10d1fb0a4SAlex Dewar // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
3c5d4bb17SJeff Dike * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
41da177e4SLinus Torvalds */
51da177e4SLinus Torvalds
6c5d4bb17SJeff Dike #include <linux/ctype.h>
7c5d4bb17SJeff Dike #include <linux/init.h>
8c5d4bb17SJeff Dike #include <linux/kernel.h>
96613c5e8SAlexey Dobriyan #include <linux/module.h>
10c5d4bb17SJeff Dike #include <linux/proc_fs.h>
116613c5e8SAlexey Dobriyan #include <linux/seq_file.h>
12c5d4bb17SJeff Dike #include <linux/types.h>
137c0f6ba6SLinus Torvalds #include <linux/uaccess.h>
141da177e4SLinus Torvalds
15c5d4bb17SJeff Dike /*
16c5d4bb17SJeff Dike * If read and write race, the read will still atomically read a valid
171da177e4SLinus Torvalds * value.
181da177e4SLinus Torvalds */
191da177e4SLinus Torvalds int uml_exitcode = 0;
201da177e4SLinus Torvalds
exitcode_proc_show(struct seq_file * m,void * v)216613c5e8SAlexey Dobriyan static int exitcode_proc_show(struct seq_file *m, void *v)
221da177e4SLinus Torvalds {
236613c5e8SAlexey Dobriyan int val;
241da177e4SLinus Torvalds
25c5d4bb17SJeff Dike /*
26c5d4bb17SJeff Dike * Save uml_exitcode in a local so that we don't need to guarantee
27730760e9SJeff Dike * that sprintf accesses it atomically.
28730760e9SJeff Dike */
29730760e9SJeff Dike val = uml_exitcode;
306613c5e8SAlexey Dobriyan seq_printf(m, "%d\n", val);
316613c5e8SAlexey Dobriyan return 0;
321da177e4SLinus Torvalds }
331da177e4SLinus Torvalds
exitcode_proc_open(struct inode * inode,struct file * file)346613c5e8SAlexey Dobriyan static int exitcode_proc_open(struct inode *inode, struct file *file)
356613c5e8SAlexey Dobriyan {
366613c5e8SAlexey Dobriyan return single_open(file, exitcode_proc_show, NULL);
376613c5e8SAlexey Dobriyan }
386613c5e8SAlexey Dobriyan
exitcode_proc_write(struct file * file,const char __user * buffer,size_t count,loff_t * pos)396613c5e8SAlexey Dobriyan static ssize_t exitcode_proc_write(struct file *file,
406613c5e8SAlexey Dobriyan const char __user *buffer, size_t count, loff_t *pos)
411da177e4SLinus Torvalds {
421da177e4SLinus Torvalds char *end, buf[sizeof("nnnnn\0")];
43201f99f1SDan Carpenter size_t size;
441da177e4SLinus Torvalds int tmp;
451da177e4SLinus Torvalds
46201f99f1SDan Carpenter size = min(count, sizeof(buf));
47201f99f1SDan Carpenter if (copy_from_user(buf, buffer, size))
48e16f5350SJeff Dike return -EFAULT;
49e16f5350SJeff Dike
501da177e4SLinus Torvalds tmp = simple_strtol(buf, &end, 0);
511da177e4SLinus Torvalds if ((*end != '\0') && !isspace(*end))
52e16f5350SJeff Dike return -EINVAL;
53e16f5350SJeff Dike
541da177e4SLinus Torvalds uml_exitcode = tmp;
55e16f5350SJeff Dike return count;
561da177e4SLinus Torvalds }
571da177e4SLinus Torvalds
5897a32539SAlexey Dobriyan static const struct proc_ops exitcode_proc_ops = {
5997a32539SAlexey Dobriyan .proc_open = exitcode_proc_open,
6097a32539SAlexey Dobriyan .proc_read = seq_read,
6197a32539SAlexey Dobriyan .proc_lseek = seq_lseek,
6297a32539SAlexey Dobriyan .proc_release = single_release,
6397a32539SAlexey Dobriyan .proc_write = exitcode_proc_write,
646613c5e8SAlexey Dobriyan };
656613c5e8SAlexey Dobriyan
make_proc_exitcode(void)661da177e4SLinus Torvalds static int make_proc_exitcode(void)
671da177e4SLinus Torvalds {
681da177e4SLinus Torvalds struct proc_dir_entry *ent;
691da177e4SLinus Torvalds
7097a32539SAlexey Dobriyan ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_ops);
711da177e4SLinus Torvalds if (ent == NULL) {
7230f417c6SChristophe Lucas printk(KERN_WARNING "make_proc_exitcode : Failed to register "
731da177e4SLinus Torvalds "/proc/exitcode\n");
74e16f5350SJeff Dike return 0;
751da177e4SLinus Torvalds }
76e16f5350SJeff Dike return 0;
771da177e4SLinus Torvalds }
781da177e4SLinus Torvalds
791da177e4SLinus Torvalds __initcall(make_proc_exitcode);
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