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 <asm/io.h>
19
 
 
20static int kmsg_open(struct inode * inode, struct file * file)
21{
22	return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC);
23}
24
25static int kmsg_release(struct inode * inode, struct file * file)
26{
27	(void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC);
28	return 0;
29}
30
31static ssize_t kmsg_read(struct file *file, char __user *buf,
32			 size_t count, loff_t *ppos)
33{
34	if ((file->f_flags & O_NONBLOCK) &&
35	    !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
36		return -EAGAIN;
37	return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC);
38}
39
40static __poll_t kmsg_poll(struct file *file, poll_table *wait)
41{
42	poll_wait(file, &log_wait, wait);
43	if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
44		return EPOLLIN | EPOLLRDNORM;
45	return 0;
46}
47
48
49static const struct proc_ops kmsg_proc_ops = {
50	.proc_flags	= PROC_ENTRY_PERMANENT,
51	.proc_read	= kmsg_read,
52	.proc_poll	= kmsg_poll,
53	.proc_open	= kmsg_open,
54	.proc_release	= kmsg_release,
55	.proc_lseek	= generic_file_llseek,
56};
57
58static int __init proc_kmsg_init(void)
59{
60	proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops);
61	return 0;
62}
63fs_initcall(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 file_operations proc_kmsg_operations = {
53	.read		= kmsg_read,
54	.poll		= kmsg_poll,
55	.open		= kmsg_open,
56	.release	= kmsg_release,
57	.llseek		= generic_file_llseek,
 
58};
59
60static int __init proc_kmsg_init(void)
61{
62	proc_create("kmsg", S_IRUSR, NULL, &proc_kmsg_operations);
63	return 0;
64}
65fs_initcall(proc_kmsg_init);