blob: b8e8b0acf9bd8df4b3ca369a152afbe01cd9d476 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/binfmt_em86.c
3 *
4 * Based on linux/fs/binfmt_script.c
Jan Engelhardt96de0e22007-10-19 23:21:04 +02005 * Copyright (C) 1996 Martin von Löwis
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * original #!-checking implemented by tytso.
7 *
8 * em86 changes Copyright (C) 1997 Jim Paradis
9 */
10
11#include <linux/module.h>
12#include <linux/string.h>
13#include <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/binfmts.h>
15#include <linux/elf.h>
16#include <linux/init.h>
17#include <linux/fs.h>
18#include <linux/file.h>
19#include <linux/errno.h>
20
21
22#define EM86_INTERP "/usr/bin/em86"
23#define EM86_I_NAME "em86"
24
25static int load_em86(struct linux_binprm *bprm,struct pt_regs *regs)
26{
27 char *interp, *i_name, *i_arg;
28 struct file * file;
29 int retval;
30 struct elfhdr elf_ex;
31
32 /* Make sure this is a Linux/Intel ELF executable... */
33 elf_ex = *((struct elfhdr *)bprm->buf);
34
35 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
36 return -ENOEXEC;
37
38 /* First of all, some simple consistency checks */
39 if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
40 (!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) ||
41 (!bprm->file->f_op || !bprm->file->f_op->mmap)) {
42 return -ENOEXEC;
43 }
44
Kirill A. Shutemovbf2a9a32008-10-15 22:02:39 -070045 bprm->recursion_depth++; /* Well, the bang-shell is implicit... */
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 allow_write_access(bprm->file);
47 fput(bprm->file);
48 bprm->file = NULL;
49
50 /* Unlike in the script case, we don't have to do any hairy
51 * parsing to find our interpreter... it's hardcoded!
52 */
53 interp = EM86_INTERP;
54 i_name = EM86_I_NAME;
55 i_arg = NULL; /* We reserve the right to add an arg later */
56
57 /*
58 * Splice in (1) the interpreter's name for argv[0]
59 * (2) (optional) argument to interpreter
60 * (3) filename of emulated file (replace argv[0])
61 *
62 * This is done in reverse order, because of how the
63 * user environment and arguments are stored.
64 */
65 remove_arg_zero(bprm);
66 retval = copy_strings_kernel(1, &bprm->filename, bprm);
67 if (retval < 0) return retval;
68 bprm->argc++;
69 if (i_arg) {
70 retval = copy_strings_kernel(1, &i_arg, bprm);
71 if (retval < 0) return retval;
72 bprm->argc++;
73 }
74 retval = copy_strings_kernel(1, &i_name, bprm);
75 if (retval < 0) return retval;
76 bprm->argc++;
77
78 /*
79 * OK, now restart the process with the interpreter's inode.
80 * Note that we use open_exec() as the name is now in kernel
81 * space, and we don't need to copy it.
82 */
83 file = open_exec(interp);
84 if (IS_ERR(file))
85 return PTR_ERR(file);
86
87 bprm->file = file;
88
89 retval = prepare_binprm(bprm);
90 if (retval < 0)
91 return retval;
92
93 return search_binary_handler(bprm, regs);
94}
95
96static struct linux_binfmt em86_format = {
97 .module = THIS_MODULE,
98 .load_binary = load_em86,
99};
100
101static int __init init_em86_binfmt(void)
102{
103 return register_binfmt(&em86_format);
104}
105
106static void __exit exit_em86_binfmt(void)
107{
108 unregister_binfmt(&em86_format);
109}
110
111core_initcall(init_em86_binfmt);
112module_exit(exit_em86_binfmt);
113MODULE_LICENSE("GPL");