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b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT
2/*
3 * linux/fs/seq_file.c
4 *
5 * helper functions for making synthetic files from sequences of records.
6 * initial implementation -- AV, Oct 2001.
7 */
8
09652320 9#include <linux/cache.h>
1da177e4 10#include <linux/fs.h>
630d9c47 11#include <linux/export.h>
1da177e4 12#include <linux/seq_file.h>
058504ed 13#include <linux/vmalloc.h>
1da177e4 14#include <linux/slab.h>
adb37c4c 15#include <linux/cred.h>
058504ed 16#include <linux/mm.h>
37607102 17#include <linux/printk.h>
25c6bb76 18#include <linux/string_helpers.h>
1da177e4 19
7c0f6ba6 20#include <linux/uaccess.h>
1da177e4
LT
21#include <asm/page.h>
22
09652320
AD
23static struct kmem_cache *seq_file_cache __ro_after_init;
24
e075f591
KH
25static void seq_set_overflow(struct seq_file *m)
26{
27 m->count = m->size;
28}
29
058504ed
HC
30static void *seq_buf_alloc(unsigned long size)
31{
d64d01a1 32 return kvmalloc(size, GFP_KERNEL_ACCOUNT);
058504ed
HC
33}
34
1da177e4
LT
35/**
36 * seq_open - initialize sequential file
37 * @file: file we initialize
38 * @op: method table describing the sequence
39 *
40 * seq_open() sets @file, associating it with a sequence described
41 * by @op. @op->start() sets the iterator up and returns the first
42 * element of sequence. @op->stop() shuts it down. @op->next()
43 * returns the next element of sequence. @op->show() prints element
44 * into the buffer. In case of error ->start() and ->next() return
45 * ERR_PTR(error). In the end of sequence they return %NULL. ->show()
46 * returns 0 in case of success and negative number in case of error.
521b5d0c 47 * Returning SEQ_SKIP means "discard this element and move on".
460b865e
YD
48 * Note: seq_open() will allocate a struct seq_file and store its
49 * pointer in @file->private_data. This pointer should not be modified.
1da177e4 50 */
15ad7cdc 51int seq_open(struct file *file, const struct seq_operations *op)
1da177e4 52{
189f9841
YD
53 struct seq_file *p;
54
55 WARN_ON(file->private_data);
56
09652320 57 p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL);
189f9841
YD
58 if (!p)
59 return -ENOMEM;
60
61 file->private_data = p;
1abe77b0 62
0ac1759a 63 mutex_init(&p->lock);
1da177e4 64 p->op = op;
34dbbcdb
LT
65
66 // No refcounting: the lifetime of 'p' is constrained
67 // to the lifetime of the file.
68 p->file = file;
1da177e4
LT
69
70 /*
71 * Wrappers around seq_open(e.g. swaps_open) need to be
72 * aware of this. If they set f_version themselves, they
73 * should call seq_open first and then set f_version.
74 */
75 file->f_version = 0;
76
8f19d472
EB
77 /*
78 * seq_files support lseek() and pread(). They do not implement
79 * write() at all, but we clear FMODE_PWRITE here for historical
80 * reasons.
81 *
82 * If a client of seq_files a) implements file.write() and b) wishes to
83 * support pwrite() then that client will need to implement its own
84 * file.open() which calls seq_open() and then sets FMODE_PWRITE.
85 */
86 file->f_mode &= ~FMODE_PWRITE;
1da177e4
LT
87 return 0;
88}
89EXPORT_SYMBOL(seq_open);
90
33da8892
EB
91static int traverse(struct seq_file *m, loff_t offset)
92{
1f4aace6 93 loff_t pos = 0;
33da8892
EB
94 int error = 0;
95 void *p;
96
97 m->version = 0;
1f4aace6 98 m->index = 0;
33da8892 99 m->count = m->from = 0;
1f4aace6 100 if (!offset)
33da8892 101 return 0;
1f4aace6 102
33da8892 103 if (!m->buf) {
058504ed 104 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
33da8892
EB
105 if (!m->buf)
106 return -ENOMEM;
107 }
1f4aace6 108 p = m->op->start(m, &m->index);
33da8892
EB
109 while (p) {
110 error = PTR_ERR(p);
111 if (IS_ERR(p))
112 break;
113 error = m->op->show(m, p);
114 if (error < 0)
115 break;
116 if (unlikely(error)) {
117 error = 0;
118 m->count = 0;
119 }
1f33c41c 120 if (seq_has_overflowed(m))
33da8892
EB
121 goto Eoverflow;
122 if (pos + m->count > offset) {
123 m->from = offset - pos;
124 m->count -= m->from;
33da8892
EB
125 break;
126 }
127 pos += m->count;
128 m->count = 0;
1f4aace6
N
129 p = m->op->next(m, p, &m->index);
130 if (pos == offset)
33da8892 131 break;
33da8892
EB
132 }
133 m->op->stop(m, p);
134 return error;
135
136Eoverflow:
137 m->op->stop(m, p);
058504ed 138 kvfree(m->buf);
801a7605 139 m->count = 0;
058504ed 140 m->buf = seq_buf_alloc(m->size <<= 1);
33da8892
EB
141 return !m->buf ? -ENOMEM : -EAGAIN;
142}
143
1da177e4
LT
144/**
145 * seq_read - ->read() method for sequential files.
