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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
20#define pr_fmt(fmt) "logger: " fmt
21
22#include <linux/sched.h>
23#include <linux/module.h>
24#include <linux/fs.h>
25#include <linux/miscdevice.h>
26#include <linux/uaccess.h>
27#include <linux/poll.h>
28#include <linux/slab.h>
29#include <linux/time.h>
30#include <linux/vmalloc.h>
31#include <linux/aio.h>
32#include "logger.h"
33
34#include <asm/ioctls.h>
35
36/**
37 * struct logger_log - represents a specific log, such as 'main' or 'radio'
38 * @buffer: The actual ring buffer
39 * @misc: The "misc" device representing the log
40 * @wq: The wait queue for @readers
41 * @readers: This log's readers
42 * @mutex: The mutex that protects the @buffer
43 * @w_off: The current write head offset
44 * @head: The head, or location that readers start reading at.
45 * @size: The size of the log
46 * @logs: The list of log channels
47 *
48 * This structure lives from module insertion until module removal, so it does
49 * not need additional reference counting. The structure is protected by the
50 * mutex 'mutex'.
51 */
52struct logger_log {
53 unsigned char *buffer;
54 struct miscdevice misc;
55 wait_queue_head_t wq;
56 struct list_head readers;
57 struct mutex mutex;
58 size_t w_off;
59 size_t head;
60 size_t size;
61 struct list_head logs;
62};
63
64static LIST_HEAD(log_list);
65
66
67/**
68 * struct logger_reader - a logging device open for reading
69 * @log: The associated log
70 * @list: The associated entry in @logger_log's list
71 * @r_off: The current read head offset.
72 * @r_all: Reader can read all entries
73 * @r_ver: Reader ABI version
74 *
75 * This object lives from open to release, so we don't need additional
76 * reference counting. The structure is protected by log->mutex.
77 */
78struct logger_reader {
79 struct logger_log *log;
80 struct list_head list;
81 size_t r_off;
82 bool r_all;
83 int r_ver;
84};
85
86/* logger_offset - returns index 'n' into the log via (optimized) modulus */
87static size_t logger_offset(struct logger_log *log, size_t n)
88{
89 return n & (log->size - 1);
90}
91
92
93/*
94 * file_get_log - Given a file structure, return the associated log
95 *
96 * This isn't aesthetic. We have several goals:
97 *
98 * 1) Need to quickly obtain the associated log during an I/O operation
99 * 2) Readers need to maintain state (logger_reader)
100 * 3) Writers need to be very fast (open() should be a near no-op)
101 *
102 * In the reader case, we can trivially go file->logger_reader->logger_log.
103 * For a writer, we don't want to maintain a logger_reader, so we just go
104 * file->logger_log. Thus what file->private_data points at depends on whether
105 * or not the file was opened for reading. This function hides that dirtiness.
106 */
107static inline struct logger_log *file_get_log(struct file *file)
108{
109 if (file->f_mode & FMODE_READ) {
110 struct logger_reader *reader = file->private_data;
111 return reader->log;
112 } else
113 return file->private_data;
114}
115
116/*
117 * get_entry_header - returns a pointer to the logger_entry header within
118 * 'log' starting at offset 'off'. A temporary logger_entry 'scratch' must
119 * be provided. Typically the return value will be a pointer within
120 * 'logger->buf'. However, a pointer to 'scratch' may be returned if
121 * the log entry spans the end and beginning of the circular buffer.
122 */
123static struct logger_entry *get_entry_header(struct logger_log *log,
124 size_t off, struct logger_entry *scratch)
125{
126 size_t len = min(sizeof(struct logger_entry), log->size - off);
127 if (len != sizeof(struct logger_entry)) {
128 memcpy(((void *) scratch), log->buffer + off, len);
129 memcpy(((void *) scratch) + len, log->buffer,
130 sizeof(struct logger_entry) - len);
131 return scratch;
132 }
133
134 return (struct logger_entry *) (log->buffer + off);
135}
136
137/*
138 * get_entry_msg_len - Grabs the length of the message of the entry
139 * starting from from 'off'.
140 *
141 * An entry length is 2 bytes (16 bits) in host endian order.
142 * In the log, the length does not include the size of the log entry structure.
