Commit | Line | Data |
---|---|---|
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 | ||
a3963015 JP |
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
10 | ||
09652320 | 11 | #include <linux/cache.h> |
1da177e4 | 12 | #include <linux/fs.h> |
630d9c47 | 13 | #include <linux/export.h> |
1da177e4 | 14 | #include <linux/seq_file.h> |
058504ed | 15 | #include <linux/vmalloc.h> |
1da177e4 | 16 | #include <linux/slab.h> |
adb37c4c | 17 | #include <linux/cred.h> |
058504ed | 18 | #include <linux/mm.h> |
37607102 | 19 | #include <linux/printk.h> |
25c6bb76 | 20 | #include <linux/string_helpers.h> |
1da177e4 | 21 | |
7c0f6ba6 | 22 | #include <linux/uaccess.h> |
1da177e4 LT |
23 | #include <asm/page.h> |
24 | ||
09652320 AD |
25 | static struct kmem_cache *seq_file_cache __ro_after_init; |
26 | ||
e075f591 KH |
27 | static void seq_set_overflow(struct seq_file *m) |
28 | { | |
29 | m->count = m->size; | |
30 | } | |
31 | ||
058504ed HC |
32 | static void *seq_buf_alloc(unsigned long size) |
33 | { | |
d64d01a1 | 34 | return kvmalloc(size, GFP_KERNEL_ACCOUNT); |
058504ed HC |
35 | } |
36 | ||
1da177e4 LT |
37 | /** |
38 | * seq_open - initialize sequential file | |
39 | * @file: file we initialize | |
40 | * @op: method table describing the sequence | |
41 | * | |
42 | * seq_open() sets @file, associating it with a sequence described | |
43 | * by @op. @op->start() sets the iterator up and returns the first | |
44 | * element of sequence. @op->stop() shuts it down. @op->next() | |
45 | * returns the next element of sequence. @op->show() prints element | |
46 | * into the buffer. In case of error ->start() and ->next() return | |
47 | * ERR_PTR(error). In the end of sequence they return %NULL. ->show() | |
48 | * returns 0 in case of success and negative number in case of error. | |
521b5d0c | 49 | * Returning SEQ_SKIP means "discard this element and move on". |
460b865e YD |
50 | * Note: seq_open() will allocate a struct seq_file and store its |
51 | * pointer in @file->private_data. This pointer should not be modified. | |
1da177e4 | 52 | */ |
15ad7cdc | 53 | int seq_open(struct file *file, const struct seq_operations *op) |
1da177e4 | 54 | { |
189f9841 YD |
55 | struct seq_file *p; |
56 | ||
57 | WARN_ON(file->private_data); | |
58 | ||
09652320 | 59 | p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL); |
189f9841 YD |
60 | if (!p) |
61 | return -ENOMEM; | |
62 | ||
63 | file->private_data = p; | |
1abe77b0 | 64 | |
0ac1759a | 65 | mutex_init(&p->lock); |
1da177e4 | 66 | p->op = op; |
34dbbcdb LT |
67 | |
68 | // No refcounting: the lifetime of 'p' is constrained | |
69 | // to the lifetime of the file. | |
70 | p->file = file; | |
1da177e4 | 71 | |
8f19d472 EB |
72 | /* |
73 | * seq_files support lseek() and pread(). They do not implement | |
74 | * write() at all, but we clear FMODE_PWRITE here for historical | |
75 | * reasons. | |
76 | * | |
77 | * If a client of seq_files a) implements file.write() and b) wishes to | |
78 | * support pwrite() then that client will need to implement its own | |
79 | * file.open() which calls seq_open() and then sets FMODE_PWRITE. | |
80 | */ | |
81 | file->f_mode &= ~FMODE_PWRITE; | |
1da177e4 LT |
82 | return 0; |
83 | } | |
84 | EXPORT_SYMBOL(seq_open); | |
85 | ||
33da8892 EB |
86 | static int traverse(struct seq_file *m, loff_t offset) |
87 | { | |
1f4aace6 | 88 | loff_t pos = 0; |
33da8892 EB |
89 | int error = 0; |
90 | void *p; | |
91 | ||
1f4aace6 | 92 | m->index = 0; |
33da8892 | 93 | m->count = m->from = 0; |
1f4aace6 | 94 | if (!offset) |
33da8892 | 95 | return 0; |
1f4aace6 | 96 | |
33da8892 | 97 | if (!m->buf) { |
058504ed | 98 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
33da8892 EB |
99 | if (!m->buf) |
100 | return -ENOMEM; | |
101 | } | |
1f4aace6 | 102 | p = m->op->start(m, &m->index); |
33da8892 EB |
103 | while (p) { |
104 | error = PTR_ERR(p); | |
105 | if (IS_ERR(p)) | |
106 | break; | |
107 | error = m->op->show(m, p); | |
108 | if (error < 0) | |
109 | break; | |
110 | if (unlikely(error)) { | |
111 | error = 0; | |
112 | m->count = 0; | |
113 | } | |
1f33c41c | 114 | if (seq_has_overflowed(m)) |
33da8892 | 115 | goto Eoverflow; |
6a2aeab5 | 116 | p = m->op->next(m, p, &m->index); |
33da8892 EB |
117 | if (pos + m->count > offset) { |
118 | m->from = offset - pos; | |
119 | m->count -= m->from; | |
33da8892 EB |
120 | break; |
121 | } | |
122 | pos += m->count; | |
123 | m->count = 0; | |
1f4aace6 | 124 | if (pos == offset) |
