drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings
[linux-block.git] / fs / seq_file.c
CommitLineData
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 69
8f19d472
EB
70 /*
71 * seq_files support lseek() and pread(). They do not implement
72 * write() at all, but we clear FMODE_PWRITE here for historical
73 * reasons.
74 *
75 * If a client of seq_files a) implements file.write() and b) wishes to
76 * support pwrite() then that client will need to implement its own
77 * file.open() which calls seq_open() and then sets FMODE_PWRITE.
78 */
79 file->f_mode &= ~FMODE_PWRITE;
1da177e4
LT
80 return 0;
81}
82EXPORT_SYMBOL(seq_open);
83
33da8892
EB
84static int traverse(struct seq_file *m, loff_t offset)
85{
1f4aace6 86 loff_t pos = 0;
33da8892
EB
87 int error = 0;
88 void *p;
89
1f4aace6 90 m->index = 0;
33da8892 91 m->count = m->from = 0;
1f4aace6 92 if (!offset)
33da8892 93 return 0;
1f4aace6 94
33da8892 95 if (!m->buf) {
058504ed 96 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
33da8892
EB
97 if (!m->buf)
98 return -ENOMEM;
99 }
1f4aace6 100 p = m->op->start(m, &m->index);
33da8892
EB
101 while (p) {
102 error = PTR_ERR(p);
103 if (IS_ERR(p))
104 break;
105 error = m->op->show(m, p);
106 if (error < 0)
107 break;
108 if (unlikely(error)) {
109 error = 0;
110 m->count = 0;
111 }
1f33c41c 112 if (seq_has_overflowed(m))
33da8892 113 goto Eoverflow;
6a2aeab5 114 p = m->op->next(m, p, &m->index);
33da8892
EB
115 if (pos + m->count > offset) {
116 m->from = offset - pos;
117 m->count -= m->from;
33da8892
EB
118 break;
119 }
120 pos += m->count;
121 m->count = 0;
1f4aace6 122 if (pos == offset)
33da8892 123 break;
33da8892
EB
124 }
125 m->op->stop(m, p);
126 return error;
127
128Eoverflow:
129 m->op->stop(m, p);
058504ed 130 kvfree(m->buf);
801a7605 131 m->count = 0;
058504ed 132 m->buf = seq_buf_alloc(m->size <<= 1);
33da8892
EB
133 return !m->buf ? -ENOMEM : -EAGAIN;
134}
135
1da177e4
LT
136/**
137 * seq_read - ->read() method for sequential files.
67be2dd1
MW
138 * @file: the file to read from
139 * @buf: the buffer to read to
140 * @size: the maximum number of bytes to read
141 * @ppos: the current position in the file
1da177e4
LT
142 *
143 * Ready-made ->f_op->read()
144 */
145ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
146{
8209e2f4 147 struct seq_file *m = file->private_data;
1da177e4 148 size_t copied = 0;
1da177e4
LT
149 size_t n;
150 void *p;
151 int err = 0;
152
0ac1759a 153 mutex_lock(&m->lock);
8f19d472 154
e522751d
TM
155 /*
156 * if request is to read from zero offset, reset iterator to first
157 * record as it might have been already advanced by previous requests
158 */
cf5eebae 159 if (*ppos == 0) {
e522751d 160 m->index = 0;
cf5eebae
MS
161 m->count = 0;
162 }
e522751d 163
8f19d472
EB
164 /* Don't assume *ppos is where we left it */
165 if (unlikely(*ppos != m->read_pos)) {
8f19d472
EB
166 while ((err = traverse(m, *ppos)) == -EAGAIN)
167 ;
168 if (err) {
169 /* With prejudice... */
170 m->read_pos = 0;
8f19d472
EB
171 m->index = 0;
172 m->count = 0;
173 goto Done;
7904ac84
EC
174 } else {
175 m->read_pos = *ppos;
8f19d472
EB
176 }
177 }
178
1da177e4
LT
179 /* grab buffer if we didn't have one */
180 if (!m->buf) {
058504ed 181 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
1da177e4
LT
182 if (!m->buf)
183 goto Enomem;
184 }
185 /* if not empty - flush it first */
186 if (m->count) {
187 n = min(m->count, size);
