Commit | Line | Data |
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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 | ||
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> |
d4d50710 | 21 | #include <linux/uio.h> |
1da177e4 | 22 | |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 LT |
24 | #include <asm/page.h> |
25 | ||
09652320 AD |
26 | static struct kmem_cache *seq_file_cache __ro_after_init; |
27 | ||
e075f591 KH |
28 | static void seq_set_overflow(struct seq_file *m) |
29 | { | |
30 | m->count = m->size; | |
31 | } | |
32 | ||
058504ed HC |
33 | static void *seq_buf_alloc(unsigned long size) |
34 | { | |
d64d01a1 | 35 | return kvmalloc(size, GFP_KERNEL_ACCOUNT); |
058504ed HC |
36 | } |
37 | ||
1da177e4 LT |
38 | /** |
39 | * seq_open - initialize sequential file | |
40 | * @file: file we initialize | |
41 | * @op: method table describing the sequence | |
42 | * | |
43 | * seq_open() sets @file, associating it with a sequence described | |
44 | * by @op. @op->start() sets the iterator up and returns the first | |
45 | * element of sequence. @op->stop() shuts it down. @op->next() | |
46 | * returns the next element of sequence. @op->show() prints element | |
47 | * into the buffer. In case of error ->start() and ->next() return | |
48 | * ERR_PTR(error). In the end of sequence they return %NULL. ->show() | |
49 | * returns 0 in case of success and negative number in case of error. | |
521b5d0c | 50 | * Returning SEQ_SKIP means "discard this element and move on". |
460b865e YD |
51 | * Note: seq_open() will allocate a struct seq_file and store its |
52 | * pointer in @file->private_data. This pointer should not be modified. | |
1da177e4 | 53 | */ |
15ad7cdc | 54 | int seq_open(struct file *file, const struct seq_operations *op) |
1da177e4 | 55 | { |
189f9841 YD |
56 | struct seq_file *p; |
57 | ||
58 | WARN_ON(file->private_data); | |
59 | ||
09652320 | 60 | p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL); |
189f9841 YD |
61 | if (!p) |
62 | return -ENOMEM; | |
63 | ||
64 | file->private_data = p; | |
1abe77b0 | 65 | |
0ac1759a | 66 | mutex_init(&p->lock); |
1da177e4 | 67 | p->op = op; |
34dbbcdb LT |
68 | |
69 | // No refcounting: the lifetime of 'p' is constrained | |
70 | // to the lifetime of the file. | |
71 | p->file = file; | |
1da177e4 | 72 | |
8f19d472 EB |
73 | /* |
74 | * seq_files support lseek() and pread(). They do not implement | |
75 | * write() at all, but we clear FMODE_PWRITE here for historical | |
76 | * reasons. | |
77 | * | |
78 | * If a client of seq_files a) implements file.write() and b) wishes to | |
79 | * support pwrite() then that client will need to implement its own | |
80 | * file.open() which calls seq_open() and then sets FMODE_PWRITE. | |
81 | */ | |
82 | file->f_mode &= ~FMODE_PWRITE; | |
1da177e4 LT |
83 | return 0; |
84 | } | |
85 | EXPORT_SYMBOL(seq_open); | |
86 | ||
33da8892 EB |
87 | static int traverse(struct seq_file *m, loff_t offset) |
88 | { | |
1f4aace6 | 89 | loff_t pos = 0; |
33da8892 EB |
90 | int error = 0; |
91 | void *p; | |
92 | ||
1f4aace6 | 93 | m->index = 0; |
33da8892 | 94 | m->count = m->from = 0; |
1f4aace6 | 95 | if (!offset) |
33da8892 | 96 | return 0; |
1f4aace6 | 97 | |
33da8892 | 98 | if (!m->buf) { |
058504ed | 99 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
33da8892 EB |
100 | if (!m->buf) |
101 | return -ENOMEM; | |
102 | } | |
1f4aace6 | 103 | p = m->op->start(m, &m->index); |
33da8892 EB |
104 | while (p) { |
105 | error = PTR_ERR(p); | |
106 | if (IS_ERR(p)) | |
107 | break; | |
108 | error = m->op->show(m, p); | |
109 | if (error < 0) | |
110 | break; | |
111 | if (unlikely(error)) { | |
112 | error = 0; | |
113 | m->count = 0; | |
114 | } | |
1f33c41c | 115 | if (seq_has_overflowed(m)) |
33da8892 | 116 | goto Eoverflow; |
6a2aeab5 | 117 | p = m->op->next(m, p, &m->index); |
33da8892 EB |
118 | if (pos + m->count > offset) { |
119 | m->from = offset - pos; | |
120 | m->count -= m->from; | |
33da8892 EB |
121 | break; |
122 | } | |
123 | pos += m->count; | |
124 | m->count = 0; | |
1f4aace6 | 125 | if (pos == offset) |
33da8892 | 126 | break; |
33da8892 EB |
127 | } |
128 | m->op->stop(m, p); | |
129 | return error; | |
130 | ||
131 | Eoverflow: | |
132 | m->op->stop(m, p); | |
058504ed | 133 | kvfree(m->buf); |
801a7605 | 134 | m->count = 0; |
058504ed | 135 | m->buf = seq_buf_alloc(m->size <<= 1); |
33da8892 EB |
136 | return !m->buf ? -ENOMEM : -EAGAIN; |
137 | } | |
138 | ||
1da177e4 LT |
139 | /** |
140 | * seq_read - ->read() method for sequential files. | |
67be2dd1 MW |
141 | * @file: the file to read from |
