1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/proc/kmsg.c
*
* Copyright (C) 1992 by Linus Torvalds
*
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/fs.h>
#include <linux/syslog.h>
#include <asm/io.h>
static int kmsg_open(struct inode * inode, struct file * file)
{
return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC);
}
static int kmsg_release(struct inode * inode, struct file * file)
{
(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC);
return 0;
}
static ssize_t kmsg_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
if ((file->f_flags & O_NONBLOCK) &&
!do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
return -EAGAIN;
return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC);
}
static __poll_t kmsg_poll(struct file *file, poll_table *wait)
{
poll_wait(file, &log_wait, wait);
if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
return EPOLLIN | EPOLLRDNORM;
return 0;
}
static const struct proc_ops kmsg_proc_ops = {
.proc_flags = PROC_ENTRY_PERMANENT,
.proc_read = kmsg_read,
.proc_poll = kmsg_poll,
.proc_open = kmsg_open,
.proc_release = kmsg_release,
.proc_lseek = generic_file_llseek,
};
static int __init proc_kmsg_init(void)
{
proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops);
return 0;
}
fs_initcall(proc_kmsg_init);
|
