Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/ctype.h>
7#include <linux/init.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/proc_fs.h>
11#include <linux/seq_file.h>
12#include <linux/types.h>
13#include <asm/uaccess.h>
14
15/*
16 * If read and write race, the read will still atomically read a valid
17 * value.
18 */
19int uml_exitcode = 0;
20
21static int exitcode_proc_show(struct seq_file *m, void *v)
22{
23 int val;
24
25 /*
26 * Save uml_exitcode in a local so that we don't need to guarantee
27 * that sprintf accesses it atomically.
28 */
29 val = uml_exitcode;
30 seq_printf(m, "%d\n", val);
31 return 0;
32}
33
34static int exitcode_proc_open(struct inode *inode, struct file *file)
35{
36 return single_open(file, exitcode_proc_show, NULL);
37}
38
39static ssize_t exitcode_proc_write(struct file *file,
40 const char __user *buffer, size_t count, loff_t *pos)
41{
42 char *end, buf[sizeof("nnnnn\0")];
43 int tmp;
44
45 if (copy_from_user(buf, buffer, count))
46 return -EFAULT;
47
48 tmp = simple_strtol(buf, &end, 0);
49 if ((*end != '\0') && !isspace(*end))
50 return -EINVAL;
51
52 uml_exitcode = tmp;
53 return count;
54}
55
56static const struct file_operations exitcode_proc_fops = {
57 .owner = THIS_MODULE,
58 .open = exitcode_proc_open,
59 .read = seq_read,
60 .llseek = seq_lseek,
61 .release = single_release,
62 .write = exitcode_proc_write,
63};
64
65static int make_proc_exitcode(void)
66{
67 struct proc_dir_entry *ent;
68
69 ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_fops);
70 if (ent == NULL) {
71 printk(KERN_WARNING "make_proc_exitcode : Failed to register "
72 "/proc/exitcode\n");
73 return 0;
74 }
75 return 0;
76}
77
78__initcall(make_proc_exitcode);