blob: 368bfb92b115c0e99ce4c654f6fdecb6ec5a2763
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/vmalloc.h> |
12 | #include <linux/slab.h> |
13 | #include <linux/cred.h> |
14 | #include <linux/mm.h> |
15 | #include <linux/printk.h> |
16 | #include <linux/string_helpers.h> |
17 | |
18 | #include <asm/uaccess.h> |
19 | #include <asm/page.h> |
20 | |
21 | static void seq_set_overflow(struct seq_file *m) |
22 | { |
23 | m->count = m->size; |
24 | } |
25 | |
26 | static void *seq_buf_alloc(unsigned long size) |
27 | { |
28 | void *buf; |
29 | gfp_t gfp = GFP_KERNEL; |
30 | |
31 | /* |
32 | * For high order allocations, use __GFP_NORETRY to avoid oom-killing - |
33 | * it's better to fall back to vmalloc() than to kill things. For small |
34 | * allocations, just use GFP_KERNEL which will oom kill, thus no need |
35 | * for vmalloc fallback. |
36 | */ |
37 | if (size > PAGE_SIZE) |
38 | gfp |= __GFP_NORETRY | __GFP_NOWARN; |
39 | buf = kmalloc(size, gfp); |
40 | if (!buf && size > PAGE_SIZE) |
41 | buf = vmalloc(size); |
42 | return buf; |
43 | } |
44 | |
45 | /** |
46 | * seq_open - initialize sequential file |
47 | * @file: file we initialize |
48 | * @op: method table describing the sequence |
49 | * |
50 | * seq_open() sets @file, associating it with a sequence described |
51 | * by @op. @op->start() sets the iterator up and returns the first |
52 | * element of sequence. @op->stop() shuts it down. @op->next() |
53 | * returns the next element of sequence. @op->show() prints element |
54 | * into the buffer. In case of error ->start() and ->next() return |
55 | * ERR_PTR(error). In the end of sequence they return %NULL. ->show() |
56 | * returns 0 in case of success and negative number in case of error. |
57 | * Returning SEQ_SKIP means "discard this element and move on". |
58 | * Note: seq_open() will allocate a struct seq_file and store its |
59 | * pointer in @file->private_data. This pointer should not be modified. |
60 | */ |
61 | int seq_open(struct file *file, const struct seq_operations *op) |
62 | { |
63 | struct seq_file *p; |
64 | |
65 | WARN_ON(file->private_data); |
66 | |
67 | p = kzalloc(sizeof(*p), GFP_KERNEL); |
68 | if (!p) |
69 | return -ENOMEM; |
70 | |
71 | file->private_data = p; |
72 | |
73 | mutex_init(&p->lock); |
74 | p->op = op; |
75 | |
76 | // No refcounting: the lifetime of 'p' is constrained |
77 | // to the lifetime of the file. |
78 | p->file = file; |
79 | |
80 | /* |
81 | * Wrappers around seq_open(e.g. swaps_open) need to be |
82 | * aware of this. If they set f_version themselves, they |
83 | * should call seq_open first and then set f_version. |
84 | */ |
85 | file->f_version = 0; |
86 | |
87 | /* |
88 | * seq_files support lseek() and pread(). They do not implement |
89 | * write() at all, but we clear FMODE_PWRITE here for historical |
90 | * reasons. |
91 | * |
92 | * If a client of seq_files a) implements file.write() and b) wishes to |
93 | * support pwrite() then that client will need to implement its own |
94 | * file.open() which calls seq_open() and then sets FMODE_PWRITE. |
95 | */ |
96 | file->f_mode &= ~FMODE_PWRITE; |
97 | return 0; |
98 | } |
99 | EXPORT_SYMBOL(seq_open); |
100 | |
101 | static int traverse(struct seq_file *m, loff_t offset) |
102 | { |
103 | loff_t pos = 0, index; |
104 | int error = 0; |
105 | void *p; |
106 | |
107 | m->version = 0; |
108 | index = 0; |
109 | m->count = m->from = 0; |
110 | if (!offset) { |
111 | m->index = index; |
112 | return 0; |
113 | } |
114 | if (!m->buf) { |
115 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
116 | if (!m->buf) |
117 | return -ENOMEM; |
118 | } |
119 | p = m->op->start(m, &index); |
120 | while (p) { |
