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