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_FILE);
25}
26
27static int kmsg_release(struct inode * inode, struct file * file)
28{
29	(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_FILE);
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_FILE))
38		return -EAGAIN;
39	return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_FILE);
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_FILE))
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}
64module_init(proc_kmsg_init);

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *  linux/fs/proc/kmsg.c
 4 *
 5 *  Copyright (C) 1992  by Linus Torvalds
 6 *
 7 */
 8
 9#include <linux/types.h>
10#include <linux/errno.h>
11#include <linux/time.h>
12#include <linux/kernel.h>
13#include <linux/poll.h>
14#include <linux/proc_fs.h>
15#include <linux/fs.h>
16#include <linux/syslog.h>
17
18#include <linux/uaccess.h>
19#include <asm/io.h>
20
21extern wait_queue_head_t log_wait;
22
23static int kmsg_open(struct inode * inode, struct file * file)
24{
25	return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC);
26}
27
28static int kmsg_release(struct inode * inode, struct file * file)
29{
30	(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC);
31	return 0;
32}
33
34static ssize_t kmsg_read(struct file *file, char __user *buf,
35			 size_t count, loff_t *ppos)
36{
37	if ((file->f_flags & O_NONBLOCK) &&
38	    !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
39		return -EAGAIN;
40	return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC);
41}
42
43static __poll_t kmsg_poll(struct file *file, poll_table *wait)
44{
45	poll_wait(file, &log_wait, wait);
46	if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
47		return EPOLLIN | EPOLLRDNORM;
48	return 0;
49}
50
51
52static const struct proc_ops kmsg_proc_ops = {
53	.proc_flags	= PROC_ENTRY_PERMANENT,
54	.proc_read	= kmsg_read,
55	.proc_poll	= kmsg_poll,
56	.proc_open	= kmsg_open,
57	.proc_release	= kmsg_release,
58	.proc_lseek	= generic_file_llseek,
59};
60
61static int __init proc_kmsg_init(void)
62{
63	proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops);
64	return 0;
65}
66fs_initcall(proc_kmsg_init);