0001
0002
0003
0004
0005
0006
0007
0008
0009 #include <linux/types.h>
0010 #include <linux/errno.h>
0011 #include <linux/time.h>
0012 #include <linux/kernel.h>
0013 #include <linux/poll.h>
0014 #include <linux/proc_fs.h>
0015 #include <linux/fs.h>
0016 #include <linux/syslog.h>
0017
0018 #include <asm/io.h>
0019
0020 extern wait_queue_head_t log_wait;
0021
0022 static int kmsg_open(struct inode * inode, struct file * file)
0023 {
0024 return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC);
0025 }
0026
0027 static int kmsg_release(struct inode * inode, struct file * file)
0028 {
0029 (void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC);
0030 return 0;
0031 }
0032
0033 static ssize_t kmsg_read(struct file *file, char __user *buf,
0034 size_t count, loff_t *ppos)
0035 {
0036 if ((file->f_flags & O_NONBLOCK) &&
0037 !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
0038 return -EAGAIN;
0039 return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC);
0040 }
0041
0042 static __poll_t kmsg_poll(struct file *file, poll_table *wait)
0043 {
0044 poll_wait(file, &log_wait, wait);
0045 if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC))
0046 return EPOLLIN | EPOLLRDNORM;
0047 return 0;
0048 }
0049
0050
0051 static const struct proc_ops kmsg_proc_ops = {
0052 .proc_flags = PROC_ENTRY_PERMANENT,
0053 .proc_read = kmsg_read,
0054 .proc_poll = kmsg_poll,
0055 .proc_open = kmsg_open,
0056 .proc_release = kmsg_release,
0057 .proc_lseek = generic_file_llseek,
0058 };
0059
0060 static int __init proc_kmsg_init(void)
0061 {
0062 proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops);
0063 return 0;
0064 }
0065 fs_initcall(proc_kmsg_init);