188 err = copy_to_user(buf, m->buf + m->from, n);
189 if (err)
190 goto Efault;
191 m->count -= n;
192 m->from += n;
193 size -= n;
194 buf += n;
195 copied += n;
1da177e4
LT
196 if (!size)
197 goto Done;
198 }
199 /* we need at least one record in buffer */
1f4aace6
N
200 m->from = 0;
201 p = m->op->start(m, &m->index);
1da177e4 202 while (1) {
1da177e4
LT
203 err = PTR_ERR(p);
204 if (!p || IS_ERR(p))
205 break;
206 err = m->op->show(m, p);
521b5d0c 207 if (err < 0)
1da177e4 208 break;
521b5d0c
AV
209 if (unlikely(err))
210 m->count = 0;
4cdfe84b 211 if (unlikely(!m->count)) {
1f4aace6 212 p = m->op->next(m, p, &m->index);
4cdfe84b
AV
213 continue;
214 }
1da177e4
LT
215 if (m->count < m->size)
216 goto Fill;
217 m->op->stop(m, p);
058504ed 218 kvfree(m->buf);
801a7605 219 m->count = 0;
058504ed 220 m->buf = seq_buf_alloc(m->size <<= 1);
1da177e4
LT
221 if (!m->buf)
222 goto Enomem;
1f4aace6 223 p = m->op->start(m, &m->index);
1da177e4
LT
224 }
225 m->op->stop(m, p);
226 m->count = 0;
227 goto Done;
228Fill:
229 /* they want more? let's try to get some more */
1f4aace6 230 while (1) {
1da177e4 231 size_t offs = m->count;
1f4aace6
N
232 loff_t pos = m->index;
233
234 p = m->op->next(m, p, &m->index);
235 if (pos == m->index)
236 /* Buggy ->next function */
237 m->index++;
1da177e4
LT
238 if (!p || IS_ERR(p)) {
239 err = PTR_ERR(p);
240 break;
241 }
1f4aace6
N
242 if (m->count >= size)
243 break;
1da177e4 244 err = m->op->show(m, p);
1f33c41c 245 if (seq_has_overflowed(m) || err) {
1da177e4 246 m->count = offs;
521b5d0c
AV
247 if (likely(err <= 0))
248 break;
1da177e4 249 }
1da177e4
LT
250 }
251 m->op->stop(m, p);
252 n = min(m->count, size);
253 err = copy_to_user(buf, m->buf, n);
254 if (err)
255 goto Efault;
256 copied += n;
257 m->count -= n;
1f4aace6 258 m->from = n;
1da177e4
LT
259Done:
260 if (!copied)
261 copied = err;
8f19d472 262 else {
1da177e4 263 *ppos += copied;
8f19d472
EB
264 m->read_pos += copied;
265 }
0ac1759a 266 mutex_unlock(&m->lock);
1da177e4
LT
267 return copied;
268Enomem:
269 err = -ENOMEM;
270 goto Done;
271Efault:
272 err = -EFAULT;
273 goto Done;
274}
275EXPORT_SYMBOL(seq_read);
276
1da177e4
LT
277/**
278 * seq_lseek - ->llseek() method for sequential files.
67be2dd1
MW
279 * @file: the file in question
280 * @offset: new position
254adaa4 281 * @whence: 0 for absolute, 1 for relative position
1da177e4
LT
282 *
283 * Ready-made ->f_op->llseek()
284 */
965c8e59 285loff_t seq_lseek(struct file *file, loff_t offset, int whence)
1da177e4 286{
8209e2f4 287 struct seq_file *m = file->private_data;
16abef0e 288 loff_t retval = -EINVAL;
1da177e4 289
0ac1759a 290 mutex_lock(&m->lock);
965c8e59 291 switch (whence) {
5e62adef
AM
292 case SEEK_CUR:
293 offset += file->f_pos;
0a4c9265 294 /* fall through */
5e62adef
AM
295 case SEEK_SET:
296 if (offset < 0)
297 break;
298 retval = offset;
299 if (offset != m->read_pos) {
300 while ((retval = traverse(m, offset)) == -EAGAIN)
301 ;
302 if (retval) {
303 /* with extreme prejudice... */
304 file->f_pos = 0;
305 m->read_pos = 0;
5e62adef
AM
306 m->index = 0;
307 m->count = 0;
308 } else {
309 m->read_pos = offset;
310 retval = file->f_pos = offset;
1da177e4 311 }
05e16745
GZ
312 } else {
313 file->f_pos = offset;
5e62adef 314 }
1da177e4 315 }
00c5746d 316 mutex_unlock(&m->lock);
1da177e4
LT
317 return retval;
318}
319EXPORT_SYMBOL(seq_lseek);
320
321/**
322 * seq_release - free the structures associated with sequential file.
