Commit | Line | Data |
---|---|---|
e16f5350 | 1 | /* |
c5d4bb17 | 2 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | */ | |
5 | ||
c5d4bb17 JD |
6 | #include <linux/ctype.h> |
7 | #include <linux/init.h> | |
8 | #include <linux/kernel.h> | |
6613c5e8 | 9 | #include <linux/module.h> |
c5d4bb17 | 10 | #include <linux/proc_fs.h> |
6613c5e8 | 11 | #include <linux/seq_file.h> |
c5d4bb17 JD |
12 | #include <linux/types.h> |
13 | #include <asm/uaccess.h> | |
1da177e4 | 14 | |
c5d4bb17 JD |
15 | /* |
16 | * If read and write race, the read will still atomically read a valid | |
1da177e4 LT |
17 | * value. |
18 | */ | |
19 | int uml_exitcode = 0; | |
20 | ||
6613c5e8 | 21 | static int exitcode_proc_show(struct seq_file *m, void *v) |
1da177e4 | 22 | { |
6613c5e8 | 23 | int val; |
1da177e4 | 24 | |
c5d4bb17 JD |
25 | /* |
26 | * Save uml_exitcode in a local so that we don't need to guarantee | |
730760e9 JD |
27 | * that sprintf accesses it atomically. |
28 | */ | |
29 | val = uml_exitcode; | |
6613c5e8 AD |
30 | seq_printf(m, "%d\n", val); |
31 | return 0; | |
32 | } | |
33 | ||
34 | static int exitcode_proc_open(struct inode *inode, struct file *file) | |
35 | { | |
36 | return single_open(file, exitcode_proc_show, NULL); | |
1da177e4 LT |
37 | } |
38 | ||
6613c5e8 AD |
39 | static ssize_t exitcode_proc_write(struct file *file, |
40 | const char __user *buffer, size_t count, loff_t *pos) | |
1da177e4 LT |
41 | { |
42 | char *end, buf[sizeof("nnnnn\0")]; | |
43 | int tmp; | |
44 | ||
c5d4bb17 | 45 | if (copy_from_user(buf, buffer, count)) |
e16f5350 JD |
46 | return -EFAULT; |
47 | ||
1da177e4 | 48 | tmp = simple_strtol(buf, &end, 0); |
c5d4bb17 | 49 | if ((*end != '\0') && !isspace(*end)) |
e16f5350 JD |
50 | return -EINVAL; |
51 | ||
1da177e4 | 52 | uml_exitcode = tmp; |
e16f5350 | 53 | return count; |
1da177e4 LT |
54 | } |
55 | ||
6613c5e8 AD |
56 | static 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 | ||
1da177e4 LT |
65 | static int make_proc_exitcode(void) |
66 | { | |
67 | struct proc_dir_entry *ent; | |
68 | ||
6613c5e8 | 69 | ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_fops); |
c5d4bb17 | 70 | if (ent == NULL) { |
30f417c6 | 71 | printk(KERN_WARNING "make_proc_exitcode : Failed to register " |
1da177e4 | 72 | "/proc/exitcode\n"); |
e16f5350 | 73 | return 0; |
1da177e4 | 74 | } |
e16f5350 | 75 | return 0; |
1da177e4 LT |
76 | } |
77 | ||
78 | __initcall(make_proc_exitcode); |