121 | error = PTR_ERR(p); |
122 | if (IS_ERR(p)) |
123 | break; |
124 | error = m->op->show(m, p); |
125 | if (error < 0) |
126 | break; |
127 | if (unlikely(error)) { |
128 | error = 0; |
129 | m->count = 0; |
130 | } |
131 | if (seq_has_overflowed(m)) |
132 | goto Eoverflow; |
133 | if (pos + m->count > offset) { |
134 | m->from = offset - pos; |
135 | m->count -= m->from; |
136 | m->index = index; |
137 | break; |
138 | } |
139 | pos += m->count; |
140 | m->count = 0; |
141 | if (pos == offset) { |
142 | index++; |
143 | m->index = index; |
144 | break; |
145 | } |
146 | p = m->op->next(m, p, &index); |
147 | } |
148 | m->op->stop(m, p); |
149 | m->index = index; |
150 | return error; |
151 | |
152 | Eoverflow: |
153 | m->op->stop(m, p); |
154 | kvfree(m->buf); |
155 | m->count = 0; |
156 | m->buf = seq_buf_alloc(m->size <<= 1); |
157 | return !m->buf ? -ENOMEM : -EAGAIN; |
158 | } |
159 | |
160 | /** |
161 | * seq_read - ->read() method for sequential files. |
162 | * @file: the file to read from |
163 | * @buf: the buffer to read to |
164 | * @size: the maximum number of bytes to read |
165 | * @ppos: the current position in the file |
166 | * |
167 | * Ready-made ->f_op->read() |
168 | */ |
169 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) |
170 | { |
171 | struct seq_file *m = file->private_data; |
172 | size_t copied = 0; |
173 | loff_t pos; |
174 | size_t n; |
175 | void *p; |
176 | int err = 0; |
177 | |
178 | mutex_lock(&m->lock); |
179 | |
180 | /* |
181 | * seq_file->op->..m_start/m_stop/m_next may do special actions |
182 | * or optimisations based on the file->f_version, so we want to |
183 | * pass the file->f_version to those methods. |
184 | * |
185 | * seq_file->version is just copy of f_version, and seq_file |
186 | * methods can treat it simply as file version. |
187 | * It is copied in first and copied out after all operations. |
188 | * It is convenient to have it as part of structure to avoid the |
189 | * need of passing another argument to all the seq_file methods. |
190 | */ |
191 | m->version = file->f_version; |
192 | |
193 | /* Don't assume *ppos is where we left it */ |
194 | if (unlikely(*ppos != m->read_pos)) { |
195 | while ((err = traverse(m, *ppos)) == -EAGAIN) |
196 | ; |
197 | if (err) { |
198 | /* With prejudice... */ |
199 | m->read_pos = 0; |
200 | m->version = 0; |
201 | m->index = 0; |
202 | m->count = 0; |
203 | goto Done; |
204 | } else { |
205 | m->read_pos = *ppos; |
206 | } |
207 | } |
208 | |
209 | /* grab buffer if we didn't have one */ |
210 | if (!m->buf) { |
211 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
212 | if (!m->buf) |
213 | goto Enomem; |
214 | } |
215 | /* if not empty - flush it first */ |
216 | if (m->count) { |
217 | n = min(m->count, size); |
218 | err = copy_to_user(buf, m->buf + m->from, n); |
219 | if (err) |
220 | goto Efault; |
221 | m->count -= n; |
222 | m->from += n; |
223 | size -= n; |
224 | buf += n; |
225 | copied += n; |
226 | if (!m->count) { |
227 | m->from = 0; |
228 | m->index++; |
229 | } |
230 | if (!size) |
231 | goto Done; |
232 | } |
233 | /* we need at least one record in buffer */ |
234 | pos = m->index; |
235 | p = m->op->start(m, &pos); |
236 | while (1) { |
237 | err = PTR_ERR(p); |
238 | if (!p || IS_ERR(p)) |
239 | break; |
240 | err = m->op->show(m, p); |
241 | if (err < 0) |
242 | break; |
243 | if (unlikely(err)) |
244 | m->count = 0; |
245 | if (unlikely(!m->count)) { |
246 | p = m->op->next(m, p, &pos); |
247 | m->index = pos; |
248 | continue; |
249 | } |
250 | if (m->count < m->size) |
251 | goto Fill; |
252 | m->op->stop(m, p); |
253 | kvfree(m->buf); |
254 | m->count = 0; |
255 | m->buf = seq_buf_alloc(m->size <<= 1); |