323 * @file: file in question
6131ffaa 324 * @inode: its inode
1da177e4
LT
325 *
326 * Frees the structures associated with sequential file; can be used
327 * as ->f_op->release() if you don't have private data to destroy.
328 */
329int seq_release(struct inode *inode, struct file *file)
330{
8209e2f4 331 struct seq_file *m = file->private_data;
058504ed 332 kvfree(m->buf);
09652320 333 kmem_cache_free(seq_file_cache, m);
1da177e4
LT
334 return 0;
335}
336EXPORT_SYMBOL(seq_release);
337
338/**
339 * seq_escape - print string into buffer, escaping some characters
340 * @m: target buffer
341 * @s: string
342 * @esc: set of characters that need escaping
343 *
344 * Puts string into buffer, replacing each occurrence of character from
6798a8ca
JP
345 * @esc with usual octal escape.
346 * Use seq_has_overflowed() to check for errors.
1da177e4 347 */
6798a8ca 348void seq_escape(struct seq_file *m, const char *s, const char *esc)
1da177e4 349{
25c6bb76
AS
350 char *buf;
351 size_t size = seq_get_buf(m, &buf);
352 int ret;
1da177e4 353
25c6bb76
AS
354 ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc);
355 seq_commit(m, ret < size ? ret : -1);
1da177e4
LT
356}
357EXPORT_SYMBOL(seq_escape);
358
ea053e16
BF
359void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz)
360{
361 char *buf;
362 size_t size = seq_get_buf(m, &buf);
363 int ret;
364
365 ret = string_escape_mem_ascii(src, isz, buf, size);
366 seq_commit(m, ret < size ? ret : -1);
367}
368EXPORT_SYMBOL(seq_escape_mem_ascii);
369
6798a8ca 370void seq_vprintf(struct seq_file *m, const char *f, va_list args)
1da177e4 371{
1da177e4
LT
372 int len;
373
374 if (m->count < m->size) {
1da177e4 375 len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
1da177e4
LT
376 if (m->count + len < m->size) {
377 m->count += len;
6798a8ca 378 return;
1da177e4
LT
379 }
380 }
e075f591 381 seq_set_overflow(m);
1da177e4 382}
a4808147
SW
383EXPORT_SYMBOL(seq_vprintf);
384
6798a8ca 385void seq_printf(struct seq_file *m, const char *f, ...)
a4808147 386{
a4808147
SW
387 va_list args;
388
389 va_start(args, f);
6798a8ca 390 seq_vprintf(m, f, args);
a4808147 391 va_end(args);
a4808147 392}
1da177e4
LT
393EXPORT_SYMBOL(seq_printf);
394
74e2f334 395/**
958086d1
TE
396 * mangle_path - mangle and copy path to buffer beginning
397 * @s: buffer start
398 * @p: beginning of path in above buffer
399 * @esc: set of characters that need escaping
74e2f334
TE
400 *
401 * Copy the path from @p to @s, replacing each occurrence of character from
402 * @esc with usual octal escape.
403 * Returns pointer past last written character in @s, or NULL in case of
404 * failure.