33da8892 | 125 | break; |
33da8892 EB |
126 | } |
127 | m->op->stop(m, p); | |
128 | return error; | |
129 | ||
130 | Eoverflow: | |
131 | m->op->stop(m, p); | |
058504ed | 132 | kvfree(m->buf); |
801a7605 | 133 | m->count = 0; |
058504ed | 134 | m->buf = seq_buf_alloc(m->size <<= 1); |
33da8892 EB |
135 | return !m->buf ? -ENOMEM : -EAGAIN; |
136 | } | |
137 | ||
1da177e4 LT |
138 | /** |
139 | * seq_read - ->read() method for sequential files. | |
67be2dd1 MW |
140 | * @file: the file to read from |
141 | * @buf: the buffer to read to | |
142 | * @size: the maximum number of bytes to read | |
143 | * @ppos: the current position in the file | |
1da177e4 LT |
144 | * |
145 | * Ready-made ->f_op->read() | |
146 | */ | |
147 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
148 | { | |
8209e2f4 | 149 | struct seq_file *m = file->private_data; |
1da177e4 | 150 | size_t copied = 0; |
1da177e4 LT |
151 | size_t n; |
152 | void *p; | |
153 | int err = 0; | |
154 | ||
0ac1759a | 155 | mutex_lock(&m->lock); |
8f19d472 | 156 | |
e522751d TM |
157 | /* |
158 | * if request is to read from zero offset, reset iterator to first | |
159 | * record as it might have been already advanced by previous requests | |
160 | */ | |
cf5eebae | 161 | if (*ppos == 0) { |
e522751d | 162 | m->index = 0; |
cf5eebae MS |
163 | m->count = 0; |
164 | } | |
e522751d | 165 | |
8f19d472 EB |
166 | /* Don't assume *ppos is where we left it */ |
167 | if (unlikely(*ppos != m->read_pos)) { | |
8f19d472 EB |
168 | while ((err = traverse(m, *ppos)) == -EAGAIN) |
169 | ; | |
170 | if (err) { | |
171 | /* With prejudice... */ | |
172 | m->read_pos = 0; | |
8f19d472 EB |
173 | m->index = 0; |
174 | m->count = 0; | |
175 | goto Done; | |
7904ac84 EC |
176 | } else { |
177 | m->read_pos = *ppos; | |
8f19d472 EB |
178 | } |
179 | } | |
180 | ||
1da177e4 LT |
181 | /* grab buffer if we didn't have one */ |
182 | if (!m->buf) { | |
058504ed | 183 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
1da177e4 LT |
184 | if (!m->buf) |
185 | goto Enomem; | |
186 | } | |
187 | /* if not empty - flush it first */ | |
188 | if (m->count) { | |
189 | n = min(m->count, size); | |
190 | err = copy_to_user(buf, m->buf + m->from, n); | |
191 | if (err) | |
192 | goto Efault; | |
193 | m->count -= n; | |
194 | m->from += n; | |
195 | size -= n; | |
196 | buf += n; | |
197 | copied += n; | |
1da177e4 LT |
198 | if (!size) |
199 | goto Done; | |
200 | } | |
201 | /* we need at least one record in buffer */ | |
1f4aace6 N |
202 | m->from = 0; |
203 | p = m->op->start(m, &m->index); | |
1da177e4 | 204 | while (1) { |
1da177e4 LT |
205 | err = PTR_ERR(p); |
206 | if (!p || IS_ERR(p)) | |
207 | break; | |
208 | err = m->op->show(m, p); | |
521b5d0c | 209 | if (err < 0) |
1da177e4 | 210 | break; |
521b5d0c AV |
211 | if (unlikely(err)) |
212 | m->count = 0; | |
4cdfe84b | 213 | if (unlikely(!m->count)) { |
1f4aace6 | 214 | p = m->op->next(m, p, &m->index); |
4cdfe84b AV |
215 | continue; |
216 | } | |
1da177e4 LT |
217 | if (m->count < m->size) |
218 | goto Fill; | |
219 | m->op->stop(m, p); | |
058504ed | 220 | kvfree(m->buf); |
801a7605 | 221 | m->count = 0; |
058504ed | 222 | m->buf = seq_buf_alloc(m->size <<= 1); |
1da177e4 LT |
223 | if (!m->buf) |
224 | goto Enomem; | |
1f4aace6 | 225 | p = m->op->start(m, &m->index); |
1da177e4 LT |
226 | } |
227 | m->op->stop(m, p); | |
228 | m->count = 0; | |
229 | goto Done; | |
230 | Fill: | |
231 | /* they want more? let's try to get some more */ | |
1f4aace6 | 232 | while (1) { |
1da177e4 | 233 | size_t offs = m->count; |
1f4aace6 N |
234 | loff_t pos = m->index; |
235 | ||
236 | p = m->op->next(m, p, &m->index); | |
3bfa7e14 | 237 | if (pos == m->index) { |
a3963015 JP |
238 | pr_info_ratelimited("buggy .next function %ps did not update position index\n", |
239 | m->op->next); | |
1f4aace6 | 240 | m->index++; |
3bfa7e14 | 241 | } |
1da177e4 LT |
242 | if (!p || IS_ERR(p)) { |
243 | err = PTR_ERR(p); | |
244 | break; | |
245 | } | |
1f4aace6 N |
246 | if (m->count >= size) |
247 | break; | |
1da177e4 | 248 | err = m->op->show(m, p); |
1f33c41c | 249 | if (seq_has_overflowed(m) || err) { |
1da177e4 | 250 | m->count = offs; |
521b5d0c AV |
251 | if (likely(err <= 0)) |
252 | break; | |
1da177e4 | 253 | } |
1da177e4 LT |
254 | } |
255 | m->op->stop(m, p); | |
256 | n = min(m->count, size); | |
257 | err = copy_to_user(buf, m->buf, n); | |
258 | if (err) | |
259 | goto Efault; | |
260 | copied += n; | |
