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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 | ||
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 |
23 | static struct kmem_cache *seq_file_cache __ro_after_init; |
24 | ||
e075f591 KH |
25 | static void seq_set_overflow(struct seq_file *m) |
26 | { | |
27 | m->count = m->size; | |
28 | } | |
29 | ||
058504ed HC |
30 | static 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 | 51 | int 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 | } | |
82 | EXPORT_SYMBOL(seq_open); | |
83 | ||
33da8892 EB |
84 | static 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 | ||
128 | Eoverflow: | |
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 | */ | |
145 | ssize_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; | |
228 | Fill: | |
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); | |
3bfa7e14 VA |
235 | if (pos == m->index) { |
236 | pr_info_ratelimited("buggy seq_file .next function %ps " | |
237 | "did not updated position index\n", | |
238 | m->op->next); | |
1f4aace6 | 239 | m->index++; |
3bfa7e14 | 240 | } |
1da177e4 LT |
241 | if (!p || IS_ERR(p)) { |
242 | err = PTR_ERR(p); | |
243 | break; | |
244 | } | |
1f4aace6 N |
245 | if (m->count >= size) |
246 | break; | |
1da177e4 | 247 | err = m->op->show(m, p); |
1f33c41c | 248 | if (seq_has_overflowed(m) || err) { |
1da177e4 | 249 | m->count = offs; |
521b5d0c AV |
250 | if (likely(err <= 0)) |
251 | break; | |
1da177e4 | 252 | } |
1da177e4 LT |
253 | } |
254 | m->op->stop(m, p); | |
255 | n = min(m->count, size); | |
256 | err = copy_to_user(buf, m->buf, n); | |
257 | if (err) | |
258 | goto Efault; | |
259 | copied += n; | |
260 | m->count -= n; | |
1f4aace6 | 261 | m->from = n; |
1da177e4 LT |
262 | Done: |
263 | if (!copied) | |
264 | copied = err; | |
8f19d472 | 265 | else { |
1da177e4 | 266 | *ppos += copied; |
8f19d472 EB |
267 | m->read_pos += copied; |
268 | } | |
0ac1759a | 269 | mutex_unlock(&m->lock); |
1da177e4 LT |
270 | return copied; |
271 | Enomem: | |
272 | err = -ENOMEM; | |
273 | goto Done; | |
274 | Efault: | |
275 | err = -EFAULT; | |
276 | goto Done; | |
277 | } | |
278 | EXPORT_SYMBOL(seq_read); | |
279 | ||
1da177e4 LT |
280 | /** |
281 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
282 | * @file: the file in question |
283 | * @offset: new position | |
254adaa4 | 284 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
285 | * |
286 | * Ready-made ->f_op->llseek() | |
287 | */ | |
965c8e59 | 288 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 289 | { |
8209e2f4 | 290 | struct seq_file *m = file->private_data; |
16abef0e | 291 | loff_t retval = -EINVAL; |
1da177e4 | 292 | |
0ac1759a | 293 | mutex_lock(&m->lock); |
965c8e59 | 294 | switch (whence) { |
5e62adef AM |
295 | case SEEK_CUR: |
296 | offset += file->f_pos; | |
0a4c9265 | 297 | /* fall through */ |
5e62adef AM |
298 | case SEEK_SET: |
299 | if (offset < 0) | |
300 | break; | |
301 | retval = offset; | |
302 | if (offset != m->read_pos) { | |
303 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
304 | ; | |
305 | if (retval) { | |
306 | /* with extreme prejudice... */ | |
307 | file->f_pos = 0; | |
308 | m->read_pos = 0; | |
5e62adef AM |
309 | m->index = 0; |
310 | m->count = 0; | |
311 | } else { | |
312 | m->read_pos = offset; | |
313 | retval = file->f_pos = offset; | |
1da177e4 | 314 | } |
05e16745 GZ |
315 | } else { |
316 | file->f_pos = offset; | |
5e62adef | 317 | } |
1da177e4 | 318 | } |
00c5746d | 319 | mutex_unlock(&m->lock); |
1da177e4 LT |
320 | return retval; |
