/* *  linux/fs/binfmt_script.c * *  Copyright (C) 1996  Martin von Löwis *  original #!-checking implemented by tytso. */ #include <linux/module.h>#include <linux/string.h>#include <linux/stat.h>#include <linux/binfmts.h>#include <linux/init.h>#include <linux/file.h>#include <linux/err.h>#include <linux/fs.h> static int load_script(struct linux_binprm *bprm,struct pt_regs *regs){	const char *i_arg, *i_name;	char *cp;	struct file *file;	char interp[BINPRM_BUF_SIZE];	int retval; 	if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!') ||	    (bprm->recursion_depth > BINPRM_MAX_RECURSION))		return -ENOEXEC;	/*	 * This section does the #! interpretation.	 * Sorta complicated, but hopefully it will work.  -TYT	 */ 	bprm->recursion_depth++;	allow_write_access(bprm->file);	fput(bprm->file);	bprm->file = NULL; 	bprm->buf[BINPRM_BUF_SIZE - 1] = '\0';	if ((cp = strchr(bprm->buf, '\n')) == NULL)		cp = bprm->buf+BINPRM_BUF_SIZE-1;	*cp = '\0';	while (cp > bprm->buf) {		cp--;		if ((*cp == ' ') || (*cp == '\t'))			*cp = '\0';		else			break;	}	for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++);	if (*cp == '\0') 		return -ENOEXEC; /* No interpreter name found */	i_name = cp;	i_arg = NULL;	for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++)		/* nothing */ ;	while ((*cp == ' ') || (*cp == '\t'))		*cp++ = '\0';	if (*cp)		i_arg = cp;	strcpy (interp, i_name);	/*	 * OK, we've parsed out the interpreter name and	 * (optional) argument.	 * Splice in (1) the interpreter's name for argv[0]	 *           (2) (optional) argument to interpreter	 *           (3) filename of shell script (replace argv[0])	 *	 * This is done in reverse order, because of how the	 * user environment and arguments are stored.	 */	retval = remove_arg_zero(bprm);	if (retval)		return retval;	retval = copy_strings_kernel(1, &bprm->interp, bprm);	if (retval < 0) return retval; 	bprm->argc++;	if (i_arg) {		retval = copy_strings_kernel(1, &i_arg, bprm);		if (retval < 0) return retval; 		bprm->argc++;	}	retval = copy_strings_kernel(1, &i_name, bprm);	if (retval) return retval; 	bprm->argc++;	bprm->interp = interp; 	/*	 * OK, now restart the process with the interpreter's dentry.	 */	file = open_exec(interp);	if (IS_ERR(file))		return PTR_ERR(file); 	bprm->file = file;	retval = prepare_binprm(bprm);	if (retval < 0)		return retval;	return search_binary_handler(bprm,regs);} static struct linux_binfmt script_format = {	.module		= THIS_MODULE,	.load_binary	= load_script,}; static int __init init_script_binfmt(void){	register_binfmt(&script_format);	return 0;} static void __exit exit_script_binfmt(void){	unregister_binfmt(&script_format);} core_initcall(init_script_binfmt);module_exit(exit_script_binfmt);MODULE_LICENSE("GPL");