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
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 #ifndef __HAVE_ARCH_STRNCHR
66 extern char * strnchr(const char *, size_t, int);
67 #endif
68 #ifndef __HAVE_ARCH_STRRCHR
69 extern char * strrchr(const char *,int);
70 #endif
71 extern char * __must_check skip_spaces(const char *);
72
73 extern char *strim(char *);
74
strstrip(char * str)75 static inline __must_check char *strstrip(char *str)
76 {
77 return strim(str);
78 }
79
80 #ifndef __HAVE_ARCH_STRSTR
81 extern char * strstr(const char *, const char *);
82 #endif
83 #ifndef __HAVE_ARCH_STRNSTR
84 extern char * strnstr(const char *, const char *, size_t);
85 #endif
86 #ifndef __HAVE_ARCH_STRLEN
87 extern __kernel_size_t strlen(const char *);
88 #endif
89 #ifndef __HAVE_ARCH_STRNLEN
90 extern __kernel_size_t strnlen(const char *,__kernel_size_t);
91 #endif
92 #ifndef __HAVE_ARCH_STRPBRK
93 extern char * strpbrk(const char *,const char *);
94 #endif
95 #ifndef __HAVE_ARCH_STRSEP
96 extern char * strsep(char **,const char *);
97 #endif
98 #ifndef __HAVE_ARCH_STRSPN
99 extern __kernel_size_t strspn(const char *,const char *);
100 #endif
101 #ifndef __HAVE_ARCH_STRCSPN
102 extern __kernel_size_t strcspn(const char *,const char *);
103 #endif
104
105 #ifndef __HAVE_ARCH_MEMSET
106 extern void * memset(void *,int,__kernel_size_t);
107 #endif
108
109 #ifndef __HAVE_ARCH_MEMSET16
110 extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
111 #endif
112
113 #ifndef __HAVE_ARCH_MEMSET32
114 extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
115 #endif
116
117 #ifndef __HAVE_ARCH_MEMSET64
118 extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
119 #endif
120
memset_l(unsigned long * p,unsigned long v,__kernel_size_t n)121 static inline void *memset_l(unsigned long *p, unsigned long v,
122 __kernel_size_t n)
123 {
124 if (BITS_PER_LONG == 32)
125 return memset32((uint32_t *)p, v, n);
126 else
127 return memset64((uint64_t *)p, v, n);
128 }
129
memset_p(void ** p,void * v,__kernel_size_t n)130 static inline void *memset_p(void **p, void *v, __kernel_size_t n)
131 {
132 if (BITS_PER_LONG == 32)
133 return memset32((uint32_t *)p, (uintptr_t)v, n);
134 else
135 return memset64((uint64_t *)p, (uintptr_t)v, n);
136 }
137
138 #ifndef __HAVE_ARCH_MEMCPY
139 extern void * memcpy(void *,const void *,__kernel_size_t);
140 #endif
141 #ifndef __HAVE_ARCH_MEMMOVE
142 extern void * memmove(void *,const void *,__kernel_size_t);
143 #endif
144 #ifndef __HAVE_ARCH_MEMSCAN
145 extern void * memscan(void *,int,__kernel_size_t);
146 #endif
147 #ifndef __HAVE_ARCH_MEMCMP
148 extern int memcmp(const void *,const void *,__kernel_size_t);
149 #endif
150 #ifndef __HAVE_ARCH_BCMP
151 extern int bcmp(const void *,const void *,__kernel_size_t);
152 #endif
153 #ifndef __HAVE_ARCH_MEMCHR
154 extern void * memchr(const void *,int,__kernel_size_t);
155 #endif
156 #ifndef __HAVE_ARCH_MEMCPY_MCSAFE
memcpy_mcsafe(void * dst,const void * src,size_t cnt)157 static inline __must_check unsigned long memcpy_mcsafe(void *dst,
158 const void *src, size_t cnt)
159 {
160 memcpy(dst, src, cnt);
161 return 0;
162 }
163 #endif
164 #ifndef __HAVE_ARCH_MEMCPY_FLUSHCACHE
memcpy_flushcache(void * dst,const void * src,size_t cnt)165 static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
166 {
167 memcpy(dst, src, cnt);
168 }
169 #endif
170 void *memchr_inv(const void *s, int c, size_t n);
171 char *strreplace(char *s, char old, char new);
172
173 extern void kfree_const(const void *x);
174
175 extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
176 extern const char *kstrdup_const(const char *s, gfp_t gfp);
177 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
178 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
