifndef __HAVE_ARCH_STRSTR
77 extern char * strstr(const char *, const char *);
78 #endif
79 #ifndef __HAVE_ARCH_STRNSTR
80 extern char * strnstr(const char *, const char *, size_t);
81 #endif
82 #ifndef __HAVE_ARCH_STRLEN
83 extern __kernel_size_t strlen(const char *);
84 #endif
85 #ifndef __HAVE_ARCH_STRNLEN
86 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
87 #endif
88 #ifndef __HAVE_ARCH_STRPBRK
89 extern char * strpbrk(const char *,const char *);
90 #endif
91 #ifndef __HAVE_ARCH_STRSEP
92 extern char * strsep(char **,const char *);
93 #endif
94 #ifndef __HAVE_ARCH_STRSPN
95 extern __kernel_size_t strspn(const char *,const char *);
96 #endif
97 #ifndef __HAVE_ARCH_STRCSPN
98 extern __kernel_size_t strcspn(const char *,const char *);
99 #endif
100
101 #ifndef __HAVE_ARCH_MEMSET
102 extern void * memset(void *,int,__kernel_size_t);
103 #endif
104
105 #ifndef __HAVE_ARCH_MEMSET16
106 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
107 #endif
108
109 #ifndef __HAVE_ARCH_MEMSET32
110 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
111 #endif
112
113 #ifndef __HAVE_ARCH_MEMSET64
114 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
115 #endif
116
memset_l(unsigned long * p,unsigned long v,__kernel_size_t n)117 static inline void *memset_l(unsigned long *p, unsigned long v,
118 __kernel_size_t n)
119 {
120 if (BITS_PER_LONG == 32)
121 return memset32((uint32_t *)p, v, n);
122 else
123 return memset64((uint64_t *)p, v, n);
124 }
125
memset_p(void ** p,void * v,__kernel_size_t n)126 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
127 {
128 if (BITS_PER_LONG == 32)
129 return memset32((uint32_t *)p, (uintptr_t)v, n);
130 else
131 return memset64((uint64_t *)p, (uintptr_t)v, n);
132 }
133
134 #ifndef __HAVE_ARCH_MEMCPY
135 extern void * memcpy(void *,const void *,__kernel_size_t);
136 #endif
137 #ifndef __HAVE_ARCH_MEMMOVE
138 extern void * memmove(void *,const void *,__kernel_size_t);
139 #endif
140 #ifndef __HAVE_ARCH_MEMSCAN
141 extern void * memscan(void *,int,__kernel_size_t);
142 #endif
143 #ifndef __HAVE_ARCH_MEMCMP
144 extern int memcmp(const void *,const void *,__kernel_size_t);
145 #endif
146 #ifndef __HAVE_ARCH_MEMCHR
147 extern void * memchr(const void *,int,__kernel_size_t);
148 #endif
149 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
memcpy_mcsafe(void * dst,const void * src,size_t cnt)150 static inline __must_check unsigned long memcpy_mcsafe(void *dst,
151 const void *src, size_t cnt)
152 {
153 memcpy(dst, src, cnt);
154 return 0;
155 }
156 #endif
157 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
memcpy_flushcache(void * dst,const void * src,size_t cnt)158 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
159 {
160 memcpy(dst, src, cnt);
161 }
162 #endif
163 void *memchr_inv(const void *s, int c, size_t n);
164 char *strreplace(char *s, char old, char new);
165
166 extern void kfree_const(const void *x);
167
168 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
169 extern const char *kstrdup_const(const char *s, gfp_t gfp);
170 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
171 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
172 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
173
174 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
175 extern void argv_free(char **argv);
176
177 extern bool sysfs_streq(const char *s1, const char *s2);
178 extern int kstrtobool(const char *s, bool *res);
strtobool(const char * s,bool * res)179 static inline int strtobool(const char *s, bool *res)
180 {
181 return kstrtobool(s, res);
182 }
183
184 int match_string(const char * const *array, size_t n, const char *string);
185 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
186
187 /**
188 * sysfs_match_string - matches given string in an array
189 * @_a: array of strings
190 * @_s: string to match with
191 *
192 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
193 */
194 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
195
196 #ifdef CONFIG_BINARY_PRINTF
197 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
198 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
199 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
200 #endif
201
202 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
203 const void *from, size_t available);
204
205 /**
206 * strstarts - does @str start with @prefix?
