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355b0502 GKH |
1 | /* |
2 | * drivers/misc/logger.c | |
3 | * | |
4 | * A Logging Subsystem | |
5 | * | |
6 | * Copyright (C) 2007-2008 Google, Inc. | |
7 | * | |
8 | * Robert Love <rlove@google.com> | |
9 | * | |
10 | * This software is licensed under the terms of the GNU General Public | |
11 | * License version 2, as published by the Free Software Foundation, and | |
12 | * may be copied, distributed, and modified under those terms. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
23687af9 | 20 | #include <linux/sched.h> |
355b0502 GKH |
21 | #include <linux/module.h> |
22 | #include <linux/fs.h> | |
23 | #include <linux/miscdevice.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/poll.h> | |
c11a166c | 26 | #include <linux/slab.h> |
355b0502 | 27 | #include <linux/time.h> |
10b24199 | 28 | #include <linux/vmalloc.h> |
355b0502 GKH |
29 | #include "logger.h" |
30 | ||
31 | #include <asm/ioctls.h> | |
32 | ||
33 | /* | |
34 | * struct logger_log - represents a specific log, such as 'main' or 'radio' | |
35 | * | |
36 | * This structure lives from module insertion until module removal, so it does | |
37 | * not need additional reference counting. The structure is protected by the | |
38 | * mutex 'mutex'. | |
39 | */ | |
40 | struct logger_log { | |
277cdd01 | 41 | unsigned char *buffer;/* the ring buffer itself */ |
355b0502 GKH |
42 | struct miscdevice misc; /* misc device representing the log */ |
43 | wait_queue_head_t wq; /* wait queue for readers */ | |
44 | struct list_head readers; /* this log's readers */ | |
45 | struct mutex mutex; /* mutex protecting buffer */ | |
46 | size_t w_off; /* current write head offset */ | |
47 | size_t head; /* new readers start here */ | |
48 | size_t size; /* size of the log */ | |
10b24199 | 49 | struct list_head logs; /* list of log channels (myself)*/ |
355b0502 GKH |
50 | }; |
51 | ||
10b24199 TB |
52 | static LIST_HEAD(log_list); |
53 | ||
54 | ||
355b0502 GKH |
55 | /* |
56 | * struct logger_reader - a logging device open for reading | |
57 | * | |
58 | * This object lives from open to release, so we don't need additional | |
59 | * reference counting. The structure is protected by log->mutex. | |
60 | */ | |
61 | struct logger_reader { | |
62 | struct logger_log *log; /* associated log */ | |
63 | struct list_head list; /* entry in logger_log's list */ | |
64 | size_t r_off; /* current read head offset */ | |
65 | }; | |
66 | ||
67 | /* logger_offset - returns index 'n' into the log via (optimized) modulus */ | |
c626224d TB |
68 | size_t logger_offset(struct logger_log *log, size_t n) |
69 | { | |
70 | return n & (log->size-1); | |
71 | } | |
72 | ||
355b0502 GKH |
73 | |
74 | /* | |
75 | * file_get_log - Given a file structure, return the associated log | |
76 | * | |
77 | * This isn't aesthetic. We have several goals: | |
78 | * | |
277cdd01 MN |
79 | * 1) Need to quickly obtain the associated log during an I/O operation |
80 | * 2) Readers need to maintain state (logger_reader) | |
81 | * 3) Writers need to be very fast (open() should be a near no-op) | |
355b0502 GKH |
82 | * |
83 | * In the reader case, we can trivially go file->logger_reader->logger_log. | |
84 | * For a writer, we don't want to maintain a logger_reader, so we just go | |
85 | * file->logger_log. Thus what file->private_data points at depends on whether | |
86 | * or not the file was opened for reading. This function hides that dirtiness. | |
87 | */ | |
88 | static inline struct logger_log *file_get_log(struct file *file) | |
89 | { | |
90 | if (file->f_mode & FMODE_READ) { | |
91 | struct logger_reader *reader = file->private_data; | |
92 | return reader->log; | |
93 | } else | |