143 * This function returns the size including the log entry structure.
144 *
145 * Caller needs to hold log->mutex.
146 */
147static __u32 get_entry_msg_len(struct logger_log *log, size_t off)
148{
149 struct logger_entry scratch;
150 struct logger_entry *entry;
151
152 entry = get_entry_header(log, off, &scratch);
153 return entry->len;
154}
155
156static size_t get_user_hdr_len(int ver)
157{
158 if (ver < 2)
159 return sizeof(struct user_logger_entry_compat);
160 else
161 return sizeof(struct logger_entry);
162}
163
164static ssize_t copy_header_to_user(int ver, struct logger_entry *entry,
165 char __user *buf)
166{
167 void *hdr;
168 size_t hdr_len;
169 struct user_logger_entry_compat v1;
170
171 if (ver < 2) {
172 v1.len = entry->len;
173 v1.__pad = 0;
174 v1.pid = entry->pid;
175 v1.tid = entry->tid;
176 v1.sec = entry->sec;
177 v1.nsec = entry->nsec;
178 hdr = &v1;
179 hdr_len = sizeof(struct user_logger_entry_compat);
180 } else {
181 hdr = entry;
182 hdr_len = sizeof(struct logger_entry);
183 }
184
185 return copy_to_user(buf, hdr, hdr_len);
186}
187
188/*
189 * do_read_log_to_user - reads exactly 'count' bytes from 'log' into the
190 * user-space buffer 'buf'. Returns 'count' on success.
191 *
192 * Caller must hold log->mutex.
193 */
194static ssize_t do_read_log_to_user(struct logger_log *log,
195 struct logger_reader *reader,
196 char __user *buf,
197 size_t count)
198{
199 struct logger_entry scratch;
200 struct logger_entry *entry;
201 size_t len;
202 size_t msg_start;
203
204 /*
205 * First, copy the header to userspace, using the version of
206 * the header requested
207 */
208 entry = get_entry_header(log, reader->r_off, &scratch);
209 if (copy_header_to_user(reader->r_ver, entry, buf))
210 return -EFAULT;
211
212 count -= get_user_hdr_len(reader->r_ver);
213 buf += get_user_hdr_len(reader->r_ver);
214 msg_start = logger_offset(log,
215 reader->r_off + sizeof(struct logger_entry));
216
217 /*
218 * We read from the msg in two disjoint operations. First, we read from
219 * the current msg head offset up to 'count' bytes or to the end of
220 * the log, whichever comes first.
221 */
222 len = min(count, log->size - msg_start);
223 if (copy_to_user(buf, log->buffer + msg_start, len))
224 return -EFAULT;
225
226 /*
227 * Second, we read any remaining bytes, starting back at the head of
228 * the log.
229 */
230 if (count != len)
231 if (copy_to_user(buf + len, log->buffer, count - len))
232 return -EFAULT;
233
234 reader->r_off = logger_offset(log, reader->r_off +
235 sizeof(struct logger_entry) + count);
236
237 return count + get_user_hdr_len(reader->r_ver);
238}
239
240/*
241 * get_next_entry_by_uid - Starting at 'off', returns an offset into
242 * 'log->buffer' which contains the first entry readable by 'euid'
243 */
244static size_t get_next_entry_by_uid(struct logger_log *log,
245 size_t off, kuid_t euid)
246{
247 while (off != log->w_off) {
248 struct logger_entry *entry;
249 struct logger_entry scratch;
250 size_t next_len;
251
252 entry = get_entry_header(log, off, &scratch);
253
254 if (uid_eq(entry->euid, euid))
255 return off;
256
257 next_len = sizeof(struct logger_entry) + entry->len;
258 off = logger_offset(log, off + next_len);
259 }
260
261 return off;
262}
263
264/*
265 * logger_read - our log's read() method
266 *
267 * Behavior:
268 *
269 * - O_NONBLOCK works
270 * - If there are no log entries to read, blocks until log is written to
271 * - Atomically reads exactly one log entry
272 *
273 * Will set errno to EINVAL if read
274 * buffer is insufficient to hold next entry.