67be2dd1
MW
146 * @file: the file to read from
147 * @buf: the buffer to read to
148 * @size: the maximum number of bytes to read
149 * @ppos: the current position in the file
1da177e4
LT
150 *
151 * Ready-made ->f_op->read()
152 */
153ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
154{
8209e2f4 155 struct seq_file *m = file->private_data;
1da177e4 156 size_t copied = 0;
1da177e4
LT
157 size_t n;
158 void *p;
159 int err = 0;
160
0ac1759a 161 mutex_lock(&m->lock);
8f19d472 162
7904ac84
EC
163 /*
164 * seq_file->op->..m_start/m_stop/m_next may do special actions
165 * or optimisations based on the file->f_version, so we want to
166 * pass the file->f_version to those methods.
167 *
168 * seq_file->version is just copy of f_version, and seq_file
169 * methods can treat it simply as file version.
170 * It is copied in first and copied out after all operations.
171 * It is convenient to have it as part of structure to avoid the
172 * need of passing another argument to all the seq_file methods.
173 */
174 m->version = file->f_version;
175
e522751d
TM
176 /*
177 * if request is to read from zero offset, reset iterator to first
178 * record as it might have been already advanced by previous requests
179 */
cf5eebae 180 if (*ppos == 0) {
e522751d 181 m->index = 0;
cf5eebae
MS
182 m->version = 0;
183 m->count = 0;
184 }
e522751d 185
8f19d472
EB
186 /* Don't assume *ppos is where we left it */
187 if (unlikely(*ppos != m->read_pos)) {
8f19d472
EB
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;
7904ac84
EC
197 } else {
198 m->read_pos = *ppos;
8f19d472
EB
199 }
200 }
201
1da177e4
LT
202 /* grab buffer if we didn't have one */
203 if (!m->buf) {
058504ed 204 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
1da177e4
LT
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;
1da177e4
LT
219 if (!size)
220 goto Done;
221 }
222 /* we need at least one record in buffer */
1f4aace6
N
223 m->from = 0;
224 p = m->op->start(m, &m->index);
1da177e4 225 while (1) {
1da177e4
LT
226 err = PTR_ERR(p);
227 if (!p || IS_ERR(p))
228 break;
229 err = m->op->show(m, p);
521b5d0c 230 if (err < 0)
1da177e4 231 break;
521b5d0c
AV
232 if (unlikely(err))
233 m->count = 0;
4cdfe84b 234 if (unlikely(!m->count)) {
1f4aace6 235 p = m->op->next(m, p, &m->index);
4cdfe84b
AV
236 continue;
237 }
1da177e4
LT
238 if (m->count < m->size)
239 goto Fill;
240 m->op->stop(m, p);
058504ed 241 kvfree(m->buf);
801a7605 242 m->count = 0;
058504ed 243 m->buf = seq_buf_alloc(m->size <<= 1);
1da177e4
LT
244 if (!m->buf)
245 goto Enomem;
1da177e4 246 m->version = 0;
1f4aace6 247 p = m->op->start(m, &m->index);
1da177e4
LT
248 }
249 m->op->stop(m, p);
250 m->count = 0;
251 goto Done;
252Fill:
253 /* they want more? let's try to get some more */
1f4aace6 254 while (1) {
1da177e4 255 size_t offs = m->count;
1f4aace6
N
256 loff_t pos = m->index;
257
258 p = m->op->next(m, p, &m->index);
259 if (pos == m->index)
260 /* Buggy ->next function */
261 m->index++;
1da177e4
LT
262 if (!p || IS_ERR(p)) {
263 err = PTR_ERR(p);
264 break;
265 }
1f4aace6
N
266 if (m->count >= size)
267 break;
1da177e4 268 err = m->op->show(m, p);
1f33c41c 269 if (seq_has_overflowed(m) || err) {
1da177e4 270 m->count = offs;
521b5d0c
AV
271 if (likely(err <= 0))
272 break;
1da177e4 273 }
1da177e4
LT
274 }
275 m->op->stop(m, p);
276 n = min(m->count, size);
277 err = copy_to_user(buf, m->buf, n);
278 if (err)
279 goto Efault;
280 copied += n;
281 m->count -= n;
1f4aace6 282 m->from = n;
1da177e4
LT
283Done:
284 if (!copied)
285 copied = err;
8f19d472 286 else {
1da177e4 287 *ppos += copied;
8f19d472
EB
288 m->read_pos += copied;
289 }
1da177e4 290 file->f_version = m->version;
0ac1759a 291 mutex_unlock(&m->lock);
1da177e4
LT
292 return copied;
293Enomem:
294 err = -ENOMEM;
295 goto Done;
296Efault:
297 err = -EFAULT;
298 goto Done;
299}
300EXPORT_SYMBOL(seq_read);
301
1da177e4
LT
302/**
303 * seq_lseek - ->llseek() method for sequential files.