179 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
180
181 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
182 extern void argv_free(char **argv);
183
184 extern bool sysfs_streq(const char *s1, const char *s2);
185 extern int kstrtobool(const char *s, bool *res);
strtobool(const char * s,bool * res)186 static inline int strtobool(const char *s, bool *res)
187 {
188 return kstrtobool(s, res);
189 }
190
191 int match_string(const char * const *array, size_t n, const char *string);
192 int __sysfs_match_string(const char * const *array, size_t n, const char *s);
193
194 /**
195 * sysfs_match_string - matches given string in an array
196 * @_a: array of strings
197 * @_s: string to match with
198 *
199 * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
200 */
201 #define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
202
203 #ifdef CONFIG_BINARY_PRINTF
204 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
205 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
206 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
207 #endif
208
209 extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
210 const void *from, size_t available);
211
212 /**
213 * strstarts - does @str start with @prefix?
214 * @str: string to examine
215 * @prefix: prefix to look for.
216 */
strstarts(const char * str,const char * prefix)217 static inline bool strstarts(const char *str, const char *prefix)
218 {
219 return strncmp(str, prefix, strlen(prefix)) == 0;
220 }
221
222 size_t memweight(const void *ptr, size_t bytes);
223 void memzero_explicit(void *s, size_t count);
224
225 /**
226 * kbasename - return the last part of a pathname.
227 *
228 * @path: path to extract the filename from.
229 */
kbasename(const char * path)230 static inline const char *kbasename(const char *path)
231 {
232 const char *tail = strrchr(path, '/');
233 return tail ? tail + 1 : path;
234 }
235
236 #define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
237 #define __RENAME(x) __asm__(#x)
238
239 void fortify_panic(const char *name) __noreturn __cold;
240 void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
241 void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
242 void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
243 void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
244
245 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
246
247 #ifdef CONFIG_KASAN
248 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
249 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
250 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
251 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove);
252 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset);
253 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat);
254 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy);
255 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
256 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
257 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
258 #else
259 #define __underlying_memchr __builtin_memchr
260 #define __underlying_memcmp __builtin_memcmp
261 #define __underlying_memcpy __builtin_memcpy
262 #define __underlying_memmove __builtin_memmove
263 #define __underlying_memset __builtin_memset
264 #define __underlying_strcat __builtin_strcat
265 #define __underlying_strcpy __builtin_strcpy
266 #define __underlying_strlen __builtin_strlen
267 #define __underlying_strncat __builtin_strncat
268 #define __underlying_strncpy __builtin_strncpy
269 #endif
270
strncpy(char * p,const char * q,__kernel_size_t size)271 __FORTIFY_INLINE char *strncpy(char *p, const char *q, __kernel_size_t size)
272 {
273 size_t p_size = __builtin_object_size(p, 0);
274 if (__builtin_constant_p(size) && p_size < size)
275 __write_overflow();
