Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/seq_file.c | |
4 | * | |
5 | * helper functions for making synthetic files from sequences of records. | |
6 | * initial implementation -- AV, Oct 2001. | |
7 | */ | |
8 | ||
9 | #include <linux/fs.h> | |
630d9c47 | 10 | #include <linux/export.h> |
1da177e4 | 11 | #include <linux/seq_file.h> |
058504ed | 12 | #include <linux/vmalloc.h> |
1da177e4 | 13 | #include <linux/slab.h> |
adb37c4c | 14 | #include <linux/cred.h> |
058504ed | 15 | #include <linux/mm.h> |
37607102 | 16 | #include <linux/printk.h> |
25c6bb76 | 17 | #include <linux/string_helpers.h> |
1da177e4 | 18 | |
7c0f6ba6 | 19 | #include <linux/uaccess.h> |
1da177e4 LT |
20 | #include <asm/page.h> |
21 | ||
e075f591 KH |
22 | static void seq_set_overflow(struct seq_file *m) |
23 | { | |
24 | m->count = m->size; | |
25 | } | |
26 | ||
058504ed HC |
27 | static void *seq_buf_alloc(unsigned long size) |
28 | { | |
a7c3e901 | 29 | return kvmalloc(size, GFP_KERNEL); |
058504ed HC |
30 | } |
31 | ||
1da177e4 LT |
32 | /** |
33 | * seq_open - initialize sequential file | |
34 | * @file: file we initialize | |
35 | * @op: method table describing the sequence | |
36 | * | |
37 | * seq_open() sets @file, associating it with a sequence described | |
38 | * by @op. @op->start() sets the iterator up and returns the first | |
39 | * element of sequence. @op->stop() shuts it down. @op->next() | |
40 | * returns the next element of sequence. @op->show() prints element | |
41 | * into the buffer. In case of error ->start() and ->next() return | |
42 | * ERR_PTR(error). In the end of sequence they return %NULL. ->show() | |
43 | * returns 0 in case of success and negative number in case of error. | |
521b5d0c | 44 | * Returning SEQ_SKIP means "discard this element and move on". |
460b865e YD |
45 | * Note: seq_open() will allocate a struct seq_file and store its |
46 | * pointer in @file->private_data. This pointer should not be modified. | |
1da177e4 | 47 | */ |
15ad7cdc | 48 | int seq_open(struct file *file, const struct seq_operations *op) |
1da177e4 | 49 | { |
189f9841 YD |
50 | struct seq_file *p; |
51 | ||
52 | WARN_ON(file->private_data); | |
53 | ||
54 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
55 | if (!p) | |
56 | return -ENOMEM; | |
57 | ||
58 | file->private_data = p; | |
1abe77b0 | 59 | |
0ac1759a | 60 | mutex_init(&p->lock); |
1da177e4 | 61 | p->op = op; |
34dbbcdb LT |
62 | |
63 | // No refcounting: the lifetime of 'p' is constrained | |
64 | // to the lifetime of the file. | |
65 | p->file = file; | |
1da177e4 LT |
66 | |
67 | /* | |
68 | * Wrappers around seq_open(e.g. swaps_open) need to be | |
69 | * aware of this. If they set f_version themselves, they | |
70 | * should call seq_open first and then set f_version. | |
71 | */ | |
72 | file->f_version = 0; | |
73 | ||
8f19d472 EB |
74 | /* |
75 | * seq_files support lseek() and pread(). They do not implement | |
76 | * write() at all, but we clear FMODE_PWRITE here for historical | |
77 | * reasons. | |
78 | * | |
79 | * If a client of seq_files a) implements file.write() and b) wishes to | |
80 | * support pwrite() then that client will need to implement its own | |
81 | * file.open() which calls seq_open() and then sets FMODE_PWRITE. | |
82 | */ | |
83 | file->f_mode &= ~FMODE_PWRITE; | |
1da177e4 LT |
84 | return 0; |
85 | } | |
86 | EXPORT_SYMBOL(seq_open); | |
87 | ||
33da8892 EB |
88 | static int traverse(struct seq_file *m, loff_t offset) |
89 | { | |
90 | loff_t pos = 0, index; | |
91 | int error = 0; | |
92 | void *p; | |
93 | ||
94 | m->version = 0; | |
95 | index = 0; | |
96 | m->count = m->from = 0; | |
97 | if (!offset) { | |
98 | m->index = index; | |
99 | return 0; | |
100 | } | |
101 | if (!m->buf) { | |
058504ed | 102 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
33da8892 EB |
103 | if (!m->buf) |
104 | return -ENOMEM; | |
105 | } | |
106 | p = m->op->start(m, &index); | |
107 | while (p) { | |
108 | error = PTR_ERR(p); | |
109 | if (IS_ERR(p)) | |
110 | break; | |
111 | error = m->op->show(m, p); | |
112 | if (error < 0) | |
113 | break; | |
114 | if (unlikely(error)) { | |
115 | error = 0; | |
116 | m->count = 0; | |
117 | } | |
1f33c41c | 118 | if (seq_has_overflowed(m)) |