67be2dd1
MW
304 * @file: the file in question
305 * @offset: new position
254adaa4 306 * @whence: 0 for absolute, 1 for relative position
1da177e4
LT
307 *
308 * Ready-made ->f_op->llseek()
309 */
965c8e59 310loff_t seq_lseek(struct file *file, loff_t offset, int whence)
1da177e4 311{
8209e2f4 312 struct seq_file *m = file->private_data;
16abef0e 313 loff_t retval = -EINVAL;
1da177e4 314
0ac1759a 315 mutex_lock(&m->lock);
1da177e4 316 m->version = file->f_version;
965c8e59 317 switch (whence) {
5e62adef
AM
318 case SEEK_CUR:
319 offset += file->f_pos;
0a4c9265 320 /* fall through */
5e62adef
AM
321 case SEEK_SET:
322 if (offset < 0)
323 break;
324 retval = offset;
325 if (offset != m->read_pos) {
326 while ((retval = traverse(m, offset)) == -EAGAIN)
327 ;
328 if (retval) {
329 /* with extreme prejudice... */
330 file->f_pos = 0;
331 m->read_pos = 0;
332 m->version = 0;
333 m->index = 0;
334 m->count = 0;
335 } else {
336 m->read_pos = offset;
337 retval = file->f_pos = offset;
1da177e4 338 }
05e16745
GZ
339 } else {
340 file->f_pos = offset;
5e62adef 341 }
1da177e4 342 }
1da177e4 343 file->f_version = m->version;
00c5746d 344 mutex_unlock(&m->lock);
1da177e4
LT
345 return retval;
346}
347EXPORT_SYMBOL(seq_lseek);
348
349/**
350 * seq_release - free the structures associated with sequential file.
351 * @file: file in question
6131ffaa 352 * @inode: its inode
1da177e4
LT
353 *
354 * Frees the structures associated with sequential file; can be used
355 * as ->f_op->release() if you don't have private data to destroy.
356 */
357int seq_release(struct inode *inode, struct file *file)
358{
8209e2f4 359 struct seq_file *m = file->private_data;
058504ed 360 kvfree(m->buf);
09652320 361 kmem_cache_free(seq_file_cache, m);
1da177e4
LT
362 return 0;
363}
364EXPORT_SYMBOL(seq_release);
365
366/**
367 * seq_escape - print string into buffer, escaping some characters
368 * @m: target buffer
369 * @s: string
370 * @esc: set of characters that need escaping
371 *
372 * Puts string into buffer, replacing each occurrence of character from
6798a8ca
JP
373 * @esc with usual octal escape.
374 * Use seq_has_overflowed() to check for errors.
