xref: /openbmc/linux/fs/proc/kmsg.c (revision 4b6f5d20)
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 extern wait_queue_head_t log_wait;
19 
20 extern int do_syslog(int type, char __user *bug, int count);
21 
22 static int kmsg_open(struct inode * inode, struct file * file)
23 {
24 	return do_syslog(1,NULL,0);
25 }
26 
27 static int kmsg_release(struct inode * inode, struct file * file)
28 {
29 	(void) do_syslog(0,NULL,0);
30 	return 0;
31 }
32 
33 static 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) && !do_syslog(9, NULL, 0))
37 		return -EAGAIN;
38 	return do_syslog(2, buf, count);
39 }
40 
41 static unsigned int kmsg_poll(struct file *file, poll_table *wait)
42 {
43 	poll_wait(file, &log_wait, wait);
44 	if (do_syslog(9, NULL, 0))
45 		return POLLIN | POLLRDNORM;
46 	return 0;
47 }
48 
49 
50 const struct file_operations proc_kmsg_operations = {
51 	.read		= kmsg_read,
52 	.poll		= kmsg_poll,
53 	.open		= kmsg_open,
54 	.release	= kmsg_release,
55 };
56