275 */
276static ssize_t logger_read(struct file *file, char __user *buf,
277 size_t count, loff_t *pos)
278{
279 struct logger_reader *reader = file->private_data;
280 struct logger_log *log = reader->log;
281 ssize_t ret;
282 DEFINE_WAIT(wait);
283
284start:
285 while (1) {
286 mutex_lock(&log->mutex);
287
288 prepare_to_wait(&log->wq, &wait, TASK_INTERRUPTIBLE);
289
290 ret = (log->w_off == reader->r_off);
291 mutex_unlock(&log->mutex);
292 if (!ret)
293 break;
294
295 if (file->f_flags & O_NONBLOCK) {
296 ret = -EAGAIN;
297 break;
298 }
299
300 if (signal_pending(current)) {
301 ret = -EINTR;
302 break;
303 }
304
305 schedule();
306 }
307
308 finish_wait(&log->wq, &wait);
309 if (ret)
310 return ret;
311
312 mutex_lock(&log->mutex);
313
314 if (!reader->r_all)
315 reader->r_off = get_next_entry_by_uid(log,
316 reader->r_off, current_euid());
317
318 /* is there still something to read or did we race? */
319 if (unlikely(log->w_off == reader->r_off)) {
320 mutex_unlock(&log->mutex);
321 goto start;
322 }
323
324 /* get the size of the next entry */
325 ret = get_user_hdr_len(reader->r_ver) +
326 get_entry_msg_len(log, reader->r_off);
327 if (count < ret) {
328 ret = -EINVAL;
329 goto out;
330 }
331
332 /* get exactly one entry from the log */
333 ret = do_read_log_to_user(log, reader, buf, ret);
334
335out:
336 mutex_unlock(&log->mutex);
337
338 return ret;
339}
340
341/*
342 * get_next_entry - return the offset of the first valid entry at least 'len'
343 * bytes after 'off'.
344 *
345 * Caller must hold log->mutex.
346 */
347static size_t get_next_entry(struct logger_log *log, size_t off, size_t len)
348{
349 size_t count = 0;
350
351 do {
352 size_t nr = sizeof(struct logger_entry) +
353 get_entry_msg_len(log, off);
354 off = logger_offset(log, off + nr);
355 count += nr;
356 } while (count < len);
357
358 return off;
359}
360
361/*
362 * is_between - is a < c < b, accounting for wrapping of a, b, and c
363 * positions in the buffer
364 *
365 * That is, if a<b, check for c between a and b
366 * and if a>b, check for c outside (not between) a and b
367 *
368 * |------- a xxxxxxxx b --------|
369 * c^
370 *
371 * |xxxxx b --------- a xxxxxxxxx|
372 * c^
373 * or c^
374 */
375static inline int is_between(size_t a, size_t b, size_t c)
376{
377 if (a < b) {
378 /* is c between a and b? */
379 if (a < c && c <= b)
380 return 1;
381 } else {
382 /* is c outside of b through a? */
383 if (c <= b || a < c)
384 return 1;
385 }
386
387 return 0;
388}
389
390/*
391 * fix_up_readers - walk the list of all readers and "fix up" any who were
392 * lapped by the writer; also do the same for the default "start head".
393 * We do this by "pulling forward" the readers and start head to the first
394 * entry after the new write head.
395 *
396 * The caller needs to hold log->mutex.
397 */
398static void fix_up_readers(struct logger_log *log, size_t len)
399{
400 size_t old = log->w_off;
401 size_t new = logger_offset(log, old + len);
402 struct logger_reader *reader;
403
404 if (is_between(old, new, log->head))
405 log->head = get_next_entry(log, log->head, len);
406
407 list_for_each_entry(reader, &log->readers, list)
408 if (is_between(old, new, reader->r_off))
409 reader->r_off = get_next_entry(log, reader->r_off, len);
410}
411
412/*
413 * do_write_log - writes 'len' bytes from 'buf' to 'log'
414 *
415 * The caller needs to hold log->mutex.
416 */
417static void do_write_log(struct logger_log *log, const void *buf, size_t count)
418{
419 size_t len;
420
421 len = min(count, log->size - log->w_off);
422 memcpy(log->buffer + log->w_off, buf, len);
423
424 if (count != len)
425 memcpy(log->buffer, buf + len, count - len);
426
427 log->w_off = logger_offset(log, log->w_off + count);
428
429}
430
431/*
432 * do_write_log_user - writes 'len' bytes from the user-space buffer 'buf' to
433 * the log 'log'
434 *
435 * The caller needs to hold log->mutex.