1da177e4 375 */
6798a8ca 376void seq_escape(struct seq_file *m, const char *s, const char *esc)
1da177e4 377{
25c6bb76
AS
378 char *buf;
379 size_t size = seq_get_buf(m, &buf);
380 int ret;
1da177e4 381
25c6bb76
AS
382 ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc);
383 seq_commit(m, ret < size ? ret : -1);
1da177e4
LT
384}
385EXPORT_SYMBOL(seq_escape);
386
6798a8ca 387void seq_vprintf(struct seq_file *m, const char *f, va_list args)
1da177e4 388{
1da177e4
LT
389 int len;
390
391 if (m->count < m->size) {
1da177e4 392 len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
1da177e4
LT
393 if (m->count + len < m->size) {
394 m->count += len;
6798a8ca 395 return;
1da177e4
LT
396 }
397 }
e075f591 398 seq_set_overflow(m);
1da177e4 399}
a4808147
SW
400EXPORT_SYMBOL(seq_vprintf);
401
6798a8ca 402void seq_printf(struct seq_file *m, const char *f, ...)
a4808147 403{
a4808147
SW
404 va_list args;
405
406 va_start(args, f);
6798a8ca 407 seq_vprintf(m, f, args);
a4808147 408 va_end(args);
a4808147 409}
1da177e4
LT
410EXPORT_SYMBOL(seq_printf);
411
74e2f334 412/**
958086d1
TE
413 * mangle_path - mangle and copy path to buffer beginning
414 * @s: buffer start
415 * @p: beginning of path in above buffer
416 * @esc: set of characters that need escaping
74e2f334
TE
417 *
418 * Copy the path from @p to @s, replacing each occurrence of character from
419 * @esc with usual octal escape.
420 * Returns pointer past last written character in @s, or NULL in case of
421 * failure.
422 */
8c9379e9 423char *mangle_path(char *s, const char *p, const char *esc)
6092d048
RP
424{
425 while (s <= p) {
426 char c = *p++;
427 if (!c) {
428 return s;
429 } else if (!strchr(esc, c)) {
430 *s++ = c;
431 } else if (s + 4 > p) {
432 break;
433 } else {
434 *s++ = '\\';
435 *s++ = '0' + ((c & 0300) >> 6);
436 *s++ = '0' + ((c & 070) >> 3);
437 *s++ = '0' + (c & 07);
438 }
439 }
440 return NULL;
441}
604094f4 442EXPORT_SYMBOL(mangle_path);
6092d048 443
52afeefb
AV
444/**
445 * seq_path - seq_file interface to print a pathname
446 * @m: the seq_file handle
447 * @path: the struct path to print
448 * @esc: set of characters to escape in the output
449 *
450 * return the absolute path of 'path', as represented by the
451 * dentry / mnt pair in the path parameter.
6092d048 452 */
8c9379e9 453int seq_path(struct seq_file *m, const struct path *path, const char *esc)
1da177e4 454{
f8439806
MS
455 char *buf;
456 size_t size = seq_get_buf(m, &buf);
457 int res = -1;
458
459 if (size) {
460 char *p = d_path(path, buf, size);
1da177e4 461 if (!IS_ERR(p)) {
f8439806
MS
462 char *end = mangle_path(buf, p, esc);
463 if (end)
464 res = end - buf;
1da177e4
LT
465 }
466 }
f8439806
MS
467 seq_commit(m, res);
468
469 return res;
1da177e4
LT
470}
471EXPORT_SYMBOL(seq_path);
472
2726d566
MS
473/**
474 * seq_file_path - seq_file interface to print a pathname of a file
475 * @m: the seq_file handle
476 * @file: the struct file to print
477 * @esc: set of characters to escape in the output
478 *
479 * return the absolute path to the file.
480 */
481int seq_file_path(struct seq_file *m, struct file *file, const char *esc)
482{
483 return seq_path(m, &file->f_path, esc);
484}
485EXPORT_SYMBOL(seq_file_path);
486
9d1bc601
MS
487/*
488 * Same as seq_path, but relative to supplied root.
9d1bc601 489 */
8c9379e9
AV
490int seq_path_root(struct seq_file *m, const struct path *path,
491 const struct path *root, const char *esc)
9d1bc601 492{
f8439806
MS
493 char *buf;
494 size_t size = seq_get_buf(m, &buf);
495 int res = -ENAMETOOLONG;
496
497 if (size) {
9d1bc601
MS
498 char *p;
499
f8439806 500 p = __d_path(path, root, buf, size);
02125a82
AV
501 if (!p)
502 return SEQ_SKIP;
f8439806 503 res = PTR_ERR(p);
9d1bc601 504 if (!IS_ERR(p)) {
f8439806
MS
505 char *end = mangle_path(buf, p, esc);
506 if (end)
507 res = end - buf;
508 else
509 res = -ENAMETOOLONG;
9d1bc601
MS
510 }
511 }
f8439806
MS
512 seq_commit(m, res);
513
02125a82 514 return res < 0 && res != -ENAMETOOLONG ? res : 0;
9d1bc601
MS
515}
516
6092d048
RP
517/*
518 * returns the path of the 'dentry' from the root of its filesystem.
