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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 | #include <linux/string_helpers.h> | |
17 | ||
18 | #include <linux/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 | /* | |
194 | * if request is to read from zero offset, reset iterator to first | |
195 | * record as it might have been already advanced by previous requests | |
196 | */ | |
197 | if (*ppos == 0) | |
198 | m->index = 0; | |
199 | ||
200 | /* Don't assume *ppos is where we left it */ | |
201 | if (unlikely(*ppos != m->read_pos)) { | |
202 | while ((err = traverse(m, *ppos)) == -EAGAIN) | |
203 | ; | |
204 | if (err) { | |
205 | /* With prejudice... */ | |
206 | m->read_pos = 0; | |
207 | m->version = 0; | |
208 | m->index = 0; | |
209 | m->count = 0; | |
210 | goto Done; | |
211 | } else { | |
212 | m->read_pos = *ppos; | |
213 | } | |
214 | } | |
215 | ||
216 | /* grab buffer if we didn't have one */ | |
217 | if (!m->buf) { | |
218 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); | |
219 | if (!m->buf) | |
220 | goto Enomem; | |
221 | } | |
222 | /* if not empty - flush it first */ | |
223 | if (m->count) { | |
224 | n = min(m->count, size); | |
225 | err = copy_to_user(buf, m->buf + m->from, n); | |
226 | if (err) | |
227 | goto Efault; | |
228 | m->count -= n; | |
229 | m->from += n; | |
230 | size -= n; | |
231 | buf += n; | |
232 | copied += n; | |
233 | if (!m->count) { | |
234 | m->from = 0; | |
235 | m->index++; | |
236 | } | |
237 | if (!size) | |
238 | goto Done; | |
239 | } | |
240 | /* we need at least one record in buffer */ | |
241 | pos = m->index; | |
242 | p = m->op->start(m, &pos); | |
243 | while (1) { | |
244 | err = PTR_ERR(p); | |
245 | if (!p || IS_ERR(p)) | |
246 | break; | |
247 | err = m->op->show(m, p); | |
248 | if (err < 0) | |
249 | break; | |
250 | if (unlikely(err)) | |
251 | m->count = 0; | |
252 | if (unlikely(!m->count)) { | |
253 | p = m->op->next(m, p, &pos); | |
254 | m->index = pos; | |
255 | continue; | |
256 | } | |
257 | if (m->count < m->size) | |
258 | goto Fill; | |
259 | m->op->stop(m, p); | |
260 | kvfree(m->buf); | |
261 | m->count = 0; | |
262 | m->buf = seq_buf_alloc(m->size <<= 1); | |
263 | if (!m->buf) | |
264 | goto Enomem; | |
265 | m->version = 0; | |
266 | pos = m->index; | |
267 | p = m->op->start(m, &pos); | |
268 | } | |
269 | m->op->stop(m, p); | |
270 | m->count = 0; | |
271 | goto Done; | |
272 | Fill: | |
273 | /* they want more? let's try to get some more */ | |
274 | while (m->count < size) { | |
275 | size_t offs = m->count; | |
276 | loff_t next = pos; | |
277 | p = m->op->next(m, p, &next); | |
278 | if (!p || IS_ERR(p)) { | |
279 | err = PTR_ERR(p); | |
280 | break; | |
281 | } | |
282 | err = m->op->show(m, p); | |
283 | if (seq_has_overflowed(m) || err) { | |
284 | m->count = offs; | |
285 | if (likely(err <= 0)) | |
286 | break; | |
287 | } | |
288 | pos = next; | |
289 | } | |
290 | m->op->stop(m, p); | |
291 | n = min(m->count, size); | |
292 | err = copy_to_user(buf, m->buf, n); | |
293 | if (err) | |
294 | goto Efault; | |
295 | copied += n; | |
296 | m->count -= n; | |
297 | if (m->count) | |
298 | m->from = n; | |
299 | else | |
300 | pos++; | |
301 | m->index = pos; | |
302 | Done: | |
303 | if (!copied) | |
304 | copied = err; | |
305 | else { | |
306 | *ppos += copied; | |
307 | m->read_pos += copied; | |
308 | } | |
309 | file->f_version = m->version; | |
310 | mutex_unlock(&m->lock); | |
311 | return copied; | |
312 | Enomem: | |
313 | err = -ENOMEM; | |
314 | goto Done; | |
315 | Efault: | |
316 | err = -EFAULT; | |
317 | goto Done; | |
318 | } | |
319 | EXPORT_SYMBOL(seq_read); | |