33da8892 EB |
119 | goto Eoverflow; |
120 | if (pos + m->count > offset) { | |
121 | m->from = offset - pos; | |
122 | m->count -= m->from; | |
123 | m->index = index; | |
124 | break; | |
125 | } | |
126 | pos += m->count; | |
127 | m->count = 0; | |
128 | if (pos == offset) { | |
129 | index++; | |
130 | m->index = index; | |
131 | break; | |
132 | } | |
133 | p = m->op->next(m, p, &index); | |
134 | } | |
135 | m->op->stop(m, p); | |
f01d1d54 | 136 | m->index = index; |
33da8892 EB |
137 | return error; |
138 | ||
139 | Eoverflow: | |
140 | m->op->stop(m, p); | |
058504ed | 141 | kvfree(m->buf); |
801a7605 | 142 | m->count = 0; |
058504ed | 143 | m->buf = seq_buf_alloc(m->size <<= 1); |
33da8892 EB |
144 | return !m->buf ? -ENOMEM : -EAGAIN; |
145 | } | |
146 | ||
1da177e4 LT |
147 | /** |
148 | * seq_read - ->read() method for sequential files. | |
67be2dd1 MW |
149 | * @file: the file to read from |
150 | * @buf: the buffer to read to | |
151 | * @size: the maximum number of bytes to read | |
152 | * @ppos: the current position in the file | |
1da177e4 LT |
153 | * |
154 | * Ready-made ->f_op->read() | |
155 | */ | |
156 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
157 | { | |
8209e2f4 | 158 | struct seq_file *m = file->private_data; |
1da177e4 LT |
159 | size_t copied = 0; |
160 | loff_t pos; | |
161 | size_t n; | |
162 | void *p; | |
163 | int err = 0; | |
164 | ||
0ac1759a | 165 | mutex_lock(&m->lock); |
8f19d472 | 166 | |
7904ac84 EC |
167 | /* |
168 | * seq_file->op->..m_start/m_stop/m_next may do special actions | |
169 | * or optimisations based on the file->f_version, so we want to | |
170 | * pass the file->f_version to those methods. | |
171 | * | |
172 | * seq_file->version is just copy of f_version, and seq_file | |
173 | * methods can treat it simply as file version. | |
174 | * It is copied in first and copied out after all operations. | |
175 | * It is convenient to have it as part of structure to avoid the | |
176 | * need of passing another argument to all the seq_file methods. | |
177 | */ | |
178 | m->version = file->f_version; | |
179 | ||
e522751d TM |
180 | /* |
181 | * if request is to read from zero offset, reset iterator to first | |
182 | * record as it might have been already advanced by previous requests | |
183 | */ | |
cf5eebae | 184 | if (*ppos == 0) { |
e522751d | 185 | m->index = 0; |
cf5eebae MS |
186 | m->version = 0; |
187 | m->count = 0; | |
188 | } | |
e522751d | 189 | |
8f19d472 EB |
190 | /* Don't assume *ppos is where we left it */ |
191 | if (unlikely(*ppos != m->read_pos)) { | |
8f19d472 EB |
192 | while ((err = traverse(m, *ppos)) == -EAGAIN) |
193 | ; | |
194 | if (err) { | |
195 | /* With prejudice... */ | |
196 | m->read_pos = 0; | |
197 | m->version = 0; | |
198 | m->index = 0; | |
199 | m->count = 0; | |
200 | goto Done; | |
7904ac84 EC |
201 | } else { |
202 | m->read_pos = *ppos; | |
8f19d472 EB |
203 | } |
204 | } | |
205 | ||
1da177e4 LT |
206 | /* grab buffer if we didn't have one */ |
207 | if (!m->buf) { | |
058504ed | 208 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
1da177e4 LT |
209 | if (!m->buf) |
210 | goto Enomem; | |
211 | } | |
212 | /* if not empty - flush it first */ | |
213 | if (m->count) { | |
214 | n = min(m->count, size); | |
215 | err = copy_to_user(buf, m->buf + m->from, n); | |
216 | if (err) | |
217 | goto Efault; | |
218 | m->count -= n; | |
219 | m->from += n; | |
220 | size -= n; | |
221 | buf += n; | |
222 | copied += n; | |
088bf2ff VN |
223 | if (!m->count) { |
224 | m->from = 0; | |
1da177e4 | 225 | m->index++; |
088bf2ff | 226 | } |
1da177e4 LT |
227 | if (!size) |
228 | goto Done; | |
229 | } | |
230 | /* we need at least one record in buffer */ | |
4cdfe84b AV |
231 | pos = m->index; |
232 | p = m->op->start(m, &pos); | |
1da177e4 | 233 | while (1) { |
1da177e4 LT |
234 | err = PTR_ERR(p); |
235 | if (!p || IS_ERR(p)) | |
236 | break; | |
237 | err = m->op->show(m, p); | |
521b5d0c | 238 | if (err < 0) |
1da177e4 | 239 | break; |
521b5d0c AV |
240 | if (unlikely(err)) |
241 | m->count = 0; | |
4cdfe84b AV |
242 | if (unlikely(!m->count)) { |
243 | p = m->op->next(m, p, &pos); | |
244 | m->index = pos; | |
245 | continue; | |
246 | } | |