94 | return file->private_data; | |
95 | } | |
96 | ||
97 | /* | |
98 | * get_entry_len - Grabs the length of the payload of the next entry starting | |
99 | * from 'off'. | |
100 | * | |
3bcfa431 TB |
101 | * An entry length is 2 bytes (16 bits) in host endian order. |
102 | * In the log, the length does not include the size of the log entry structure. | |
103 | * This function returns the size including the log entry structure. | |
104 | * | |
355b0502 GKH |
105 | * Caller needs to hold log->mutex. |
106 | */ | |
107 | static __u32 get_entry_len(struct logger_log *log, size_t off) | |
108 | { | |
109 | __u16 val; | |
110 | ||
3bcfa431 TB |
111 | /* copy 2 bytes from buffer, in memcpy order, */ |
112 | /* handling possible wrap at end of buffer */ | |
113 | ||
114 | ((__u8 *)&val)[0] = log->buffer[off]; | |
115 | if (likely(off+1 < log->size)) | |
116 | ((__u8 *)&val)[1] = log->buffer[off+1]; | |
117 | else | |
118 | ((__u8 *)&val)[1] = log->buffer[0]; | |
355b0502 GKH |
119 | |
120 | return sizeof(struct logger_entry) + val; | |
121 | } | |
122 | ||
123 | /* | |
124 | * do_read_log_to_user - reads exactly 'count' bytes from 'log' into the | |
125 | * user-space buffer 'buf'. Returns 'count' on success. | |
126 | * | |
127 | * Caller must hold log->mutex. | |
128 | */ | |
129 | static ssize_t do_read_log_to_user(struct logger_log *log, | |
130 | struct logger_reader *reader, | |
131 | char __user *buf, | |
132 | size_t count) | |
133 | { | |
134 | size_t len; | |
135 | ||
136 | /* | |
137 | * We read from the log in two disjoint operations. First, we read from | |
138 | * the current read head offset up to 'count' bytes or to the end of | |
139 | * the log, whichever comes first. | |
140 | */ | |
141 | len = min(count, log->size - reader->r_off); | |
142 | if (copy_to_user(buf, log->buffer + reader->r_off, len)) | |
143 | return -EFAULT; | |
144 | ||
145 | /* | |
146 | * Second, we read any remaining bytes, starting back at the head of | |
147 | * the log. | |
148 | */ | |
149 | if (count != len) | |
150 | if (copy_to_user(buf + len, log->buffer, count - len)) | |
151 | return -EFAULT; | |
152 | ||
c626224d | 153 | reader->r_off = logger_offset(log, reader->r_off + count); |
355b0502 GKH |
154 | |
155 | return count; | |
156 | } | |
157 | ||
158 | /* | |
159 | * logger_read - our log's read() method | |
160 | * | |
161 | * Behavior: | |
162 | * | |
277cdd01 MN |
163 | * - O_NONBLOCK works |
164 | * - If there are no log entries to read, blocks until log is written to | |
165 | * - Atomically reads exactly one log entry | |
355b0502 GKH |
166 | * |
167 | * Optimal read size is LOGGER_ENTRY_MAX_LEN. Will set errno to EINVAL if read | |
168 | * buffer is insufficient to hold next entry. | |
169 | */ | |
170 | static ssize_t logger_read(struct file *file, char __user *buf, | |
171 | size_t count, loff_t *pos) | |
172 | { | |
173 | struct logger_reader *reader = file->private_data; | |
174 | struct logger_log *log = reader->log; | |
175 | ssize_t ret; | |
176 | DEFINE_WAIT(wait); | |
177 | ||
178 | start: | |
179 | while (1) { | |
c76c7ca3 TB |
180 | mutex_lock(&log->mutex); |
181 | ||
355b0502 GKH |
182 | prepare_to_wait(&log->wq, &wait, TASK_INTERRUPTIBLE); |
183 | ||
355b0502 GKH |
184 | ret = (log->w_off == reader->r_off); |
185 | mutex_unlock(&log->mutex); | |
186 | if (!ret) | |
187 | break; | |
188 | ||
189 | if (file->f_flags & O_NONBLOCK) { | |
190 | ret = -EAGAIN; | |
191 | break; | |
192 | } | |
193 | ||
194 | if (signal_pending(current)) { | |
195 | ret = -EINTR; | |
196 | break; | |
197 | } | |
198 | ||
199 | schedule(); | |
200 | } | |
201 | ||
202 | finish_wait(&log->wq, &wait); | |
203 | if (ret) | |
204 | return ret; | |
205 | ||