321 | } | |
322 | EXPORT_SYMBOL(seq_lseek); | |
323 | ||
324 | /** | |
325 | * seq_release - free the structures associated with sequential file. | |
326 | * @file: file in question | |
6131ffaa | 327 | * @inode: its inode |
1da177e4 LT |
328 | * |
329 | * Frees the structures associated with sequential file; can be used | |
330 | * as ->f_op->release() if you don't have private data to destroy. | |
331 | */ | |
332 | int seq_release(struct inode *inode, struct file *file) | |
333 | { | |
8209e2f4 | 334 | struct seq_file *m = file->private_data; |
058504ed | 335 | kvfree(m->buf); |
09652320 | 336 | kmem_cache_free(seq_file_cache, m); |
1da177e4 LT |
337 | return 0; |
338 | } | |
339 | EXPORT_SYMBOL(seq_release); | |
340 | ||
341 | /** | |
342 | * seq_escape - print string into buffer, escaping some characters | |
343 | * @m: target buffer | |
344 | * @s: string | |
345 | * @esc: set of characters that need escaping | |
346 | * | |
347 | * Puts string into buffer, replacing each occurrence of character from | |
6798a8ca JP |
348 | * @esc with usual octal escape. |
349 | * Use seq_has_overflowed() to check for errors. | |
1da177e4 | 350 | */ |
6798a8ca | 351 | void seq_escape(struct seq_file *m, const char *s, const char *esc) |
1da177e4 | 352 | { |
25c6bb76 AS |
353 | char *buf; |
354 | size_t size = seq_get_buf(m, &buf); | |
355 | int ret; | |
1da177e4 | 356 | |
25c6bb76 AS |
357 | ret = string_escape_str(s, buf, size, ESCAPE_OCTAL, esc); |
358 | seq_commit(m, ret < size ? ret : -1); | |
1da177e4 LT |
359 | } |
360 | EXPORT_SYMBOL(seq_escape); | |
361 | ||
ea053e16 BF |
362 | void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz) |
363 | { | |
364 | char *buf; | |
365 | size_t size = seq_get_buf(m, &buf); | |
366 | int ret; | |
367 | ||
368 | ret = string_escape_mem_ascii(src, isz, buf, size); | |
369 | seq_commit(m, ret < size ? ret : -1); | |
370 | } | |
371 | EXPORT_SYMBOL(seq_escape_mem_ascii); | |
372 | ||
6798a8ca | 373 | void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 374 | { |
1da177e4 LT |
375 | int len; |
376 | ||
377 | if (m->count < m->size) { | |
1da177e4 | 378 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
379 | if (m->count + len < m->size) { |
380 | m->count += len; | |
6798a8ca | 381 | return; |
1da177e4 LT |
382 | } |
383 | } | |
e075f591 | 384 | seq_set_overflow(m); |
1da177e4 | 385 | } |
a4808147 SW |
386 | EXPORT_SYMBOL(seq_vprintf); |
387 | ||
6798a8ca | 388 | void seq_printf(struct seq_file *m, const char *f, ...) |
a4808147 | 389 | { |
a4808147 SW |
390 | va_list args; |
391 | ||
392 | va_start(args, f); | |
6798a8ca | 393 | seq_vprintf(m, f, args); |
a4808147 | 394 | va_end(args); |
a4808147 | 395 | } |
1da177e4 LT |
396 | EXPORT_SYMBOL(seq_printf); |
397 | ||
74e2f334 | 398 | /** |
958086d1 TE |
399 | * mangle_path - mangle and copy path to buffer beginning |
400 | * @s: buffer start | |
401 | * @p: beginning of path in above buffer | |
402 | * @esc: set of characters that need escaping | |
74e2f334 TE |
403 | * |
404 | * Copy the path from @p to @s, replacing each occurrence of character from | |
405 | * @esc with usual octal escape. | |
406 | * Returns pointer past last written character in @s, or NULL in case of | |
407 | * failure. | |
408 | */ | |
8c9379e9 | 409 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
410 | { |
411 | while (s <= p) { | |
412 | char c = *p++; | |
413 | if (!c) { | |
414 | return s; | |
415 | } else if (!strchr(esc, c)) { | |
416 | *s++ = c; | |
417 | } else if (s + 4 > p) { | |
418 | break; | |
419 | } else { | |