142 | * @buf: the buffer to read to | |
143 | * @size: the maximum number of bytes to read | |
144 | * @ppos: the current position in the file | |
1da177e4 LT |
145 | * |
146 | * Ready-made ->f_op->read() | |
147 | */ | |
148 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
149 | { | |
d4d50710 CH |
150 | struct iovec iov = { .iov_base = buf, .iov_len = size}; |
151 | struct kiocb kiocb; | |
152 | struct iov_iter iter; | |
153 | ssize_t ret; | |
154 | ||
155 | init_sync_kiocb(&kiocb, file); | |
156 | iov_iter_init(&iter, READ, &iov, 1, size); | |
157 | ||
158 | kiocb.ki_pos = *ppos; | |
159 | ret = seq_read_iter(&kiocb, &iter); | |
160 | *ppos = kiocb.ki_pos; | |
161 | return ret; | |
162 | } | |
163 | EXPORT_SYMBOL(seq_read); | |
164 | ||
165 | /* | |
166 | * Ready-made ->f_op->read_iter() | |
167 | */ | |
168 | ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter) | |
169 | { | |
170 | struct seq_file *m = iocb->ki_filp->private_data; | |
1da177e4 | 171 | size_t copied = 0; |
1da177e4 LT |
172 | size_t n; |
173 | void *p; | |
174 | int err = 0; | |
175 | ||
4bbf439b AV |
176 | if (!iov_iter_count(iter)) |
177 | return 0; | |
178 | ||
0ac1759a | 179 | mutex_lock(&m->lock); |
8f19d472 | 180 | |
e522751d TM |
181 | /* |
182 | * if request is to read from zero offset, reset iterator to first | |
183 | * record as it might have been already advanced by previous requests | |
184 | */ | |
d4d50710 | 185 | if (iocb->ki_pos == 0) { |
e522751d | 186 | m->index = 0; |
cf5eebae MS |
187 | m->count = 0; |
188 | } | |
e522751d | 189 | |
d4d50710 CH |
190 | /* Don't assume ki_pos is where we left it */ |
191 | if (unlikely(iocb->ki_pos != m->read_pos)) { | |
192 | while ((err = traverse(m, iocb->ki_pos)) == -EAGAIN) | |
8f19d472 EB |
193 | ; |
194 | if (err) { | |
195 | /* With prejudice... */ | |
196 | m->read_pos = 0; | |
8f19d472 EB |
197 | m->index = 0; |
198 | m->count = 0; | |
199 | goto Done; | |
7904ac84 | 200 | } else { |
d4d50710 | 201 | m->read_pos = iocb->ki_pos; |
8f19d472 EB |
202 | } |
203 | } | |
204 | ||
1da177e4 LT |
205 | /* grab buffer if we didn't have one */ |
206 | if (!m->buf) { | |
058504ed | 207 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
1da177e4 LT |
208 | if (!m->buf) |
209 | goto Enomem; | |
210 | } | |
4bbf439b | 211 | // something left in the buffer - copy it out first |
1da177e4 | 212 | if (m->count) { |
4bbf439b | 213 | n = copy_to_iter(m->buf + m->from, m->count, iter); |
1da177e4 LT |
214 | m->count -= n; |
215 | m->from += n; | |
1da177e4 | 216 | copied += n; |
4bbf439b | 217 | if (m->count) // hadn't managed to copy everything |
1da177e4 LT |
218 | goto Done; |
219 | } | |
4bbf439b | 220 | // get a non-empty record in the buffer |
1f4aace6 N |
221 | m->from = 0; |
222 | p = m->op->start(m, &m->index); | |
1da177e4 | 223 | while (1) { |
1da177e4 | 224 | err = PTR_ERR(p); |
4bbf439b | 225 | if (!p || IS_ERR(p)) // EOF or an error |
1da177e4 LT |
226 | break; |
227 | err = m->op->show(m, p); | |
4bbf439b | 228 | if (err < 0) // hard error |
1da177e4 | 229 | break; |
4bbf439b | 230 | if (unlikely(err)) // ->show() says "skip it" |
521b5d0c | 231 | m->count = 0; |
4bbf439b | 232 | if (unlikely(!m->count)) { // empty record |
1f4aace6 | 233 | p = m->op->next(m, p, &m->index); |
4cdfe84b AV |
234 | continue; |
235 | } | |
4bbf439b | 236 | if (!seq_has_overflowed(m)) // got it |
1da177e4 | 237 | goto Fill; |
4bbf439b | 238 | // need a bigger buffer |
1da177e4 | 239 | m->op->stop(m, p); |
058504ed | 240 | kvfree(m->buf); |
801a7605 | 241 | m->count = 0; |
058504ed | 242 | m->buf = seq_buf_alloc(m->size <<= 1); |
1da177e4 LT |
243 | if (!m->buf) |
244 | goto Enomem; | |
1f4aace6 | 245 | p = m->op->start(m, &m->index); |
1da177e4 | 246 | } |
4bbf439b | 247 | // EOF or an error |
1da177e4 LT |
248 | m->op->stop(m, p); |
249 | m->count = 0; | |
250 | goto Done; | |
251 | Fill: | |
4bbf439b AV |
252 | // one non-empty record is in the buffer; if they want more, |
253 | // try to fit more in, but in any case we need to advance | |
254 | // the iterator once for every record shown. | |
1f4aace6 | 255 | while (1) { |
1da177e4 | 256 | size_t offs = m->count; |
1f4aace6 N |
257 | loff_t pos = m->index; |
258 | ||
259 | p = m->op->next(m, p, &m->index); | |
3bfa7e14 | 260 | if (pos == m->index) { |
a3963015 JP |
261 | pr_info_ratelimited("buggy .next function %ps did not update position index\n", |
262 | m->op->next); | |
1f4aace6 | 263 | m->index++; |
3bfa7e14 | 264 | } |
4bbf439b | 265 | if (!p || IS_ERR(p)) // no next record for us |
1da177e4 | 266 | break; |
4bbf439b | 267 | if (m->count >= iov_iter_count(iter)) |
1f4aace6 | 268 | break; |