261 | m->count -= n; | |
1f4aace6 | 262 | m->from = n; |
1da177e4 LT |
263 | Done: |
264 | if (!copied) | |
265 | copied = err; | |
8f19d472 | 266 | else { |
1da177e4 | 267 | *ppos += copied; |
8f19d472 EB |
268 | m->read_pos += copied; |
269 | } | |
0ac1759a | 270 | mutex_unlock(&m->lock); |
1da177e4 LT |
271 | return copied; |
272 | Enomem: | |
273 | err = -ENOMEM; | |
274 | goto Done; | |
275 | Efault: | |
276 | err = -EFAULT; | |
277 | goto Done; | |
278 | } | |
279 | EXPORT_SYMBOL(seq_read); | |
280 | ||
1da177e4 LT |
281 | /** |
282 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
283 | * @file: the file in question |
284 | * @offset: new position | |
254adaa4 | 285 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
286 | * |
287 | * Ready-made ->f_op->llseek() | |
288 | */ | |
965c8e59 | 289 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 290 | { |
8209e2f4 | 291 | struct seq_file *m = file->private_data; |
16abef0e | 292 | loff_t retval = -EINVAL; |
1da177e4 | 293 | |
0ac1759a | 294 | mutex_lock(&m->lock); |
965c8e59 | 295 | switch (whence) { |
5e62adef AM |
296 | case SEEK_CUR: |
297 | offset += file->f_pos; | |
df561f66 | 298 | fallthrough; |
5e62adef AM |
299 | case SEEK_SET: |
300 | if (offset < 0) | |
301 | break; | |
302 | retval = offset; | |
303 | if (offset != m->read_pos) { | |
304 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
305 | ; | |
306 | if (retval) { | |
307 | /* with extreme prejudice... */ | |
308 | file->f_pos = 0; | |
309 | m->read_pos = 0; | |
5e62adef AM |
310 | m->index = 0; |
311 | m->count = 0; | |
312 | } else { | |
313 | m->read_pos = offset; | |
314 | retval = file->f_pos = offset; | |
1da177e4 | 315 | } |
05e16745 GZ |
316 | } else { |
317 | file->f_pos = offset; | |
5e62adef | 318 | } |
1da177e4 | 319 | } |
00c5746d | 320 | mutex_unlock(&m->lock); |
1da177e4 LT |
321 | return retval; |
322 | } | |
323 | EXPORT_SYMBOL(seq_lseek); | |
324 | ||
325 | /** | |
326 | * seq_release - free the structures associated with sequential file. | |
327 | * @file: file in question | |
6131ffaa | 328 | * @inode: its inode |
1da177e4 LT |
329 | * |
330 | * Frees the structures associated with sequential file; can be used | |
331 | * as ->f_op->release() if you don't have private data to destroy. | |
332 | */ | |
333 | int seq_release(struct inode *inode, struct file *file) | |
334 | { | |
8209e2f4 | 335 | struct seq_file *m = file->private_data; |
058504ed | 336 | kvfree(m->buf); |
09652320 | 337 | kmem_cache_free(seq_file_cache, m); |
1da177e4 LT |
338 | return 0; |
339 | } | |
340 | EXPORT_SYMBOL(seq_release); | |
341 | ||
342 | /** | |
343 | * seq_escape - print string into buffer, escaping some characters | |
344 | * @m: target buffer | |
345 | * @s: string | |
346 | * @esc: set of characters that need escaping | |
347 | * | |
348 | * Puts string into buffer, replacing each occurrence of character from | |
6798a8ca JP |
349 | * @esc with usual octal escape. |
350 | * Use seq_has_overflowed() to check for errors. | |
1da177e4 | 351 | */ |
6798a8ca | 352 | void seq_escape(struct seq_file *m, const char *s, const char *esc) |
1da177e4 | 353 | { |
25c6bb76 AS |
354 | char *buf; |
355 | size_t size = seq_get_buf(m, &buf); | |
356 | int ret; | |
1da177e4 | 357 | |
25c6bb76 AS |
358 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); |
359 | seq_commit(m, ret < size ? ret : -1); | |
1da177e4 LT |
360 | } |
361 | EXPORT_SYMBOL(seq_escape); | |
362 | ||
ea053e16 BF |
363 | void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz) |
364 | { | |
365 | char *buf; | |
366 | size_t size = seq_get_buf(m, &buf); | |
367 | int ret; | |
368 | ||
369 | ret = string_escape_mem_ascii(src, isz, buf, size); | |
370 | seq_commit(m, ret < size ? ret : -1); | |
371 | } | |
372 | EXPORT_SYMBOL(seq_escape_mem_ascii); | |
373 | ||
6798a8ca | 374 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 375 | { |
1da177e4 LT |
376 | int len; |
377 | ||
378 | if (m->count < m->size) { | |
1da177e4 | 379 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
380 | if (m->count + len < m->size) { |
381 | m->count += len; | |
6798a8ca | 382 | return; |
1da177e4 LT |
383 | } |
384 | } | |
e075f591 | 385 | seq_set_overflow(m); |
1da177e4 | 386 | } |
a4808147 SW |
387 | EXPORT_SYMBOL(seq_vprintf); |
388 | ||
6798a8ca | 389 | void seq_printf(struct seq_file *m, const char *f, ...) |
a4808147 | 390 | { |
a4808147 SW |
391 | va_list args; |
392 | ||
393 | va_start(args, f); | |
