exitcode.c (1733B)
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 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 <linux/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 size_t size; 44 int tmp; 45 46 size = min(count, sizeof(buf)); 47 if (copy_from_user(buf, buffer, size)) 48 return -EFAULT; 49 50 tmp = simple_strtol(buf, &end, 0); 51 if ((*end != '\0') && !isspace(*end)) 52 return -EINVAL; 53 54 uml_exitcode = tmp; 55 return count; 56} 57 58static 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, 64}; 65 66static int make_proc_exitcode(void) 67{ 68 struct proc_dir_entry *ent; 69 70 ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_ops); 71 if (ent == NULL) { 72 printk(KERN_WARNING "make_proc_exitcode : Failed to register " 73 "/proc/exitcode\n"); 74 return 0; 75 } 76 return 0; 77} 78 79__initcall(make_proc_exitcode);