405 */
8c9379e9 406char *mangle_path(char *s, const char *p, const char *esc)
6092d048
RP
407{
408 while (s <= p) {
409 char c = *p++;
410 if (!c) {
411 return s;
412 } else if (!strchr(esc, c)) {
413 *s++ = c;
414 } else if (s + 4 > p) {
415 break;
416 } else {
417 *s++ = '\\';
418 *s++ = '0' + ((c & 0300) >> 6);
419 *s++ = '0' + ((c & 070) >> 3);
420 *s++ = '0' + (c & 07);
421 }
422 }
423 return NULL;
424}
604094f4 425EXPORT_SYMBOL(mangle_path);
6092d048 426
52afeefb
AV
427/**
428 * seq_path - seq_file interface to print a pathname
429 * @m: the seq_file handle
430 * @path: the struct path to print
431 * @esc: set of characters to escape in the output
432 *
433 * return the absolute path of 'path', as represented by the
434 * dentry / mnt pair in the path parameter.
6092d048 435 */
8c9379e9 436int seq_path(struct seq_file *m, const struct path *path, const char *esc)
1da177e4 437{
f8439806
MS
438 char *buf;
439 size_t size = seq_get_buf(m, &buf);
440 int res = -1;
441
442 if (size) {
443 char *p = d_path(path, buf, size);
1da177e4 444 if (!IS_ERR(p)) {
f8439806
MS
445 char *end = mangle_path(buf, p, esc);
446 if (end)
447 res = end - buf;
1da177e4
LT
448 }
449 }
f8439806
MS
450 seq_commit(m, res);
451
452 return res;
1da177e4
LT
453}
454EXPORT_SYMBOL(seq_path);
455
2726d566
MS
456/**
457 * seq_file_path - seq_file interface to print a pathname of a file
458 * @m: the seq_file handle
459 * @file: the struct file to print
460 * @esc: set of characters to escape in the output
461 *
462 * return the absolute path to the file.
463 */
464int seq_file_path(struct seq_file *m, struct file *file, const char *esc)
465{
466 return seq_path(m, &file->f_path, esc);
467}
468EXPORT_SYMBOL(seq_file_path);
469
9d1bc601
MS
470/*
471 * Same as seq_path, but relative to supplied root.
9d1bc601 472 */
8c9379e9
AV
473int seq_path_root(struct seq_file *m, const struct path *path,
474 const struct path *root, const char *esc)
9d1bc601 475{
f8439806
MS
476 char *buf;
477 size_t size = seq_get_buf(m, &buf);
478 int res = -ENAMETOOLONG;
479
480 if (size) {
9d1bc601
MS
481 char *p;
482
f8439806 483 p = __d_path(path, root, buf, size);
02125a82
AV
484 if (!p)
485 return SEQ_SKIP;
f8439806 486 res = PTR_ERR(p);
9d1bc601 487 if (!IS_ERR(p)) {
f8439806
MS
488 char *end = mangle_path(buf, p, esc);
489 if (end)
490 res = end - buf;
491 else
492 res = -ENAMETOOLONG;
9d1bc601
MS
493 }
494 }
f8439806
MS
495 seq_commit(m, res);
496
02125a82 497 return res < 0 && res != -ENAMETOOLONG ? res : 0;
9d1bc601
MS
498}
499
6092d048
RP
500/*
501 * returns the path of the 'dentry' from the root of its filesystem.
