diff options
Diffstat (limited to 'fs/proc/kmsg.c')
-rw-r--r-- | fs/proc/kmsg.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/fs/proc/kmsg.c b/fs/proc/kmsg.c new file mode 100644 index 000000000..b38ad5528 --- /dev/null +++ b/fs/proc/kmsg.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/proc/kmsg.c + * + * Copyright (C) 1992 by Linus Torvalds + * + */ + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/poll.h> +#include <linux/proc_fs.h> +#include <linux/fs.h> +#include <linux/syslog.h> + +#include <linux/uaccess.h> +#include <asm/io.h> + +extern wait_queue_head_t log_wait; + +static int kmsg_open(struct inode * inode, struct file * file) +{ + return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC); +} + +static int kmsg_release(struct inode * inode, struct file * file) +{ + (void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC); + return 0; +} + +static ssize_t kmsg_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + if ((file->f_flags & O_NONBLOCK) && + !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC)) + return -EAGAIN; + return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC); +} + +static __poll_t kmsg_poll(struct file *file, poll_table *wait) +{ + poll_wait(file, &log_wait, wait); + if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC)) + return EPOLLIN | EPOLLRDNORM; + return 0; +} + + +static const struct proc_ops kmsg_proc_ops = { + .proc_flags = PROC_ENTRY_PERMANENT, + .proc_read = kmsg_read, + .proc_poll = kmsg_poll, + .proc_open = kmsg_open, + .proc_release = kmsg_release, + .proc_lseek = generic_file_llseek, +}; + +static int __init proc_kmsg_init(void) +{ + proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops); + return 0; +} +fs_initcall(proc_kmsg_init); |