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/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/types.h>
#include <asm/uaccess.h>
/*
* If read and write race, the read will still atomically read a valid
* value.
*/
int uml_exitcode = 0;
static int read_proc_exitcode(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len, val;
/*
* Save uml_exitcode in a local so that we don't need to guarantee
* that sprintf accesses it atomically.
*/
val = uml_exitcode;
len = sprintf(page, "%d\n", val);
len -= off;
if (len <= off+count)
*eof = 1;
*start = page + off;
if (len > count)
len = count;
if (len < 0)
len = 0;
return len;
}
static int write_proc_exitcode(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
char *end, buf[sizeof("nnnnn\0")];
int tmp;
if (copy_from_user(buf, buffer, count))
return -EFAULT;
tmp = simple_strtol(buf, &end, 0);
if ((*end != '\0') && !isspace(*end))
return -EINVAL;
uml_exitcode = tmp;
return count;
}
static int make_proc_exitcode(void)
{
struct proc_dir_entry *ent;
ent = create_proc_entry("exitcode", 0600, NULL);
if (ent == NULL) {
printk(KERN_WARNING "make_proc_exitcode : Failed to register "
"/proc/exitcode\n");
return 0;
}
ent->read_proc = read_proc_exitcode;
ent->write_proc = write_proc_exitcode;
return 0;
}
__initcall(make_proc_exitcode);
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