320 | ||
321 | /** | |
322 | * seq_lseek - ->llseek() method for sequential files. | |
323 | * @file: the file in question | |
324 | * @offset: new position | |
325 | * @whence: 0 for absolute, 1 for relative position | |
326 | * | |
327 | * Ready-made ->f_op->llseek() | |
328 | */ | |
329 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) | |
330 | { | |
331 | struct seq_file *m = file->private_data; | |
332 | loff_t retval = -EINVAL; | |
333 | ||
334 | mutex_lock(&m->lock); | |
335 | m->version = file->f_version; | |
336 | switch (whence) { | |
337 | case SEEK_CUR: | |
338 | offset += file->f_pos; | |
339 | case SEEK_SET: | |
340 | if (offset < 0) | |
341 | break; | |
342 | retval = offset; | |
343 | if (offset != m->read_pos) { | |
344 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
345 | ; | |
346 | if (retval) { | |
347 | /* with extreme prejudice... */ | |
348 | file->f_pos = 0; | |
349 | m->read_pos = 0; | |
350 | m->version = 0; | |
351 | m->index = 0; | |
352 | m->count = 0; | |
353 | } else { | |
354 | m->read_pos = offset; | |
355 | retval = file->f_pos = offset; | |
356 | } | |
357 | } else { | |
358 | file->f_pos = offset; | |
359 | } | |
360 | } | |
361 | file->f_version = m->version; | |
362 | mutex_unlock(&m->lock); | |
363 | return retval; | |
364 | } | |
365 | EXPORT_SYMBOL(seq_lseek); | |
366 | ||
367 | /** | |
368 | * seq_release - free the structures associated with sequential file. | |
369 | * @file: file in question | |
370 | * @inode: its inode | |
371 | * | |
372 | * Frees the structures associated with sequential file; can be used | |
373 | * as ->f_op->release() if you don't have private data to destroy. | |
374 | */ | |
375 | int seq_release(struct inode *inode, struct file *file) | |
376 | { | |
377 | struct seq_file *m = file->private_data; | |
378 | kvfree(m->buf); | |
379 | kfree(m); | |
380 | return 0; | |
381 | } | |
382 | EXPORT_SYMBOL(seq_release); | |
383 | ||
384 | /** | |
385 | * seq_escape - print string into buffer, escaping some characters | |
386 | * @m: target buffer | |
387 | * @s: string | |
388 | * @esc: set of characters that need escaping | |
389 | * | |
390 | * Puts string into buffer, replacing each occurrence of character from | |
391 | * @esc with usual octal escape. | |
392 | * Use seq_has_overflowed() to check for errors. | |
393 | */ | |
394 | void seq_escape(struct seq_file *m, const char *s, const char *esc) | |
395 | { | |
396 | char *buf; | |
397 | size_t size = seq_get_buf(m, &buf); | |
398 | int ret; | |
399 | ||
400 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); | |
401 | seq_commit(m, ret < size ? ret : -1); | |
402 | } | |
403 | EXPORT_SYMBOL(seq_escape); | |
404 | ||
405 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) | |
406 | { | |
407 | int len; | |
408 | ||
409 | if (m->count < m->size) { | |
410 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); | |
411 | if (m->count + len < m->size) { | |
412 | m->count += len; | |
413 | return; | |
414 | } | |
415 | } | |
416 | seq_set_overflow(m); | |
417 | } | |
418 | EXPORT_SYMBOL(seq_vprintf); | |
419 | ||
420 | void seq_printf(struct seq_file *m, const char *f, ...) | |
421 | { | |
422 | va_list args; | |
423 | ||
424 | va_start(args, f); | |
425 | seq_vprintf(m, f, args); | |
426 | va_end(args); | |
427 | } | |
428 | EXPORT_SYMBOL(seq_printf); | |
429 | ||
430 | /** | |
431 | * mangle_path - mangle and copy path to buffer beginning | |
432 | * @s: buffer start | |
433 | * @p: beginning of path in above buffer | |
434 | * @esc: set of characters that need escaping | |
435 | * | |
436 | * Copy the path from @p to @s, replacing each occurrence of character from | |
