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0d1fb0a4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e16f5350 | 2 | /* |
c5d4bb17 | 3 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
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 | 12 | #include <linux/types.h> |
7c0f6ba6 | 13 | #include <linux/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")]; | |
201f99f1 | 43 | size_t size; |
1da177e4 LT |
44 | int tmp; |
45 | ||
201f99f1 DC |
46 | size = min(count, sizeof(buf)); |
47 | if (copy_from_user(buf, buffer, size)) | |
e16f5350 JD |
48 | return -EFAULT; |
49 | ||
1da177e4 | 50 | tmp = simple_strtol(buf, &end, 0); |
c5d4bb17 | 51 | if ((*end != '\0') && !isspace(*end)) |
e16f5350 JD |
52 | return -EINVAL; |
53 | ||
1da177e4 | 54 | uml_exitcode = tmp; |
e16f5350 | 55 | return count; |
1da177e4 LT |
56 | } |
57 | ||
97a32539 AD |
58 | static const struct proc_ops exitcode_proc_ops = { |
59 | .proc_open = exitcode_proc_open, | |
60 | .proc_read = seq_read, | |
61 | .proc_lseek = seq_lseek, | |
62 | .proc_release = single_release, | |
63 | .proc_write = exitcode_proc_write, | |
6613c5e8 AD |
64 | }; |
65 | ||
1da177e4 LT |
66 | static int make_proc_exitcode(void) |
67 | { | |
68 | struct proc_dir_entry *ent; | |
69 | ||
97a32539 | 70 | ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_ops); |
c5d4bb17 | 71 | if (ent == NULL) { |
30f417c6 | 72 | printk(KERN_WARNING "make_proc_exitcode : Failed to register " |
1da177e4 | 73 | "/proc/exitcode\n"); |
e16f5350 | 74 | return 0; |
1da177e4 | 75 | } |
e16f5350 | 76 | return 0; |
1da177e4 LT |
77 | } |
78 | ||
79 | __initcall(make_proc_exitcode); |