1da177e4 | 269 | err = m->op->show(m, p); |
4bbf439b | 270 | if (err > 0) { // ->show() says "skip it" |
1da177e4 | 271 | m->count = offs; |
4bbf439b AV |
272 | } else if (err || seq_has_overflowed(m)) { |
273 | m->count = offs; | |
274 | break; | |
1da177e4 | 275 | } |
1da177e4 LT |
276 | } |
277 | m->op->stop(m, p); | |
4bbf439b | 278 | n = copy_to_iter(m->buf, m->count, iter); |
1da177e4 LT |
279 | copied += n; |
280 | m->count -= n; | |
1f4aace6 | 281 | m->from = n; |
1da177e4 | 282 | Done: |
4bbf439b AV |
283 | if (unlikely(!copied)) { |
284 | copied = m->count ? -EFAULT : err; | |
285 | } else { | |
d4d50710 | 286 | iocb->ki_pos += copied; |
8f19d472 EB |
287 | m->read_pos += copied; |
288 | } | |
0ac1759a | 289 | mutex_unlock(&m->lock); |
1da177e4 LT |
290 | return copied; |
291 | Enomem: | |
292 | err = -ENOMEM; | |
293 | goto Done; | |
1da177e4 | 294 | } |
d4d50710 | 295 | EXPORT_SYMBOL(seq_read_iter); |
1da177e4 | 296 | |
1da177e4 LT |
297 | /** |
298 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
299 | * @file: the file in question |
300 | * @offset: new position | |
254adaa4 | 301 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
302 | * |
303 | * Ready-made ->f_op->llseek() | |
304 | */ | |
965c8e59 | 305 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 306 | { |
8209e2f4 | 307 | struct seq_file *m = file->private_data; |
16abef0e | 308 | loff_t retval = -EINVAL; |
1da177e4 | 309 | |
0ac1759a | 310 | mutex_lock(&m->lock); |
965c8e59 | 311 | switch (whence) { |
5e62adef AM |
312 | case SEEK_CUR: |
313 | offset += file->f_pos; | |
df561f66 | 314 | fallthrough; |
5e62adef AM |
315 | case SEEK_SET: |
316 | if (offset < 0) | |
317 | break; | |
318 | retval = offset; | |
319 | if (offset != m->read_pos) { | |
320 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
321 | ; | |
322 | if (retval) { | |
323 | /* with extreme prejudice... */ | |
324 | file->f_pos = 0; | |
325 | m->read_pos = 0; | |
5e62adef AM |
326 | m->index = 0; |
327 | m->count = 0; | |
328 | } else { | |
329 | m->read_pos = offset; | |
330 | retval = file->f_pos = offset; | |
1da177e4 | 331 | } |
05e16745 GZ |
332 | } else { |
333 | file->f_pos = offset; | |
5e62adef | 334 | } |
1da177e4 | 335 | } |
00c5746d | 336 | mutex_unlock(&m->lock); |
1da177e4 LT |
337 | return retval; |
338 | } | |
339 | EXPORT_SYMBOL(seq_lseek); | |
340 | ||
341 | /** | |
342 | * seq_release - free the structures associated with sequential file. | |
343 | * @file: file in question | |
6131ffaa | 344 | * @inode: its inode |
1da177e4 LT |
345 | * |
346 | * Frees the structures associated with sequential file; can be used | |
347 | * as ->f_op->release() if you don't have private data to destroy. | |
348 | */ | |
349 | int seq_release(struct inode *inode, struct file *file) | |
350 | { | |
8209e2f4 | 351 | struct seq_file *m = file->private_data; |
058504ed | 352 | kvfree(m->buf); |
09652320 | 353 | kmem_cache_free(seq_file_cache, m); |
1da177e4 LT |
354 | return 0; |
355 | } | |
356 | EXPORT_SYMBOL(seq_release); | |
357 | ||
358 | /** | |
359 | * seq_escape - print string into buffer, escaping some characters | |
360 | * @m: target buffer | |
361 | * @s: string | |
362 | * @esc: set of characters that need escaping | |
363 | * | |
364 | * Puts string into buffer, replacing each occurrence of character from | |
6798a8ca JP |
365 | * @esc with usual octal escape. |
366 | * Use seq_has_overflowed() to check for errors. | |
1da177e4 | 367 | */ |
6798a8ca | 368 | void seq_escape(struct seq_file *m, const char *s, const char *esc) |
1da177e4 | 369 | { |
25c6bb76 AS |
370 | char *buf; |
371 | size_t size = seq_get_buf(m, &buf); | |
372 | int ret; | |
1da177e4 | 373 | |
25c6bb76 AS |
374 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); |
375 | seq_commit(m, ret < size ? ret : -1); | |
1da177e4 LT |
376 | } |
377 | EXPORT_SYMBOL(seq_escape); | |
378 | ||
ea053e16 BF |
379 | void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz) |
380 | { | |
381 | char *buf; | |
382 | size_t size = seq_get_buf(m, &buf); | |
383 | int ret; | |
384 | ||
385 | ret = string_escape_mem_ascii(src, isz, buf, size); | |
386 | seq_commit(m, ret < size ? ret : -1); | |
387 | } | |
388 | EXPORT_SYMBOL(seq_escape_mem_ascii); | |
389 | ||
6798a8ca | 390 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 391 | { |
1da177e4 LT |
392 | int len; |
393 | ||
394 | if (m->count < m->size) { | |
1da177e4 | 395 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
396 | if (m->count + len < m->size) { |
397 | m->count += len; | |
6798a8ca | 398 | return; |
1da177e4 LT |
399 | } |
400 | } | |