207 * @str: string to examine
208 * @prefix: prefix to look for.
209 */
strstarts(const char * str,const char * prefix)210 static inline bool strstarts(const char *str, const char *prefix)
211 {
212 return strncmp(str, prefix, strlen(prefix)) == 0;
213 }
214
215 size_t memweight(const void *ptr, size_t bytes);
216 void memzero_explicit(void *s, size_t count);
217
218 /**
219 * kbasename - return the last part of a pathname.
220 *
221 * @path: path to extract the filename from.
222 */
kbasename(const char * path)223 static inline const char *kbasename(const char *path)
224 {
225 const char *tail = strrchr(path, '/');
226 return tail ? tail + 1 : path;
227 }
228
229 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
230 #define __RENAME(x) __asm__(#x)
231
232 void fortify_panic(const char *name) __noreturn __cold;
233 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
234 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
235 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
236 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
237
238 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
strncpy(char * p,const char * q,__kernel_size_t size)239 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
240 {
241 size_t p_size = __builtin_object_size(p, 0);
242 if (__builtin_constant_p(size) && p_size < size)
243 __write_overflow();
244 if (p_size < size)
245 fortify_panic(__func__);
246 return __builtin_strncpy(p, q, size);
247 }
248
strcat(char * p,const char * q)249 __FORTIFY_INLINE char *strcat(char *p, const char *q)
250 {
251 size_t p_size = __builtin_object_size(p, 0);
252 if (p_size == (size_t)-1)
253 return __builtin_strcat(p, q);
254 if (strlcat(p, q, p_size) >= p_size)
255 fortify_panic(__func__);
256 return p;
257 }
258
strlen(const char * p)259 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
260 {
261 __kernel_size_t ret;
262 size_t p_size = __builtin_object_size(p, 0);
263
264 /* Work around gcc excess stack consumption issue */
265 if (p_size == (size_t)-1 ||
266 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
267 return __builtin_strlen(p);
268 ret = strnlen(p, p_size);
269 if (p_size <= ret)
270 fortify_panic(__func__);
271 return ret;
272 }
273
274 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
strnlen(const char * p,__kernel_size_t maxlen)275 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
276 {
277 size_t p_size = __builtin_object_size(p, 0);
278 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
279 if (p_size <= ret && maxlen != ret)
280 fortify_panic(__func__);
281 return ret;
282 }
283
284 /* defined after fortified strlen to reuse it */
285 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
strlcpy(char * p,const char * q,size_t size)286 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
287 {
288 size_t ret;
289 size_t p_size = __builtin_object_size(p, 0);
290 size_t q_size = __builtin_object_size(q, 0);
291 if (p_size == (size_t)-1 && q_size == (size_t)-1)
292 return __real_strlcpy(p, q, size);
293 ret = strlen(q);
294 if (size) {
295 size_t len = (ret >= size) ? size - 1 : ret;
296 if (__builtin_constant_p(len) && len >= p_size)
297 __write_overflow();
298 if (len >= p_size)
299 fortify_panic(__func__);
300 __builtin_memcpy(p, q, len);
301 p[len] = '\0';
302 }
303 return ret;
304 }
305
306 /* defined after fortified strlen and strnlen to reuse them */
strncat(char * p,const char * q,__kernel_size_t count)307 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
308 {
309 size_t p_len, copy_len;
310 size_t p_size = __builtin_object_size(p, 0);
311 size_t q_size = __builtin_object_size(q, 0);
312 if (p_size == (size_t)-1 && q_size == (size_t)-1)
313 return __builtin_strncat(p, q, count);
314 p_len = strlen(p);
315 copy_len = strnlen(q, count);
316 if (p_size < p_len + copy_len + 1)
317 fortify_panic(__func__);
318 __builtin_memcpy(p + p_len, q, copy_len);
319 p[p_len + copy_len] = '\0';
320 return p;
321 }
322
memset(void * p,int c,__kernel_size_t size)323 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
324 {
325 size_t p_size = __builtin_object_size(p, 0);