437 | * @esc with usual octal escape. | |
438 | * Returns pointer past last written character in @s, or NULL in case of | |
439 | * failure. | |
440 | */ | |
441 | char *mangle_path(char *s, const char *p, const char *esc) | |
442 | { | |
443 | while (s <= p) { | |
444 | char c = *p++; | |
445 | if (!c) { | |
446 | return s; | |
447 | } else if (!strchr(esc, c)) { | |
448 | *s++ = c; | |
449 | } else if (s + 4 > p) { | |
450 | break; | |
451 | } else { | |
452 | *s++ = '\\'; | |
453 | *s++ = '0' + ((c & 0300) >> 6); | |
454 | *s++ = '0' + ((c & 070) >> 3); | |
455 | *s++ = '0' + (c & 07); | |
456 | } | |
457 | } | |
458 | return NULL; | |
459 | } | |
460 | EXPORT_SYMBOL(mangle_path); | |
461 | ||
462 | /** | |
463 | * seq_path - seq_file interface to print a pathname | |
464 | * @m: the seq_file handle | |
465 | * @path: the struct path to print | |
466 | * @esc: set of characters to escape in the output | |
467 | * | |
468 | * return the absolute path of 'path', as represented by the | |
469 | * dentry / mnt pair in the path parameter. | |
470 | */ | |
471 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) | |
472 | { | |
473 | char *buf; | |
474 | size_t size = seq_get_buf(m, &buf); | |
475 | int res = -1; | |
476 | ||
477 | if (size) { | |
478 | char *p = d_path(path, buf, size); | |
479 | if (!IS_ERR(p)) { | |
480 | char *end = mangle_path(buf, p, esc); | |
481 | if (end) | |
482 | res = end - buf; | |
483 | } | |
484 | } | |
485 | seq_commit(m, res); | |
486 | ||
487 | return res; | |
488 | } | |
489 | EXPORT_SYMBOL(seq_path); | |
490 | ||
491 | /** | |
492 | * seq_file_path - seq_file interface to print a pathname of a file | |
493 | * @m: the seq_file handle | |
494 | * @file: the struct file to print | |
495 | * @esc: set of characters to escape in the output | |
496 | * | |
497 | * return the absolute path to the file. | |
498 | */ | |
499 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
500 | { | |
501 | return seq_path(m, &file->f_path, esc); | |
502 | } | |
503 | EXPORT_SYMBOL(seq_file_path); | |
504 | ||
505 | /* | |
506 | * Same as seq_path, but relative to supplied root. | |
507 | */ | |
508 | int seq_path_root(struct seq_file *m, const struct path *path, | |
509 | const struct path *root, const char *esc) | |
510 | { | |
511 | char *buf; | |
512 | size_t size = seq_get_buf(m, &buf); | |
513 | int res = -ENAMETOOLONG; | |
514 | ||
515 | if (size) { | |
516 | char *p; | |
517 | ||
518 | p = __d_path(path, root, buf, size); | |
519 | if (!p) | |
520 | return SEQ_SKIP; | |
521 | res = PTR_ERR(p); | |
522 | if (!IS_ERR(p)) { | |
523 | char *end = mangle_path(buf, p, esc); | |
524 | if (end) | |
525 | res = end - buf; | |
526 | else | |
527 | res = -ENAMETOOLONG; | |
528 | } | |
529 | } | |
530 | seq_commit(m, res); | |
531 | ||
532 | return res < 0 && res != -ENAMETOOLONG ? res : 0; | |
533 | } | |
534 | ||
535 | /* | |
536 | * returns the path of the 'dentry' from the root of its filesystem. | |
537 | */ | |
538 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) | |
539 | { | |
540 | char *buf; | |
541 | size_t size = seq_get_buf(m, &buf); | |
542 | int res = -1; | |
543 | ||
544 | if (size) { | |
545 | char *p = dentry_path(dentry, buf, size); | |
546 | if (!IS_ERR(p)) { | |
547 | char *end = mangle_path(buf, p, esc); | |
548 | if (end) | |
549 | res = end - buf; | |
550 | } | |
551 | } | |
552 | seq_commit(m, res); | |
553 | ||
554 | return res; | |
555 | } | |
556 | EXPORT_SYMBOL(seq_dentry); | |
557 | ||
558 | static void *single_start(struct seq_file *p, loff_t *pos) | |
559 | { | |
560 | return NULL + (*pos == 0); | |
561 | } | |
562 | ||
563 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
