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
12extern char *strndup_user(const char __user *, long);
13extern void *memdup_user(const void __user *, size_t);
14extern void *vmemdup_user(const void __user *, size_t);
15extern 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
23extern char * strcpy(char *,const char *);
24#endif
25#ifndef __HAVE_ARCH_STRNCPY
26extern char * strncpy(char *,const char *, __kernel_size_t);
27#endif
28#ifndef __HAVE_ARCH_STRLCPY
29size_t strlcpy(char *, const char *, size_t);
30#endif
31#ifndef __HAVE_ARCH_STRSCPY
32ssize_t strscpy(char *, const char *, size_t);
33#endif
34#ifndef __HAVE_ARCH_STRCAT
35extern char * strcat(char *, const char *);
36#endif
37#ifndef __HAVE_ARCH_STRNCAT
38extern char * strncat(char *, const char *, __kernel_size_t);
39#endif
40#ifndef __HAVE_ARCH_STRLCAT
41extern size_t strlcat(char *, const char *, __kernel_size_t);
42#endif
43#ifndef __HAVE_ARCH_STRCMP
44extern int strcmp(const char *,const char *);
45#endif
46#ifndef __HAVE_ARCH_STRNCMP
47extern int strncmp(const char *,const char *,__kernel_size_t);
48#endif
49#ifndef __HAVE_ARCH_STRCASECMP
50extern int strcasecmp(const char *s1, const char *s2);
51#endif
52#ifndef __HAVE_ARCH_STRNCASECMP
53extern int strncasecmp(const char *s1, const char *s2, size_t n);
54#endif
55#ifndef __HAVE_ARCH_STRCHR
56extern char * strchr(const char *,int);
57#endif
58#ifndef __HAVE_ARCH_STRCHRNUL
59extern char * strchrnul(const char *,int);
60#endif
61#ifndef __HAVE_ARCH_STRNCHR
62extern char * strnchr(const char *, size_t, int);
63#endif
64#ifndef __HAVE_ARCH_STRRCHR
65extern char * strrchr(const char *,int);
66#endif
67extern char * __must_check skip_spaces(const char *);
68
69extern char *strim(char *);
70
71static inline __must_check char *strstrip(char *str)
72{
73 return strim(str);
74}
75
76#ifndef __HAVE_ARCH_STRSTR
77extern char * strstr(const char *, const char *);
78#endif
79#ifndef __HAVE_ARCH_STRNSTR
80extern char * strnstr(const char *, const char *, size_t);
81#endif
82#ifndef __HAVE_ARCH_STRLEN
83extern __kernel_size_t strlen(const char *);
84#endif
85#ifndef __HAVE_ARCH_STRNLEN
86extern __kernel_size_t strnlen(const char *,__kernel_size_t);
87#endif
88#ifndef __HAVE_ARCH_STRPBRK
89extern char * strpbrk(const char *,const char *);
90#endif
91#ifndef __HAVE_ARCH_STRSEP
92extern char * strsep(char **,const char *);
93#endif
94#ifndef __HAVE_ARCH_STRSPN
95extern __kernel_size_t strspn(const char *,const char *);
96#endif
97#ifndef __HAVE_ARCH_STRCSPN
98extern __kernel_size_t strcspn(const char *,const char *);
99#endif
100
101#ifndef __HAVE_ARCH_MEMSET
102extern void * memset(void *,int,__kernel_size_t);
103#endif
104
105#ifndef __HAVE_ARCH_MEMSET16
106extern void *memset16(uint16_t *, uint16_t, __kernel_size_t);
107#endif
108
109#ifndef __HAVE_ARCH_MEMSET32
110extern void *memset32(uint32_t *, uint32_t, __kernel_size_t);
111#endif
112
113#ifndef __HAVE_ARCH_MEMSET64
114extern void *memset64(uint64_t *, uint64_t, __kernel_size_t);
115#endif
116
117static 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
126static 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
135extern void * memcpy(void *,const void *,__kernel_size_t);
136#endif
137#ifndef __HAVE_ARCH_MEMMOVE
138extern void * memmove(void *,const void *,__kernel_size_t);
139#endif
140#ifndef __HAVE_ARCH_MEMSCAN
141extern void * memscan(void *,int,__kernel_size_t);
142#endif
143#ifndef __HAVE_ARCH_MEMCMP
144extern int memcmp(const void *,const void *,__kernel_size_t);
145#endif
146#ifndef __HAVE_ARCH_MEMCHR
147extern void * memchr(const void *,int,__kernel_size_t);
148#endif
149#ifndef __HAVE_ARCH_MEMCPY_MCSAFE
150static 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
158static inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
159{
160 memcpy(dst, src, cnt);
161}
162#endif
163void *memchr_inv(const void *s, int c, size_t n);
164char *strreplace(char *s, char old, char new);
165
166extern void kfree_const(const void *x);
167
168extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
169extern const char *kstrdup_const(const char *s, gfp_t gfp);
170extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
171extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
172extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
173
174extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
175extern void argv_free(char **argv);
176
177extern bool sysfs_streq(const char *s1, const char *s2);
178extern int kstrtobool(const char *s, bool *res);
179static inline int strtobool(const char *s, bool *res)
180{
181 return kstrtobool(s, res);
182}
183
184int match_string(const char * const *array, size_t n, const char *string);
185int __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
197int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
198int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
199int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
200#endif
201
202extern 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 */
210static inline bool strstarts(const char *str, const char *prefix)
211{
212 return strncmp(str, prefix, strlen(prefix)) == 0;
213}
214
215size_t memweight(const void *ptr, size_t bytes);
216void 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 */
223static 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
232void fortify_panic(const char *name) __noreturn __cold;
233void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
234void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
235void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
236void __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)
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
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
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
274extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
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 */
285extern size_t __real_strlcpy(char *, const char *, size_t) __RENAME(strlcpy);
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 */
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
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
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
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
363extern void *__real_memscan(void *, int, __kernel_size_t) __RENAME(memscan);
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
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
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
399void *__real_memchr_inv(const void *s, int c, size_t n) __RENAME(memchr_inv);
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
410extern void *__real_kmemdup(const void *src, size_t len, gfp_t gfp) __RENAME(kmemdup);
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 */
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 */
442static 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