1da177e4 LT |
247 | if (m->count < m->size) |
248 | goto Fill; | |
249 | m->op->stop(m, p); | |
058504ed | 250 | kvfree(m->buf); |
801a7605 | 251 | m->count = 0; |
058504ed | 252 | m->buf = seq_buf_alloc(m->size <<= 1); |
1da177e4 LT |
253 | if (!m->buf) |
254 | goto Enomem; | |
1da177e4 | 255 | m->version = 0; |
4cdfe84b AV |
256 | pos = m->index; |
257 | p = m->op->start(m, &pos); | |
1da177e4 LT |
258 | } |
259 | m->op->stop(m, p); | |
260 | m->count = 0; | |
261 | goto Done; | |
262 | Fill: | |
263 | /* they want more? let's try to get some more */ | |
264 | while (m->count < size) { | |
265 | size_t offs = m->count; | |
266 | loff_t next = pos; | |
267 | p = m->op->next(m, p, &next); | |
268 | if (!p || IS_ERR(p)) { | |
269 | err = PTR_ERR(p); | |
270 | break; | |
271 | } | |
272 | err = m->op->show(m, p); | |
1f33c41c | 273 | if (seq_has_overflowed(m) || err) { |
1da177e4 | 274 | m->count = offs; |
521b5d0c AV |
275 | if (likely(err <= 0)) |
276 | break; | |
1da177e4 LT |
277 | } |
278 | pos = next; | |
279 | } | |
280 | m->op->stop(m, p); | |
281 | n = min(m->count, size); | |
282 | err = copy_to_user(buf, m->buf, n); | |
283 | if (err) | |
284 | goto Efault; | |
285 | copied += n; | |
286 | m->count -= n; | |
287 | if (m->count) | |
288 | m->from = n; | |
289 | else | |
290 | pos++; | |
291 | m->index = pos; | |
292 | Done: | |
293 | if (!copied) | |
294 | copied = err; | |
8f19d472 | 295 | else { |
1da177e4 | 296 | *ppos += copied; |
8f19d472 EB |
297 | m->read_pos += copied; |
298 | } | |
1da177e4 | 299 | file->f_version = m->version; |
0ac1759a | 300 | mutex_unlock(&m->lock); |
1da177e4 LT |
301 | return copied; |
302 | Enomem: | |
303 | err = -ENOMEM; | |
304 | goto Done; | |
305 | Efault: | |
306 | err = -EFAULT; | |
307 | goto Done; | |
308 | } | |
309 | EXPORT_SYMBOL(seq_read); | |
310 | ||
1da177e4 LT |
311 | /** |
312 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
313 | * @file: the file in question |
314 | * @offset: new position | |
254adaa4 | 315 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
316 | * |
317 | * Ready-made ->f_op->llseek() | |
318 | */ | |
965c8e59 | 319 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 320 | { |
8209e2f4 | 321 | struct seq_file *m = file->private_data; |
16abef0e | 322 | loff_t retval = -EINVAL; |
1da177e4 | 323 | |
0ac1759a | 324 | mutex_lock(&m->lock); |
1da177e4 | 325 | m->version = file->f_version; |
965c8e59 | 326 | switch (whence) { |
5e62adef AM |
327 | case SEEK_CUR: |
328 | offset += file->f_pos; | |
329 | case SEEK_SET: | |
330 | if (offset < 0) | |
331 | break; | |
332 | retval = offset; | |
333 | if (offset != m->read_pos) { | |
334 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
335 | ; | |
336 | if (retval) { | |
337 | /* with extreme prejudice... */ | |
338 | file->f_pos = 0; | |
339 | m->read_pos = 0; | |
340 | m->version = 0; | |
341 | m->index = 0; | |
342 | m->count = 0; | |
343 | } else { | |
344 | m->read_pos = offset; | |
345 | retval = file->f_pos = offset; | |
1da177e4 | 346 | } |
05e16745 GZ |
347 | } else { |
348 | file->f_pos = offset; | |
5e62adef | 349 | } |
1da177e4 | 350 | } |
1da177e4 | 351 | file->f_version = m->version; |
00c5746d | 352 | mutex_unlock(&m->lock); |
1da177e4 LT |
353 | return retval; |
354 | } | |
355 | EXPORT_SYMBOL(seq_lseek); | |
356 | ||
357 | /** | |
358 | * seq_release - free the structures associated with sequential file. | |
359 | * @file: file in question | |
6131ffaa | 360 | * @inode: its inode |
1da177e4 LT |
361 | * |
362 | * Frees the structures associated with sequential file; can be used | |
363 | * as ->f_op->release() if you don't have private data to destroy. | |
364 | */ | |
365 | int seq_release(struct inode *inode, struct file *file) | |
366 | { | |
8209e2f4 | 367 | struct seq_file *m = file->private_data; |
058504ed | 368 | kvfree(m->buf); |
1da177e4 LT |
369 | kfree(m); |
370 | return 0; | |
371 | } | |
372 | EXPORT_SYMBOL(seq_release); | |
373 | ||
374 | /** | |
375 | * seq_escape - print string into buffer, escaping some characters | |
376 | * @m: target buffer | |
377 | * @s: string | |
378 | * @esc: set of characters that need escaping | |
379 | * | |
380 | * Puts string into buffer, replacing each occurrence of character from | |