564 | { | |
565 | ++*pos; | |
566 | return NULL; | |
567 | } | |
568 | ||
569 | static void single_stop(struct seq_file *p, void *v) | |
570 | { | |
571 | } | |
572 | ||
573 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
574 | void *data) | |
575 | { | |
576 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL); | |
577 | int res = -ENOMEM; | |
578 | ||
579 | if (op) { | |
580 | op->start = single_start; | |
581 | op->next = single_next; | |
582 | op->stop = single_stop; | |
583 | op->show = show; | |
584 | res = seq_open(file, op); | |
585 | if (!res) | |
586 | ((struct seq_file *)file->private_data)->private = data; | |
587 | else | |
588 | kfree(op); | |
589 | } | |
590 | return res; | |
591 | } | |
592 | EXPORT_SYMBOL(single_open); | |
593 | ||
594 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), | |
595 | void *data, size_t size) | |
596 | { | |
597 | char *buf = seq_buf_alloc(size); | |
598 | int ret; | |
599 | if (!buf) | |
600 | return -ENOMEM; | |
601 | ret = single_open(file, show, data); | |
602 | if (ret) { | |
603 | kvfree(buf); | |
604 | return ret; | |
605 | } | |
606 | ((struct seq_file *)file->private_data)->buf = buf; | |
607 | ((struct seq_file *)file->private_data)->size = size; | |
608 | return 0; | |
609 | } | |
610 | EXPORT_SYMBOL(single_open_size); | |
611 | ||
612 | int single_release(struct inode *inode, struct file *file) | |
613 | { | |
614 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; | |
615 | int res = seq_release(inode, file); | |
616 | kfree(op); | |
617 | return res; | |
618 | } | |
619 | EXPORT_SYMBOL(single_release); | |
620 | ||
621 | int seq_release_private(struct inode *inode, struct file *file) | |
622 | { | |
623 | struct seq_file *seq = file->private_data; | |
624 | ||
625 | kfree(seq->private); | |
626 | seq->private = NULL; | |
627 | return seq_release(inode, file); | |
628 | } | |
629 | EXPORT_SYMBOL(seq_release_private); | |
630 | ||
631 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, | |
632 | int psize) | |
633 | { | |
634 | int rc; | |
635 | void *private; | |
636 | struct seq_file *seq; | |
637 | ||
638 | private = kzalloc(psize, GFP_KERNEL); | |
639 | if (private == NULL) | |
640 | goto out; | |
641 | ||
642 | rc = seq_open(f, ops); | |
643 | if (rc < 0) | |
644 | goto out_free; | |
645 | ||
646 | seq = f->private_data; | |
647 | seq->private = private; | |
648 | return private; | |
649 | ||
650 | out_free: | |
651 | kfree(private); | |
652 | out: | |
653 | return NULL; | |
654 | } | |
655 | EXPORT_SYMBOL(__seq_open_private); | |
656 | ||
657 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
658 | int psize) | |
659 | { | |
660 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
661 | } | |
662 | EXPORT_SYMBOL(seq_open_private); | |
663 | ||
664 | void seq_putc(struct seq_file *m, char c) | |
665 | { | |
666 | if (m->count >= m->size) | |
667 | return; | |
668 | ||
669 | m->buf[m->count++] = c; | |
670 | } | |
671 | EXPORT_SYMBOL(seq_putc); | |
672 | ||
673 | void seq_puts(struct seq_file *m, const char *s) | |
674 | { | |
675 | int len = strlen(s); | |
676 | ||
677 | if (m->count + len >= m->size) { | |
678 | seq_set_overflow(m); | |
679 | return; | |
680 | } | |
681 | memcpy(m->buf + m->count, s, len); | |
682 | m->count += len; | |
683 | } | |
684 | EXPORT_SYMBOL(seq_puts); | |
685 | ||
686 | /* | |
687 | * A helper routine for putting decimal numbers without rich format of printf(). | |
688 | * only 'unsigned long long' is supported. | |
689 | * This routine will put strlen(delimiter) + number into seq_file. | |
690 | * This routine is very quick when you show lots of numbers. | |