e075f591 | 401 | seq_set_overflow(m); |
1da177e4 | 402 | } |
a4808147 SW |
403 | EXPORT_SYMBOL(seq_vprintf); |
404 | ||
6798a8ca | 405 | void seq_printf(struct seq_file *m, const char *f, ...) |
a4808147 | 406 | { |
a4808147 SW |
407 | va_list args; |
408 | ||
409 | va_start(args, f); | |
6798a8ca | 410 | seq_vprintf(m, f, args); |
a4808147 | 411 | va_end(args); |
a4808147 | 412 | } |
1da177e4 LT |
413 | EXPORT_SYMBOL(seq_printf); |
414 | ||
76d6a133 FR |
415 | #ifdef CONFIG_BINARY_PRINTF |
416 | void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary) | |
417 | { | |
418 | int len; | |
419 | ||
420 | if (m->count < m->size) { | |
421 | len = bstr_printf(m->buf + m->count, m->size - m->count, f, | |
422 | binary); | |
423 | if (m->count + len < m->size) { | |
424 | m->count += len; | |
425 | return; | |
426 | } | |
427 | } | |
428 | seq_set_overflow(m); | |
429 | } | |
430 | EXPORT_SYMBOL(seq_bprintf); | |
431 | #endif /* CONFIG_BINARY_PRINTF */ | |
432 | ||
74e2f334 | 433 | /** |
958086d1 TE |
434 | * mangle_path - mangle and copy path to buffer beginning |
435 | * @s: buffer start | |
436 | * @p: beginning of path in above buffer | |
437 | * @esc: set of characters that need escaping | |
74e2f334 TE |
438 | * |
439 | * Copy the path from @p to @s, replacing each occurrence of character from | |
440 | * @esc with usual octal escape. | |
441 | * Returns pointer past last written character in @s, or NULL in case of | |
442 | * failure. | |
443 | */ | |
8c9379e9 | 444 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
445 | { |
446 | while (s <= p) { | |
447 | char c = *p++; | |
448 | if (!c) { | |
449 | return s; | |
450 | } else if (!strchr(esc, c)) { | |
451 | *s++ = c; | |
452 | } else if (s + 4 > p) { | |
453 | break; | |
454 | } else { | |
455 | *s++ = '\\'; | |
456 | *s++ = '0' + ((c & 0300) >> 6); | |
457 | *s++ = '0' + ((c & 070) >> 3); | |
458 | *s++ = '0' + (c & 07); | |
459 | } | |
460 | } | |
461 | return NULL; | |
462 | } | |
604094f4 | 463 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 464 | |
52afeefb AV |
465 | /** |
466 | * seq_path - seq_file interface to print a pathname | |
467 | * @m: the seq_file handle | |
468 | * @path: the struct path to print | |
469 | * @esc: set of characters to escape in the output | |
470 | * | |
471 | * return the absolute path of 'path', as represented by the | |
472 | * dentry / mnt pair in the path parameter. | |
6092d048 | 473 | */ |
8c9379e9 | 474 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 475 | { |
f8439806 MS |
476 | char *buf; |
477 | size_t size = seq_get_buf(m, &buf); | |
478 | int res = -1; | |
479 | ||
480 | if (size) { | |
481 | char *p = d_path(path, buf, size); | |
1da177e4 | 482 | if (!IS_ERR(p)) { |
f8439806 MS |
483 | char *end = mangle_path(buf, p, esc); |
484 | if (end) | |
485 | res = end - buf; | |
1da177e4 LT |
486 | } |
487 | } | |
f8439806 MS |
488 | seq_commit(m, res); |
489 | ||
490 | return res; | |
1da177e4 LT |
491 | } |
492 | EXPORT_SYMBOL(seq_path); | |
493 | ||
2726d566 MS |
494 | /** |
495 | * seq_file_path - seq_file interface to print a pathname of a file | |
496 | * @m: the seq_file handle | |
497 | * @file: the struct file to print | |
498 | * @esc: set of characters to escape in the output | |
499 | * | |
500 | * return the absolute path to the file. | |
501 | */ | |
502 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
503 | { | |
504 | return seq_path(m, &file->f_path, esc); | |
505 | } | |
506 | EXPORT_SYMBOL(seq_file_path); | |
507 | ||
9d1bc601 MS |
508 | /* |
509 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 510 | */ |
8c9379e9 AV |
511 | int seq_path_root(struct seq_file *m, const struct path *path, |
512 | const struct path *root, const char *esc) | |
9d1bc601 | 513 | { |
f8439806 MS |
514 | char *buf; |
515 | size_t size = seq_get_buf(m, &buf); | |
516 | int res = -ENAMETOOLONG; | |
517 | ||
518 | if (size) { | |
9d1bc601 MS |
519 | char *p; |
520 | ||
f8439806 | 521 | p = __d_path(path, root, buf, size); |
02125a82 AV |
522 | if (!p) |
523 | return SEQ_SKIP; | |
f8439806 | 524 | res = PTR_ERR(p); |
9d1bc601 | 525 | if (!IS_ERR(p)) { |
f8439806 MS |
526 | char *end = mangle_path(buf, p, esc); |
527 | if (end) | |
528 | res = end - buf; | |
529 | else | |
530 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
531 | } |
532 | } | |
f8439806 MS |
533 | seq_commit(m, res); |
534 | ||
02125a82 | 535 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
536 | } |
537 | ||
6092d048 RP |
538 | /* |
539 | * returns the path of the 'dentry' from the root of its filesystem. | |
540 | */ | |
