// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) */ #include <linux/ctype.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/types.h>#include <linux/uaccess.h> /* * If read and write race, the read will still atomically read a valid * value. */int uml_exitcode = 0; static int exitcode_proc_show(struct seq_file *m, void *v){	int val; 	/*	 * Save uml_exitcode in a local so that we don't need to guarantee	 * that sprintf accesses it atomically.	 */	val = uml_exitcode;	seq_printf(m, "%d\n", val);	return 0;} static int exitcode_proc_open(struct inode *inode, struct file *file){	return single_open(file, exitcode_proc_show, NULL);} static ssize_t exitcode_proc_write(struct file *file,		const char __user *buffer, size_t count, loff_t *pos){	char *end, buf[sizeof("nnnnn\0")];	size_t size;	int tmp; 	size = min(count, sizeof(buf));	if (copy_from_user(buf, buffer, size))		return -EFAULT; 	tmp = simple_strtol(buf, &end, 0);	if ((*end != '\0') && !isspace(*end))		return -EINVAL; 	uml_exitcode = tmp;	return count;} static const struct proc_ops exitcode_proc_ops = {	.proc_open	= exitcode_proc_open,	.proc_read	= seq_read,	.proc_lseek	= seq_lseek,	.proc_release	= single_release,	.proc_write	= exitcode_proc_write,}; static int make_proc_exitcode(void){	struct proc_dir_entry *ent; 	ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_ops);	if (ent == NULL) {		printk(KERN_WARNING "make_proc_exitcode : Failed to register "		       "/proc/exitcode\n");		return 0;	}	return 0;} __initcall(make_proc_exitcode);