519 */
8c9379e9 520int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc)
6092d048 521{
f8439806
MS
522 char *buf;
523 size_t size = seq_get_buf(m, &buf);
524 int res = -1;
525
526 if (size) {
527 char *p = dentry_path(dentry, buf, size);
6092d048 528 if (!IS_ERR(p)) {
f8439806
MS
529 char *end = mangle_path(buf, p, esc);
530 if (end)
531 res = end - buf;
6092d048
RP
532 }
533 }
f8439806
MS
534 seq_commit(m, res);
535
536 return res;
6092d048 537}
c8d3fe02 538EXPORT_SYMBOL(seq_dentry);
6092d048 539
1da177e4
LT
540static void *single_start(struct seq_file *p, loff_t *pos)
541{
542 return NULL + (*pos == 0);
543}
544
545static void *single_next(struct seq_file *p, void *v, loff_t *pos)
546{
547 ++*pos;
548 return NULL;
549}
550
551static void single_stop(struct seq_file *p, void *v)
552{
553}
554
555int single_open(struct file *file, int (*show)(struct seq_file *, void *),
556 void *data)
557{
d64d01a1 558 struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT);
1da177e4
LT
559 int res = -ENOMEM;
560
561 if (op) {
562 op->start = single_start;
563 op->next = single_next;
564 op->stop = single_stop;
565 op->show = show;
566 res = seq_open(file, op);
567 if (!res)
568 ((struct seq_file *)file->private_data)->private = data;
569 else
570 kfree(op);
571 }
572 return res;
573}
574EXPORT_SYMBOL(single_open);
575
2043f495
AV
576int single_open_size(struct file *file, int (*show)(struct seq_file *, void *),
577 void *data, size_t size)
578{
058504ed 579 char *buf = seq_buf_alloc(size);
2043f495
AV
580 int ret;
581 if (!buf)
582 return -ENOMEM;
583 ret = single_open(file, show, data);
584 if (ret) {
058504ed 585 kvfree(buf);
2043f495
AV
586 return ret;
587 }
588 ((struct seq_file *)file->private_data)->buf = buf;
589 ((struct seq_file *)file->private_data)->size = size;
590 return 0;
591}
592EXPORT_SYMBOL(single_open_size);
593
1da177e4
LT
594int single_release(struct inode *inode, struct file *file)
595{
15ad7cdc 596 const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
1da177e4
LT
597 int res = seq_release(inode, file);
598 kfree(op);
599 return res;
600}
601EXPORT_SYMBOL(single_release);
602
603int seq_release_private(struct inode *inode, struct file *file)
604{
605 struct seq_file *seq = file->private_data;
606
607 kfree(seq->private);
608 seq->private = NULL;
609 return seq_release(inode, file);
610}
611EXPORT_SYMBOL(seq_release_private);
612
39699037
PE
613void *__seq_open_private(struct file *f, const struct seq_operations *ops,
614 int psize)
615{
616 int rc;
617 void *private;
618 struct seq_file *seq;
619
d64d01a1 620 private = kzalloc(psize, GFP_KERNEL_ACCOUNT);
39699037
PE
621 if (private == NULL)
622 goto out;
623
624 rc = seq_open(f, ops);
625 if (rc < 0)
626 goto out_free;
627
628 seq = f->private_data;
629 seq->private = private;
630 return private;
631
632out_free:
633 kfree(private);
634out:
635 return NULL;
636}
637EXPORT_SYMBOL(__seq_open_private);
638
639int seq_open_private(struct file *filp, const struct seq_operations *ops,
640 int psize)
641{
642 return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
643}
644EXPORT_SYMBOL(seq_open_private);
645
6798a8ca 646void seq_putc(struct seq_file *m, char c)
1da177e4 647{
6798a8ca
JP
648 if (m->count >= m->size)
649 return;
650
651 m->buf[m->count++] = c;
1da177e4
LT
652}
653EXPORT_SYMBOL(seq_putc);
654
6798a8ca 655void seq_puts(struct seq_file *m, const char *s)
1da177e4
LT
656{
657 int len = strlen(s);
6798a8ca
JP
658
659 if (m->count + len >= m->size) {
660 seq_set_overflow(m);
661 return;
1da177e4 662 }
6798a8ca
JP
663 memcpy(m->buf + m->count, s, len);
664 m->count += len;
1da177e4
LT
665}
666EXPORT_SYMBOL(seq_puts);
bcf67e16 667
d1be35cb 668/**
1ac101a5
KH
669 * A helper routine for putting decimal numbers without rich format of printf().