6798a8ca JP |
381 | * @esc with usual octal escape. |
382 | * Use seq_has_overflowed() to check for errors. | |
1da177e4 | 383 | */ |
6798a8ca | 384 | void seq_escape(struct seq_file *m, const char *s, const char *esc) |
1da177e4 | 385 | { |
25c6bb76 AS |
386 | char *buf; |
387 | size_t size = seq_get_buf(m, &buf); | |
388 | int ret; | |
1da177e4 | 389 | |
25c6bb76 AS |
390 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); |
391 | seq_commit(m, ret < size ? ret : -1); | |
1da177e4 LT |
392 | } |
393 | EXPORT_SYMBOL(seq_escape); | |
394 | ||
6798a8ca | 395 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 396 | { |
1da177e4 LT |
397 | int len; |
398 | ||
399 | if (m->count < m->size) { | |
1da177e4 | 400 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
401 | if (m->count + len < m->size) { |
402 | m->count += len; | |
6798a8ca | 403 | return; |
1da177e4 LT |
404 | } |
405 | } | |
e075f591 | 406 | seq_set_overflow(m); |
1da177e4 | 407 | } |
a4808147 SW |
408 | EXPORT_SYMBOL(seq_vprintf); |
409 | ||
6798a8ca | 410 | void seq_printf(struct seq_file *m, const char *f, ...) |
a4808147 | 411 | { |
a4808147 SW |
412 | va_list args; |
413 | ||
414 | va_start(args, f); | |
6798a8ca | 415 | seq_vprintf(m, f, args); |
a4808147 | 416 | va_end(args); |
a4808147 | 417 | } |
1da177e4 LT |
418 | EXPORT_SYMBOL(seq_printf); |
419 | ||
74e2f334 | 420 | /** |
958086d1 TE |
421 | * mangle_path - mangle and copy path to buffer beginning |
422 | * @s: buffer start | |
423 | * @p: beginning of path in above buffer | |
424 | * @esc: set of characters that need escaping | |
74e2f334 TE |
425 | * |
426 | * Copy the path from @p to @s, replacing each occurrence of character from | |
427 | * @esc with usual octal escape. | |
428 | * Returns pointer past last written character in @s, or NULL in case of | |
429 | * failure. | |
430 | */ | |
8c9379e9 | 431 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
432 | { |
433 | while (s <= p) { | |
434 | char c = *p++; | |
435 | if (!c) { | |
436 | return s; | |
437 | } else if (!strchr(esc, c)) { | |
438 | *s++ = c; | |
439 | } else if (s + 4 > p) { | |
440 | break; | |
441 | } else { | |
442 | *s++ = '\\'; | |
443 | *s++ = '0' + ((c & 0300) >> 6); | |
444 | *s++ = '0' + ((c & 070) >> 3); | |
445 | *s++ = '0' + (c & 07); | |
446 | } | |
447 | } | |
448 | return NULL; | |
449 | } | |
604094f4 | 450 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 451 | |
52afeefb AV |
452 | /** |
453 | * seq_path - seq_file interface to print a pathname | |
454 | * @m: the seq_file handle | |
455 | * @path: the struct path to print | |
456 | * @esc: set of characters to escape in the output | |
457 | * | |
458 | * return the absolute path of 'path', as represented by the | |
459 | * dentry / mnt pair in the path parameter. | |
6092d048 | 460 | */ |
8c9379e9 | 461 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 462 | { |
f8439806 MS |
463 | char *buf; |
464 | size_t size = seq_get_buf(m, &buf); | |
465 | int res = -1; | |
466 | ||
467 | if (size) { | |
468 | char *p = d_path(path, buf, size); | |
1da177e4 | 469 | if (!IS_ERR(p)) { |
f8439806 MS |
470 | char *end = mangle_path(buf, p, esc); |
471 | if (end) | |
472 | res = end - buf; | |
1da177e4 LT |
473 | } |
474 | } | |
f8439806 MS |
475 | seq_commit(m, res); |
476 | ||
477 | return res; | |
1da177e4 LT |
478 | } |
479 | EXPORT_SYMBOL(seq_path); | |
480 | ||
2726d566 MS |
481 | /** |
482 | * seq_file_path - seq_file interface to print a pathname of a file | |
483 | * @m: the seq_file handle | |
484 | * @file: the struct file to print | |
485 | * @esc: set of characters to escape in the output | |
486 | * | |
487 | * return the absolute path to the file. | |
488 | */ | |
489 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
490 | { | |
491 | return seq_path(m, &file->f_path, esc); | |
492 | } | |
493 | EXPORT_SYMBOL(seq_file_path); | |
494 | ||
9d1bc601 MS |
495 | /* |
496 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 497 | */ |
8c9379e9 AV |
498 | int seq_path_root(struct seq_file *m, const struct path *path, |
499 | const struct path *root, const char *esc) | |
9d1bc601 | 500 | { |
f8439806 MS |
501 | char *buf; |
502 | size_t size = seq_get_buf(m, &buf); | |