256 | if (!m->buf) |
257 | goto Enomem; |
258 | m->version = 0; |
259 | pos = m->index; |
260 | p = m->op->start(m, &pos); |
261 | } |
262 | m->op->stop(m, p); |
263 | m->count = 0; |
264 | goto Done; |
265 | Fill: |
266 | /* they want more? let's try to get some more */ |
267 | while (m->count < size) { |
268 | size_t offs = m->count; |
269 | loff_t next = pos; |
270 | p = m->op->next(m, p, &next); |
271 | if (!p || IS_ERR(p)) { |
272 | err = PTR_ERR(p); |
273 | break; |
274 | } |
275 | err = m->op->show(m, p); |
276 | if (seq_has_overflowed(m) || err) { |
277 | m->count = offs; |
278 | if (likely(err <= 0)) |
279 | break; |
280 | } |
281 | pos = next; |
282 | } |
283 | m->op->stop(m, p); |
284 | n = min(m->count, size); |
285 | err = copy_to_user(buf, m->buf, n); |
286 | if (err) |
287 | goto Efault; |
288 | copied += n; |
289 | m->count -= n; |
290 | if (m->count) |
291 | m->from = n; |
292 | else |
293 | pos++; |
294 | m->index = pos; |
295 | Done: |
296 | if (!copied) |
297 | copied = err; |
298 | else { |
299 | *ppos += copied; |
300 | m->read_pos += copied; |
301 | } |
302 | file->f_version = m->version; |
303 | mutex_unlock(&m->lock); |
304 | return copied; |
305 | Enomem: |
306 | err = -ENOMEM; |
307 | goto Done; |
308 | Efault: |
309 | err = -EFAULT; |
310 | goto Done; |
311 | } |
312 | EXPORT_SYMBOL(seq_read); |
313 | |
314 | /** |
315 | * seq_lseek - ->llseek() method for sequential files. |
316 | * @file: the file in question |
317 | * @offset: new position |
318 | * @whence: 0 for absolute, 1 for relative position |
319 | * |
320 | * Ready-made ->f_op->llseek() |
321 | */ |
322 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
323 | { |
324 | struct seq_file *m = file->private_data; |
325 | loff_t retval = -EINVAL; |
326 | |
327 | mutex_lock(&m->lock); |
328 | m->version = file->f_version; |
329 | switch (whence) { |
330 | case SEEK_CUR: |
331 | offset += file->f_pos; |
332 | case SEEK_SET: |
333 | if (offset < 0) |
334 | break; |
335 | retval = offset; |
336 | if (offset != m->read_pos) { |
337 | while ((retval = traverse(m, offset)) == -EAGAIN) |
338 | ; |
339 | if (retval) { |
340 | /* with extreme prejudice... */ |
341 | file->f_pos = 0; |
342 | m->read_pos = 0; |
343 | m->version = 0; |
344 | m->index = 0; |
345 | m->count = 0; |
346 | } else { |
347 | m->read_pos = offset; |
348 | retval = file->f_pos = offset; |
349 | } |
350 | } else { |
351 | file->f_pos = offset; |
352 | } |
353 | } |
354 | file->f_version = m->version; |
355 | mutex_unlock(&m->lock); |
356 | return retval; |
357 | } |
358 | EXPORT_SYMBOL(seq_lseek); |
359 | |
360 | /** |
361 | * seq_release - free the structures associated with sequential file. |
362 | * @file: file in question |
363 | * @inode: its inode |
364 | * |
365 | * Frees the structures associated with sequential file; can be used |
366 | * as ->f_op->release() if you don't have private data to destroy. |
367 | */ |
368 | int seq_release(struct inode *inode, struct file *file) |
369 | { |
370 | struct seq_file *m = file->private_data; |
371 | kvfree(m->buf); |
372 | kfree(m); |
373 | return 0; |
374 | } |
375 | EXPORT_SYMBOL(seq_release); |
376 | |
377 | /** |
378 | * seq_escape - print string into buffer, escaping some characters |
379 | * @m: target buffer |
380 | * @s: string |
381 | * @esc: set of characters that need escaping |
382 | * |
383 | * Puts string into buffer, replacing each occurrence of character from |
384 | * @esc with usual octal escape. |
385 | * Use seq_has_overflowed() to check for errors. |
386 | */ |
387 | void seq_escape(struct seq_file *m, const char *s, const char *esc) |
388 | { |
389 | char *buf; |
390 | size_t size = seq_get_buf(m, &buf); |
