1/*
2 *  linux/fs/proc/kmsg.c
3 *
4 *  Copyright (C) 1992  by Linus Torvalds
5 *
6 */
7
8#include <linux/types.h>
9#include <linux/errno.h>
10#include <linux/time.h>
11#include <linux/kernel.h>
12#include <linux/poll.h>
13#include <linux/proc_fs.h>
14#include <linux/fs.h>
15#include <linux/syslog.h>
16
17#include <asm/uaccess.h>
18#include <asm/io.h>
19
20extern wait_queue_head_t log_wait;
21
22static int kmsg_open(struct inode * inode, struct file * file)
23{
24	return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC);
25}
26
27static int kmsg_release(struct inode * inode, struct file * file)
28{
29	(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC);
30	return 0;
31}
32
33static ssize_t kmsg_read(struct file *file, char __user *buf,
34			 size_t count, loff_t *ppos)
35{
36	if ((file->f_flags & O_NONBLOCK) &&
37	    !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
38		return -EAGAIN;
39	return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC);
40}
41
42static unsigned int kmsg_poll(struct file *file, poll_table *wait)
43{
44	poll_wait(file, &log_wait, wait);
45	if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
46		return POLLIN | POLLRDNORM;
47	return 0;
48}
49
50
51static const struct file_operations proc_kmsg_operations = {
52	.read		= kmsg_read,
53	.poll		= kmsg_poll,
54	.open		= kmsg_open,
55	.release	= kmsg_release,
56	.llseek		= generic_file_llseek,
57};
58
59static int __init proc_kmsg_init(void)
60{
61	proc_create("kmsg", S_IRUSR, NULL, &proc_kmsg_operations);
62	return 0;
63}
64fs_initcall(proc_kmsg_init);
65