420 | *s++ = '\\'; | |
421 | *s++ = '0' + ((c & 0300) >> 6); | |
422 | *s++ = '0' + ((c & 070) >> 3); | |
423 | *s++ = '0' + (c & 07); | |
424 | } | |
425 | } | |
426 | return NULL; | |
427 | } | |
604094f4 | 428 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 429 | |
52afeefb AV |
430 | /** |
431 | * seq_path - seq_file interface to print a pathname | |
432 | * @m: the seq_file handle | |
433 | * @path: the struct path to print | |
434 | * @esc: set of characters to escape in the output | |
435 | * | |
436 | * return the absolute path of 'path', as represented by the | |
437 | * dentry / mnt pair in the path parameter. | |
6092d048 | 438 | */ |
8c9379e9 | 439 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 440 | { |
f8439806 MS |
441 | char *buf; |
442 | size_t size = seq_get_buf(m, &buf); | |
443 | int res = -1; | |
444 | ||
445 | if (size) { | |
446 | char *p = d_path(path, buf, size); | |
1da177e4 | 447 | if (!IS_ERR(p)) { |
f8439806 MS |
448 | char *end = mangle_path(buf, p, esc); |
449 | if (end) | |
450 | res = end - buf; | |
1da177e4 LT |
451 | } |
452 | } | |
f8439806 MS |
453 | seq_commit(m, res); |
454 | ||
455 | return res; | |
1da177e4 LT |
456 | } |
457 | EXPORT_SYMBOL(seq_path); | |
458 | ||
2726d566 MS |
459 | /** |
460 | * seq_file_path - seq_file interface to print a pathname of a file | |
461 | * @m: the seq_file handle | |
462 | * @file: the struct file to print | |
463 | * @esc: set of characters to escape in the output | |
464 | * | |
465 | * return the absolute path to the file. | |
466 | */ | |
467 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
468 | { | |
469 | return seq_path(m, &file->f_path, esc); | |
470 | } | |
471 | EXPORT_SYMBOL(seq_file_path); | |
472 | ||
9d1bc601 MS |
473 | /* |
474 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 475 | */ |
8c9379e9 AV |
476 | int seq_path_root(struct seq_file *m, const struct path *path, |
477 | const struct path *root, const char *esc) | |
9d1bc601 | 478 | { |
f8439806 MS |
479 | char *buf; |
480 | size_t size = seq_get_buf(m, &buf); | |
481 | int res = -ENAMETOOLONG; | |
482 | ||
483 | if (size) { | |
9d1bc601 MS |
484 | char *p; |
485 | ||
f8439806 | 486 | p = __d_path(path, root, buf, size); |
02125a82 AV |
487 | if (!p) |
488 | return SEQ_SKIP; | |
f8439806 | 489 | res = PTR_ERR(p); |
9d1bc601 | 490 | if (!IS_ERR(p)) { |
f8439806 MS |
491 | char *end = mangle_path(buf, p, esc); |
492 | if (end) | |
493 | res = end - buf; | |
494 | else | |
495 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
496 | } |
497 | } | |
f8439806 MS |
498 | seq_commit(m, res); |
499 | ||
02125a82 | 500 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
501 | } |
502 | ||
6092d048 RP |
503 | /* |
504 | * returns the path of the 'dentry' from the root of its filesystem. | |
505 | */ | |
8c9379e9 | 506 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 507 | { |
f8439806 MS |
508 | char *buf; |
509 | size_t size = seq_get_buf(m, &buf); | |
510 | int res = -1; | |
511 | ||
512 | if (size) { | |
513 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 514 | if (!IS_ERR(p)) { |
f8439806 MS |
515 | char *end = mangle_path(buf, p, esc); |
516 | if (end) | |
517 | res = end - buf; | |
6092d048 RP |
518 | } |
519 | } | |
f8439806 MS |
520 | seq_commit(m, res); |
521 | ||
522 | return res; | |
6092d048 | 523 | } |
c8d3fe02 | 524 | EXPORT_SYMBOL(seq_dentry); |
6092d048 | 525 | |
1da177e4 LT |
526 | static void *single_start(struct seq_file *p, loff_t *pos) |
527 | { | |
528 | return NULL + (*pos == 0); | |
529 | } | |
530 | ||