276 if (p_size < size)
277 fortify_panic(__func__);
278 return __underlying_strncpy(p, q, size);
279 }
280
strcat(char * p,const char * q)281 __FORTIFY_INLINE char *strcat(char *p, const char *q)
282 {
283 size_t p_size = __builtin_object_size(p, 0);
284 if (p_size == (size_t)-1)
285 return __underlying_strcat(p, q);
286 if (strlcat(p, q, p_size) >= p_size)
287 fortify_panic(__func__);
288 return p;
289 }
290
strlen(const char * p)291 __FORTIFY_INLINE __kernel_size_t strlen(const char *p)
292 {
293 __kernel_size_t ret;
294 size_t p_size = __builtin_object_size(p, 0);
295
296 /* Work around gcc excess stack consumption issue */
297 if (p_size == (size_t)-1 ||
298 (__builtin_constant_p(p[p_size - 1]) && p[p_size - 1] == '\0'))
299 return __underlying_strlen(p);
300 ret = strnlen(p, p_size);
301 if (p_size <= ret)
302 fortify_panic(__func__);
303 return ret;
304 }
305
306 extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
strnlen(const char * p,__kernel_size_t maxlen)307 __FORTIFY_INLINE __kernel_size_t strnlen(const char *p, __kernel_size_t maxlen)
308 {
309 size_t p_size = __builtin_object_size(p, 0);
310 __kernel_size_t ret = __real_strnlen(p, maxlen < p_size ? maxlen : p_size);
311 if (p_size <= ret && maxlen != ret)
312 fortify_panic(__func__);
313 return ret;
314 }
315
316 /* defined after fortified strlen to reuse it */
317 extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
strlcpy(char * p,const char * q,size_t size)318 __FORTIFY_INLINE size_t strlcpy(char *p, const char *q, size_t size)
319 {
320 size_t ret;
321 size_t p_size = __builtin_object_size(p, 0);
322 size_t q_size = __builtin_object_size(q, 0);
323 if (p_size == (size_t)-1 && q_size == (size_t)-1)
324 return __real_strlcpy(p, q, size);
325 ret = strlen(q);
326 if (size) {
327 size_t len = (ret >= size) ? size - 1 : ret;
328 if (__builtin_constant_p(len) && len >= p_size)
329 __write_overflow();
330 if (len >= p_size)
331 fortify_panic(__func__);
332 __underlying_memcpy(p, q, len);
333 p[len] = '\0';
334 }
335 return ret;
336 }
337
338 /* defined after fortified strlen and strnlen to reuse them */
strncat(char * p,const char * q,__kernel_size_t count)339 __FORTIFY_INLINE char *strncat(char *p, const char *q, __kernel_size_t count)
340 {
341 size_t p_len, copy_len;
342 size_t p_size = __builtin_object_size(p, 0);
343 size_t q_size = __builtin_object_size(q, 0);
344 if (p_size == (size_t)-1 && q_size == (size_t)-1)
345 return __underlying_strncat(p, q, count);
346 p_len = strlen(p);
347 copy_len = strnlen(q, count);
348 if (p_size < p_len + copy_len + 1)
349 fortify_panic(__func__);
350 __underlying_memcpy(p + p_len, q, copy_len);
351 p[p_len + copy_len] = '\0';
352 return p;
353 }
354
memset(void * p,int c,__kernel_size_t size)355 __FORTIFY_INLINE void *memset(void *p, int c, __kernel_size_t size)
356 {
357 size_t p_size = __builtin_object_size(p, 0);
358 if (__builtin_constant_p(size) && p_size < size)
359 __write_overflow();
360 if (p_size < size)
361 fortify_panic(__func__);
362 return __underlying_memset(p, c, size);
363 }
364
memcpy(void * p,const void * q,__kernel_size_t size)365 __FORTIFY_INLINE void *memcpy(void *p, const void *q, __kernel_size_t size)
366 {
367 size_t p_size = __builtin_object_size(p, 0);
368 size_t q_size = __builtin_object_size(q, 0);
369 if (__builtin_constant_p(size)) {
370 if (p_size < size)
371 __write_overflow();
372 if (q_size < size)
373 __read_overflow2();
374 }
375 if (p_size < size || q_size < size)
376 fortify_panic(__func__);
377 return __underlying_memcpy(p, q, size);
378 }
379
memmove(void * p,const void * q,__kernel_size_t size)380 __FORTIFY_INLINE void *memmove(void *p, const void *q, __kernel_size_t size)
381 {
382 size_t p_size = __builtin_object_size(p, 0);
383 size_t q_size = __builtin_object_size(q, 0);