6798a8ca | 394 | seq_vprintf(m, f, args); |
a4808147 | 395 | va_end(args); |
a4808147 | 396 | } |
1da177e4 LT |
397 | EXPORT_SYMBOL(seq_printf); |
398 | ||
74e2f334 | 399 | /** |
958086d1 TE |
400 | * mangle_path - mangle and copy path to buffer beginning |
401 | * @s: buffer start | |
402 | * @p: beginning of path in above buffer | |
403 | * @esc: set of characters that need escaping | |
74e2f334 TE |
404 | * |
405 | * Copy the path from @p to @s, replacing each occurrence of character from | |
406 | * @esc with usual octal escape. | |
407 | * Returns pointer past last written character in @s, or NULL in case of | |
408 | * failure. | |
409 | */ | |
8c9379e9 | 410 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
411 | { |
412 | while (s <= p) { | |
413 | char c = *p++; | |
414 | if (!c) { | |
415 | return s; | |
416 | } else if (!strchr(esc, c)) { | |
417 | *s++ = c; | |
418 | } else if (s + 4 > p) { | |
419 | break; | |
420 | } else { | |
421 | *s++ = '\\'; | |
422 | *s++ = '0' + ((c & 0300) >> 6); | |
423 | *s++ = '0' + ((c & 070) >> 3); | |
424 | *s++ = '0' + (c & 07); | |
425 | } | |
426 | } | |
427 | return NULL; | |
428 | } | |
604094f4 | 429 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 430 | |
52afeefb AV |
431 | /** |
432 | * seq_path - seq_file interface to print a pathname | |
433 | * @m: the seq_file handle | |
434 | * @path: the struct path to print | |
435 | * @esc: set of characters to escape in the output | |
436 | * | |
437 | * return the absolute path of 'path', as represented by the | |
438 | * dentry / mnt pair in the path parameter. | |
6092d048 | 439 | */ |
8c9379e9 | 440 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 441 | { |
f8439806 MS |
442 | char *buf; |
443 | size_t size = seq_get_buf(m, &buf); | |
444 | int res = -1; | |
445 | ||
446 | if (size) { | |
447 | char *p = d_path(path, buf, size); | |
1da177e4 | 448 | if (!IS_ERR(p)) { |
f8439806 MS |
449 | char *end = mangle_path(buf, p, esc); |
450 | if (end) | |
451 | res = end - buf; | |
1da177e4 LT |
452 | } |
453 | } | |
f8439806 MS |
454 | seq_commit(m, res); |
455 | ||
456 | return res; | |
1da177e4 LT |
457 | } |
458 | EXPORT_SYMBOL(seq_path); | |
459 | ||
2726d566 MS |
460 | /** |
461 | * seq_file_path - seq_file interface to print a pathname of a file | |
462 | * @m: the seq_file handle | |
463 | * @file: the struct file to print | |
464 | * @esc: set of characters to escape in the output | |
465 | * | |
466 | * return the absolute path to the file. | |
467 | */ | |
468 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
469 | { | |
470 | return seq_path(m, &file->f_path, esc); | |
471 | } | |
472 | EXPORT_SYMBOL(seq_file_path); | |
473 | ||
9d1bc601 MS |
474 | /* |
475 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 476 | */ |
8c9379e9 AV |
477 | int seq_path_root(struct seq_file *m, const struct path *path, |
478 | const struct path *root, const char *esc) | |
9d1bc601 | 479 | { |
f8439806 MS |
480 | char *buf; |
481 | size_t size = seq_get_buf(m, &buf); | |
482 | int res = -ENAMETOOLONG; | |
483 | ||
484 | if (size) { | |
9d1bc601 MS |
485 | char *p; |
486 | ||
f8439806 | 487 | p = __d_path(path, root, buf, size); |
02125a82 AV |
488 | if (!p) |
489 | return SEQ_SKIP; | |
f8439806 | 490 | res = PTR_ERR(p); |
9d1bc601 | 491 | if (!IS_ERR(p)) { |
f8439806 MS |
492 | char *end = mangle_path(buf, p, esc); |
493 | if (end) | |
494 | res = end - buf; | |
495 | else | |
496 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
497 | } |
498 | } | |
f8439806 MS |
499 | seq_commit(m, res); |
500 | ||
02125a82 | 501 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
502 | } |
503 | ||
6092d048 RP |
504 | /* |
505 | * returns the path of the 'dentry' from the root of its filesystem. | |
506 | */ | |
8c9379e9 | 507 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 508 | { |
f8439806 MS |
509 | char *buf; |
510 | size_t size = seq_get_buf(m, &buf); | |
511 | int res = -1; | |
512 | ||
513 | if (size) { | |
514 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 515 | if (!IS_ERR(p)) { |
f8439806 MS |
516 | char *end = mangle_path(buf, p, esc); |
517 | if (end) | |
518 | res = end - buf; | |
6092d048 RP |
519 | } |
520 | } | |
f8439806 MS |
521 | seq_commit(m, res); |
522 | ||
523 | return res; | |
6092d048 | 524 | } |
c8d3fe02 | 525 | EXPORT_SYMBOL(seq_dentry); |
6092d048 | 526 | |
1da177e4 LT |
527 | static void *single_start(struct seq_file *p, loff_t *pos) |
528 | { | |