502 */
8c9379e9 503int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc)
6092d048 504{
f8439806
MS
505 char *buf;
506 size_t size = seq_get_buf(m, &buf);
507 int res = -1;
508
509 if (size) {
510 char *p = dentry_path(dentry, buf, size);
6092d048 511 if (!IS_ERR(p)) {
f8439806
MS
512 char *end = mangle_path(buf, p, esc);
513 if (end)
514 res = end - buf;
6092d048
RP
515 }
516 }
f8439806
MS
517 seq_commit(m, res);
518
519 return res;
6092d048 520}
c8d3fe02 521EXPORT_SYMBOL(seq_dentry);
6092d048 522
1da177e4
LT
523static void *single_start(struct seq_file *p, loff_t *pos)
524{
525 return NULL + (*pos == 0);
526}
527
528static void *single_next(struct seq_file *p, void *v, loff_t *pos)
529{
530 ++*pos;
531 return NULL;
532}
533
534static void single_stop(struct seq_file *p, void *v)
535{
536}
537
538int single_open(struct file *file, int (*show)(struct seq_file *, void *),
539 void *data)
540{
d64d01a1 541 struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT);
1da177e4
LT
542 int res = -ENOMEM;
543
544 if (op) {
545 op->start = single_start;
546 op->next = single_next;
547 op->stop = single_stop;
548 op->show = show;
549 res = seq_open(file, op);
550 if (!res)
551 ((struct seq_file *)file->private_data)->private = data;
552 else
553 kfree(op);
554 }
555 return res;
556}
557EXPORT_SYMBOL(single_open);
558
2043f495
AV
559int single_open_size(struct file *file, int (*show)(struct seq_file *, void *),
560 void *data, size_t size)
561{
058504ed 562 char *buf = seq_buf_alloc(size);
2043f495
AV
563 int ret;
564 if (!buf)
565 return -ENOMEM;
566 ret = single_open(file, show, data);
567 if (ret) {
058504ed 568 kvfree(buf);
2043f495
AV
569 return ret;
570 }
571 ((struct seq_file *)file->private_data)->buf = buf;
572 ((struct seq_file *)file->private_data)->size = size;
573 return 0;
574}
575EXPORT_SYMBOL(single_open_size);
576
1da177e4
LT
577int single_release(struct inode *inode, struct file *file)
578{
15ad7cdc 579 const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
1da177e4
LT
580 int res = seq_release(inode, file);
581 kfree(op);
582 return res;
583}
584EXPORT_SYMBOL(single_release);
585
586int seq_release_private(struct inode *inode, struct file *file)
587{
588 struct seq_file *seq = file->private_data;
589
590 kfree(seq->private);
591 seq->private = NULL;
592 return seq_release(inode, file);
593}
594EXPORT_SYMBOL(seq_release_private);
595
39699037
PE
596void *__seq_open_private(struct file *f, const struct seq_operations *ops,
597 int psize)
598{
599 int rc;
600 void *private;
601 struct seq_file *seq;
602
d64d01a1 603 private = kzalloc(psize, GFP_KERNEL_ACCOUNT);
39699037
PE
604 if (private == NULL)
605 goto out;
606
607 rc = seq_open(f, ops);
608 if (rc < 0)
609 goto out_free;
610
611 seq = f->private_data;
612 seq->private = private;
613 return private;
614
615out_free:
616 kfree(private);
617out:
618 return NULL;
619}
620EXPORT_SYMBOL(__seq_open_private);
621
622int seq_open_private(struct file *filp, const struct seq_operations *ops,
623 int psize)
624{
625 return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
626}
627EXPORT_SYMBOL(seq_open_private);
628
6798a8ca 629void seq_putc(struct seq_file *m, char c)
1da177e4 630{
6798a8ca
JP
631 if (m->count >= m->size)
632 return;
633
634 m->buf[m->count++] = c;
1da177e4
LT
635}
636EXPORT_SYMBOL(seq_putc);
637
6798a8ca 638void seq_puts(struct seq_file *m, const char *s)
1da177e4
LT
639{
640 int len = strlen(s);
6798a8ca
JP
641
642 if (m->count + len >= m->size) {
643 seq_set_overflow(m);
644 return;
1da177e4 645 }
6798a8ca
JP
646 memcpy(m->buf + m->count, s, len);
647 m->count += len;
1da177e4
LT
648}
649EXPORT_SYMBOL(seq_puts);
bcf67e16 650
d1be35cb 651/**
1ac101a5
KH
652 * A helper routine for putting decimal numbers without rich format of printf().
653 * only 'unsigned long long' is supported.
d1be35cb
AV
654 * @m: seq_file identifying the buffer to which data should be written
655 * @delimiter: a string which is printed before the number
656 * @num: the number
657 * @width: a minimum field width
658 *
659 * This routine will put strlen(delimiter) + number into seq_filed.
1ac101a5
KH
660 * This routine is very quick when you show lots of numbers.
661 * In usual cases, it will be better to use seq_printf(). It's easier to read.