531 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
532 | { | |
533 | ++*pos; | |
534 | return NULL; | |
535 | } | |
536 | ||
537 | static void single_stop(struct seq_file *p, void *v) | |
538 | { | |
539 | } | |
540 | ||
541 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
542 | void *data) | |
543 | { | |
d64d01a1 | 544 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT); |
1da177e4 LT |
545 | int res = -ENOMEM; |
546 | ||
547 | if (op) { | |
548 | op->start = single_start; | |
549 | op->next = single_next; | |
550 | op->stop = single_stop; | |
551 | op->show = show; | |
552 | res = seq_open(file, op); | |
553 | if (!res) | |
554 | ((struct seq_file *)file->private_data)->private = data; | |
555 | else | |
556 | kfree(op); | |
557 | } | |
558 | return res; | |
559 | } | |
560 | EXPORT_SYMBOL(single_open); | |
561 | ||
2043f495 AV |
562 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
563 | void *data, size_t size) | |
564 | { | |
058504ed | 565 | char *buf = seq_buf_alloc(size); |
2043f495 AV |
566 | int ret; |
567 | if (!buf) | |
568 | return -ENOMEM; | |
569 | ret = single_open(file, show, data); | |
570 | if (ret) { | |
058504ed | 571 | kvfree(buf); |
2043f495 AV |
572 | return ret; |
573 | } | |
574 | ((struct seq_file *)file->private_data)->buf = buf; | |
575 | ((struct seq_file *)file->private_data)->size = size; | |
576 | return 0; | |
577 | } | |
578 | EXPORT_SYMBOL(single_open_size); | |
579 | ||
1da177e4 LT |
580 | int single_release(struct inode *inode, struct file *file) |
581 | { | |
15ad7cdc | 582 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
583 | int res = seq_release(inode, file); |
584 | kfree(op); | |
585 | return res; | |
586 | } | |
587 | EXPORT_SYMBOL(single_release); | |
588 | ||
589 | int seq_release_private(struct inode *inode, struct file *file) | |
590 | { | |
591 | struct seq_file *seq = file->private_data; | |
592 | ||
593 | kfree(seq->private); | |
594 | seq->private = NULL; | |
595 | return seq_release(inode, file); | |
596 | } | |
597 | EXPORT_SYMBOL(seq_release_private); | |
598 | ||
39699037 PE |
599 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
600 | int psize) | |
601 | { | |
602 | int rc; | |
603 | void *private; | |
604 | struct seq_file *seq; | |
605 | ||
d64d01a1 | 606 | private = kzalloc(psize, GFP_KERNEL_ACCOUNT); |
39699037 PE |
607 | if (private == NULL) |
608 | goto out; | |
609 | ||
610 | rc = seq_open(f, ops); | |
611 | if (rc < 0) | |
612 | goto out_free; | |
613 | ||
614 | seq = f->private_data; | |
615 | seq->private = private; | |
616 | return private; | |
617 | ||
618 | out_free: | |
619 | kfree(private); | |
620 | out: | |
621 | return NULL; | |
622 | } | |
623 | EXPORT_SYMBOL(__seq_open_private); | |
624 | ||
625 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
626 | int psize) | |
627 | { | |
628 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
629 | } | |
630 | EXPORT_SYMBOL(seq_open_private); | |
631 | ||
6798a8ca | 632 | void seq_putc(struct seq_file *m, char c) |
1da177e4 | 633 | { |
6798a8ca JP |
634 | if (m->count >= m->size) |
635 | return; | |
636 | ||
637 | m->buf[m->count++] = c; | |
1da177e4 LT |
638 | } |
639 | EXPORT_SYMBOL(seq_putc); | |
640 | ||
6798a8ca | 641 | void seq_puts(struct seq_file *m, const char *s) |
1da177e4 LT |
642 | { |
643 | int len = strlen(s); | |
6798a8ca JP |
644 | |
645 | if (m->count + len >= m->size) { | |
646 | seq_set_overflow(m); | |
647 | return; | |
1da177e4 | 648 | } |
6798a8ca JP |
649 | memcpy(m->buf + m->count, s, len); |
650 | m->count += len; | |
1da177e4 LT |
651 | } |