529 | return NULL + (*pos == 0); | |
530 | } | |
531 | ||
532 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
533 | { | |
534 | ++*pos; | |
535 | return NULL; | |
536 | } | |
537 | ||
538 | static void single_stop(struct seq_file *p, void *v) | |
539 | { | |
540 | } | |
541 | ||
542 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
543 | void *data) | |
544 | { | |
d64d01a1 | 545 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT); |
1da177e4 LT |
546 | int res = -ENOMEM; |
547 | ||
548 | if (op) { | |
549 | op->start = single_start; | |
550 | op->next = single_next; | |
551 | op->stop = single_stop; | |
552 | op->show = show; | |
553 | res = seq_open(file, op); | |
554 | if (!res) | |
555 | ((struct seq_file *)file->private_data)->private = data; | |
556 | else | |
557 | kfree(op); | |
558 | } | |
559 | return res; | |
560 | } | |
561 | EXPORT_SYMBOL(single_open); | |
562 | ||
2043f495 AV |
563 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
564 | void *data, size_t size) | |
565 | { | |
058504ed | 566 | char *buf = seq_buf_alloc(size); |
2043f495 AV |
567 | int ret; |
568 | if (!buf) | |
569 | return -ENOMEM; | |
570 | ret = single_open(file, show, data); | |
571 | if (ret) { | |
058504ed | 572 | kvfree(buf); |
2043f495 AV |
573 | return ret; |
574 | } | |
575 | ((struct seq_file *)file->private_data)->buf = buf; | |
576 | ((struct seq_file *)file->private_data)->size = size; | |
577 | return 0; | |
578 | } | |
579 | EXPORT_SYMBOL(single_open_size); | |
580 | ||
1da177e4 LT |
581 | int single_release(struct inode *inode, struct file *file) |
582 | { | |
15ad7cdc | 583 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
584 | int res = seq_release(inode, file); |
585 | kfree(op); | |
586 | return res; | |
587 | } | |
588 | EXPORT_SYMBOL(single_release); | |
589 | ||
590 | int seq_release_private(struct inode *inode, struct file *file) | |
591 | { | |
592 | struct seq_file *seq = file->private_data; | |
593 | ||
594 | kfree(seq->private); | |
595 | seq->private = NULL; | |
596 | return seq_release(inode, file); | |
597 | } | |
598 | EXPORT_SYMBOL(seq_release_private); | |
599 | ||
39699037 PE |
600 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
601 | int psize) | |
602 | { | |
603 | int rc; | |
604 | void *private; | |
605 | struct seq_file *seq; | |
606 | ||
d64d01a1 | 607 | private = kzalloc(psize, GFP_KERNEL_ACCOUNT); |
39699037 PE |
608 | if (private == NULL) |
609 | goto out; | |
610 | ||
611 | rc = seq_open(f, ops); | |
612 | if (rc < 0) | |
613 | goto out_free; | |
614 | ||
615 | seq = f->private_data; | |
616 | seq->private = private; | |
617 | return private; | |
618 | ||
619 | out_free: | |
620 | kfree(private); | |
621 | out: | |
622 | return NULL; | |
623 | } | |
624 | EXPORT_SYMBOL(__seq_open_private); | |
625 | ||
626 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
627 | int psize) | |
628 | { | |
629 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
630 | } | |
631 | EXPORT_SYMBOL(seq_open_private); | |
632 | ||
6798a8ca | 633 | void seq_putc(struct seq_file *m, char c) |
1da177e4 | 634 | { |
6798a8ca JP |
635 | if (m->count >= m->size) |
636 | return; | |
637 | ||
638 | m->buf[m->count++] = c; | |
1da177e4 LT |
639 | } |
640 | EXPORT_SYMBOL(seq_putc); | |
641 | ||
6798a8ca | 642 | void seq_puts(struct seq_file *m, const char *s) |
1da177e4 LT |
643 | { |
644 | int len = strlen(s); | |
6798a8ca JP |
645 | |
646 | if (m->count + len >= m->size) { | |
647 | seq_set_overflow(m); | |
648 | return; | |
1da177e4 | 649 | } |
6798a8ca JP |
650 | memcpy(m->buf + m->count, s, len); |
651 | m->count += len; | |
1da177e4 LT |
652 | } |
653 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 654 | |
d1be35cb | 655 | /** |
1ac101a5 KH |
656 | * A helper routine for putting decimal numbers without rich format of printf(). |
657 | * only 'unsigned long long' is supported. | |
d1be35cb AV |
658 | * @m: seq_file identifying the buffer to which data should be written |
659 | * @delimiter: a string which is printed before the number | |
660 | * @num: the number | |
661 | * @width: a minimum field width | |
662 | * | |
663 | * This routine will put strlen(delimiter) + number into seq_filed. | |
1ac101a5 KH |
664 | * This routine is very quick when you show lots of numbers. |
665 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
666 | */ | |
d1be35cb AV |
667 | void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, |
668 | unsigned long long num, unsigned int width) | |