391 | int ret; |
392 | |
393 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); |
394 | seq_commit(m, ret < size ? ret : -1); |
395 | } |
396 | EXPORT_SYMBOL(seq_escape); |
397 | |
398 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
399 | { |
400 | int len; |
401 | |
402 | if (m->count < m->size) { |
403 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
404 | if (m->count + len < m->size) { |
405 | m->count += len; |
406 | return; |
407 | } |
408 | } |
409 | seq_set_overflow(m); |
410 | } |
411 | EXPORT_SYMBOL(seq_vprintf); |
412 | |
413 | void seq_printf(struct seq_file *m, const char *f, ...) |
414 | { |
415 | va_list args; |
416 | |
417 | va_start(args, f); |
418 | seq_vprintf(m, f, args); |
419 | va_end(args); |
420 | } |
421 | EXPORT_SYMBOL(seq_printf); |
422 | |
423 | /** |
424 | * mangle_path - mangle and copy path to buffer beginning |
425 | * @s: buffer start |
426 | * @p: beginning of path in above buffer |
427 | * @esc: set of characters that need escaping |
428 | * |
429 | * Copy the path from @p to @s, replacing each occurrence of character from |
430 | * @esc with usual octal escape. |
431 | * Returns pointer past last written character in @s, or NULL in case of |
432 | * failure. |
433 | */ |
434 | char *mangle_path(char *s, const char *p, const char *esc) |
435 | { |
436 | while (s <= p) { |
437 | char c = *p++; |
438 | if (!c) { |
439 | return s; |
440 | } else if (!strchr(esc, c)) { |
441 | *s++ = c; |
442 | } else if (s + 4 > p) { |
443 | break; |
444 | } else { |
445 | *s++ = '\\'; |
446 | *s++ = '0' + ((c & 0300) >> 6); |
447 | *s++ = '0' + ((c & 070) >> 3); |
448 | *s++ = '0' + (c & 07); |
449 | } |
450 | } |
451 | return NULL; |
452 | } |
453 | EXPORT_SYMBOL(mangle_path); |
454 | |
455 | /** |
456 | * seq_path - seq_file interface to print a pathname |
457 | * @m: the seq_file handle |
458 | * @path: the struct path to print |
459 | * @esc: set of characters to escape in the output |
460 | * |
461 | * return the absolute path of 'path', as represented by the |
462 | * dentry / mnt pair in the path parameter. |
463 | */ |
464 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
465 | { |
466 | char *buf; |
467 | size_t size = seq_get_buf(m, &buf); |
468 | int res = -1; |
469 | |
470 | if (size) { |
471 | char *p = d_path(path, buf, size); |
472 | if (!IS_ERR(p)) { |
473 | char *end = mangle_path(buf, p, esc); |
474 | if (end) |
475 | res = end - buf; |
476 | } |
477 | } |
478 | seq_commit(m, res); |
479 | |
480 | return res; |
481 | } |
482 | EXPORT_SYMBOL(seq_path); |
483 | |
484 | /** |
485 | * seq_file_path - seq_file interface to print a pathname of a file |
486 | * @m: the seq_file handle |
487 | * @file: the struct file to print |
488 | * @esc: set of characters to escape in the output |
489 | * |
490 | * return the absolute path to the file. |
491 | */ |
492 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) |
493 | { |
494 | return seq_path(m, &file->f_path, esc); |
495 | } |
496 | EXPORT_SYMBOL(seq_file_path); |
497 | |
498 | /* |
499 | * Same as seq_path, but relative to supplied root. |
500 | */ |
501 | int seq_path_root(struct seq_file *m, const struct path *path, |
502 | const struct path *root, const char *esc) |
503 | { |
504 | char *buf; |
505 | size_t size = seq_get_buf(m, &buf); |
506 | int res = -ENAMETOOLONG; |
507 | |
508 | if (size) { |
509 | char *p; |
510 | |
511 | p = __d_path(path, root, buf, size); |
512 | if (!p) |
513 | return SEQ_SKIP; |
514 | res = PTR_ERR(p); |
515 | if (!IS_ERR(p)) { |
516 | char *end = mangle_path(buf, p, esc); |
517 | if (end) |
518 | res = end - buf; |
519 | else |
520 | res = -ENAMETOOLONG; |
521 | } |
522 | } |
523 | seq_commit(m, res); |