670 * only 'unsigned long long' is supported.
d1be35cb
AV
671 * @m: seq_file identifying the buffer to which data should be written
672 * @delimiter: a string which is printed before the number
673 * @num: the number
674 * @width: a minimum field width
675 *
676 * This routine will put strlen(delimiter) + number into seq_filed.
1ac101a5
KH
677 * This routine is very quick when you show lots of numbers.
678 * In usual cases, it will be better to use seq_printf(). It's easier to read.
679 */
d1be35cb
AV
680void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
681 unsigned long long num, unsigned int width)
1ac101a5
KH
682{
683 int len;
684
685 if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */
686 goto overflow;
687
48dffbf8
AV
688 if (delimiter && delimiter[0]) {
689 if (delimiter[1] == 0)
690 seq_putc(m, delimiter[0]);
691 else
692 seq_puts(m, delimiter);
693 }
75ba1d07 694
d1be35cb
AV
695 if (!width)
696 width = 1;
697
698 if (m->count + width >= m->size)
75ba1d07 699 goto overflow;
1ac101a5 700
d1be35cb 701 len = num_to_str(m->buf + m->count, m->size - m->count, num, width);
1ac101a5
KH
702 if (!len)
703 goto overflow;
75ba1d07 704
1ac101a5 705 m->count += len;
6798a8ca
JP
706 return;
707
1ac101a5 708overflow:
e075f591 709 seq_set_overflow(m);
1ac101a5 710}
d1be35cb
AV
711
712void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
713 unsigned long long num)
714{
715 return seq_put_decimal_ull_width(m, delimiter, num, 0);
716}
1ac101a5
KH
717EXPORT_SYMBOL(seq_put_decimal_ull);
718
0e3dc019
AV
719/**
720 * seq_put_hex_ll - put a number in hexadecimal notation
721 * @m: seq_file identifying the buffer to which data should be written
722 * @delimiter: a string which is printed before the number
723 * @v: the number
724 * @width: a minimum field width
725 *
726 * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v)
727 *
728 * This routine is very quick when you show lots of numbers.
729 * In usual cases, it will be better to use seq_printf(). It's easier to read.
730 */
731void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
732 unsigned long long v, unsigned int width)
733{
734 unsigned int len;
735 int i;
736
737 if (delimiter && delimiter[0]) {
738 if (delimiter[1] == 0)
739 seq_putc(m, delimiter[0]);
740 else
741 seq_puts(m, delimiter);
742 }
743
744 /* If x is 0, the result of __builtin_clzll is undefined */
745 if (v == 0)
746 len = 1;
747 else
748 len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4;
749
750 if (len < width)
751 len = width;
752
753 if (m->count + len > m->size) {
754 seq_set_overflow(m);
755 return;
756 }
757
758 for (i = len - 1; i >= 0; i--) {
759 m->buf[m->count + i] = hex_asc[0xf & v];
760 v = v >> 4;
761 }
762 m->count += len;
763}
764
75ba1d07 765void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num)
bda7bad6 766{
75ba1d07
JP
767 int len;
768
769 if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */
770 goto overflow;
771
48dffbf8
AV
772 if (delimiter && delimiter[0]) {
773 if (delimiter[1] == 0)
774 seq_putc(m, delimiter[0]);
775 else
776 seq_puts(m, delimiter);
777 }
75ba1d07
JP
778
779 if (m->count + 2 >= m->size)
780 goto overflow;
781
bda7bad6 782 if (num < 0) {
75ba1d07 783 m->buf[m->count++] = '-';
bda7bad6 784 num = -num;
bda7bad6 785 }
75ba1d07
JP
786
787 if (num < 10) {
788 m->buf[m->count++] = num + '0';
789 return;
790 }
791
d1be35cb 792 len = num_to_str(m->buf + m->count, m->size - m->count, num, 0);
75ba1d07
JP
793 if (!len)
794 goto overflow;
795
796 m->count += len;
797 return;
798
799overflow:
800 seq_set_overflow(m);
bda7bad6
KH
801}
802EXPORT_SYMBOL(seq_put_decimal_ll);
803
0b923606
PO
804/**
805 * seq_write - write arbitrary data to buffer
806 * @seq: seq_file identifying the buffer to which data should be written
807 * @data: data address
808 * @len: number of bytes
809 *
810 * Return 0 on success, non-zero otherwise.