206 | mutex_lock(&log->mutex); | |
207 | ||
208 | /* is there still something to read or did we race? */ | |
209 | if (unlikely(log->w_off == reader->r_off)) { | |
210 | mutex_unlock(&log->mutex); | |
211 | goto start; | |
212 | } | |
213 | ||
214 | /* get the size of the next entry */ | |
215 | ret = get_entry_len(log, reader->r_off); | |
216 | if (count < ret) { | |
217 | ret = -EINVAL; | |
218 | goto out; | |
219 | } | |
220 | ||
221 | /* get exactly one entry from the log */ | |
222 | ret = do_read_log_to_user(log, reader, buf, ret); | |
223 | ||
224 | out: | |
225 | mutex_unlock(&log->mutex); | |
226 | ||
227 | return ret; | |
228 | } | |
229 | ||
230 | /* | |
231 | * get_next_entry - return the offset of the first valid entry at least 'len' | |
232 | * bytes after 'off'. | |
233 | * | |
234 | * Caller must hold log->mutex. | |
235 | */ | |
236 | static size_t get_next_entry(struct logger_log *log, size_t off, size_t len) | |
237 | { | |
238 | size_t count = 0; | |
239 | ||
240 | do { | |
241 | size_t nr = get_entry_len(log, off); | |
c626224d | 242 | off = logger_offset(log, off + nr); |
355b0502 GKH |
243 | count += nr; |
244 | } while (count < len); | |
245 | ||
246 | return off; | |
247 | } | |
248 | ||
249 | /* | |
169c843a TB |
250 | * is_between - is a < c < b, accounting for wrapping of a, b, and c |
251 | * positions in the buffer | |
252 | * | |
253 | * That is, if a<b, check for c between a and b | |
254 | * and if a>b, check for c outside (not between) a and b | |
255 | * | |
256 | * |------- a xxxxxxxx b --------| | |
257 | * c^ | |
258 | * | |
259 | * |xxxxx b --------- a xxxxxxxxx| | |
260 | * c^ | |
261 | * or c^ | |
355b0502 | 262 | */ |
169c843a | 263 | static inline int is_between(size_t a, size_t b, size_t c) |
355b0502 | 264 | { |
169c843a TB |
265 | if (a < b) { |
266 | /* is c between a and b? */ | |
267 | if (a < c && c <= b) | |
355b0502 GKH |
268 | return 1; |
269 | } else { | |
169c843a TB |
270 | /* is c outside of b through a? */ |
271 | if (c <= b || a < c) | |
355b0502 GKH |
272 | return 1; |
273 | } | |
274 | ||
275 | return 0; | |
276 | } | |
277 | ||
278 | /* | |
279 | * fix_up_readers - walk the list of all readers and "fix up" any who were | |
280 | * lapped by the writer; also do the same for the default "start head". | |
281 | * We do this by "pulling forward" the readers and start head to the first | |
282 | * entry after the new write head. | |
283 | * | |
284 | * The caller needs to hold log->mutex. | |
285 | */ | |
286 | static void fix_up_readers(struct logger_log *log, size_t len) | |
287 | { | |
288 | size_t old = log->w_off; | |
c626224d | 289 | size_t new = logger_offset(log, old + len); |
355b0502 GKH |
290 | struct logger_reader *reader; |
291 | ||
169c843a | 292 | if (is_between(old, new, log->head)) |
355b0502 GKH |
293 | log->head = get_next_entry(log, log->head, len); |
294 | ||
295 | list_for_each_entry(reader, &log->readers, list) | |
169c843a | 296 | if (is_between(old, new, reader->r_off)) |
355b0502 GKH |
297 | reader->r_off = get_next_entry(log, reader->r_off, len); |
298 | } | |
299 | ||
300 | /* | |
301 | * do_write_log - writes 'len' bytes from 'buf' to 'log' | |
302 | * | |
303 | * The caller needs to hold log->mutex. | |
304 | */ | |
305 | static void do_write_log(struct logger_log *log, const void *buf, size_t count) | |
306 | { | |
307 | size_t len; | |
308 | ||
309 | len = min(count, log->size - log->w_off); | |
310 | memcpy(log->buffer + log->w_off, buf, len); | |
311 | ||
312 | if (count != len) | |
313 | memcpy(log->buffer, buf + len, count - len); | |
314 | ||
c626224d | 315 | log->w_off = logger_offset(log, log->w_off + count); |
355b0502 GKH |
316 | |
317 | } | |
318 | ||
319 | /* | |