652 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 653 | |
d1be35cb | 654 | /** |
1ac101a5 KH |
655 | * A helper routine for putting decimal numbers without rich format of printf(). |
656 | * only 'unsigned long long' is supported. | |
d1be35cb AV |
657 | * @m: seq_file identifying the buffer to which data should be written |
658 | * @delimiter: a string which is printed before the number | |
659 | * @num: the number | |
660 | * @width: a minimum field width | |
661 | * | |
662 | * This routine will put strlen(delimiter) + number into seq_filed. | |
1ac101a5 KH |
663 | * This routine is very quick when you show lots of numbers. |
664 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
665 | */ | |
d1be35cb AV |
666 | void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, |
667 | unsigned long long num, unsigned int width) | |
1ac101a5 KH |
668 | { |
669 | int len; | |
670 | ||
671 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
672 | goto overflow; | |
673 | ||
48dffbf8 AV |
674 | if (delimiter && delimiter[0]) { |
675 | if (delimiter[1] == 0) | |
676 | seq_putc(m, delimiter[0]); | |
677 | else | |
678 | seq_puts(m, delimiter); | |
679 | } | |
75ba1d07 | 680 | |
d1be35cb AV |
681 | if (!width) |
682 | width = 1; | |
683 | ||
684 | if (m->count + width >= m->size) | |
75ba1d07 | 685 | goto overflow; |
1ac101a5 | 686 | |
d1be35cb | 687 | len = num_to_str(m->buf + m->count, m->size - m->count, num, width); |
1ac101a5 KH |
688 | if (!len) |
689 | goto overflow; | |
75ba1d07 | 690 | |
1ac101a5 | 691 | m->count += len; |
6798a8ca JP |
692 | return; |
693 | ||
1ac101a5 | 694 | overflow: |
e075f591 | 695 | seq_set_overflow(m); |
1ac101a5 | 696 | } |
d1be35cb AV |
697 | |
698 | void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, | |
699 | unsigned long long num) | |
700 | { | |
701 | return seq_put_decimal_ull_width(m, delimiter, num, 0); | |
702 | } | |
1ac101a5 KH |
703 | EXPORT_SYMBOL(seq_put_decimal_ull); |
704 | ||
0e3dc019 AV |
705 | /** |
706 | * seq_put_hex_ll - put a number in hexadecimal notation | |
707 | * @m: seq_file identifying the buffer to which data should be written | |
708 | * @delimiter: a string which is printed before the number | |
709 | * @v: the number | |
710 | * @width: a minimum field width | |
711 | * | |
712 | * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v) | |
713 | * | |
714 | * This routine is very quick when you show lots of numbers. | |
715 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
716 | */ | |
717 | void seq_put_hex_ll(struct seq_file *m, const char *delimiter, | |
718 | unsigned long long v, unsigned int width) | |
719 | { | |
720 | unsigned int len; | |
721 | int i; | |
722 | ||
723 | if (delimiter && delimiter[0]) { | |
724 | if (delimiter[1] == 0) | |
725 | seq_putc(m, delimiter[0]); | |
726 | else | |
727 | seq_puts(m, delimiter); | |
728 | } | |
729 | ||
730 | /* If x is 0, the result of __builtin_clzll is undefined */ | |
731 | if (v == 0) | |
732 | len = 1; | |
733 | else | |
734 | len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4; | |
735 | ||
736 | if (len < width) | |
737 | len = width; | |
738 | ||
739 | if (m->count + len > m->size) { | |
740 | seq_set_overflow(m); | |
741 | return; | |
742 | } | |
743 | ||
744 | for (i = len - 1; i >= 0; i--) { | |
745 | m->buf[m->count + i] = hex_asc[0xf & v]; | |
746 | v = v >> 4; | |
747 | } | |
748 | m->count += len; | |
749 | } | |
750 | ||
75ba1d07 | 751 | void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
bda7bad6 | 752 | { |
75ba1d07 JP |
753 | int len; |
754 | ||