524 | |
525 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
526 | } |
527 | |
528 | /* |
529 | * returns the path of the 'dentry' from the root of its filesystem. |
530 | */ |
531 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
532 | { |
533 | char *buf; |
534 | size_t size = seq_get_buf(m, &buf); |
535 | int res = -1; |
536 | |
537 | if (size) { |
538 | char *p = dentry_path(dentry, buf, size); |
539 | if (!IS_ERR(p)) { |
540 | char *end = mangle_path(buf, p, esc); |
541 | if (end) |
542 | res = end - buf; |
543 | } |
544 | } |
545 | seq_commit(m, res); |
546 | |
547 | return res; |
548 | } |
549 | EXPORT_SYMBOL(seq_dentry); |
550 | |
551 | static void *single_start(struct seq_file *p, loff_t *pos) |
552 | { |
553 | return NULL + (*pos == 0); |
554 | } |
555 | |
556 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) |
557 | { |
558 | ++*pos; |
559 | return NULL; |
560 | } |
561 | |
562 | static void single_stop(struct seq_file *p, void *v) |
563 | { |
564 | } |
565 | |
566 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), |
567 | void *data) |
568 | { |
569 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL); |
570 | int res = -ENOMEM; |
571 | |
572 | if (op) { |
573 | op->start = single_start; |
574 | op->next = single_next; |
575 | op->stop = single_stop; |
576 | op->show = show; |
577 | res = seq_open(file, op); |
578 | if (!res) |
579 | ((struct seq_file *)file->private_data)->private = data; |
580 | else |
581 | kfree(op); |
582 | } |
583 | return res; |
584 | } |
585 | EXPORT_SYMBOL(single_open); |
586 | |
587 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
588 | void *data, size_t size) |
589 | { |
590 | char *buf = seq_buf_alloc(size); |
591 | int ret; |
592 | if (!buf) |
593 | return -ENOMEM; |
594 | ret = single_open(file, show, data); |
595 | if (ret) { |
596 | kvfree(buf); |
597 | return ret; |
598 | } |
599 | ((struct seq_file *)file->private_data)->buf = buf; |
600 | ((struct seq_file *)file->private_data)->size = size; |
601 | return 0; |
602 | } |
603 | EXPORT_SYMBOL(single_open_size); |
604 | |
605 | int single_release(struct inode *inode, struct file *file) |
606 | { |
607 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
608 | int res = seq_release(inode, file); |
609 | kfree(op); |
610 | return res; |
611 | } |
612 | EXPORT_SYMBOL(single_release); |
613 | |
614 | int seq_release_private(struct inode *inode, struct file *file) |
615 | { |
616 | struct seq_file *seq = file->private_data; |
617 | |
618 | kfree(seq->private); |
619 | seq->private = NULL; |
620 | return seq_release(inode, file); |
621 | } |
622 | EXPORT_SYMBOL(seq_release_private); |
623 | |
624 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
625 | int psize) |
626 | { |
627 | int rc; |
628 | void *private; |
629 | struct seq_file *seq; |
630 | |
631 | private = kzalloc(psize, GFP_KERNEL); |
632 | if (private == NULL) |
633 | goto out; |
634 | |
635 | rc = seq_open(f, ops); |
636 | if (rc < 0) |
637 | goto out_free; |
638 | |
639 | seq = f->private_data; |
640 | seq->private = private; |
641 | return private; |
642 | |
643 | out_free: |
644 | kfree(private); |
645 | out: |
646 | return NULL; |
647 | } |
648 | EXPORT_SYMBOL(__seq_open_private); |
649 | |
650 | int seq_open_private(struct file *filp, const struct seq_operations *ops, |
651 | int psize) |
652 | { |
653 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; |
654 | } |
655 | EXPORT_SYMBOL(seq_open_private); |
656 | |
657 | void seq_putc(struct seq_file *m, char c) |
658 | { |
659 | if (m->count >= m->size) |
660 | return; |
661 | |
662 | m->buf[m->count++] = c; |
663 | } |
664 | EXPORT_SYMBOL(seq_putc); |
665 | |
666 | void seq_puts(struct seq_file *m, const char *s) |
