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