755 | if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ | |
756 | goto overflow; | |
757 | ||
48dffbf8 AV |
758 | if (delimiter && delimiter[0]) { |
759 | if (delimiter[1] == 0) | |
760 | seq_putc(m, delimiter[0]); | |
761 | else | |
762 | seq_puts(m, delimiter); | |
763 | } | |
75ba1d07 JP |
764 | |
765 | if (m->count + 2 >= m->size) | |
766 | goto overflow; | |
767 | ||
bda7bad6 | 768 | if (num < 0) { |
75ba1d07 | 769 | m->buf[m->count++] = '-'; |
bda7bad6 | 770 | num = -num; |
bda7bad6 | 771 | } |
75ba1d07 JP |
772 | |
773 | if (num < 10) { | |
774 | m->buf[m->count++] = num + '0'; | |
775 | return; | |
776 | } | |
777 | ||
d1be35cb | 778 | len = num_to_str(m->buf + m->count, m->size - m->count, num, 0); |
75ba1d07 JP |
779 | if (!len) |
780 | goto overflow; | |
781 | ||
782 | m->count += len; | |
783 | return; | |
784 | ||
785 | overflow: | |
786 | seq_set_overflow(m); | |
bda7bad6 KH |
787 | } |
788 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
789 | ||
0b923606 PO |
790 | /** |
791 | * seq_write - write arbitrary data to buffer | |
792 | * @seq: seq_file identifying the buffer to which data should be written | |
793 | * @data: data address | |
794 | * @len: number of bytes | |
795 | * | |
796 | * Return 0 on success, non-zero otherwise. | |
797 | */ | |
798 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
799 | { | |
800 | if (seq->count + len < seq->size) { | |
801 | memcpy(seq->buf + seq->count, data, len); | |
802 | seq->count += len; | |
803 | return 0; | |
804 | } | |
e075f591 | 805 | seq_set_overflow(seq); |
0b923606 PO |
806 | return -1; |
807 | } | |
808 | EXPORT_SYMBOL(seq_write); | |
809 | ||
839cc2a9 TH |
810 | /** |
811 | * seq_pad - write padding spaces to buffer | |
812 | * @m: seq_file identifying the buffer to which data should be written | |
813 | * @c: the byte to append after padding if non-zero | |
814 | */ | |
815 | void seq_pad(struct seq_file *m, char c) | |
816 | { | |
817 | int size = m->pad_until - m->count; | |
8cfa67b4 AV |
818 | if (size > 0) { |
819 | if (size + m->count > m->size) { | |
820 | seq_set_overflow(m); | |
821 | return; | |
822 | } | |
823 | memset(m->buf + m->count, ' ', size); | |
824 | m->count += size; | |
825 | } | |
839cc2a9 TH |
826 | if (c) |
827 | seq_putc(m, c); | |
828 | } | |
829 | EXPORT_SYMBOL(seq_pad); | |
830 | ||
37607102 AS |
831 | /* A complete analogue of print_hex_dump() */ |
832 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
833 | int rowsize, int groupsize, const void *buf, size_t len, | |
834 | bool ascii) | |
835 | { | |
836 | const u8 *ptr = buf; | |
837 | int i, linelen, remaining = len; | |
8b91a318 AS |
838 | char *buffer; |
839 | size_t size; | |
37607102 AS |
840 | int ret; |
841 | ||
842 | if (rowsize != 16 && rowsize != 32) | |
843 | rowsize = 16; | |
844 | ||
845 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
846 | linelen = min(remaining, rowsize); | |
847 | remaining -= rowsize; | |
848 | ||
849 | switch (prefix_type) { | |
850 | case DUMP_PREFIX_ADDRESS: | |
851 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
852 | break; | |
853 | case DUMP_PREFIX_OFFSET: | |
854 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
855 | break; | |
856 | default: | |
857 | seq_printf(m, "%s", prefix_str); | |
858 | break; | |
859 | } | |
860 | ||
8b91a318 | 861 | size = seq_get_buf(m, &buffer); |
37607102 | 862 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
8b91a318 AS |
863 | buffer, size, ascii); |
864 | seq_commit(m, ret < size ? ret : -1); | |
865 | ||
866 | seq_putc(m, '\n'); | |