436 *
437 * Returns 'count' on success, negative error code on failure.
438 */
439static ssize_t do_write_log_from_user(struct logger_log *log,
440 const void __user *buf, size_t count)
441{
442 size_t len;
443
444 len = min(count, log->size - log->w_off);
445 if (len && copy_from_user(log->buffer + log->w_off, buf, len))
446 return -EFAULT;
447
448 if (count != len)
449 if (copy_from_user(log->buffer, buf + len, count - len))
450 /*
451 * Note that by not updating w_off, this abandons the
452 * portion of the new entry that *was* successfully
453 * copied, just above. This is intentional to avoid
454 * message corruption from missing fragments.
455 */
456 return -EFAULT;
457
458 log->w_off = logger_offset(log, log->w_off + count);
459
460 return count;
461}
462
463/*
464 * logger_aio_write - our write method, implementing support for write(),
465 * writev(), and aio_write(). Writes are our fast path, and we try to optimize
466 * them above all else.
467 */
468static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
469 unsigned long nr_segs, loff_t ppos)
470{
471 struct logger_log *log = file_get_log(iocb->ki_filp);
472 size_t orig;
473 struct logger_entry header;
474 struct timespec now;
475 ssize_t ret = 0;
476
477 now = current_kernel_time();
478
479 header.pid = current->tgid;
480 header.tid = current->pid;
481 header.sec = now.tv_sec;
482 header.nsec = now.tv_nsec;
483 header.euid = current_euid();
484 header.len = min_t(size_t, iocb->ki_nbytes, LOGGER_ENTRY_MAX_PAYLOAD);
485 header.hdr_size = sizeof(struct logger_entry);
486
487 /* null writes succeed, return zero */
488 if (unlikely(!header.len))
489 return 0;
490
491 mutex_lock(&log->mutex);
492
493 orig = log->w_off;
494
495 /*
496 * Fix up any readers, pulling them forward to the first readable
497 * entry after (what will be) the new write offset. We do this now
498 * because if we partially fail, we can end up with clobbered log
499 * entries that encroach on readable buffer.
500 */
501 fix_up_readers(log, sizeof(struct logger_entry) + header.len);
502
503 do_write_log(log, &header, sizeof(struct logger_entry));
504
505 while (nr_segs-- > 0) {
506 size_t len;
507 ssize_t nr;
508
509 /* figure out how much of this vector we can keep */
510 len = min_t(size_t, iov->iov_len, header.len - ret);
511
512 /* write out this segment's payload */
513 nr = do_write_log_from_user(log, iov->iov_base, len);
514 if (unlikely(nr < 0)) {
515 log->w_off = orig;
516 mutex_unlock(&log->mutex);
517 return nr;
518 }
519
520 iov++;
521 ret += nr;
522 }
523
524 mutex_unlock(&log->mutex);
525
526 /* wake up any blocked readers */
527 wake_up_interruptible(&log->wq);
528
529 return ret;
530}
531
532static struct logger_log *get_log_from_minor(int minor)
533{
534 struct logger_log *log;
535
536 list_for_each_entry(log, &log_list, logs)
537 if (log->misc.minor == minor)
538 return log;
539 return NULL;
540}
541
542/*
543 * logger_open - the log's open() file operation
544 *
545 * Note how near a no-op this is in the write-only case. Keep it that way!
546 */
547static int logger_open(struct inode *inode, struct file *file)
548{
549 struct logger_log *log;
550 int ret;
551
552 ret = nonseekable_open(inode, file);
553 if (ret)
554 return ret;
555
556 log = get_log_from_minor(MINOR(inode->i_rdev));
557 if (!log)
558 return -ENODEV;
559
560 if (file->f_mode & FMODE_READ) {
561 struct logger_reader *reader;
562
563 reader = kmalloc(sizeof(struct logger_reader), GFP_KERNEL);
564 if (!reader)
565 return -ENOMEM;
566
567 reader->log = log;
568 reader->r_ver = 1;
569 reader->r_all = in_egroup_p(inode->i_gid) ||
570 capable(CAP_SYSLOG);
571
572 INIT_LIST_HEAD(&reader->list);
573
574 mutex_lock(&log->mutex);
575 reader->r_off = log->head;
576 list_add_tail(&reader->list, &log->readers);
577 mutex_unlock(&log->mutex);
578
579 file->private_data = reader;
580 } else
581 file->private_data = log;
582
583 return 0;
584}
585
586/*
587 * logger_release - the log's release file operation
588 *
589 * Note this is a total no-op in the write-only case. Keep it that way!