811 */
812int seq_write(struct seq_file *seq, const void *data, size_t len)
813{
814 if (seq->count + len < seq->size) {
815 memcpy(seq->buf + seq->count, data, len);
816 seq->count += len;
817 return 0;
818 }
e075f591 819 seq_set_overflow(seq);
0b923606
PO
820 return -1;
821}
822EXPORT_SYMBOL(seq_write);
823
839cc2a9
TH
824/**
825 * seq_pad - write padding spaces to buffer
826 * @m: seq_file identifying the buffer to which data should be written
827 * @c: the byte to append after padding if non-zero
828 */
829void seq_pad(struct seq_file *m, char c)
830{
831 int size = m->pad_until - m->count;
8cfa67b4
AV
832 if (size > 0) {
833 if (size + m->count > m->size) {
834 seq_set_overflow(m);
835 return;
836 }
837 memset(m->buf + m->count, ' ', size);
838 m->count += size;
839 }
839cc2a9
TH
840 if (c)
841 seq_putc(m, c);
842}
843EXPORT_SYMBOL(seq_pad);
844
37607102
AS
845/* A complete analogue of print_hex_dump() */
846void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
847 int rowsize, int groupsize, const void *buf, size_t len,
848 bool ascii)
849{
850 const u8 *ptr = buf;
851 int i, linelen, remaining = len;
8b91a318
AS
852 char *buffer;
853 size_t size;
37607102
AS
854 int ret;
855
856 if (rowsize != 16 && rowsize != 32)
857 rowsize = 16;
858
859 for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) {
860 linelen = min(remaining, rowsize);
861 remaining -= rowsize;
862
863 switch (prefix_type) {
864 case DUMP_PREFIX_ADDRESS:
865 seq_printf(m, "%s%p: ", prefix_str, ptr + i);
866 break;
867 case DUMP_PREFIX_OFFSET:
868 seq_printf(m, "%s%.8x: ", prefix_str, i);
869 break;
870 default:
871 seq_printf(m, "%s", prefix_str);
872 break;
873 }
874
8b91a318 875 size = seq_get_buf(m, &buffer);
37607102 876 ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
8b91a318
AS
877 buffer, size, ascii);
878 seq_commit(m, ret < size ? ret : -1);
879
880 seq_putc(m, '\n');
37607102
AS
881 }
882}
883EXPORT_SYMBOL(seq_hex_dump);
884
bcf67e16
PE
885struct list_head *seq_list_start(struct list_head *head, loff_t pos)
886{
887 struct list_head *lh;
888
889 list_for_each(lh, head)
890 if (pos-- == 0)
891 return lh;
892
893 return NULL;
894}
bcf67e16
PE
895EXPORT_SYMBOL(seq_list_start);
896
897struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
898{
899 if (!pos)
900 return head;
901
902 return seq_list_start(head, pos - 1);
903}
bcf67e16
PE
904EXPORT_SYMBOL(seq_list_start_head);
905
906struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
907{
908 struct list_head *lh;
909
910 lh = ((struct list_head *)v)->next;
911 ++*ppos;
912 return lh == head ? NULL : lh;
913}
bcf67e16 914EXPORT_SYMBOL(seq_list_next);
66655de6
LZ
915
916/**
917 * seq_hlist_start - start an iteration of a hlist
918 * @head: the head of the hlist
919 * @pos: the start position of the sequence
920 *
921 * Called at seq_file->op->start().
922 */
923struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
924{
925 struct hlist_node *node;
926
927 hlist_for_each(node, head)
928 if (pos-- == 0)
929 return node;
930 return NULL;
931}
932EXPORT_SYMBOL(seq_hlist_start);
933
934/**
935 * seq_hlist_start_head - start an iteration of a hlist
936 * @head: the head of the hlist
937 * @pos: the start position of the sequence
938 *
939 * Called at seq_file->op->start(). Call this function if you want to
940 * print a header at the top of the output.
941 */
942struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
943{
944 if (!pos)
945 return SEQ_START_TOKEN;
946
947 return seq_hlist_start(head, pos - 1);
948}
949EXPORT_SYMBOL(seq_hlist_start_head);
950
951/**
952 * seq_hlist_next - move to the next position of the hlist
953 * @v: the current iterator
954 * @head: the head of the hlist
138860b9 955 * @ppos: the current position
66655de6
LZ
956 *
957 * Called at seq_file->op->next().