8c9379e9 | 541 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 542 | { |
f8439806 MS |
543 | char *buf; |
544 | size_t size = seq_get_buf(m, &buf); | |
545 | int res = -1; | |
546 | ||
547 | if (size) { | |
548 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 549 | if (!IS_ERR(p)) { |
f8439806 MS |
550 | char *end = mangle_path(buf, p, esc); |
551 | if (end) | |
552 | res = end - buf; | |
6092d048 RP |
553 | } |
554 | } | |
f8439806 MS |
555 | seq_commit(m, res); |
556 | ||
557 | return res; | |
6092d048 | 558 | } |
c8d3fe02 | 559 | EXPORT_SYMBOL(seq_dentry); |
6092d048 | 560 | |
1da177e4 LT |
561 | static void *single_start(struct seq_file *p, loff_t *pos) |
562 | { | |
563 | return NULL + (*pos == 0); | |
564 | } | |
565 | ||
566 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
567 | { | |
568 | ++*pos; | |
569 | return NULL; | |
570 | } | |
571 | ||
572 | static void single_stop(struct seq_file *p, void *v) | |
573 | { | |
574 | } | |
575 | ||
576 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
577 | void *data) | |
578 | { | |
d64d01a1 | 579 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT); |
1da177e4 LT |
580 | int res = -ENOMEM; |
581 | ||
582 | if (op) { | |
583 | op->start = single_start; | |
584 | op->next = single_next; | |
585 | op->stop = single_stop; | |
586 | op->show = show; | |
587 | res = seq_open(file, op); | |
588 | if (!res) | |
589 | ((struct seq_file *)file->private_data)->private = data; | |
590 | else | |
591 | kfree(op); | |
592 | } | |
593 | return res; | |
594 | } | |
595 | EXPORT_SYMBOL(single_open); | |
596 | ||
2043f495 AV |
597 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
598 | void *data, size_t size) | |
599 | { | |
058504ed | 600 | char *buf = seq_buf_alloc(size); |
2043f495 AV |
601 | int ret; |
602 | if (!buf) | |
603 | return -ENOMEM; | |
604 | ret = single_open(file, show, data); | |
605 | if (ret) { | |
058504ed | 606 | kvfree(buf); |
2043f495 AV |
607 | return ret; |
608 | } | |
609 | ((struct seq_file *)file->private_data)->buf = buf; | |
610 | ((struct seq_file *)file->private_data)->size = size; | |
611 | return 0; | |
612 | } | |
613 | EXPORT_SYMBOL(single_open_size); | |
614 | ||
1da177e4 LT |
615 | int single_release(struct inode *inode, struct file *file) |
616 | { | |
15ad7cdc | 617 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
618 | int res = seq_release(inode, file); |
619 | kfree(op); | |
620 | return res; | |
621 | } | |
622 | EXPORT_SYMBOL(single_release); | |
623 | ||
624 | int seq_release_private(struct inode *inode, struct file *file) | |
625 | { | |
626 | struct seq_file *seq = file->private_data; | |
627 | ||
628 | kfree(seq->private); | |
629 | seq->private = NULL; | |
630 | return seq_release(inode, file); | |
631 | } | |
632 | EXPORT_SYMBOL(seq_release_private); | |
633 | ||
39699037 PE |
634 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
635 | int psize) | |
636 | { | |
637 | int rc; | |
638 | void *private; | |
639 | struct seq_file *seq; | |
640 | ||
d64d01a1 | 641 | private = kzalloc(psize, GFP_KERNEL_ACCOUNT); |
39699037 PE |
642 | if (private == NULL) |
643 | goto out; | |
644 | ||
645 | rc = seq_open(f, ops); | |
646 | if (rc < 0) | |
647 | goto out_free; | |
648 | ||
649 | seq = f->private_data; | |
650 | seq->private = private; | |
651 | return private; | |
652 | ||
653 | out_free: | |
654 | kfree(private); | |
655 | out: | |
656 | return NULL; | |
657 | } | |
658 | EXPORT_SYMBOL(__seq_open_private); | |
659 | ||
660 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
661 | int psize) | |
662 | { | |
663 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
664 | } | |
665 | EXPORT_SYMBOL(seq_open_private); | |
666 | ||
6798a8ca | 667 | void seq_putc(struct seq_file *m, char c) |
1da177e4 | 668 | { |
6798a8ca JP |
669 | if (m->count >= m->size) |
670 | return; | |
671 | ||
672 | m->buf[m->count++] = c; | |
1da177e4 LT |
673 | } |
674 | EXPORT_SYMBOL(seq_putc); | |
675 | ||
6798a8ca | 676 | void seq_puts(struct seq_file *m, const char *s) |
1da177e4 LT |
677 | { |
678 | int len = strlen(s); | |
6798a8ca JP |
679 | |
680 | if (m->count + len >= m->size) { | |
681 | seq_set_overflow(m); | |
682 | return; | |
1da177e4 | 683 | } |
6798a8ca JP |
684 | memcpy(m->buf + m->count, s, len); |
685 | m->count += len; | |
1da177e4 LT |
686 | } |
687 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 688 | |
d1be35cb | 689 | /** |
961f3c89 MCC |
690 | * seq_put_decimal_ull_width - A helper routine for putting decimal numbers |
691 | * without rich format of printf(). | |
1ac101a5 | 692 | * only 'unsigned long long' is supported. |
d1be35cb AV |
