xref: /openbmc/linux/fs/proc/kmsg.c (revision 6e644c31)
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/fs.h>
14 
15 #include <asm/uaccess.h>
16 #include <asm/io.h>
17 
18 #include "internal.h"
19 
20 extern wait_queue_head_t log_wait;
21 
22 extern int do_syslog(int type, char __user *bug, int count);
23 
24 static int kmsg_open(struct inode * inode, struct file * file)
25 {
26 	return do_syslog(1,NULL,0);
27 }
28 
29 static int kmsg_release(struct inode * inode, struct file * file)
30 {
31 	(void) do_syslog(0,NULL,0);
32 	return 0;
33 }
34 
35 static ssize_t kmsg_read(struct file *file, char __user *buf,
36 			 size_t count, loff_t *ppos)
37 {
38 	if ((file->f_flags & O_NONBLOCK) && !do_syslog(9, NULL, 0))
39 		return -EAGAIN;
40 	return do_syslog(2, buf, count);
41 }
42 
43 static unsigned int kmsg_poll(struct file *file, poll_table *wait)
44 {
45 	poll_wait(file, &log_wait, wait);
46 	if (do_syslog(9, NULL, 0))
47 		return POLLIN | POLLRDNORM;
48 	return 0;
49 }
50 
51 
52 const struct file_operations proc_kmsg_operations = {
53 	.read		= kmsg_read,
54 	.poll		= kmsg_poll,
55 	.open		= kmsg_open,
56 	.release	= kmsg_release,
57 };
58