37607102 AS |
867 | } |
868 | } | |
869 | EXPORT_SYMBOL(seq_hex_dump); | |
870 | ||
bcf67e16 PE |
871 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
872 | { | |
873 | struct list_head *lh; | |
874 | ||
875 | list_for_each(lh, head) | |
876 | if (pos-- == 0) | |
877 | return lh; | |
878 | ||
879 | return NULL; | |
880 | } | |
bcf67e16 PE |
881 | EXPORT_SYMBOL(seq_list_start); |
882 | ||
883 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
884 | { | |
885 | if (!pos) | |
886 | return head; | |
887 | ||
888 | return seq_list_start(head, pos - 1); | |
889 | } | |
bcf67e16 PE |
890 | EXPORT_SYMBOL(seq_list_start_head); |
891 | ||
892 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
893 | { | |
894 | struct list_head *lh; | |
895 | ||
896 | lh = ((struct list_head *)v)->next; | |
897 | ++*ppos; | |
898 | return lh == head ? NULL : lh; | |
899 | } | |
bcf67e16 | 900 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
901 | |
902 | /** | |
903 | * seq_hlist_start - start an iteration of a hlist | |
904 | * @head: the head of the hlist | |
905 | * @pos: the start position of the sequence | |
906 | * | |
907 | * Called at seq_file->op->start(). | |
908 | */ | |
909 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
910 | { | |
911 | struct hlist_node *node; | |
912 | ||
913 | hlist_for_each(node, head) | |
914 | if (pos-- == 0) | |
915 | return node; | |
916 | return NULL; | |
917 | } | |
918 | EXPORT_SYMBOL(seq_hlist_start); | |
919 | ||
920 | /** | |
921 | * seq_hlist_start_head - start an iteration of a hlist | |
922 | * @head: the head of the hlist | |
923 | * @pos: the start position of the sequence | |
924 | * | |
925 | * Called at seq_file->op->start(). Call this function if you want to | |
926 | * print a header at the top of the output. | |
927 | */ | |
928 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
929 | { | |
930 | if (!pos) | |
931 | return SEQ_START_TOKEN; | |
932 | ||
933 | return seq_hlist_start(head, pos - 1); | |
934 | } | |
935 | EXPORT_SYMBOL(seq_hlist_start_head); | |
936 | ||
937 | /** | |
938 | * seq_hlist_next - move to the next position of the hlist | |
939 | * @v: the current iterator | |
940 | * @head: the head of the hlist | |
138860b9 | 941 | * @ppos: the current position |
66655de6 LZ |
942 | * |
943 | * Called at seq_file->op->next(). | |
944 | */ | |
945 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
946 | loff_t *ppos) | |
947 | { | |
948 | struct hlist_node *node = v; | |
949 | ||
950 | ++*ppos; | |
951 | if (v == SEQ_START_TOKEN) | |
952 | return head->first; | |
953 | else | |
954 | return node->next; | |
955 | } | |
956 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 957 | |
958 | /** | |
959 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
960 | * @head: the head of the hlist | |
961 | * @pos: the start position of the sequence | |
962 | * | |
963 | * Called at seq_file->op->start(). | |
964 | * | |
965 | * This list-traversal primitive may safely run concurrently with | |
966 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
967 | * as long as the traversal is guarded by rcu_read_lock(). | |
968 | */ | |
969 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
970 | loff_t pos) | |
971 | { | |
972 | struct hlist_node *node; | |
973 | ||
974 | __hlist_for_each_rcu(node, head) | |
975 | if (pos-- == 0) | |
976 | return node; | |
977 | return NULL; | |
978 | } | |
979 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
980 | ||
981 | /** | |
982 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
983 | * @head: the head of the hlist | |