693 | * @m: seq_file identifying the buffer to which data should be written |
694 | * @delimiter: a string which is printed before the number | |
695 | * @num: the number | |
696 | * @width: a minimum field width | |
697 | * | |
698 | * This routine will put strlen(delimiter) + number into seq_filed. | |
1ac101a5 KH |
699 | * This routine is very quick when you show lots of numbers. |
700 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
701 | */ | |
d1be35cb AV |
702 | void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, |
703 | unsigned long long num, unsigned int width) | |
1ac101a5 KH |
704 | { |
705 | int len; | |
706 | ||
707 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
708 | goto overflow; | |
709 | ||
48dffbf8 AV |
710 | if (delimiter && delimiter[0]) { |
711 | if (delimiter[1] == 0) | |
712 | seq_putc(m, delimiter[0]); | |
713 | else | |
714 | seq_puts(m, delimiter); | |
715 | } | |
75ba1d07 | 716 | |
d1be35cb AV |
717 | if (!width) |
718 | width = 1; | |
719 | ||
720 | if (m->count + width >= m->size) | |
75ba1d07 | 721 | goto overflow; |
1ac101a5 | 722 | |
d1be35cb | 723 | len = num_to_str(m->buf + m->count, m->size - m->count, num, width); |
1ac101a5 KH |
724 | if (!len) |
725 | goto overflow; | |
75ba1d07 | 726 | |
1ac101a5 | 727 | m->count += len; |
6798a8ca JP |
728 | return; |
729 | ||
1ac101a5 | 730 | overflow: |
e075f591 | 731 | seq_set_overflow(m); |
1ac101a5 | 732 | } |
d1be35cb AV |
733 | |
734 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, | |
735 | unsigned long long num) | |
736 | { | |
737 | return seq_put_decimal_ull_width(m, delimiter, num, 0); | |
738 | } | |
1ac101a5 KH |
739 | EXPORT_SYMBOL(seq_put_decimal_ull); |
740 | ||
0e3dc019 AV |
741 | /** |
742 | * seq_put_hex_ll - put a number in hexadecimal notation | |
743 | * @m: seq_file identifying the buffer to which data should be written | |
744 | * @delimiter: a string which is printed before the number | |
745 | * @v: the number | |
746 | * @width: a minimum field width | |
747 | * | |
748 | * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v) | |
749 | * | |
750 | * This routine is very quick when you show lots of numbers. | |
751 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
752 | */ | |
753 | void seq_put_hex_ll(struct seq_file *m, const char *delimiter, | |
754 | unsigned long long v, unsigned int width) | |
755 | { | |
756 | unsigned int len; | |
757 | int i; | |
758 | ||
759 | if (delimiter && delimiter[0]) { | |
760 | if (delimiter[1] == 0) | |
761 | seq_putc(m, delimiter[0]); | |
762 | else | |
763 | seq_puts(m, delimiter); | |
764 | } | |
765 | ||
766 | /* If x is 0, the result of __builtin_clzll is undefined */ | |
767 | if (v == 0) | |
768 | len = 1; | |
769 | else | |
770 | len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4; | |
771 | ||
772 | if (len < width) | |
773 | len = width; | |
774 | ||
775 | if (m->count + len > m->size) { | |
776 | seq_set_overflow(m); | |
777 | return; | |
778 | } | |
779 | ||
780 | for (i = len - 1; i >= 0; i--) { | |
781 | m->buf[m->count + i] = hex_asc[0xf & v]; | |
782 | v = v >> 4; | |
783 | } | |
784 | m->count += len; | |
785 | } | |
786 | ||
75ba1d07 | 787 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
bda7bad6 | 788 | { |
75ba1d07 JP |
789 | int len; |
790 | ||
791 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ | |
792 | goto overflow; | |
793 | ||
48dffbf8 AV |
794 | if (delimiter && delimiter[0]) { |
795 | if (delimiter[1] == 0) | |
796 | seq_putc(m, delimiter[0]); | |
797 | else | |
798 | seq_puts(m, delimiter); | |
799 | } | |
75ba1d07 JP |
800 | |
801 | if (m->count + 2 >= m->size) | |
802 | goto overflow; | |
803 | ||
bda7bad6 | 804 | if (num < 0) { |
75ba1d07 | 805 | m->buf[m->count++] = '-'; |
bda7bad6 | 806 | num = -num; |
bda7bad6 | 807 | } |
75ba1d07 JP |
808 | |
809 | if (num < 10) { | |
810 | m->buf[m->count++] = num + '0'; | |
811 | return; | |
812 | } | |
813 | ||
d1be35cb | 814 | len = num_to_str(m->buf + m->count, m->size - m->count, num, 0); |
75ba1d07 JP |
815 | if (!len) |
816 | goto overflow; | |
817 | ||
818 | m->count += len; | |
819 | return; | |
820 | ||
821 | overflow: | |
822 | seq_set_overflow(m); | |
bda7bad6 KH |
823 | } |
824 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
825 | ||
0b923606 PO |
826 | /** |
827 | * seq_write - write arbitrary data to buffer | |
828 | * @seq: seq_file identifying the buffer to which data should be written | |
829 | * @data: data address | |
830 | * @len: number of bytes | |
831 | * | |
832 | * Return 0 on success, non-zero otherwise. | |
833 | */ | |
834 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