958 */
959struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
960 loff_t *ppos)
961{
962 struct hlist_node *node = v;
963
964 ++*ppos;
965 if (v == SEQ_START_TOKEN)
966 return head->first;
967 else
968 return node->next;
969}
970EXPORT_SYMBOL(seq_hlist_next);
1cc52327 971
972/**
973 * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU
974 * @head: the head of the hlist
975 * @pos: the start position of the sequence
976 *
977 * Called at seq_file->op->start().
978 *
979 * This list-traversal primitive may safely run concurrently with
980 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
981 * as long as the traversal is guarded by rcu_read_lock().
982 */
983struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
984 loff_t pos)
985{
986 struct hlist_node *node;
987
988 __hlist_for_each_rcu(node, head)
989 if (pos-- == 0)
990 return node;
991 return NULL;
992}
993EXPORT_SYMBOL(seq_hlist_start_rcu);
994
995/**
996 * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU
997 * @head: the head of the hlist
998 * @pos: the start position of the sequence
999 *
1000 * Called at seq_file->op->start(). Call this function if you want to
1001 * print a header at the top of the output.
1002 *
1003 * This list-traversal primitive may safely run concurrently with
1004 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
1005 * as long as the traversal is guarded by rcu_read_lock().
1006 */
1007struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
1008 loff_t pos)
1009{
1010 if (!pos)
1011 return SEQ_START_TOKEN;
1012
1013 return seq_hlist_start_rcu(head, pos - 1);
1014}
1015EXPORT_SYMBOL(seq_hlist_start_head_rcu);
1016
1017/**
1018 * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU
1019 * @v: the current iterator
1020 * @head: the head of the hlist
138860b9 1021 * @ppos: the current position
1cc52327 1022 *
1023 * Called at seq_file->op->next().
1024 *
1025 * This list-traversal primitive may safely run concurrently with
1026 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
1027 * as long as the traversal is guarded by rcu_read_lock().
1028 */
1029struct hlist_node *seq_hlist_next_rcu(void *v,
1030 struct hlist_head *head,
1031 loff_t *ppos)
1032{
1033 struct hlist_node *node = v;
1034
1035 ++*ppos;
1036 if (v == SEQ_START_TOKEN)
1037 return rcu_dereference(head->first);
1038 else
1039 return rcu_dereference(node->next);
1040}
1041EXPORT_SYMBOL(seq_hlist_next_rcu);
0bc77381
JL
1042
1043/**
1044 * seq_hlist_start_precpu - start an iteration of a percpu hlist array
1045 * @head: pointer to percpu array of struct hlist_heads
1046 * @cpu: pointer to cpu "cursor"
1047 * @pos: start position of sequence
1048 *
1049 * Called at seq_file->op->start().
1050 */
1051struct hlist_node *
1052seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos)
1053{
1054 struct hlist_node *node;
1055
1056 for_each_possible_cpu(*cpu) {
1057 hlist_for_each(node, per_cpu_ptr(head, *cpu)) {
1058 if (pos-- == 0)
1059 return node;
1060 }
1061 }
1062 return NULL;
1063}
1064EXPORT_SYMBOL(seq_hlist_start_percpu);
1065
1066/**
1067 * seq_hlist_next_percpu - move to the next position of the percpu hlist array
1068 * @v: pointer to current hlist_node
1069 * @head: pointer to percpu array of struct hlist_heads
1070 * @cpu: pointer to cpu "cursor"
1071 * @pos: start position of sequence
1072 *
1073 * Called at seq_file->op->next().
1074 */
1075struct hlist_node *
1076seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head,
1077 int *cpu, loff_t *pos)
1078{
1079 struct hlist_node *node = v;
1080
1081 ++*pos;
1082
1083 if (node->next)
1084 return node->next;
1085
1086 for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids;
1087 *cpu = cpumask_next(*cpu, cpu_possible_mask)) {
1088 struct hlist_head *bucket = per_cpu_ptr(head, *cpu);
1089
1090 if (!hlist_empty(bucket))
1091 return bucket->first;
1092 }
1093 return NULL;
1094}
1095EXPORT_SYMBOL(seq_hlist_next_percpu);
09652320
AD
1096
1097void __init seq_file_init(void)
1098{
d64d01a1 1099 seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC);
09652320 1100}