1ac101a5 KH |
669 | { |
670 | int len; | |
671 | ||
672 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
673 | goto overflow; | |
674 | ||
48dffbf8 AV |
675 | if (delimiter && delimiter[0]) { |
676 | if (delimiter[1] == 0) | |
677 | seq_putc(m, delimiter[0]); | |
678 | else | |
679 | seq_puts(m, delimiter); | |
680 | } | |
75ba1d07 | 681 | |
d1be35cb AV |
682 | if (!width) |
683 | width = 1; | |
684 | ||
685 | if (m->count + width >= m->size) | |
75ba1d07 | 686 | goto overflow; |
1ac101a5 | 687 | |
d1be35cb | 688 | len = num_to_str(m->buf + m->count, m->size - m->count, num, width); |
1ac101a5 KH |
689 | if (!len) |
690 | goto overflow; | |
75ba1d07 | 691 | |
1ac101a5 | 692 | m->count += len; |
6798a8ca JP |
693 | return; |
694 | ||
1ac101a5 | 695 | overflow: |
e075f591 | 696 | seq_set_overflow(m); |
1ac101a5 | 697 | } |
d1be35cb AV |
698 | |
699 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, | |
700 | unsigned long long num) | |
701 | { | |
702 | return seq_put_decimal_ull_width(m, delimiter, num, 0); | |
703 | } | |
1ac101a5 KH |
704 | EXPORT_SYMBOL(seq_put_decimal_ull); |
705 | ||
0e3dc019 AV |
706 | /** |
707 | * seq_put_hex_ll - put a number in hexadecimal notation | |
708 | * @m: seq_file identifying the buffer to which data should be written | |
709 | * @delimiter: a string which is printed before the number | |
710 | * @v: the number | |
711 | * @width: a minimum field width | |
712 | * | |
713 | * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v) | |
714 | * | |
715 | * This routine is very quick when you show lots of numbers. | |
716 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
717 | */ | |
718 | void seq_put_hex_ll(struct seq_file *m, const char *delimiter, | |
719 | unsigned long long v, unsigned int width) | |
720 | { | |
721 | unsigned int len; | |
722 | int i; | |
723 | ||
724 | if (delimiter && delimiter[0]) { | |
725 | if (delimiter[1] == 0) | |
726 | seq_putc(m, delimiter[0]); | |
727 | else | |
728 | seq_puts(m, delimiter); | |
729 | } | |
730 | ||
731 | /* If x is 0, the result of __builtin_clzll is undefined */ | |
732 | if (v == 0) | |
733 | len = 1; | |
734 | else | |
735 | len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4; | |
736 | ||
737 | if (len < width) | |
738 | len = width; | |
739 | ||
740 | if (m->count + len > m->size) { | |
741 | seq_set_overflow(m); | |
742 | return; | |
743 | } | |
744 | ||
745 | for (i = len - 1; i >= 0; i--) { | |
746 | m->buf[m->count + i] = hex_asc[0xf & v]; | |
747 | v = v >> 4; | |
748 | } | |
749 | m->count += len; | |
750 | } | |
751 | ||
75ba1d07 | 752 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
bda7bad6 | 753 | { |
75ba1d07 JP |
754 | int len; |
755 | ||
756 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ | |
757 | goto overflow; | |
758 | ||
48dffbf8 AV |
759 | if (delimiter && delimiter[0]) { |
760 | if (delimiter[1] == 0) | |
761 | seq_putc(m, delimiter[0]); | |
762 | else | |
763 | seq_puts(m, delimiter); | |
764 | } | |
75ba1d07 JP |
765 | |
766 | if (m->count + 2 >= m->size) | |
767 | goto overflow; | |
768 | ||
bda7bad6 | 769 | if (num < 0) { |
75ba1d07 | 770 | m->buf[m->count++] = '-'; |
bda7bad6 | 771 | num = -num; |
bda7bad6 | 772 | } |
75ba1d07 JP |
773 | |
774 | if (num < 10) { | |
775 | m->buf[m->count++] = num + '0'; | |
776 | return; | |
777 | } | |
778 | ||
d1be35cb | 779 | len = num_to_str(m->buf + m->count, m->size - m->count, num, 0); |
75ba1d07 JP |
780 | if (!len) |
781 | goto overflow; | |
782 | ||
783 | m->count += len; | |
784 | return; | |
785 | ||
786 | overflow: | |
787 | seq_set_overflow(m); | |
bda7bad6 KH |
788 | } |
789 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
790 | ||
0b923606 PO |
791 | /** |
792 | * seq_write - write arbitrary data to buffer | |
793 | * @seq: seq_file identifying the buffer to which data should be written | |
794 | * @data: data address | |
795 | * @len: number of bytes | |
796 | * | |
797 | * Return 0 on success, non-zero otherwise. | |
798 | */ | |
799 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
800 | { | |
801 | if (seq->count + len < seq->size) { | |
802 | memcpy(seq->buf + seq->count, data, len); | |
803 | seq->count += len; | |
804 | return 0; | |
805 | } | |
e075f591 | 806 | seq_set_overflow(seq); |
0b923606 PO |
807 | return -1; |
808 | } | |
809 | EXPORT_SYMBOL(seq_write); | |
810 | ||
839cc2a9 TH |
811 | /** |
812 | * seq_pad - write padding spaces to buffer | |