835 | { | |
836 | if (seq->count + len < seq->size) { | |
837 | memcpy(seq->buf + seq->count, data, len); | |
838 | seq->count += len; | |
839 | return 0; | |
840 | } | |
e075f591 | 841 | seq_set_overflow(seq); |
0b923606 PO |
842 | return -1; |
843 | } | |
844 | EXPORT_SYMBOL(seq_write); | |
845 | ||
839cc2a9 TH |
846 | /** |
847 | * seq_pad - write padding spaces to buffer | |
848 | * @m: seq_file identifying the buffer to which data should be written | |
849 | * @c: the byte to append after padding if non-zero | |
850 | */ | |
851 | void seq_pad(struct seq_file *m, char c) | |
852 | { | |
853 | int size = m->pad_until - m->count; | |
8cfa67b4 AV |
854 | if (size > 0) { |
855 | if (size + m->count > m->size) { | |
856 | seq_set_overflow(m); | |
857 | return; | |
858 | } | |
859 | memset(m->buf + m->count, ' ', size); | |
860 | m->count += size; | |
861 | } | |
839cc2a9 TH |
862 | if (c) |
863 | seq_putc(m, c); | |
864 | } | |
865 | EXPORT_SYMBOL(seq_pad); | |
866 | ||
37607102 AS |
867 | /* A complete analogue of print_hex_dump() */ |
868 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
869 | int rowsize, int groupsize, const void *buf, size_t len, | |
870 | bool ascii) | |
871 | { | |
872 | const u8 *ptr = buf; | |
873 | int i, linelen, remaining = len; | |
8b91a318 AS |
874 | char *buffer; |
875 | size_t size; | |
37607102 AS |
876 | int ret; |
877 | ||
878 | if (rowsize != 16 && rowsize != 32) | |
879 | rowsize = 16; | |
880 | ||
881 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
882 | linelen = min(remaining, rowsize); | |
883 | remaining -= rowsize; | |
884 | ||
885 | switch (prefix_type) { | |
886 | case DUMP_PREFIX_ADDRESS: | |
887 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
888 | break; | |
889 | case DUMP_PREFIX_OFFSET: | |
890 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
891 | break; | |
892 | default: | |
893 | seq_printf(m, "%s", prefix_str); | |
894 | break; | |
895 | } | |
896 | ||
8b91a318 | 897 | size = seq_get_buf(m, &buffer); |
37607102 | 898 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
8b91a318 AS |
899 | buffer, size, ascii); |
900 | seq_commit(m, ret < size ? ret : -1); | |
901 | ||
902 | seq_putc(m, '\n'); | |
37607102 AS |
903 | } |
904 | } | |
905 | EXPORT_SYMBOL(seq_hex_dump); | |
906 | ||
bcf67e16 PE |
907 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
908 | { | |
909 | struct list_head *lh; | |
910 | ||
911 | list_for_each(lh, head) | |
912 | if (pos-- == 0) | |
913 | return lh; | |
914 | ||
915 | return NULL; | |
916 | } | |
bcf67e16 PE |
917 | EXPORT_SYMBOL(seq_list_start); |
918 | ||
919 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
920 | { | |
921 | if (!pos) | |
922 | return head; | |
923 | ||
924 | return seq_list_start(head, pos - 1); | |
925 | } | |
bcf67e16 PE |
926 | EXPORT_SYMBOL(seq_list_start_head); |
927 | ||
928 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
929 | { | |
930 | struct list_head *lh; | |
931 | ||
932 | lh = ((struct list_head *)v)->next; | |
933 | ++*ppos; | |
934 | return lh == head ? NULL : lh; | |
935 | } | |
bcf67e16 | 936 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
937 | |
938 | /** | |
939 | * seq_hlist_start - start an iteration of a hlist | |
940 | * @head: the head of the hlist | |
941 | * @pos: the start position of the sequence | |
942 | * | |
943 | * Called at seq_file->op->start(). | |
944 | */ | |
945 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
946 | { | |
947 | struct hlist_node *node; | |
948 | ||
949 | hlist_for_each(node, head) | |
950 | if (pos-- == 0) | |
951 | return node; | |
952 | return NULL; | |
953 | } | |
954 | EXPORT_SYMBOL(seq_hlist_start); | |
955 | ||
956 | /** | |
957 | * seq_hlist_start_head - start an iteration of a hlist | |
958 | * @head: the head of the hlist | |
959 | * @pos: the start position of the sequence | |
960 | * | |
961 | * Called at seq_file->op->start(). Call this function if you want to | |
962 | * print a header at the top of the output. | |
963 | */ | |
964 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
965 | { | |
966 | if (!pos) | |
967 | return SEQ_START_TOKEN; | |
968 | ||
969 | return seq_hlist_start(head, pos - 1); | |
970 | } | |
971 | EXPORT_SYMBOL(seq_hlist_start_head); | |
972 | ||
973 | /** | |
974 | * seq_hlist_next - move to the next position of the hlist | |
975 | * @v: the current iterator | |
976 | * @head: the head of the hlist | |
138860b9 | 977 | * @ppos: the current position |
66655de6 LZ |
978 | * |
979 | * Called at seq_file->op->next(). | |
980 | */ | |
981 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
982 | loff_t *ppos) | |