503 | int res = -ENAMETOOLONG; | |
504 | ||
505 | if (size) { | |
9d1bc601 MS |
506 | char *p; |
507 | ||
f8439806 | 508 | p = __d_path(path, root, buf, size); |
02125a82 AV |
509 | if (!p) |
510 | return SEQ_SKIP; | |
f8439806 | 511 | res = PTR_ERR(p); |
9d1bc601 | 512 | if (!IS_ERR(p)) { |
f8439806 MS |
513 | char *end = mangle_path(buf, p, esc); |
514 | if (end) | |
515 | res = end - buf; | |
516 | else | |
517 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
518 | } |
519 | } | |
f8439806 MS |
520 | seq_commit(m, res); |
521 | ||
02125a82 | 522 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
523 | } |
524 | ||
6092d048 RP |
525 | /* |
526 | * returns the path of the 'dentry' from the root of its filesystem. | |
527 | */ | |
8c9379e9 | 528 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 529 | { |
f8439806 MS |
530 | char *buf; |
531 | size_t size = seq_get_buf(m, &buf); | |
532 | int res = -1; | |
533 | ||
534 | if (size) { | |
535 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 536 | if (!IS_ERR(p)) { |
f8439806 MS |
537 | char *end = mangle_path(buf, p, esc); |
538 | if (end) | |
539 | res = end - buf; | |
6092d048 RP |
540 | } |
541 | } | |
f8439806 MS |
542 | seq_commit(m, res); |
543 | ||
544 | return res; | |
6092d048 | 545 | } |
c8d3fe02 | 546 | EXPORT_SYMBOL(seq_dentry); |
6092d048 | 547 | |
1da177e4 LT |
548 | static void *single_start(struct seq_file *p, loff_t *pos) |
549 | { | |
550 | return NULL + (*pos == 0); | |
551 | } | |
552 | ||
553 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
554 | { | |
555 | ++*pos; | |
556 | return NULL; | |
557 | } | |
558 | ||
559 | static void single_stop(struct seq_file *p, void *v) | |
560 | { | |
561 | } | |
562 | ||
563 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
564 | void *data) | |
565 | { | |
566 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL); | |
567 | int res = -ENOMEM; | |
568 | ||
569 | if (op) { | |
570 | op->start = single_start; | |
571 | op->next = single_next; | |
572 | op->stop = single_stop; | |
573 | op->show = show; | |
574 | res = seq_open(file, op); | |
575 | if (!res) | |
576 | ((struct seq_file *)file->private_data)->private = data; | |
577 | else | |
578 | kfree(op); | |
579 | } | |
580 | return res; | |
581 | } | |
582 | EXPORT_SYMBOL(single_open); | |
583 | ||
2043f495 AV |
584 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
585 | void *data, size_t size) | |
586 | { | |
058504ed | 587 | char *buf = seq_buf_alloc(size); |
2043f495 AV |
588 | int ret; |
589 | if (!buf) | |
590 | return -ENOMEM; | |
591 | ret = single_open(file, show, data); | |
592 | if (ret) { | |
058504ed | 593 | kvfree(buf); |
2043f495 AV |
594 | return ret; |
595 | } | |
596 | ((struct seq_file *)file->private_data)->buf = buf; | |
597 | ((struct seq_file *)file->private_data)->size = size; | |
598 | return 0; | |
599 | } | |
600 | EXPORT_SYMBOL(single_open_size); | |
601 | ||
1da177e4 LT |
602 | int single_release(struct inode *inode, struct file *file) |
603 | { | |
15ad7cdc | 604 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
605 | int res = seq_release(inode, file); |
606 | kfree(op); | |
607 | return res; | |
608 | } | |
609 | EXPORT_SYMBOL(single_release); | |
610 | ||
611 | int seq_release_private(struct inode *inode, struct file *file) | |
612 | { | |
613 | struct seq_file *seq = file->private_data; | |
614 | ||
615 | kfree(seq->private); | |
616 | seq->private = NULL; | |
617 | return seq_release(inode, file); | |
618 | } | |
619 | EXPORT_SYMBOL(seq_release_private); | |
620 | ||
39699037 PE |
621 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
622 | int psize) | |
623 | { | |
624 | int rc; | |
625 | void *private; | |
626 | struct seq_file *seq; | |
627 | ||
628 | private = kzalloc(psize, GFP_KERNEL); | |
629 | if (private == NULL) | |
630 | goto out; | |
631 | ||
632 | rc = seq_open(f, ops); | |
633 | if (rc < 0) | |
634 | goto out_free; | |
635 | ||
636 | seq = f->private_data; | |
637 | seq->private = private; | |
638 | return private; | |
639 | ||
640 | out_free: | |
641 | kfree(private); | |
642 | out: | |
643 | return NULL; | |
644 | } | |
645 | EXPORT_SYMBOL(__seq_open_private); | |
646 | ||