590 */
591static int logger_release(struct inode *ignored, struct file *file)
592{
593 if (file->f_mode & FMODE_READ) {
594 struct logger_reader *reader = file->private_data;
595 struct logger_log *log = reader->log;
596
597 mutex_lock(&log->mutex);
598 list_del(&reader->list);
599 mutex_unlock(&log->mutex);
600
601 kfree(reader);
602 }
603
604 return 0;
605}
606
607/*
608 * logger_poll - the log's poll file operation, for poll/select/epoll
609 *
610 * Note we always return POLLOUT, because you can always write() to the log.
611 * Note also that, strictly speaking, a return value of POLLIN does not
612 * guarantee that the log is readable without blocking, as there is a small
613 * chance that the writer can lap the reader in the interim between poll()
614 * returning and the read() request.
615 */
616static unsigned int logger_poll(struct file *file, poll_table *wait)
617{
618 struct logger_reader *reader;
619 struct logger_log *log;
620 unsigned int ret = POLLOUT | POLLWRNORM;
621
622 if (!(file->f_mode & FMODE_READ))
623 return ret;
624
625 reader = file->private_data;
626 log = reader->log;
627
628 poll_wait(file, &log->wq, wait);
629
630 mutex_lock(&log->mutex);
631 if (!reader->r_all)
632 reader->r_off = get_next_entry_by_uid(log,
633 reader->r_off, current_euid());
634
635 if (log->w_off != reader->r_off)
636 ret |= POLLIN | POLLRDNORM;
637 mutex_unlock(&log->mutex);
638
639 return ret;
640}
641
642static long logger_set_version(struct logger_reader *reader, void __user *arg)
643{
644 int version;
645 if (copy_from_user(&version, arg, sizeof(int)))
646 return -EFAULT;
647
648 if ((version < 1) || (version > 2))
649 return -EINVAL;
650
651 reader->r_ver = version;
652 return 0;
653}
654
655static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
656{
657 struct logger_log *log = file_get_log(file);
658 struct logger_reader *reader;
659 long ret = -EINVAL;
660 void __user *argp = (void __user *) arg;
661
662 mutex_lock(&log->mutex);
663
664 switch (cmd) {
665 case LOGGER_GET_LOG_BUF_SIZE:
666 ret = log->size;
667 break;
668 case LOGGER_GET_LOG_LEN:
669 if (!(file->f_mode & FMODE_READ)) {
670 ret = -EBADF;
671 break;
672 }
673 reader = file->private_data;
674 if (log->w_off >= reader->r_off)
675 ret = log->w_off - reader->r_off;
676 else
677 ret = (log->size - reader->r_off) + log->w_off;
678 break;
679 case LOGGER_GET_NEXT_ENTRY_LEN:
680 if (!(file->f_mode & FMODE_READ)) {
681 ret = -EBADF;
682 break;
683 }
684 reader = file->private_data;
685
686 if (!reader->r_all)
687 reader->r_off = get_next_entry_by_uid(log,
688 reader->r_off, current_euid());
689
690 if (log->w_off != reader->r_off)
691 ret = get_user_hdr_len(reader->r_ver) +
692 get_entry_msg_len(log, reader->r_off);
693 else
694 ret = 0;
695 break;
696 case LOGGER_FLUSH_LOG:
697 if (!(file->f_mode & FMODE_WRITE)) {
698 ret = -EBADF;
699 break;
700 }
701 if (!(in_egroup_p(file_inode(file)->i_gid) ||
702 capable(CAP_SYSLOG))) {
703 ret = -EPERM;
704 break;
705 }
706 list_for_each_entry(reader, &log->readers, list)
707 reader->r_off = log->w_off;
708 log->head = log->w_off;
709 ret = 0;
710 break;
711 case LOGGER_GET_VERSION:
712 if (!(file->f_mode & FMODE_READ)) {
713 ret = -EBADF;
714 break;
715 }
716 reader = file->private_data;
717 ret = reader->r_ver;
718 break;
719 case LOGGER_SET_VERSION:
720 if (!(file->f_mode & FMODE_READ)) {
721 ret = -EBADF;
722 break;
723 }
724 reader = file->private_data;
725 ret = logger_set_version(reader, argp);
726 break;
727 }
728
729 mutex_unlock(&log->mutex);
730
731 return ret;
732}
733
734static const struct file_operations logger_fops = {
735 .owner = THIS_MODULE,
736 .read = logger_read,
737 .aio_write = logger_aio_write,
738 .poll = logger_poll,
739 .unlocked_ioctl = logger_ioctl,
740 .compat_ioctl = logger_ioctl,
741 .open = logger_open,
742 .release = logger_release,
743};
744
745/*
746 * Log size must must be a power of two, and greater than
747 * (LOGGER_ENTRY_MAX_PAYLOAD + sizeof(struct logger_entry)).