983 | { | |
984 | struct hlist_node *node = v; | |
985 | ||
986 | ++*ppos; | |
987 | if (v == SEQ_START_TOKEN) | |
988 | return head->first; | |
989 | else | |
990 | return node->next; | |
991 | } | |
992 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 993 | |
994 | /** | |
995 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
996 | * @head: the head of the hlist | |
997 | * @pos: the start position of the sequence | |
998 | * | |
999 | * Called at seq_file->op->start(). | |
1000 | * | |
1001 | * This list-traversal primitive may safely run concurrently with | |
1002 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
1003 | * as long as the traversal is guarded by rcu_read_lock(). | |
1004 | */ | |
1005 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
1006 | loff_t pos) | |
1007 | { | |
1008 | struct hlist_node *node; | |
1009 | ||
1010 | __hlist_for_each_rcu(node, head) | |
1011 | if (pos-- == 0) | |
1012 | return node; | |
1013 | return NULL; | |
1014 | } | |
1015 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
1016 | ||
1017 | /** | |
1018 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
1019 | * @head: the head of the hlist | |
1020 | * @pos: the start position of the sequence | |
1021 | * | |
1022 | * Called at seq_file->op->start(). Call this function if you want to | |
1023 | * print a header at the top of the output. | |
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 | */ | |
1029 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
1030 | loff_t pos) | |
1031 | { | |
1032 | if (!pos) | |
1033 | return SEQ_START_TOKEN; | |
1034 | ||
1035 | return seq_hlist_start_rcu(head, pos - 1); | |
1036 | } | |
1037 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
1038 | ||
1039 | /** | |
1040 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
1041 | * @v: the current iterator | |
1042 | * @head: the head of the hlist | |
138860b9 | 1043 | * @ppos: the current position |
1cc52327 | 1044 | * |
1045 | * Called at seq_file->op->next(). | |
1046 | * | |
1047 | * This list-traversal primitive may safely run concurrently with | |
1048 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
1049 | * as long as the traversal is guarded by rcu_read_lock(). | |
1050 | */ | |
1051 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
1052 | struct hlist_head *head, | |
1053 | loff_t *ppos) | |
1054 | { | |
1055 | struct hlist_node *node = v; | |
1056 | ||
1057 | ++*ppos; | |
1058 | if (v == SEQ_START_TOKEN) | |
1059 | return rcu_dereference(head->first); | |
1060 | else | |
1061 | return rcu_dereference(node->next); | |
1062 | } | |
1063 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
0bc77381 JL |
1064 | |
1065 | /** | |
961f3c89 | 1066 | * seq_hlist_start_percpu - start an iteration of a percpu hlist array |
0bc77381 JL |
1067 | * @head: pointer to percpu array of struct hlist_heads |
1068 | * @cpu: pointer to cpu "cursor" | |
1069 | * @pos: start position of sequence | |
1070 | * | |
1071 | * Called at seq_file->op->start(). | |
1072 | */ | |
1073 | struct hlist_node * | |
1074 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
1075 | { | |
1076 | struct hlist_node *node; | |
1077 | ||
1078 | for_each_possible_cpu(*cpu) { | |
1079 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
1080 | if (pos-- == 0) | |
1081 | return node; | |
1082 | } | |
1083 | } | |
1084 | return NULL; | |
1085 | } | |
1086 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
1087 | ||
1088 | /** | |
1089 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1090 | * @v: pointer to current hlist_node | |
1091 | * @head: pointer to percpu array of struct hlist_heads | |
1092 | * @cpu: pointer to cpu "cursor" | |
1093 | * @pos: start position of sequence | |
1094 | * | |
1095 | * Called at seq_file->op->next(). | |
1096 | */ | |
1097 | struct hlist_node * | |
1098 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1099 | int *cpu, loff_t *pos) | |
1100 | { | |
1101 | struct hlist_node *node = v; | |
1102 | ||
1103 | ++*pos; | |
1104 | ||
1105 | if (node->next) | |
1106 | return node->next; | |
1107 | ||
1108 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1109 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1110 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1111 | ||
1112 | if (!hlist_empty(bucket)) | |
1113 | return bucket->first; | |
1114 | } | |
1115 | return NULL; | |
1116 | } | |
1117 | EXPORT_SYMBOL(seq_hlist_next_percpu); | |
09652320 AD |
1118 | |
1119 | void __init seq_file_init(void) | |
1120 | { | |
d64d01a1 | 1121 | seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC); |
09652320 | 1122 | } |