984 | * @pos: the start position of the sequence | |
985 | * | |
986 | * Called at seq_file->op->start(). Call this function if you want to | |
987 | * print a header at the top of the output. | |
988 | * | |
989 | * This list-traversal primitive may safely run concurrently with | |
990 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
991 | * as long as the traversal is guarded by rcu_read_lock(). | |
992 | */ | |
993 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
994 | loff_t pos) | |
995 | { | |
996 | if (!pos) | |
997 | return SEQ_START_TOKEN; | |
998 | ||
999 | return seq_hlist_start_rcu(head, pos - 1); | |
1000 | } | |
1001 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
1002 | ||
1003 | /** | |
1004 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
1005 | * @v: the current iterator | |
1006 | * @head: the head of the hlist | |
138860b9 | 1007 | * @ppos: the current position |
1cc52327 | 1008 | * |
1009 | * Called at seq_file->op->next(). | |
1010 | * | |
1011 | * This list-traversal primitive may safely run concurrently with | |
1012 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
1013 | * as long as the traversal is guarded by rcu_read_lock(). | |
1014 | */ | |
1015 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
1016 | struct hlist_head *head, | |
1017 | loff_t *ppos) | |
1018 | { | |
1019 | struct hlist_node *node = v; | |
1020 | ||
1021 | ++*ppos; | |
1022 | if (v == SEQ_START_TOKEN) | |
1023 | return rcu_dereference(head->first); | |
1024 | else | |
1025 | return rcu_dereference(node->next); | |
1026 | } | |
1027 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
0bc77381 JL |
1028 | |
1029 | /** | |
1030 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array | |
1031 | * @head: pointer to percpu array of struct hlist_heads | |
1032 | * @cpu: pointer to cpu "cursor" | |
1033 | * @pos: start position of sequence | |
1034 | * | |
1035 | * Called at seq_file->op->start(). | |
1036 | */ | |
1037 | struct hlist_node * | |
1038 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
1039 | { | |
1040 | struct hlist_node *node; | |
1041 | ||
1042 | for_each_possible_cpu(*cpu) { | |
1043 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
1044 | if (pos-- == 0) | |
1045 | return node; | |
1046 | } | |
1047 | } | |
1048 | return NULL; | |
1049 | } | |
1050 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
1051 | ||
1052 | /** | |
1053 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1054 | * @v: pointer to current hlist_node | |
1055 | * @head: pointer to percpu array of struct hlist_heads | |
1056 | * @cpu: pointer to cpu "cursor" | |
1057 | * @pos: start position of sequence | |
1058 | * | |
1059 | * Called at seq_file->op->next(). | |
1060 | */ | |
1061 | struct hlist_node * | |
1062 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1063 | int *cpu, loff_t *pos) | |
1064 | { | |
1065 | struct hlist_node *node = v; | |
1066 | ||
1067 | ++*pos; | |
1068 | ||
1069 | if (node->next) | |
1070 | return node->next; | |
1071 | ||
1072 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1073 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1074 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1075 | ||
1076 | if (!hlist_empty(bucket)) | |
1077 | return bucket->first; | |
1078 | } | |
1079 | return NULL; | |
1080 | } | |
1081 | EXPORT_SYMBOL(seq_hlist_next_percpu); | |
09652320 AD |
1082 | |
1083 | void __init seq_file_init(void) | |
1084 | { | |
d64d01a1 | 1085 | seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC); |
09652320 | 1086 | } |