691 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
692 | */ | |
693 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, | |
694 | unsigned long long num) | |
695 | { | |
696 | int len; | |
697 | ||
698 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
699 | goto overflow; | |
700 | ||
701 | len = strlen(delimiter); | |
702 | if (m->count + len >= m->size) | |
703 | goto overflow; | |
704 | ||
705 | memcpy(m->buf + m->count, delimiter, len); | |
706 | m->count += len; | |
707 | ||
708 | if (m->count + 1 >= m->size) | |
709 | goto overflow; | |
710 | ||
711 | if (num < 10) { | |
712 | m->buf[m->count++] = num + '0'; | |
713 | return; | |
714 | } | |
715 | ||
716 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
717 | if (!len) | |
718 | goto overflow; | |
719 | ||
720 | m->count += len; | |
721 | return; | |
722 | ||
723 | overflow: | |
724 | seq_set_overflow(m); | |
725 | } | |
726 | EXPORT_SYMBOL(seq_put_decimal_ull); | |
727 | ||
728 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) | |
729 | { | |
730 | int len; | |
731 | ||
732 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ | |
733 | goto overflow; | |
734 | ||
735 | len = strlen(delimiter); | |
736 | if (m->count + len >= m->size) | |
737 | goto overflow; | |
738 | ||
739 | memcpy(m->buf + m->count, delimiter, len); | |
740 | m->count += len; | |
741 | ||
742 | if (m->count + 2 >= m->size) | |
743 | goto overflow; | |
744 | ||
745 | if (num < 0) { | |
746 | m->buf[m->count++] = '-'; | |
747 | num = -num; | |
748 | } | |
749 | ||
750 | if (num < 10) { | |
751 | m->buf[m->count++] = num + '0'; | |
752 | return; | |
753 | } | |
754 | ||
755 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
756 | if (!len) | |
757 | goto overflow; | |
758 | ||
759 | m->count += len; | |
760 | return; | |
761 | ||
762 | overflow: | |
763 | seq_set_overflow(m); | |
764 | } | |
765 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
766 | ||
767 | /** | |
768 | * seq_write - write arbitrary data to buffer | |
769 | * @seq: seq_file identifying the buffer to which data should be written | |
770 | * @data: data address | |
771 | * @len: number of bytes | |
772 | * | |
773 | * Return 0 on success, non-zero otherwise. | |
774 | */ | |
775 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
776 | { | |
777 | if (seq->count + len < seq->size) { | |
778 | memcpy(seq->buf + seq->count, data, len); | |
779 | seq->count += len; | |
780 | return 0; | |
781 | } | |
782 | seq_set_overflow(seq); | |
783 | return -1; | |
784 | } | |
785 | EXPORT_SYMBOL(seq_write); | |
786 | ||
787 | /** | |
788 | * seq_pad - write padding spaces to buffer | |
789 | * @m: seq_file identifying the buffer to which data should be written | |
790 | * @c: the byte to append after padding if non-zero | |
791 | */ | |
792 | void seq_pad(struct seq_file *m, char c) | |
793 | { | |
794 | int size = m->pad_until - m->count; | |
795 | if (size > 0) | |
796 | seq_printf(m, "%*s", size, ""); | |
797 | if (c) | |
798 | seq_putc(m, c); | |
799 | } | |
800 | EXPORT_SYMBOL(seq_pad); | |
801 | ||
802 | /* A complete analogue of print_hex_dump() */ | |
803 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
804 | int rowsize, int groupsize, const void *buf, size_t len, | |
805 | bool ascii) | |
806 | { | |
807 | const u8 *ptr = buf; | |
808 | int i, linelen, remaining = len; | |
809 | char *buffer; | |
810 | size_t size; | |
811 | int ret; | |
812 | ||
813 | if (rowsize != 16 && rowsize != 32) | |
814 | rowsize = 16; | |
815 | ||
816 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
817 | linelen = min(remaining, rowsize); | |
818 | remaining -= rowsize; | |
819 | ||
820 | switch (prefix_type) { | |
