2 * linux/fs/binfmt_script.c
4 * Copyright (C) 1996 Martin von Löwis
5 * original #!-checking implemented by tytso.
8 #include <linux/module.h>
9 #include <linux/string.h>
10 #include <linux/stat.h>
11 #include <linux/binfmts.h>
12 #include <linux/init.h>
13 #include <linux/file.h>
14 #include <linux/err.h>
17 static int load_script(struct linux_binprm *bprm)
19 const char *i_arg, *i_name;
22 char interp[BINPRM_BUF_SIZE];
25 if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
28 * This section does the #! interpretation.
29 * Sorta complicated, but hopefully it will work. -TYT
32 allow_write_access(bprm->file);
36 bprm->buf[BINPRM_BUF_SIZE - 1] = '\0';
37 if ((cp = strchr(bprm->buf, '\n')) == NULL)
38 cp = bprm->buf+BINPRM_BUF_SIZE-1;
40 while (cp > bprm->buf) {
42 if ((*cp == ' ') || (*cp == '\t'))
47 for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++);
49 return -ENOEXEC; /* No interpreter name found */
52 for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++)
54 while ((*cp == ' ') || (*cp == '\t'))
58 strcpy (interp, i_name);
60 * OK, we've parsed out the interpreter name and
61 * (optional) argument.
62 * Splice in (1) the interpreter's name for argv[0]
63 * (2) (optional) argument to interpreter
64 * (3) filename of shell script (replace argv[0])
66 * This is done in reverse order, because of how the
67 * user environment and arguments are stored.
69 retval = remove_arg_zero(bprm);
72 retval = copy_strings_kernel(1, &bprm->interp, bprm);
73 if (retval < 0) return retval;
76 retval = copy_strings_kernel(1, &i_arg, bprm);
77 if (retval < 0) return retval;
80 retval = copy_strings_kernel(1, &i_name, bprm);
81 if (retval) return retval;
83 retval = bprm_change_interp(interp, bprm);
88 * OK, now restart the process with the interpreter's dentry.
90 file = open_exec(interp);
95 retval = prepare_binprm(bprm);
98 return search_binary_handler(bprm);
101 static struct linux_binfmt script_format = {
102 .module = THIS_MODULE,
103 .load_binary = load_script,
106 static int __init init_script_binfmt(void)
108 register_binfmt(&script_format);
112 static void __exit exit_script_binfmt(void)
114 unregister_binfmt(&script_format);
117 core_initcall(init_script_binfmt);
118 module_exit(exit_script_binfmt);
119 MODULE_LICENSE("GPL");