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] != '!'))
29 * If the script filename will be inaccessible after exec, typically
30 * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
31 * up now (on the assumption that the interpreter will want to load
34 if (bprm
->interp_flags
& BINPRM_FLAGS_PATH_INACCESSIBLE
)
38 * This section does the #! interpretation.
39 * Sorta complicated, but hopefully it will work. -TYT
42 allow_write_access(bprm
->file
);
46 bprm
->buf
[BINPRM_BUF_SIZE
- 1] = '\0';
47 if ((cp
= strchr(bprm
->buf
, '\n')) == NULL
)
48 cp
= bprm
->buf
+BINPRM_BUF_SIZE
-1;
50 while (cp
> bprm
->buf
) {
52 if ((*cp
== ' ') || (*cp
== '\t'))
57 for (cp
= bprm
->buf
+2; (*cp
== ' ') || (*cp
== '\t'); cp
++);
59 return -ENOEXEC
; /* No interpreter name found */
62 for ( ; *cp
&& (*cp
!= ' ') && (*cp
!= '\t'); cp
++)
64 while ((*cp
== ' ') || (*cp
== '\t'))
68 strcpy (interp
, i_name
);
70 * OK, we've parsed out the interpreter name and
71 * (optional) argument.
72 * Splice in (1) the interpreter's name for argv[0]
73 * (2) (optional) argument to interpreter
74 * (3) filename of shell script (replace argv[0])
76 * This is done in reverse order, because of how the
77 * user environment and arguments are stored.
79 retval
= remove_arg_zero(bprm
);
82 retval
= copy_strings_kernel(1, &bprm
->interp
, bprm
);
83 if (retval
< 0) return retval
;
86 retval
= copy_strings_kernel(1, &i_arg
, bprm
);
87 if (retval
< 0) return retval
;
90 retval
= copy_strings_kernel(1, &i_name
, bprm
);
91 if (retval
) return retval
;
93 retval
= bprm_change_interp(interp
, bprm
);
98 * OK, now restart the process with the interpreter's dentry.
100 file
= open_exec(interp
);
102 return PTR_ERR(file
);
105 retval
= prepare_binprm(bprm
);
108 return search_binary_handler(bprm
);
111 static struct linux_binfmt script_format
= {
112 .module
= THIS_MODULE
,
113 .load_binary
= load_script
,
116 static int __init
init_script_binfmt(void)
118 register_binfmt(&script_format
);
122 static void __exit
exit_script_binfmt(void)
124 unregister_binfmt(&script_format
);
127 core_initcall(init_script_binfmt
);
128 module_exit(exit_script_binfmt
);
129 MODULE_LICENSE("GPL");