821 | case DUMP_PREFIX_ADDRESS: | |
822 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
823 | break; | |
824 | case DUMP_PREFIX_OFFSET: | |
825 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
826 | break; | |
827 | default: | |
828 | seq_printf(m, "%s", prefix_str); | |
829 | break; | |
830 | } | |
831 | ||
832 | size = seq_get_buf(m, &buffer); | |
833 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, | |
834 | buffer, size, ascii); | |
835 | seq_commit(m, ret < size ? ret : -1); | |
836 | ||
837 | seq_putc(m, '\n'); | |
838 | } | |
839 | } | |
840 | EXPORT_SYMBOL(seq_hex_dump); | |
841 | ||
842 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) | |
843 | { | |
844 | struct list_head *lh; | |
845 | ||
846 | list_for_each(lh, head) | |
847 | if (pos-- == 0) | |
848 | return lh; | |
849 | ||
850 | return NULL; | |
851 | } | |
852 | EXPORT_SYMBOL(seq_list_start); | |
853 | ||
854 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
855 | { | |
856 | if (!pos) | |
857 | return head; | |
858 | ||
859 | return seq_list_start(head, pos - 1); | |
860 | } | |
861 | EXPORT_SYMBOL(seq_list_start_head); | |
862 | ||
863 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
864 | { | |
865 | struct list_head *lh; | |
866 | ||
867 | lh = ((struct list_head *)v)->next; | |
868 | ++*ppos; | |
869 | return lh == head ? NULL : lh; | |
870 | } | |
871 | EXPORT_SYMBOL(seq_list_next); | |
872 | ||
873 | /** | |
874 | * seq_hlist_start - start an iteration of a hlist | |
875 | * @head: the head of the hlist | |
876 | * @pos: the start position of the sequence | |
877 | * | |
878 | * Called at seq_file->op->start(). | |
879 | */ | |
880 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
881 | { | |
882 | struct hlist_node *node; | |
883 | ||
884 | hlist_for_each(node, head) | |
885 | if (pos-- == 0) | |
886 | return node; | |
887 | return NULL; | |
888 | } | |
889 | EXPORT_SYMBOL(seq_hlist_start); | |
890 | ||
891 | /** | |
892 | * seq_hlist_start_head - start an iteration of a hlist | |
893 | * @head: the head of the hlist | |
894 | * @pos: the start position of the sequence | |
895 | * | |
896 | * Called at seq_file->op->start(). Call this function if you want to | |
897 | * print a header at the top of the output. | |
898 | */ | |
899 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
900 | { | |
901 | if (!pos) | |
902 | return SEQ_START_TOKEN; | |
903 | ||
904 | return seq_hlist_start(head, pos - 1); | |
905 | } | |
906 | EXPORT_SYMBOL(seq_hlist_start_head); | |
907 | ||
908 | /** | |
909 | * seq_hlist_next - move to the next position of the hlist | |
910 | * @v: the current iterator | |
911 | * @head: the head of the hlist | |
912 | * @ppos: the current position | |
913 | * | |
914 | * Called at seq_file->op->next(). | |
915 | */ | |
916 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
917 | loff_t *ppos) | |
918 | { | |
919 | struct hlist_node *node = v; | |
920 | ||
921 | ++*ppos; | |
922 | if (v == SEQ_START_TOKEN) | |
923 | return head->first; | |
924 | else | |
925 | return node->next; | |
926 | } | |
927 | EXPORT_SYMBOL(seq_hlist_next); | |
928 | ||
929 | /** | |
930 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
931 | * @head: the head of the hlist | |
932 | * @pos: the start position of the sequence | |
933 | * | |
934 | * Called at seq_file->op->start(). | |
935 | * | |
936 | * This list-traversal primitive may safely run concurrently with | |
937 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
938 | * as long as the traversal is guarded by rcu_read_lock(). | |
939 | */ | |
940 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
941 | loff_t pos) | |
942 | { | |