748 */
749static int __init create_log(char *log_name, int size)
750{
751 int ret = 0;
752 struct logger_log *log;
753 unsigned char *buffer;
754
755 buffer = vmalloc(size);
756 if (buffer == NULL)
757 return -ENOMEM;
758
759 log = kzalloc(sizeof(struct logger_log), GFP_KERNEL);
760 if (log == NULL) {
761 ret = -ENOMEM;
762 goto out_free_buffer;
763 }
764 log->buffer = buffer;
765
766 log->misc.minor = MISC_DYNAMIC_MINOR;
767 log->misc.name = kstrdup(log_name, GFP_KERNEL);
768 if (log->misc.name == NULL) {
769 ret = -ENOMEM;
770 goto out_free_log;
771 }
772
773 log->misc.fops = &logger_fops;
774 log->misc.parent = NULL;
775
776 init_waitqueue_head(&log->wq);
777 INIT_LIST_HEAD(&log->readers);
778 mutex_init(&log->mutex);
779 log->w_off = 0;
780 log->head = 0;
781 log->size = size;
782
783 INIT_LIST_HEAD(&log->logs);
784 list_add_tail(&log->logs, &log_list);
785
786 /* finally, initialize the misc device for this log */
787 ret = misc_register(&log->misc);
788 if (unlikely(ret)) {
789 pr_err("failed to register misc device for log '%s'!\n",
790 log->misc.name);
791 goto out_free_log;
792 }
793
794 pr_info("created %luK log '%s'\n",
795 (unsigned long) log->size >> 10, log->misc.name);
796
797 return 0;
798
799out_free_log:
800 kfree(log);
801
802out_free_buffer:
803 vfree(buffer);
804 return ret;
805}
806
807static int __init logger_init(void)
808{
809 int ret;
810
811 ret = create_log(LOGGER_LOG_MAIN, 256*1024);
812 if (unlikely(ret))
813 goto out;
814
815 ret = create_log(LOGGER_LOG_EVENTS, 256*1024);
816 if (unlikely(ret))
817 goto out;
818
819 ret = create_log(LOGGER_LOG_RADIO, 256*1024);
820 if (unlikely(ret))
821 goto out;
822
823 ret = create_log(LOGGER_LOG_SYSTEM, 256*1024);
824 if (unlikely(ret))
825 goto out;
826
827out:
828 return ret;
829}
830
831static void __exit logger_exit(void)
832{
833 struct logger_log *current_log, *next_log;
834
835 list_for_each_entry_safe(current_log, next_log, &log_list, logs) {
836 /* we have to delete all the entry inside log_list */
837 misc_deregister(¤t_log->misc);
838 vfree(current_log->buffer);
839 kfree(current_log->misc.name);
840 list_del(¤t_log->logs);
841 kfree(current_log);
842 }
843}
844
845
846device_initcall(logger_init);
847module_exit(logger_exit);
848
849MODULE_LICENSE("GPL");
850MODULE_AUTHOR("Robert Love, <rlove@google.com>");
851MODULE_DESCRIPTION("Android Logger");