813 | * @m: seq_file identifying the buffer to which data should be written | |
814 | * @c: the byte to append after padding if non-zero | |
815 | */ | |
816 | void seq_pad(struct seq_file *m, char c) | |
817 | { | |
818 | int size = m->pad_until - m->count; | |
8cfa67b4 AV |
819 | if (size > 0) { |
820 | if (size + m->count > m->size) { | |
821 | seq_set_overflow(m); | |
822 | return; | |
823 | } | |
824 | memset(m->buf + m->count, ' ', size); | |
825 | m->count += size; | |
826 | } | |
839cc2a9 TH |
827 | if (c) |
828 | seq_putc(m, c); | |
829 | } | |
830 | EXPORT_SYMBOL(seq_pad); | |
831 | ||
37607102 AS |
832 | /* A complete analogue of print_hex_dump() */ |
833 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
834 | int rowsize, int groupsize, const void *buf, size_t len, | |
835 | bool ascii) | |
836 | { | |
837 | const u8 *ptr = buf; | |
838 | int i, linelen, remaining = len; | |
8b91a318 AS |
839 | char *buffer; |
840 | size_t size; | |
37607102 AS |
841 | int ret; |
842 | ||
843 | if (rowsize != 16 && rowsize != 32) | |
844 | rowsize = 16; | |
845 | ||
846 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
847 | linelen = min(remaining, rowsize); | |
848 | remaining -= rowsize; | |
849 | ||
850 | switch (prefix_type) { | |
851 | case DUMP_PREFIX_ADDRESS: | |
852 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
853 | break; | |
854 | case DUMP_PREFIX_OFFSET: | |
855 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
856 | break; | |
857 | default: | |
858 | seq_printf(m, "%s", prefix_str); | |
859 | break; | |
860 | } | |
861 | ||
8b91a318 | 862 | size = seq_get_buf(m, &buffer); |
37607102 | 863 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
8b91a318 AS |
864 | buffer, size, ascii); |
865 | seq_commit(m, ret < size ? ret : -1); | |
866 | ||
867 | seq_putc(m, '\n'); | |
37607102 AS |
868 | } |
869 | } | |
870 | EXPORT_SYMBOL(seq_hex_dump); | |
871 | ||
bcf67e16 PE |
872 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
873 | { | |
874 | struct list_head *lh; | |
875 | ||
876 | list_for_each(lh, head) | |
877 | if (pos-- == 0) | |
878 | return lh; | |
879 | ||
880 | return NULL; | |
881 | } | |
bcf67e16 PE |
882 | EXPORT_SYMBOL(seq_list_start); |
883 | ||
884 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
885 | { | |
886 | if (!pos) | |
887 | return head; | |
888 | ||
889 | return seq_list_start(head, pos - 1); | |
890 | } | |
bcf67e16 PE |
891 | EXPORT_SYMBOL(seq_list_start_head); |
892 | ||
893 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
894 | { | |
895 | struct list_head *lh; | |
896 | ||
897 | lh = ((struct list_head *)v)->next; | |
898 | ++*ppos; | |
899 | return lh == head ? NULL : lh; | |
900 | } | |
bcf67e16 | 901 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
902 | |
903 | /** | |
904 | * seq_hlist_start - start an iteration of a hlist | |
905 | * @head: the head of the hlist | |
906 | * @pos: the start position of the sequence | |
907 | * | |
908 | * Called at seq_file->op->start(). | |
909 | */ | |
910 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
911 | { | |
912 | struct hlist_node *node; | |
913 | ||
914 | hlist_for_each(node, head) | |
915 | if (pos-- == 0) | |
916 | return node; | |
917 | return NULL; | |
918 | } | |
919 | EXPORT_SYMBOL(seq_hlist_start); | |
920 | ||
921 | /** | |
922 | * seq_hlist_start_head - start an iteration of a hlist | |
923 | * @head: the head of the hlist | |
924 | * @pos: the start position of the sequence | |
925 | * | |
926 | * Called at seq_file->op->start(). Call this function if you want to | |
927 | * print a header at the top of the output. | |
928 | */ | |
929 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
930 | { | |
931 | if (!pos) | |
932 | return SEQ_START_TOKEN; | |
933 | ||
934 | return seq_hlist_start(head, pos - 1); | |
935 | } | |
936 | EXPORT_SYMBOL(seq_hlist_start_head); | |
937 | ||
938 | /** | |
939 | * seq_hlist_next - move to the next position of the hlist | |
940 | * @v: the current iterator | |
941 | * @head: the head of the hlist | |
138860b9 | 942 | * @ppos: the current position |
66655de6 LZ |
943 | * |
944 | * Called at seq_file->op->next(). | |
945 | */ | |
946 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
947 | loff_t *ppos) | |
948 | { | |
949 | struct hlist_node *node = v; | |
950 | ||
951 | ++*ppos; | |
952 | if (v == SEQ_START_TOKEN) | |
953 | return head->first; | |
954 | else | |
955 | return node->next; | |
956 | } | |
957 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 958 | |