647 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
648 | int psize) | |
649 | { | |
650 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
651 | } | |
652 | EXPORT_SYMBOL(seq_open_private); | |
653 | ||
6798a8ca | 654 | void seq_putc(struct seq_file *m, char c) |
1da177e4 | 655 | { |
6798a8ca JP |
656 | if (m->count >= m->size) |
657 | return; | |
658 | ||
659 | m->buf[m->count++] = c; | |
1da177e4 LT |
660 | } |
661 | EXPORT_SYMBOL(seq_putc); | |
662 | ||
6798a8ca | 663 | void seq_puts(struct seq_file *m, const char *s) |
1da177e4 LT |
664 | { |
665 | int len = strlen(s); | |
6798a8ca JP |
666 | |
667 | if (m->count + len >= m->size) { | |
668 | seq_set_overflow(m); | |
669 | return; | |
1da177e4 | 670 | } |
6798a8ca JP |
671 | memcpy(m->buf + m->count, s, len); |
672 | m->count += len; | |
1da177e4 LT |
673 | } |
674 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 675 | |
1ac101a5 KH |
676 | /* |
677 | * A helper routine for putting decimal numbers without rich format of printf(). | |
678 | * only 'unsigned long long' is supported. | |
75ba1d07 | 679 | * This routine will put strlen(delimiter) + number into seq_file. |
1ac101a5 KH |
680 | * This routine is very quick when you show lots of numbers. |
681 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
682 | */ | |
75ba1d07 | 683 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, |
6798a8ca | 684 | unsigned long long num) |
1ac101a5 KH |
685 | { |
686 | int len; | |
687 | ||
688 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
689 | goto overflow; | |
690 | ||
75ba1d07 JP |
691 | len = strlen(delimiter); |
692 | if (m->count + len >= m->size) | |
693 | goto overflow; | |
694 | ||
695 | memcpy(m->buf + m->count, delimiter, len); | |
696 | m->count += len; | |
697 | ||
698 | if (m->count + 1 >= m->size) | |
699 | goto overflow; | |
1ac101a5 KH |
700 | |
701 | if (num < 10) { | |
702 | m->buf[m->count++] = num + '0'; | |
6798a8ca | 703 | return; |
1ac101a5 KH |
704 | } |
705 | ||
706 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
707 | if (!len) | |
708 | goto overflow; | |
75ba1d07 | 709 | |
1ac101a5 | 710 | m->count += len; |
6798a8ca JP |
711 | return; |
712 | ||
1ac101a5 | 713 | overflow: |
e075f591 | 714 | seq_set_overflow(m); |
1ac101a5 KH |
715 | } |
716 | EXPORT_SYMBOL(seq_put_decimal_ull); | |
717 | ||
75ba1d07 | 718 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
bda7bad6 | 719 | { |
75ba1d07 JP |
720 | int len; |
721 | ||
722 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ | |
723 | goto overflow; | |
724 | ||
725 | len = strlen(delimiter); | |
726 | if (m->count + len >= m->size) | |
727 | goto overflow; | |
728 | ||
729 | memcpy(m->buf + m->count, delimiter, len); | |
730 | m->count += len; | |
731 | ||
732 | if (m->count + 2 >= m->size) | |
733 | goto overflow; | |
734 | ||
bda7bad6 | 735 | if (num < 0) { |
75ba1d07 | 736 | m->buf[m->count++] = '-'; |
bda7bad6 | 737 | num = -num; |
bda7bad6 | 738 | } |
75ba1d07 JP |
739 | |
740 | if (num < 10) { | |
741 | m->buf[m->count++] = num + '0'; | |
742 | return; | |
743 | } | |
744 | ||
745 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
746 | if (!len) | |
747 | goto overflow; | |
748 | ||
749 | m->count += len; | |
750 | return; | |
751 | ||
752 | overflow: | |
753 | seq_set_overflow(m); | |
bda7bad6 KH |
754 | } |
755 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
756 | ||
0b923606 PO |
757 | /** |
758 | * seq_write - write arbitrary data to buffer | |
759 | * @seq: seq_file identifying the buffer to which data should be written | |
760 | * @data: data address | |
761 | * @len: number of bytes | |
762 | * | |
763 | * Return 0 on success, non-zero otherwise. | |
764 | */ | |
765 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
766 | { | |
767 | if (seq->count + len < seq->size) { | |
768 | memcpy(seq->buf + seq->count, data, len); | |
769 | seq->count += len; | |
770 | return 0; | |
771 | } | |
e075f591 | 772 | seq_set_overflow(seq); |
0b923606 PO |
773 | return -1; |
774 | } | |
775 | EXPORT_SYMBOL(seq_write); | |
776 | ||
839cc2a9 TH |
777 | /** |
778 | * seq_pad - write padding spaces to buffer | |
779 | * @m: seq_file identifying the buffer to which data should be written | |
780 | * @c: the byte to append after padding if non-zero | |