320 | * do_write_log_user - writes 'len' bytes from the user-space buffer 'buf' to | |
321 | * the log 'log' | |
322 | * | |
323 | * The caller needs to hold log->mutex. | |
324 | * | |
325 | * Returns 'count' on success, negative error code on failure. | |
326 | */ | |
327 | static ssize_t do_write_log_from_user(struct logger_log *log, | |
328 | const void __user *buf, size_t count) | |
329 | { | |
330 | size_t len; | |
331 | ||
332 | len = min(count, log->size - log->w_off); | |
333 | if (len && copy_from_user(log->buffer + log->w_off, buf, len)) | |
334 | return -EFAULT; | |
335 | ||
336 | if (count != len) | |
337 | if (copy_from_user(log->buffer, buf + len, count - len)) | |
350a1955 TB |
338 | /* |
339 | * Note that by not updating w_off, this abandons the | |
340 | * portion of the new entry that *was* successfully | |
341 | * copied, just above. This is intentional to avoid | |
342 | * message corruption from missing fragments. | |
343 | */ | |
355b0502 GKH |
344 | return -EFAULT; |
345 | ||
c626224d | 346 | log->w_off = logger_offset(log, log->w_off + count); |
355b0502 GKH |
347 | |
348 | return count; | |
349 | } | |
350 | ||
351 | /* | |
352 | * logger_aio_write - our write method, implementing support for write(), | |
353 | * writev(), and aio_write(). Writes are our fast path, and we try to optimize | |
354 | * them above all else. | |
355 | */ | |
356 | ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov, | |
357 | unsigned long nr_segs, loff_t ppos) | |
358 | { | |
359 | struct logger_log *log = file_get_log(iocb->ki_filp); | |
360 | size_t orig = log->w_off; | |
361 | struct logger_entry header; | |
362 | struct timespec now; | |
363 | ssize_t ret = 0; | |
364 | ||
365 | now = current_kernel_time(); | |
366 | ||
367 | header.pid = current->tgid; | |
368 | header.tid = current->pid; | |
369 | header.sec = now.tv_sec; | |
370 | header.nsec = now.tv_nsec; | |
371 | header.len = min_t(size_t, iocb->ki_left, LOGGER_ENTRY_MAX_PAYLOAD); | |
372 | ||
373 | /* null writes succeed, return zero */ | |
374 | if (unlikely(!header.len)) | |
375 | return 0; | |
376 | ||
377 | mutex_lock(&log->mutex); | |
378 | ||
379 | /* | |
380 | * Fix up any readers, pulling them forward to the first readable | |
381 | * entry after (what will be) the new write offset. We do this now | |
382 | * because if we partially fail, we can end up with clobbered log | |
383 | * entries that encroach on readable buffer. | |
384 | */ | |
385 | fix_up_readers(log, sizeof(struct logger_entry) + header.len); | |
386 | ||
387 | do_write_log(log, &header, sizeof(struct logger_entry)); | |
388 | ||
389 | while (nr_segs-- > 0) { | |
390 | size_t len; | |
391 | ssize_t nr; | |
392 | ||
393 | /* figure out how much of this vector we can keep */ | |
394 | len = min_t(size_t, iov->iov_len, header.len - ret); | |
395 | ||
396 | /* write out this segment's payload */ | |
397 | nr = do_write_log_from_user(log, iov->iov_base, len); | |
398 | if (unlikely(nr < 0)) { | |
399 | log->w_off = orig; | |
400 | mutex_unlock(&log->mutex); | |
401 | return nr; | |
402 | } | |
403 | ||
404 | iov++; | |
405 | ret += nr; | |
406 | } | |
407 | ||
408 | mutex_unlock(&log->mutex); | |
409 | ||
410 | /* wake up any blocked readers */ | |
411 | wake_up_interruptible(&log->wq); | |
412 | ||
413 | return ret; | |
414 | } | |
415 | ||
10b24199 TB |
416 | static struct logger_log *get_log_from_minor(int minor) |
417 | { | |
418 | struct logger_log *log; | |
419 | ||
420 | list_for_each_entry(log, &log_list, logs) | |
421 | if (log->misc.minor == minor) | |
422 | return log; | |
423 | return NULL; | |
424 | } | |
355b0502 GKH |
425 | |
426 | /* | |
427 | * logger_open - the log's open() file operation | |
428 | * | |
