LXR linux/fs/proc/kmsg.c

   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/proc_fs.h>
  14#include <linux/fs.h>
  15
  16#include <asm/uaccess.h>
  17#include <asm/io.h>
  18
  19extern wait_queue_head_t log_wait;
  20
  21extern int do_syslog(int type, char __user *bug, int count);
  22
  23static int kmsg_open(struct inode * inode, struct file * file)
  24{
  25        return do_syslog(1,NULL,0);
  26}
  27
  28static int kmsg_release(struct inode * inode, struct file * file)
  29{
  30        (void) do_syslog(0,NULL,0);
  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) && !do_syslog(9, NULL, 0))
  38                return -EAGAIN;
  39        return do_syslog(2, buf, count);
  40}
  41
  42static unsigned int kmsg_poll(struct file *file, poll_table *wait)
  43{
  44        poll_wait(file, &log_wait, wait);
  45        if (do_syslog(9, NULL, 0))
  46                return POLLIN | POLLRDNORM;
  47        return 0;
  48}
  49
  50
  51static const struct file_operations proc_kmsg_operations = {
  52        .read           = kmsg_read,
  53        .poll           = kmsg_poll,
  54        .open           = kmsg_open,
  55        .release        = kmsg_release,
  56};
  57
  58static int __init proc_kmsg_init(void)
  59{
  60        proc_create("kmsg", S_IRUSR, NULL, &proc_kmsg_operations);
  61        return 0;
  62}
  63module_init(proc_kmsg_init);
  64