384 if (__builtin_constant_p(size)) {
385 if (p_size < size)
386 __write_overflow();
387 if (q_size < size)
388 __read_overflow2();
389 }
390 if (p_size < size || q_size < size)
391 fortify_panic(__func__);
392 return __underlying_memmove(p, q, size);
393 }
394
395 extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
memscan(void * p,int c,__kernel_size_t size)396 __FORTIFY_INLINE void *memscan(void *p, int c, __kernel_size_t size)
397 {
398 size_t p_size = __builtin_object_size(p, 0);
399 if (__builtin_constant_p(size) && p_size < size)
400 __read_overflow();
401 if (p_size < size)
402 fortify_panic(__func__);
403 return __real_memscan(p, c, size);
404 }
405
memcmp(const void * p,const void * q,__kernel_size_t size)406 __FORTIFY_INLINE int memcmp(const void *p, const void *q, __kernel_size_t size)
407 {
408 size_t p_size = __builtin_object_size(p, 0);
409 size_t q_size = __builtin_object_size(q, 0);
410 if (__builtin_constant_p(size)) {
411 if (p_size < size)
412 __read_overflow();
413 if (q_size < size)
414 __read_overflow2();
415 }
416 if (p_size < size || q_size < size)
417 fortify_panic(__func__);
418 return __underlying_memcmp(p, q, size);
419 }
420
memchr(const void * p,int c,__kernel_size_t size)421 __FORTIFY_INLINE void *memchr(const void *p, int c, __kernel_size_t size)
422 {
423 size_t p_size = __builtin_object_size(p, 0);
424 if (__builtin_constant_p(size) && p_size < size)
425 __read_overflow();
426 if (p_size < size)
427 fortify_panic(__func__);
428 return __underlying_memchr(p, c, size);
429 }
430
431 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)432 __FORTIFY_INLINE void *memchr_inv(const void *p, int c, size_t size)
433 {
434 size_t p_size = __builtin_object_size(p, 0);
435 if (__builtin_constant_p(size) && p_size < size)
436 __read_overflow();
437 if (p_size < size)
438 fortify_panic(__func__);
439 return __real_memchr_inv(p, c, size);
440 }
441
442 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)443 __FORTIFY_INLINE void *kmemdup(const void *p, size_t size, gfp_t gfp)
444 {
445 size_t p_size = __builtin_object_size(p, 0);
446 if (__builtin_constant_p(size) && p_size < size)
447 __read_overflow();
448 if (p_size < size)
449 fortify_panic(__func__);
450 return __real_kmemdup(p, size, gfp);
451 }
452
453 /* defined after fortified strlen and memcpy to reuse them */
strcpy(char * p,const char * q)454 __FORTIFY_INLINE char *strcpy(char *p, const char *q)
455 {
456 size_t p_size = __builtin_object_size(p, 0);
457 size_t q_size = __builtin_object_size(q, 0);
458 if (p_size == (size_t)-1 && q_size == (size_t)-1)
459 return __underlying_strcpy(p, q);
460 memcpy(p, q, strlen(q) + 1);
461 return p;
462 }
463
464 /* Don't use these outside the FORITFY_SOURCE implementation */
465 #undef __underlying_memchr
466 #undef __underlying_memcmp
467 #undef __underlying_memcpy
468 #undef __underlying_memmove
469 #undef __underlying_memset
470 #undef __underlying_strcat
471 #undef __underlying_strcpy
472 #undef __underlying_strlen
473 #undef __underlying_strncat
474 #undef __underlying_strncpy
475 #endif
476
477 /**
478 * memcpy_and_pad - Copy one buffer to another with padding
479 * @dest: Where to copy to
480 * @dest_len: The destination buffer size
481 * @src: Where to copy from
482 * @count: The number of bytes to copy
483 * @pad: Character to use for padding if space is left in destination.
484 */
memcpy_and_pad(void * dest,size_t dest_len,const void * src,size_t count,int pad)485 static inline void memcpy_and_pad(void *dest, size_t dest_len,
486 const void *src, size_t count, int pad)
487 {
488 if (dest_len > count) {
489 memcpy(dest, src, count);
490 memset(dest + count, pad, dest_len - count);
491 } else
492 memcpy(dest, src, dest_len);
493 }
494
495 #endif /* _LINUX_STRING_H_ */
496