667 | { |
668 | int len = strlen(s); |
669 | |
670 | if (m->count + len >= m->size) { |
671 | seq_set_overflow(m); |
672 | return; |
673 | } |
674 | memcpy(m->buf + m->count, s, len); |
675 | m->count += len; |
676 | } |
677 | EXPORT_SYMBOL(seq_puts); |
678 | |
679 | /* |
680 | * A helper routine for putting decimal numbers without rich format of printf(). |
681 | * only 'unsigned long long' is supported. |
682 | * This routine will put strlen(delimiter) + number into seq_file. |
683 | * This routine is very quick when you show lots of numbers. |
684 | * In usual cases, it will be better to use seq_printf(). It's easier to read. |
685 | */ |
686 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, |
687 | unsigned long long num) |
688 | { |
689 | int len; |
690 | |
691 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ |
692 | goto overflow; |
693 | |
694 | len = strlen(delimiter); |
695 | if (m->count + len >= m->size) |
696 | goto overflow; |
697 | |
698 | memcpy(m->buf + m->count, delimiter, len); |
699 | m->count += len; |
700 | |
701 | if (m->count + 1 >= m->size) |
702 | goto overflow; |
703 | |
704 | if (num < 10) { |
705 | m->buf[m->count++] = num + '0'; |
706 | return; |
707 | } |
708 | |
709 | len = num_to_str(m->buf + m->count, m->size - m->count, num); |
710 | if (!len) |
711 | goto overflow; |
712 | |
713 | m->count += len; |
714 | return; |
715 | |
716 | overflow: |
717 | seq_set_overflow(m); |
718 | } |
719 | EXPORT_SYMBOL(seq_put_decimal_ull); |
720 | |
721 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
722 | { |
723 | int len; |
724 | |
725 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ |
726 | goto overflow; |
727 | |
728 | len = strlen(delimiter); |
729 | if (m->count + len >= m->size) |
730 | goto overflow; |
731 | |
732 | memcpy(m->buf + m->count, delimiter, len); |
733 | m->count += len; |
734 | |
735 | if (m->count + 2 >= m->size) |
736 | goto overflow; |
737 | |
738 | if (num < 0) { |
739 | m->buf[m->count++] = '-'; |
740 | num = -num; |
741 | } |
742 | |
743 | if (num < 10) { |
744 | m->buf[m->count++] = num + '0'; |
745 | return; |
746 | } |
747 | |
748 | len = num_to_str(m->buf + m->count, m->size - m->count, num); |
749 | if (!len) |
750 | goto overflow; |
751 | |
752 | m->count += len; |
753 | return; |
754 | |
755 | overflow: |
756 | seq_set_overflow(m); |
757 | } |
758 | EXPORT_SYMBOL(seq_put_decimal_ll); |
759 | |
760 | /** |
761 | * seq_write - write arbitrary data to buffer |
762 | * @seq: seq_file identifying the buffer to which data should be written |
763 | * @data: data address |
764 | * @len: number of bytes |
765 | * |
766 | * Return 0 on success, non-zero otherwise. |
767 | */ |
768 | int seq_write(struct seq_file *seq, const void *data, size_t len) |
769 | { |
770 | if (seq->count + len < seq->size) { |
771 | memcpy(seq->buf + seq->count, data, len); |
772 | seq->count += len; |
773 | return 0; |
774 | } |
775 | seq_set_overflow(seq); |
776 | return -1; |
777 | } |
778 | EXPORT_SYMBOL(seq_write); |
779 | |
780 | /** |
781 | * seq_pad - write padding spaces to buffer |
782 | * @m: seq_file identifying the buffer to which data should be written |
783 | * @c: the byte to append after padding if non-zero |
784 | */ |
785 | void seq_pad(struct seq_file *m, char c) |
786 | { |
787 | int size = m->pad_until - m->count; |
788 | if (size > 0) |
789 | seq_printf(m, "%*s", size, ""); |
790 | if (c) |
791 | seq_putc(m, c); |
792 | } |
793 | EXPORT_SYMBOL(seq_pad); |
794 | |
795 | /* A complete analogue of print_hex_dump() */ |
796 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, |
797 | int rowsize, int groupsize, const void *buf, size_t len, |