662 */
d1be35cb
AV
663void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
664 unsigned long long num, unsigned int width)
1ac101a5
KH
665{
666 int len;
667
668 if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */
669 goto overflow;
670
48dffbf8
AV
671 if (delimiter && delimiter[0]) {
672 if (delimiter[1] == 0)
673 seq_putc(m, delimiter[0]);
674 else
675 seq_puts(m, delimiter);
676 }
75ba1d07 677
d1be35cb
AV
678 if (!width)
679 width = 1;
680
681 if (m->count + width >= m->size)
75ba1d07 682 goto overflow;
1ac101a5 683
d1be35cb 684 len = num_to_str(m->buf + m->count, m->size - m->count, num, width);
1ac101a5
KH
685 if (!len)
686 goto overflow;
75ba1d07 687
1ac101a5 688 m->count += len;
6798a8ca
JP
689 return;
690
1ac101a5 691overflow:
e075f591 692 seq_set_overflow(m);
1ac101a5 693}
d1be35cb
AV
694
695void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
696 unsigned long long num)
697{
698 return seq_put_decimal_ull_width(m, delimiter, num, 0);
699}
1ac101a5
KH
700EXPORT_SYMBOL(seq_put_decimal_ull);
701
0e3dc019
AV
702/**
703 * seq_put_hex_ll - put a number in hexadecimal notation
704 * @m: seq_file identifying the buffer to which data should be written
705 * @delimiter: a string which is printed before the number
706 * @v: the number
707 * @width: a minimum field width
708 *
709 * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v)
710 *
711 * This routine is very quick when you show lots of numbers.
712 * In usual cases, it will be better to use seq_printf(). It's easier to read.
713 */
714void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
715 unsigned long long v, unsigned int width)
716{
717 unsigned int len;
718 int i;
719
720 if (delimiter && delimiter[0]) {
721 if (delimiter[1] == 0)
722 seq_putc(m, delimiter[0]);
723 else
724 seq_puts(m, delimiter);
725 }
726
727 /* If x is 0, the result of __builtin_clzll is undefined */
728 if (v == 0)
729 len = 1;
730 else
731 len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4;
732
733 if (len < width)
734 len = width;
735
736 if (m->count + len > m->size) {
737 seq_set_overflow(m);
738 return;
739 }
740
741 for (i = len - 1; i >= 0; i--) {
742 m->buf[m->count + i] = hex_asc[0xf & v];
743 v = v >> 4;
744 }
745 m->count += len;
746}
747
75ba1d07 748void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num)
bda7bad6 749{
75ba1d07
JP
750 int len;
751
752 if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */
753 goto overflow;
754
48dffbf8
AV
755 if (delimiter && delimiter[0]) {
756 if (delimiter[1] == 0)
757 seq_putc(m, delimiter[0]);
758 else
759 seq_puts(m, delimiter);
760 }
75ba1d07
JP
761
762 if (m->count + 2 >= m->size)
763 goto overflow;
764
bda7bad6 765 if (num < 0) {
75ba1d07 766 m->buf[m->count++] = '-';
bda7bad6 767 num = -num;
bda7bad6 768 }
75ba1d07
JP
769
770 if (num < 10) {
771 m->buf[m->count++] = num + '0';
772 return;
773 }
774
d1be35cb 775 len = num_to_str(m->buf + m->count, m->size - m->count, num, 0);
75ba1d07
JP
776 if (!len)
777 goto overflow;
778
779 m->count += len;
780 return;
781
782overflow:
783 seq_set_overflow(m);
bda7bad6
KH
784}
785EXPORT_SYMBOL(seq_put_decimal_ll);
786
0b923606
PO
787/**
788 * seq_write - write arbitrary data to buffer
789 * @seq: seq_file identifying the buffer to which data should be written
790 * @data: data address
791 * @len: number of bytes
792 *
793 * Return 0 on success, non-zero otherwise.