959 | /** | |
960 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
961 | * @head: the head of the hlist | |
962 | * @pos: the start position of the sequence | |
963 | * | |
964 | * Called at seq_file->op->start(). | |
965 | * | |
966 | * This list-traversal primitive may safely run concurrently with | |
967 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
968 | * as long as the traversal is guarded by rcu_read_lock(). | |
969 | */ | |
970 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
971 | loff_t pos) | |
972 | { | |
973 | struct hlist_node *node; | |
974 | ||
975 | __hlist_for_each_rcu(node, head) | |
976 | if (pos-- == 0) | |
977 | return node; | |
978 | return NULL; | |
979 | } | |
980 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
981 | ||
982 | /** | |
983 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
984 | * @head: the head of the hlist | |
985 | * @pos: the start position of the sequence | |
986 | * | |
987 | * Called at seq_file->op->start(). Call this function if you want to | |
988 | * print a header at the top of the output. | |
989 | * | |
990 | * This list-traversal primitive may safely run concurrently with | |
991 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
992 | * as long as the traversal is guarded by rcu_read_lock(). | |
993 | */ | |
994 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
995 | loff_t pos) | |
996 | { | |
997 | if (!pos) | |
998 | return SEQ_START_TOKEN; | |
999 | ||
1000 | return seq_hlist_start_rcu(head, pos - 1); | |
1001 | } | |
1002 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
1003 | ||
1004 | /** | |
1005 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
1006 | * @v: the current iterator | |
1007 | * @head: the head of the hlist | |
138860b9 | 1008 | * @ppos: the current position |
1cc52327 | 1009 | * |
1010 | * Called at seq_file->op->next(). | |
1011 | * | |
1012 | * This list-traversal primitive may safely run concurrently with | |
1013 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
1014 | * as long as the traversal is guarded by rcu_read_lock(). | |
1015 | */ | |
1016 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
1017 | struct hlist_head *head, | |
1018 | loff_t *ppos) | |
1019 | { | |
1020 | struct hlist_node *node = v; | |
1021 | ||
1022 | ++*ppos; | |
1023 | if (v == SEQ_START_TOKEN) | |
1024 | return rcu_dereference(head->first); | |
1025 | else | |
1026 | return rcu_dereference(node->next); | |
1027 | } | |
1028 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
0bc77381 JL |
1029 | |
1030 | /** | |
1031 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array | |
1032 | * @head: pointer to percpu array of struct hlist_heads | |
1033 | * @cpu: pointer to cpu "cursor" | |
1034 | * @pos: start position of sequence | |
1035 | * | |
1036 | * Called at seq_file->op->start(). | |
1037 | */ | |
1038 | struct hlist_node * | |
1039 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
1040 | { | |
1041 | struct hlist_node *node; | |
1042 | ||
1043 | for_each_possible_cpu(*cpu) { | |
1044 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
1045 | if (pos-- == 0) | |
1046 | return node; | |
1047 | } | |
1048 | } | |
1049 | return NULL; | |
1050 | } | |
1051 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
1052 | ||
1053 | /** | |
1054 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1055 | * @v: pointer to current hlist_node | |
1056 | * @head: pointer to percpu array of struct hlist_heads | |
1057 | * @cpu: pointer to cpu "cursor" | |
1058 | * @pos: start position of sequence | |
1059 | * | |
1060 | * Called at seq_file->op->next(). | |
1061 | */ | |
1062 | struct hlist_node * | |
1063 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1064 | int *cpu, loff_t *pos) | |
1065 | { | |
1066 | struct hlist_node *node = v; | |
1067 | ||
1068 | ++*pos; | |
1069 | ||
1070 | if (node->next) | |
1071 | return node->next; | |
1072 | ||
1073 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1074 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1075 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1076 | ||
1077 | if (!hlist_empty(bucket)) | |
1078 | return bucket->first; | |
1079 | } | |
1080 | return NULL; | |
1081 | } | |
1082 | EXPORT_SYMBOL(seq_hlist_next_percpu); | |
09652320 AD |
1083 | |
1084 | void __init seq_file_init(void) | |
1085 | { | |
d64d01a1 | 1086 | seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC); |
09652320 | 1087 | } |