429 | * Note how near a no-op this is in the write-only case. Keep it that way! | |
430 | */ | |
431 | static int logger_open(struct inode *inode, struct file *file) | |
432 | { | |
433 | struct logger_log *log; | |
434 | int ret; | |
435 | ||
436 | ret = nonseekable_open(inode, file); | |
437 | if (ret) | |
438 | return ret; | |
439 | ||
440 | log = get_log_from_minor(MINOR(inode->i_rdev)); | |
441 | if (!log) | |
442 | return -ENODEV; | |
443 | ||
444 | if (file->f_mode & FMODE_READ) { | |
445 | struct logger_reader *reader; | |
446 | ||
447 | reader = kmalloc(sizeof(struct logger_reader), GFP_KERNEL); | |
448 | if (!reader) | |
449 | return -ENOMEM; | |
450 | ||
451 | reader->log = log; | |
452 | INIT_LIST_HEAD(&reader->list); | |
453 | ||
454 | mutex_lock(&log->mutex); | |
455 | reader->r_off = log->head; | |
456 | list_add_tail(&reader->list, &log->readers); | |
457 | mutex_unlock(&log->mutex); | |
458 | ||
459 | file->private_data = reader; | |
460 | } else | |
461 | file->private_data = log; | |
462 | ||
463 | return 0; | |
464 | } | |
465 | ||
466 | /* | |
467 | * logger_release - the log's release file operation | |
468 | * | |
469 | * Note this is a total no-op in the write-only case. Keep it that way! | |
470 | */ | |
471 | static int logger_release(struct inode *ignored, struct file *file) | |
472 | { | |
473 | if (file->f_mode & FMODE_READ) { | |
474 | struct logger_reader *reader = file->private_data; | |
47de87a2 RV |
475 | struct logger_log *log = reader->log; |
476 | ||
477 | mutex_lock(&log->mutex); | |
355b0502 | 478 | list_del(&reader->list); |
47de87a2 RV |
479 | mutex_unlock(&log->mutex); |
480 | ||
355b0502 GKH |
481 | kfree(reader); |
482 | } | |
483 | ||
484 | return 0; | |
485 | } | |
486 | ||
487 | /* | |
488 | * logger_poll - the log's poll file operation, for poll/select/epoll | |
489 | * | |
490 | * Note we always return POLLOUT, because you can always write() to the log. | |
491 | * Note also that, strictly speaking, a return value of POLLIN does not | |
492 | * guarantee that the log is readable without blocking, as there is a small | |
493 | * chance that the writer can lap the reader in the interim between poll() | |
494 | * returning and the read() request. | |
495 | */ | |
496 | static unsigned int logger_poll(struct file *file, poll_table *wait) | |
497 | { | |
498 | struct logger_reader *reader; | |
499 | struct logger_log *log; | |
500 | unsigned int ret = POLLOUT | POLLWRNORM; | |
501 | ||
502 | if (!(file->f_mode & FMODE_READ)) | |
503 | return ret; | |
504 | ||
505 | reader = file->private_data; | |
506 | log = reader->log; | |
507 | ||
508 | poll_wait(file, &log->wq, wait); | |
509 | ||
510 | mutex_lock(&log->mutex); | |
511 | if (log->w_off != reader->r_off) | |
512 | ret |= POLLIN | POLLRDNORM; | |
513 | mutex_unlock(&log->mutex); | |
514 | ||
515 | return ret; | |
516 | } | |
517 | ||
518 | static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
519 | { | |
520 | struct logger_log *log = file_get_log(file); | |
521 | struct logger_reader *reader; | |
522 | long ret = -ENOTTY; | |
523 | ||
524 | mutex_lock(&log->mutex); | |
525 | ||
526 | switch (cmd) { | |
527 | case LOGGER_GET_LOG_BUF_SIZE: | |
528 | ret = log->size; | |
529 | break; | |
530 | case LOGGER_GET_LOG_LEN: | |
531 | if (!(file->f_mode & FMODE_READ)) { | |
532 | ret = -EBADF; | |
533 | break; | |
534 | } | |
535 | reader = file->private_data; | |
536 | if (log->w_off >= reader->r_off) | |
537 | ret = log->w_off - reader->r_off; | |
538 | else | |
539 | ret = (log->size - reader->r_off) + log->w_off; | |
540 | break; | |
541 | case LOGGER_GET_NEXT_ENTRY_LEN: | |
542 | if (!(file->f_mode & FMODE_READ)) { | |
543 | ret = -EBADF; | |
544 | break; | |
545 | } | |
