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
;
24 if ((bprm
->buf
[0] != '#') || (bprm
->buf
[1] != '!'))
28 * If the script filename will be inaccessible after exec, typically
29 * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
30 * up now (on the assumption that the interpreter will want to load
33 if (bprm
->interp_flags
& BINPRM_FLAGS_PATH_INACCESSIBLE
)
37 * This section does the #! interpretation.
38 * Sorta complicated, but hopefully it will work. -TYT
41 allow_write_access(bprm
->file
);
45 for (cp
= bprm
->buf
+2;; cp
++) {
46 if (cp
>= bprm
->buf
+ BINPRM_BUF_SIZE
)
48 if (!*cp
|| (*cp
== '\n'))
53 while (cp
> bprm
->buf
) {
55 if ((*cp
== ' ') || (*cp
== '\t'))
60 for (cp
= bprm
->buf
+2; (*cp
== ' ') || (*cp
== '\t'); cp
++);
62 return -ENOEXEC
; /* No interpreter name found */
65 for ( ; *cp
&& (*cp
!= ' ') && (*cp
!= '\t'); cp
++)
67 while ((*cp
== ' ') || (*cp
== '\t'))
72 * OK, we've parsed out the interpreter name and
73 * (optional) argument.
74 * Splice in (1) the interpreter's name for argv[0]
75 * (2) (optional) argument to interpreter
76 * (3) filename of shell script (replace argv[0])
78 * This is done in reverse order, because of how the
79 * user environment and arguments are stored.
81 retval
= remove_arg_zero(bprm
);
84 retval
= copy_strings_kernel(1, &bprm
->interp
, bprm
);
89 retval
= copy_strings_kernel(1, &i_arg
, bprm
);
94 retval
= copy_strings_kernel(1, &i_name
, bprm
);
98 retval
= bprm_change_interp(i_name
, bprm
);
103 * OK, now restart the process with the interpreter's dentry.
105 file
= open_exec(i_name
);
107 return PTR_ERR(file
);
110 retval
= prepare_binprm(bprm
);
113 return search_binary_handler(bprm
);
116 static struct linux_binfmt script_format
= {
117 .module
= THIS_MODULE
,
118 .load_binary
= load_script
,
121 static int __init
init_script_binfmt(void)
123 register_binfmt(&script_format
);
127 static void __exit
exit_script_binfmt(void)
129 unregister_binfmt(&script_format
);
132 core_initcall(init_script_binfmt
);
133 module_exit(exit_script_binfmt
);
134 MODULE_LICENSE("GPL");