1 /* 2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/init.h" 7 #include "linux/ctype.h" 8 #include "linux/proc_fs.h" 9 #include "asm/uaccess.h" 10 11 /* If read and write race, the read will still atomically read a valid 12 * value. 13 */ 14 int uml_exitcode = 0; 15 16 static int read_proc_exitcode(char *page, char **start, off_t off, 17 int count, int *eof, void *data) 18 { 19 int len; 20 21 len = sprintf(page, "%d\n", uml_exitcode); 22 len -= off; 23 if(len <= off+count) *eof = 1; 24 *start = page + off; 25 if(len > count) len = count; 26 if(len < 0) len = 0; 27 return(len); 28 } 29 30 static int write_proc_exitcode(struct file *file, const char __user *buffer, 31 unsigned long count, void *data) 32 { 33 char *end, buf[sizeof("nnnnn\0")]; 34 int tmp; 35 36 if(copy_from_user(buf, buffer, count)) 37 return(-EFAULT); 38 tmp = simple_strtol(buf, &end, 0); 39 if((*end != '\0') && !isspace(*end)) 40 return(-EINVAL); 41 uml_exitcode = tmp; 42 return(count); 43 } 44 45 static int make_proc_exitcode(void) 46 { 47 struct proc_dir_entry *ent; 48 49 ent = create_proc_entry("exitcode", 0600, &proc_root); 50 if(ent == NULL){ 51 printk(KERN_WARNING "make_proc_exitcode : Failed to register " 52 "/proc/exitcode\n"); 53 return(0); 54 } 55 56 ent->read_proc = read_proc_exitcode; 57 ent->write_proc = write_proc_exitcode; 58 59 return(0); 60 } 61 62 __initcall(make_proc_exitcode); 63 64 /* 65 * Overrides for Emacs so that we follow Linus's tabbing style. 66 * Emacs will notice this stuff at the end of the file and automatically 67 * adjust the settings for this buffer only. This must remain at the end 68 * of the file. 69 * --------------------------------------------------------------------------- 70 * Local variables: 71 * c-file-style: "linux" 72 * End: 73 */ 74