794 */
795int seq_write(struct seq_file *seq, const void *data, size_t len)
796{
797 if (seq->count + len < seq->size) {
798 memcpy(seq->buf + seq->count, data, len);
799 seq->count += len;
800 return 0;
801 }
e075f591 802 seq_set_overflow(seq);
0b923606
PO
803 return -1;
804}
805EXPORT_SYMBOL(seq_write);
806
839cc2a9
TH
807/**
808 * seq_pad - write padding spaces to buffer
809 * @m: seq_file identifying the buffer to which data should be written
810 * @c: the byte to append after padding if non-zero
811 */
812void seq_pad(struct seq_file *m, char c)
813{
814 int size = m->pad_until - m->count;
8cfa67b4
AV
815 if (size > 0) {
816 if (size + m->count > m->size) {
817 seq_set_overflow(m);
818 return;
819 }
820 memset(m->buf + m->count, ' ', size);
821 m->count += size;
822 }
839cc2a9
TH
823 if (c)
824 seq_putc(m, c);
825}
826EXPORT_SYMBOL(seq_pad);
827
37607102
AS
828/* A complete analogue of print_hex_dump() */
829void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
830 int rowsize, int groupsize, const void *buf, size_t len,
831 bool ascii)
832{
833 const u8 *ptr = buf;
834 int i, linelen, remaining = len;
8b91a318
AS
835 char *buffer;
836 size_t size;
37607102
AS
837 int ret;
838
839 if (rowsize != 16 && rowsize != 32)
840 rowsize = 16;
841
842 for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) {
843 linelen = min(remaining, rowsize);
844 remaining -= rowsize;
845
846 switch (prefix_type) {
847 case DUMP_PREFIX_ADDRESS:
848 seq_printf(m, "%s%p: ", prefix_str, ptr + i);
849 break;
850 case DUMP_PREFIX_OFFSET:
851 seq_printf(m, "%s%.8x: ", prefix_str, i);
852 break;
853 default:
854 seq_printf(m, "%s", prefix_str);
855 break;
856 }
857
8b91a318 858 size = seq_get_buf(m, &buffer);
37607102 859 ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
8b91a318
AS
860 buffer, size, ascii);
861 seq_commit(m, ret < size ? ret : -1);
862
863 seq_putc(m, '\n');
37607102
AS
864 }
865}
866EXPORT_SYMBOL(seq_hex_dump);
867
bcf67e16
PE
868struct list_head *seq_list_start(struct list_head *head, loff_t pos)
869{
870 struct list_head *lh;
871
872 list_for_each(lh, head)
873 if (pos-- == 0)
874 return lh;
875
876 return NULL;
877}
bcf67e16
PE
878EXPORT_SYMBOL(seq_list_start);
879
880struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
881{
882 if (!pos)
883 return head;
884
885 return seq_list_start(head, pos - 1);
886}
bcf67e16
PE
887EXPORT_SYMBOL(seq_list_start_head);
888
889struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
890{
891 struct list_head *lh;
892
893 lh = ((struct list_head *)v)->next;
894 ++*ppos;
895 return lh == head ? NULL : lh;
896}
bcf67e16 897EXPORT_SYMBOL(seq_list_next);
66655de6
LZ
898
899/**
900 * seq_hlist_start - start an iteration of a hlist
901 * @head: the head of the hlist
902 * @pos: the start position of the sequence
903 *
904 * Called at seq_file->op->start().
905 */
906struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
907{
908 struct hlist_node *node;
909
910 hlist_for_each(node, head)
911 if (pos-- == 0)
912 return node;
913 return NULL;
914}
915EXPORT_SYMBOL(seq_hlist_start);
916
917/**
918 * seq_hlist_start_head - start an iteration of a hlist
919 * @head: the head of the hlist
920 * @pos: the start position of the sequence
921 *
922 * Called at seq_file->op->start(). Call this function if you want to
923 * print a header at the top of the output.
924 */
925struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
926{
927 if (!pos)
928 return SEQ_START_TOKEN;
929
930 return seq_hlist_start(head, pos - 1);
931}
932EXPORT_SYMBOL(seq_hlist_start_head);
933
934/**
935 * seq_hlist_next - move to the next position of the hlist
936 * @v: the current iterator
937 * @head: the head of the hlist
138860b9 938 * @ppos: the current position
66655de6
LZ
939 *
940 * Called at seq_file->op->next().