943 | struct hlist_node *node; | |
944 | ||
945 | __hlist_for_each_rcu(node, head) | |
946 | if (pos-- == 0) | |
947 | return node; | |
948 | return NULL; | |
949 | } | |
950 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
951 | ||
952 | /** | |
953 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
954 | * @head: the head of the hlist | |
955 | * @pos: the start position of the sequence | |
956 | * | |
957 | * Called at seq_file->op->start(). Call this function if you want to | |
958 | * print a header at the top of the output. | |
959 | * | |
960 | * This list-traversal primitive may safely run concurrently with | |
961 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
962 | * as long as the traversal is guarded by rcu_read_lock(). | |
963 | */ | |
964 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
965 | loff_t pos) | |
966 | { | |
967 | if (!pos) | |
968 | return SEQ_START_TOKEN; | |
969 | ||
970 | return seq_hlist_start_rcu(head, pos - 1); | |
971 | } | |
972 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
973 | ||
974 | /** | |
975 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
976 | * @v: the current iterator | |
977 | * @head: the head of the hlist | |
978 | * @ppos: the current position | |
979 | * | |
980 | * Called at seq_file->op->next(). | |
981 | * | |
982 | * This list-traversal primitive may safely run concurrently with | |
983 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
984 | * as long as the traversal is guarded by rcu_read_lock(). | |
985 | */ | |
986 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
987 | struct hlist_head *head, | |
988 | loff_t *ppos) | |
989 | { | |
990 | struct hlist_node *node = v; | |
991 | ||
992 | ++*ppos; | |
993 | if (v == SEQ_START_TOKEN) | |
994 | return rcu_dereference(head->first); | |
995 | else | |
996 | return rcu_dereference(node->next); | |
997 | } | |
998 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
999 | ||
1000 | /** | |
1001 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array | |
1002 | * @head: pointer to percpu array of struct hlist_heads | |
1003 | * @cpu: pointer to cpu "cursor" | |
1004 | * @pos: start position of sequence | |
1005 | * | |
1006 | * Called at seq_file->op->start(). | |
1007 | */ | |
1008 | struct hlist_node * | |
1009 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
1010 | { | |
1011 | struct hlist_node *node; | |
1012 | ||
1013 | for_each_possible_cpu(*cpu) { | |
1014 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
1015 | if (pos-- == 0) | |
1016 | return node; | |
1017 | } | |
1018 | } | |
1019 | return NULL; | |
1020 | } | |
1021 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
1022 | ||
1023 | /** | |
1024 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1025 | * @v: pointer to current hlist_node | |
1026 | * @head: pointer to percpu array of struct hlist_heads | |
1027 | * @cpu: pointer to cpu "cursor" | |
1028 | * @pos: start position of sequence | |
1029 | * | |
1030 | * Called at seq_file->op->next(). | |
1031 | */ | |
1032 | struct hlist_node * | |
1033 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1034 | int *cpu, loff_t *pos) | |
1035 | { | |
1036 | struct hlist_node *node = v; | |
1037 | ||
1038 | ++*pos; | |
1039 | ||
1040 | if (node->next) | |
1041 | return node->next; | |
1042 | ||
1043 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1044 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1045 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1046 | ||
1047 | if (!hlist_empty(bucket)) | |
1048 | return bucket->first; | |
1049 | } | |
1050 | return NULL; | |
1051 | } | |
1052 | EXPORT_SYMBOL(seq_hlist_next_percpu); |