798 | bool ascii) |
799 | { |
800 | const u8 *ptr = buf; |
801 | int i, linelen, remaining = len; |
802 | char *buffer; |
803 | size_t size; |
804 | int ret; |
805 | |
806 | if (rowsize != 16 && rowsize != 32) |
807 | rowsize = 16; |
808 | |
809 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { |
810 | linelen = min(remaining, rowsize); |
811 | remaining -= rowsize; |
812 | |
813 | switch (prefix_type) { |
814 | case DUMP_PREFIX_ADDRESS: |
815 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); |
816 | break; |
817 | case DUMP_PREFIX_OFFSET: |
818 | seq_printf(m, "%s%.8x: ", prefix_str, i); |
819 | break; |
820 | default: |
821 | seq_printf(m, "%s", prefix_str); |
822 | break; |
823 | } |
824 | |
825 | size = seq_get_buf(m, &buffer); |
826 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
827 | buffer, size, ascii); |
828 | seq_commit(m, ret < size ? ret : -1); |
829 | |
830 | seq_putc(m, '\n'); |
831 | } |
832 | } |
833 | EXPORT_SYMBOL(seq_hex_dump); |
834 | |
835 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
836 | { |
837 | struct list_head *lh; |
838 | |
839 | list_for_each(lh, head) |
840 | if (pos-- == 0) |
841 | return lh; |
842 | |
843 | return NULL; |
844 | } |
845 | EXPORT_SYMBOL(seq_list_start); |
846 | |
847 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) |
848 | { |
849 | if (!pos) |
850 | return head; |
851 | |
852 | return seq_list_start(head, pos - 1); |
853 | } |
854 | EXPORT_SYMBOL(seq_list_start_head); |
855 | |
856 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) |
857 | { |
858 | struct list_head *lh; |
859 | |
860 | lh = ((struct list_head *)v)->next; |
861 | ++*ppos; |
862 | return lh == head ? NULL : lh; |
863 | } |
864 | EXPORT_SYMBOL(seq_list_next); |
865 | |
866 | /** |
867 | * seq_hlist_start - start an iteration of a hlist |
868 | * @head: the head of the hlist |
869 | * @pos: the start position of the sequence |
870 | * |
871 | * Called at seq_file->op->start(). |
872 | */ |
873 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) |
874 | { |
875 | struct hlist_node *node; |
876 | |
877 | hlist_for_each(node, head) |
878 | if (pos-- == 0) |
879 | return node; |
880 | return NULL; |
881 | } |
882 | EXPORT_SYMBOL(seq_hlist_start); |
883 | |
884 | /** |
885 | * seq_hlist_start_head - start an iteration of a hlist |
886 | * @head: the head of the hlist |
887 | * @pos: the start position of the sequence |
888 | * |
889 | * Called at seq_file->op->start(). Call this function if you want to |
890 | * print a header at the top of the output. |
891 | */ |
892 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) |
893 | { |
894 | if (!pos) |
895 | return SEQ_START_TOKEN; |
896 | |
897 | return seq_hlist_start(head, pos - 1); |
898 | } |
899 | EXPORT_SYMBOL(seq_hlist_start_head); |
900 | |
901 | /** |
902 | * seq_hlist_next - move to the next position of the hlist |
903 | * @v: the current iterator |
904 | * @head: the head of the hlist |
905 | * @ppos: the current position |
906 | * |
907 | * Called at seq_file->op->next(). |
908 | */ |
909 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, |
910 | loff_t *ppos) |
911 | { |
912 | struct hlist_node *node = v; |
913 | |
914 | ++*ppos; |
915 | if (v == SEQ_START_TOKEN) |
916 | return head->first; |
917 | else |
918 | return node->next; |
919 | } |
920 | EXPORT_SYMBOL(seq_hlist_next); |
921 | |
922 | /** |
923 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU |
924 | * @head: the head of the hlist |
925 | * @pos: the start position of the sequence |
926 | * |
927 | * Called at seq_file->op->start(). |
928 | * |
929 | * This list-traversal primitive may safely run concurrently with |
930 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() |