781 | */ | |
782 | void seq_pad(struct seq_file *m, char c) | |
783 | { | |
784 | int size = m->pad_until - m->count; | |
785 | if (size > 0) | |
786 | seq_printf(m, "%*s", size, ""); | |
787 | if (c) | |
788 | seq_putc(m, c); | |
789 | } | |
790 | EXPORT_SYMBOL(seq_pad); | |
791 | ||
37607102 AS |
792 | /* A complete analogue of print_hex_dump() */ |
793 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
794 | int rowsize, int groupsize, const void *buf, size_t len, | |
795 | bool ascii) | |
796 | { | |
797 | const u8 *ptr = buf; | |
798 | int i, linelen, remaining = len; | |
8b91a318 AS |
799 | char *buffer; |
800 | size_t size; | |
37607102 AS |
801 | int ret; |
802 | ||
803 | if (rowsize != 16 && rowsize != 32) | |
804 | rowsize = 16; | |
805 | ||
806 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
807 | linelen = min(remaining, rowsize); | |
808 | remaining -= rowsize; | |
809 | ||
810 | switch (prefix_type) { | |
811 | case DUMP_PREFIX_ADDRESS: | |
812 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
813 | break; | |
814 | case DUMP_PREFIX_OFFSET: | |
815 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
816 | break; | |
817 | default: | |
818 | seq_printf(m, "%s", prefix_str); | |
819 | break; | |
820 | } | |
821 | ||
8b91a318 | 822 | size = seq_get_buf(m, &buffer); |
37607102 | 823 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
8b91a318 AS |
824 | buffer, size, ascii); |
825 | seq_commit(m, ret < size ? ret : -1); | |
826 | ||
827 | seq_putc(m, '\n'); | |
37607102 AS |
828 | } |
829 | } | |
830 | EXPORT_SYMBOL(seq_hex_dump); | |
831 | ||
bcf67e16 PE |
832 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
833 | { | |
834 | struct list_head *lh; | |
835 | ||
836 | list_for_each(lh, head) | |
837 | if (pos-- == 0) | |
838 | return lh; | |
839 | ||
840 | return NULL; | |
841 | } | |
bcf67e16 PE |
842 | EXPORT_SYMBOL(seq_list_start); |
843 | ||
844 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
845 | { | |
846 | if (!pos) | |
847 | return head; | |
848 | ||
849 | return seq_list_start(head, pos - 1); | |
850 | } | |
bcf67e16 PE |
851 | EXPORT_SYMBOL(seq_list_start_head); |
852 | ||
853 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
854 | { | |
855 | struct list_head *lh; | |
856 | ||
857 | lh = ((struct list_head *)v)->next; | |
858 | ++*ppos; | |
859 | return lh == head ? NULL : lh; | |
860 | } | |
bcf67e16 | 861 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
862 | |
863 | /** | |
864 | * seq_hlist_start - start an iteration of a hlist | |
865 | * @head: the head of the hlist | |
866 | * @pos: the start position of the sequence | |
867 | * | |
868 | * Called at seq_file->op->start(). | |
869 | */ | |
870 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
871 | { | |
872 | struct hlist_node *node; | |
873 | ||
874 | hlist_for_each(node, head) | |
875 | if (pos-- == 0) | |
876 | return node; | |
877 | return NULL; | |
878 | } | |
879 | EXPORT_SYMBOL(seq_hlist_start); | |
880 | ||
881 | /** | |
882 | * seq_hlist_start_head - start an iteration of a hlist | |
883 | * @head: the head of the hlist | |
884 | * @pos: the start position of the sequence | |
885 | * | |
886 | * Called at seq_file->op->start(). Call this function if you want to | |
887 | * print a header at the top of the output. | |
888 | */ | |
889 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
890 | { | |
891 | if (!pos) | |
892 | return SEQ_START_TOKEN; | |
893 | ||
894 | return seq_hlist_start(head, pos - 1); | |
895 | } | |
896 | EXPORT_SYMBOL(seq_hlist_start_head); | |
897 | ||
898 | /** | |
899 | * seq_hlist_next - move to the next position of the hlist | |
900 | * @v: the current iterator | |
901 | * @head: the head of the hlist | |
138860b9 | 902 | * @ppos: the current position |
66655de6 LZ |
903 | * |
904 | * Called at seq_file->op->next(). | |
905 | */ | |
906 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
907 | loff_t *ppos) | |
908 | { | |
909 | struct hlist_node *node = v; | |
910 | ||
911 | ++*ppos; | |
912 | if (v == SEQ_START_TOKEN) | |
913 | return head->first; | |
914 | else | |
915 | return node->next; | |
916 | } | |
917 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 918 | |