546 | reader = file->private_data; | |
547 | if (log->w_off != reader->r_off) | |
548 | ret = get_entry_len(log, reader->r_off); | |
549 | else | |
550 | ret = 0; | |
551 | break; | |
552 | case LOGGER_FLUSH_LOG: | |
553 | if (!(file->f_mode & FMODE_WRITE)) { | |
554 | ret = -EBADF; | |
555 | break; | |
556 | } | |
557 | list_for_each_entry(reader, &log->readers, list) | |
558 | reader->r_off = log->w_off; | |
559 | log->head = log->w_off; | |
560 | ret = 0; | |
561 | break; | |
562 | } | |
563 | ||
564 | mutex_unlock(&log->mutex); | |
565 | ||
566 | return ret; | |
567 | } | |
568 | ||
569 | static const struct file_operations logger_fops = { | |
570 | .owner = THIS_MODULE, | |
571 | .read = logger_read, | |
572 | .aio_write = logger_aio_write, | |
573 | .poll = logger_poll, | |
574 | .unlocked_ioctl = logger_ioctl, | |
575 | .compat_ioctl = logger_ioctl, | |
576 | .open = logger_open, | |
577 | .release = logger_release, | |
578 | }; | |
579 | ||
580 | /* | |
10b24199 TB |
581 | * Log size must be a power of two, greater than LOGGER_ENTRY_MAX_LEN, |
582 | * and less than LONG_MAX minus LOGGER_ENTRY_MAX_LEN. | |
355b0502 | 583 | */ |
10b24199 TB |
584 | static int __init create_log(char *log_name, int size) |
585 | { | |
586 | int ret = 0; | |
587 | struct logger_log *log; | |
588 | unsigned char *buffer; | |
355b0502 | 589 | |
10b24199 TB |
590 | buffer = vmalloc(size); |
591 | if (buffer == NULL) | |
592 | return -ENOMEM; | |
355b0502 | 593 | |
10b24199 TB |
594 | log = kzalloc(sizeof(struct logger_log), GFP_KERNEL); |
595 | if (log == NULL) { | |
596 | ret = -ENOMEM; | |
597 | goto out_free_buffer; | |
598 | } | |
599 | log->buffer = buffer; | |
355b0502 | 600 | |
10b24199 TB |
601 | log->misc.minor = MISC_DYNAMIC_MINOR; |
602 | log->misc.name = kstrdup(log_name, GFP_KERNEL); | |
603 | if (log->misc.name == NULL) { | |
604 | ret = -ENOMEM; | |
605 | goto out_free_log; | |
606 | } | |
607 | ||
608 | log->misc.fops = &logger_fops; | |
609 | log->misc.parent = NULL; | |
355b0502 | 610 | |
10b24199 TB |
611 | init_waitqueue_head(&log->wq); |
612 | INIT_LIST_HEAD(&log->readers); | |
613 | mutex_init(&log->mutex); | |
614 | log->w_off = 0; | |
615 | log->head = 0; | |
616 | log->size = size; | |
617 | ||
618 | INIT_LIST_HEAD(&log->logs); | |
619 | list_add_tail(&log->logs, &log_list); | |
620 | ||
621 | /* finally, initialize the misc device for this log */ | |
355b0502 GKH |
622 | ret = misc_register(&log->misc); |
623 | if (unlikely(ret)) { | |
624 | printk(KERN_ERR "logger: failed to register misc " | |
625 | "device for log '%s'!\n", log->misc.name); | |
10b24199 | 626 | goto out_free_log; |
355b0502 GKH |
627 | } |
628 | ||
629 | printk(KERN_INFO "logger: created %luK log '%s'\n", | |
630 | (unsigned long) log->size >> 10, log->misc.name); | |
631 | ||
632 | return 0; | |
10b24199 TB |
633 | |
634 | out_free_log: | |
635 | kfree(log); | |
636 | ||
637 | out_free_buffer: | |
638 | vfree(buffer); | |
639 | return ret; | |
355b0502 GKH |
640 | } |
641 | ||
642 | static int __init logger_init(void) | |
643 | { | |
644 | int ret; | |
645 | ||
10b24199 | 646 | ret = create_log(LOGGER_LOG_MAIN, 256*1024); |
355b0502 GKH |
647 | if (unlikely(ret)) |
648 | goto out; | |
649 | ||
10b24199 | 650 | ret = create_log(LOGGER_LOG_EVENTS, 256*1024); |
355b0502 GKH |
651 | if (unlikely(ret)) |
652 | goto out; | |
653 | ||
10b24199 | 654 | ret = create_log(LOGGER_LOG_RADIO, 256*1024); |
355b0502 GKH |
655 | if (unlikely(ret)) |
656 | goto out; | |
657 | ||
10b24199 | 658 | ret = create_log(LOGGER_LOG_SYSTEM, 256*1024); |
3537cdaa SM |
659 | if (unlikely(ret)) |
660 | goto out; | |
661 | ||
355b0502 GKH |
662 | out: |
663 | return ret; | |
664 | } | |
665 | device_initcall(logger_init); |