931 | * as long as the traversal is guarded by rcu_read_lock(). |
932 | */ |
933 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, |
934 | loff_t pos) |
935 | { |
936 | struct hlist_node *node; |
937 | |
938 | __hlist_for_each_rcu(node, head) |
939 | if (pos-- == 0) |
940 | return node; |
941 | return NULL; |
942 | } |
943 | EXPORT_SYMBOL(seq_hlist_start_rcu); |
944 | |
945 | /** |
946 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU |
947 | * @head: the head of the hlist |
948 | * @pos: the start position of the sequence |
949 | * |
950 | * Called at seq_file->op->start(). Call this function if you want to |
951 | * print a header at the top of the output. |
952 | * |
953 | * This list-traversal primitive may safely run concurrently with |
954 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() |
955 | * as long as the traversal is guarded by rcu_read_lock(). |
956 | */ |
957 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, |
958 | loff_t pos) |
959 | { |
960 | if (!pos) |
961 | return SEQ_START_TOKEN; |
962 | |
963 | return seq_hlist_start_rcu(head, pos - 1); |
964 | } |
965 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); |
966 | |
967 | /** |
968 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU |
969 | * @v: the current iterator |
970 | * @head: the head of the hlist |
971 | * @ppos: the current position |
972 | * |
973 | * Called at seq_file->op->next(). |
974 | * |
975 | * This list-traversal primitive may safely run concurrently with |
976 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() |
977 | * as long as the traversal is guarded by rcu_read_lock(). |
978 | */ |
979 | struct hlist_node *seq_hlist_next_rcu(void *v, |
980 | struct hlist_head *head, |
981 | loff_t *ppos) |
982 | { |
983 | struct hlist_node *node = v; |
984 | |
985 | ++*ppos; |
986 | if (v == SEQ_START_TOKEN) |
987 | return rcu_dereference(head->first); |
988 | else |
989 | return rcu_dereference(node->next); |
990 | } |
991 | EXPORT_SYMBOL(seq_hlist_next_rcu); |
992 | |
993 | /** |
994 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array |
995 | * @head: pointer to percpu array of struct hlist_heads |
996 | * @cpu: pointer to cpu "cursor" |
997 | * @pos: start position of sequence |
998 | * |
999 | * Called at seq_file->op->start(). |
1000 | */ |
1001 | struct hlist_node * |
1002 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) |
1003 | { |
1004 | struct hlist_node *node; |
1005 | |
1006 | for_each_possible_cpu(*cpu) { |
1007 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { |
1008 | if (pos-- == 0) |
1009 | return node; |
1010 | } |
1011 | } |
1012 | return NULL; |
1013 | } |
1014 | EXPORT_SYMBOL(seq_hlist_start_percpu); |
1015 | |
1016 | /** |
1017 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array |
1018 | * @v: pointer to current hlist_node |
1019 | * @head: pointer to percpu array of struct hlist_heads |
1020 | * @cpu: pointer to cpu "cursor" |
1021 | * @pos: start position of sequence |
1022 | * |
1023 | * Called at seq_file->op->next(). |
1024 | */ |
1025 | struct hlist_node * |
1026 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, |
1027 | int *cpu, loff_t *pos) |
1028 | { |
1029 | struct hlist_node *node = v; |
1030 | |
1031 | ++*pos; |
1032 | |
1033 | if (node->next) |
1034 | return node->next; |
1035 | |
1036 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; |
1037 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { |
1038 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); |
1039 | |
1040 | if (!hlist_empty(bucket)) |
1041 | return bucket->first; |
1042 | } |
1043 | return NULL; |
1044 | } |
1045 | EXPORT_SYMBOL(seq_hlist_next_percpu); |
1046 |