326 if (__builtin_constant_p(size) && p_size < size)
327 __write_overflow();
328 if (p_size < size)
329 fortify_panic(__func__);
330 return __builtin_memset(p, c, size);
331 }
332
memcpy(void * p,const void * q,__kernel_size_t size)333 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
334 {
335 size_t p_size = __builtin_object_size(p, 0);
336 size_t q_size = __builtin_object_size(q, 0);
337 if (__builtin_constant_p(size)) {
338 if (p_size < size)
339 __write_overflow();
340 if (q_size < size)
341 __read_overflow2();
342 }
343 if (p_size < size || q_size < size)
344 fortify_panic(__func__);
345 return __builtin_memcpy(p, q, size);
346 }
347
memmove(void * p,const void * q,__kernel_size_t size)348 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
349 {
350 size_t p_size = __builtin_object_size(p, 0);
351 size_t q_size = __builtin_object_size(q, 0);
352 if (__builtin_constant_p(size)) {
353 if (p_size < size)
354 __write_overflow();
355 if (q_size < size)
356 __read_overflow2();
357 }
358 if (p_size < size || q_size < size)
359 fortify_panic(__func__);
360 return __builtin_memmove(p, q, size);
361 }
362
363 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
memscan(void * p,int c,__kernel_size_t size)364 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
365 {
366 size_t p_size = __builtin_object_size(p, 0);
367 if (__builtin_constant_p(size) && p_size < size)
368 __read_overflow();
369 if (p_size < size)
370 fortify_panic(__func__);
371 return __real_memscan(p, c, size);
372 }
373
memcmp(const void * p,const void * q,__kernel_size_t size)374 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
375 {
376 size_t p_size = __builtin_object_size(p, 0);
377 size_t q_size = __builtin_object_size(q, 0);
378 if (__builtin_constant_p(size)) {
379 if (p_size < size)
380 __read_overflow();
381 if (q_size < size)
382 __read_overflow2();
383 }
384 if (p_size < size || q_size < size)
385 fortify_panic(__func__);
386 return __builtin_memcmp(p, q, size);
387 }
388
memchr(const void * p,int c,__kernel_size_t size)389 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
390 {
391 size_t p_size = __builtin_object_size(p, 0);
392 if (__builtin_constant_p(size) && p_size < size)
393 __read_overflow();
394 if (p_size < size)
395 fortify_panic(__func__);
396 return __builtin_memchr(p, c, size);
397 }
398
399 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)400 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
401 {
402 size_t p_size = __builtin_object_size(p, 0);
403 if (__builtin_constant_p(size) && p_size < size)
404 __read_overflow();
405 if (p_size < size)
406 fortify_panic(__func__);
407 return __real_memchr_inv(p, c, size);
408 }
409
410 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)411 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
412 {
413 size_t p_size = __builtin_object_size(p, 0);
414 if (__builtin_constant_p(size) && p_size < size)
415 __read_overflow();
416 if (p_size < size)
417 fortify_panic(__func__);
418 return __real_kmemdup(p, size, gfp);
419 }
420
421 /* defined after fortified strlen and memcpy to reuse them */
strcpy(char * p,const char * q)422 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
423 {
424 size_t p_size = __builtin_object_size(p, 0);
425 size_t q_size = __builtin_object_size(q, 0);
426 if (p_size == (size_t)-1 && q_size == (size_t)-1)
427 return __builtin_strcpy(p, q);
428 memcpy(p, q, strlen(q) + 1);
429 return p;
430 }
431
432 #endif
433
434 /**
435 * memcpy_and_pad - Copy one buffer to another with padding
436 * @dest: Where to copy to
437 * @dest_len: The destination buffer size
438 * @src: Where to copy from
439 * @count: The number of bytes to copy
440 * @pad: Character to use for padding if space is left in destination.
441 */
memcpy_and_pad(void * dest,size_t dest_len,const void * src,size_t count,int pad)442 static inline void memcpy_and_pad(void *dest, size_t dest_len,
443 const void *src, size_t count, int pad)
444 {
445 if (dest_len > count) {
446 memcpy(dest, src, count);
447 memset(dest + count, pad, dest_len - count);
448 } else
449 memcpy(dest, src, dest_len);
450 }
451
452 #endif /* _LINUX_STRING_H_ */
453