919 | /** | |
920 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
921 | * @head: the head of the hlist | |
922 | * @pos: the start position of the sequence | |
923 | * | |
924 | * Called at seq_file->op->start(). | |
925 | * | |
926 | * This list-traversal primitive may safely run concurrently with | |
927 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
928 | * as long as the traversal is guarded by rcu_read_lock(). | |
929 | */ | |
930 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
931 | loff_t pos) | |
932 | { | |
933 | struct hlist_node *node; | |
934 | ||
935 | __hlist_for_each_rcu(node, head) | |
936 | if (pos-- == 0) | |
937 | return node; | |
938 | return NULL; | |
939 | } | |
940 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
941 | ||
942 | /** | |
943 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
944 | * @head: the head of the hlist | |
945 | * @pos: the start position of the sequence | |
946 | * | |
947 | * Called at seq_file->op->start(). Call this function if you want to | |
948 | * print a header at the top of the output. | |
949 | * | |
950 | * This list-traversal primitive may safely run concurrently with | |
951 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
952 | * as long as the traversal is guarded by rcu_read_lock(). | |
953 | */ | |
954 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
955 | loff_t pos) | |
956 | { | |
957 | if (!pos) | |
958 | return SEQ_START_TOKEN; | |
959 | ||
960 | return seq_hlist_start_rcu(head, pos - 1); | |
961 | } | |
962 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
963 | ||
964 | /** | |
965 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
966 | * @v: the current iterator | |
967 | * @head: the head of the hlist | |
138860b9 | 968 | * @ppos: the current position |
1cc52327 | 969 | * |
970 | * Called at seq_file->op->next(). | |
971 | * | |
972 | * This list-traversal primitive may safely run concurrently with | |
973 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
974 | * as long as the traversal is guarded by rcu_read_lock(). | |
975 | */ | |
976 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
977 | struct hlist_head *head, | |
978 | loff_t *ppos) | |
979 | { | |
980 | struct hlist_node *node = v; | |
981 | ||
982 | ++*ppos; | |
983 | if (v == SEQ_START_TOKEN) | |
984 | return rcu_dereference(head->first); | |
985 | else | |
986 | return rcu_dereference(node->next); | |
987 | } | |
988 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
0bc77381 JL |
989 | |
990 | /** | |
991 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array | |
992 | * @head: pointer to percpu array of struct hlist_heads | |
993 | * @cpu: pointer to cpu "cursor" | |
994 | * @pos: start position of sequence | |
995 | * | |
996 | * Called at seq_file->op->start(). | |
997 | */ | |
998 | struct hlist_node * | |
999 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
1000 | { | |
1001 | struct hlist_node *node; | |
1002 | ||
1003 | for_each_possible_cpu(*cpu) { | |
1004 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
1005 | if (pos-- == 0) | |
1006 | return node; | |
1007 | } | |
1008 | } | |
1009 | return NULL; | |
1010 | } | |
1011 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
1012 | ||
1013 | /** | |
1014 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1015 | * @v: pointer to current hlist_node | |
1016 | * @head: pointer to percpu array of struct hlist_heads | |
1017 | * @cpu: pointer to cpu "cursor" | |
1018 | * @pos: start position of sequence | |
1019 | * | |
1020 | * Called at seq_file->op->next(). | |
1021 | */ | |
1022 | struct hlist_node * | |
1023 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1024 | int *cpu, loff_t *pos) | |
1025 | { | |
1026 | struct hlist_node *node = v; | |
1027 | ||
1028 | ++*pos; | |
1029 | ||
1030 | if (node->next) | |
1031 | return node->next; | |
1032 | ||
1033 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1034 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1035 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1036 | ||
1037 | if (!hlist_empty(bucket)) | |
1038 | return bucket->first; | |
1039 | } | |
1040 | return NULL; | |
1041 | } | |
1042 | EXPORT_SYMBOL(seq_hlist_next_percpu); |