1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 1992 by Linus Torvalds
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>
16 #include <linux/syslog.h>
18 #include <linux/uaccess.h>
21 extern wait_queue_head_t log_wait
;
23 static int kmsg_open(struct inode
* inode
, struct file
* file
)
25 return do_syslog(SYSLOG_ACTION_OPEN
, NULL
, 0, SYSLOG_FROM_PROC
);
28 static int kmsg_release(struct inode
* inode
, struct file
* file
)
30 (void) do_syslog(SYSLOG_ACTION_CLOSE
, NULL
, 0, SYSLOG_FROM_PROC
);
34 static ssize_t
kmsg_read(struct file
*file
, char __user
*buf
,
35 size_t count
, loff_t
*ppos
)
37 if ((file
->f_flags
& O_NONBLOCK
) &&
38 !do_syslog(SYSLOG_ACTION_SIZE_UNREAD
, NULL
, 0, SYSLOG_FROM_PROC
))
40 return do_syslog(SYSLOG_ACTION_READ
, buf
, count
, SYSLOG_FROM_PROC
);
43 static unsigned int kmsg_poll(struct file
*file
, poll_table
*wait
)
45 poll_wait(file
, &log_wait
, wait
);
46 if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD
, NULL
, 0, SYSLOG_FROM_PROC
))
47 return POLLIN
| POLLRDNORM
;
52 static const struct file_operations proc_kmsg_operations
= {
56 .release
= kmsg_release
,
57 .llseek
= generic_file_llseek
,
60 static int __init
proc_kmsg_init(void)
62 proc_create("kmsg", S_IRUSR
, NULL
, &proc_kmsg_operations
);
65 fs_initcall(proc_kmsg_init
);