941 */
942struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
943 loff_t *ppos)
944{
945 struct hlist_node *node = v;
946
947 ++*ppos;
948 if (v == SEQ_START_TOKEN)
949 return head->first;
950 else
951 return node->next;
952}
953EXPORT_SYMBOL(seq_hlist_next);
1cc52327 954
955/**
956 * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU
957 * @head: the head of the hlist
958 * @pos: the start position of the sequence
959 *
960 * Called at seq_file->op->start().
961 *
962 * This list-traversal primitive may safely run concurrently with
963 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
964 * as long as the traversal is guarded by rcu_read_lock().
965 */
966struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
967 loff_t pos)
968{
969 struct hlist_node *node;
970
971 __hlist_for_each_rcu(node, head)
972 if (pos-- == 0)
973 return node;
974 return NULL;
975}
976EXPORT_SYMBOL(seq_hlist_start_rcu);
977
978/**
979 * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU
980 * @head: the head of the hlist
981 * @pos: the start position of the sequence
982 *
983 * Called at seq_file->op->start(). Call this function if you want to
984 * print a header at the top of the output.
985 *
986 * This list-traversal primitive may safely run concurrently with
987 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
988 * as long as the traversal is guarded by rcu_read_lock().
989 */
990struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
991 loff_t pos)
992{
993 if (!pos)
994 return SEQ_START_TOKEN;
995
996 return seq_hlist_start_rcu(head, pos - 1);
997}
998EXPORT_SYMBOL(seq_hlist_start_head_rcu);
999
1000/**
1001 * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU
1002 * @v: the current iterator
1003 * @head: the head of the hlist
138860b9 1004 * @ppos: the current position
1cc52327 1005 *
1006 * Called at seq_file->op->next().
1007 *
1008 * This list-traversal primitive may safely run concurrently with
1009 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
1010 * as long as the traversal is guarded by rcu_read_lock().
1011 */
1012struct hlist_node *seq_hlist_next_rcu(void *v,
1013 struct hlist_head *head,
1014 loff_t *ppos)
1015{
1016 struct hlist_node *node = v;
1017
1018 ++*ppos;
1019 if (v == SEQ_START_TOKEN)
1020 return rcu_dereference(head->first);
1021 else
1022 return rcu_dereference(node->next);
1023}
1024EXPORT_SYMBOL(seq_hlist_next_rcu);
0bc77381
JL
1025
1026/**
1027 * seq_hlist_start_precpu - start an iteration of a percpu hlist array
1028 * @head: pointer to percpu array of struct hlist_heads
1029 * @cpu: pointer to cpu "cursor"
1030 * @pos: start position of sequence
1031 *
1032 * Called at seq_file->op->start().
1033 */
1034struct hlist_node *
1035seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos)
1036{
1037 struct hlist_node *node;
1038
1039 for_each_possible_cpu(*cpu) {
1040 hlist_for_each(node, per_cpu_ptr(head, *cpu)) {
1041 if (pos-- == 0)
1042 return node;
1043 }
1044 }
1045 return NULL;
1046}
1047EXPORT_SYMBOL(seq_hlist_start_percpu);
1048
1049/**
1050 * seq_hlist_next_percpu - move to the next position of the percpu hlist array
1051 * @v: pointer to current hlist_node
1052 * @head: pointer to percpu array of struct hlist_heads
1053 * @cpu: pointer to cpu "cursor"
1054 * @pos: start position of sequence
1055 *
1056 * Called at seq_file->op->next().
1057 */
1058struct hlist_node *
1059seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head,
1060 int *cpu, loff_t *pos)
1061{
1062 struct hlist_node *node = v;
1063
1064 ++*pos;
1065
1066 if (node->next)
1067 return node->next;
1068
1069 for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids;
1070 *cpu = cpumask_next(*cpu, cpu_possible_mask)) {
1071 struct hlist_head *bucket = per_cpu_ptr(head, *cpu);
1072
1073 if (!hlist_empty(bucket))
1074 return bucket->first;
1075 }
1076 return NULL;
1077}
1078EXPORT_SYMBOL(seq_hlist_next_percpu);
09652320
AD
1079
1080void __init seq_file_init(void)
1081{
d64d01a1 1082 seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC);
09652320 1083}