blob: dd2d3f0cd55d8dfae7dabde8d0dbaf664033702f [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
Al Viro71613c32012-10-20 22:00:48 -040025static int load_em86(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070026{
Daniel Wagnera310dcb2016-08-02 14:04:57 -070027 const char *i_name, *i_arg;
28 char *interp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 struct file * file;
30 int retval;
31 struct elfhdr elf_ex;
32
33 /* Make sure this is a Linux/Intel ELF executable... */
34 elf_ex = *((struct elfhdr *)bprm->buf);
35
36 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
37 return -ENOEXEC;
38
39 /* First of all, some simple consistency checks */
40 if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
41 (!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) ||
Al Viro72c2d532013-09-22 16:27:52 -040042 !bprm->file->f_op->mmap) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 return -ENOEXEC;
44 }
45
David Drysdale51f39a12014-12-12 16:57:29 -080046 /* Need to be able to load the file after exec */
47 if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
48 return -ENOENT;
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 allow_write_access(bprm->file);
51 fput(bprm->file);
52 bprm->file = NULL;
53
54 /* Unlike in the script case, we don't have to do any hairy
55 * parsing to find our interpreter... it's hardcoded!
56 */
57 interp = EM86_INTERP;
58 i_name = EM86_I_NAME;
59 i_arg = NULL; /* We reserve the right to add an arg later */
60
61 /*
62 * Splice in (1) the interpreter's name for argv[0]
63 * (2) (optional) argument to interpreter
64 * (3) filename of emulated file (replace argv[0])
65 *
66 * This is done in reverse order, because of how the
67 * user environment and arguments are stored.
68 */
69 remove_arg_zero(bprm);
70 retval = copy_strings_kernel(1, &bprm->filename, bprm);
71 if (retval < 0) return retval;
72 bprm->argc++;
73 if (i_arg) {
74 retval = copy_strings_kernel(1, &i_arg, bprm);
75 if (retval < 0) return retval;
76 bprm->argc++;
77 }
78 retval = copy_strings_kernel(1, &i_name, bprm);
79 if (retval < 0) return retval;
80 bprm->argc++;
81
82 /*
83 * OK, now restart the process with the interpreter's inode.
84 * Note that we use open_exec() as the name is now in kernel
85 * space, and we don't need to copy it.
86 */
87 file = open_exec(interp);
88 if (IS_ERR(file))
89 return PTR_ERR(file);
90
91 bprm->file = file;
92
93 retval = prepare_binprm(bprm);
94 if (retval < 0)
95 return retval;
96
Al Viro3c456bf2012-10-20 21:53:31 -040097 return search_binary_handler(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098}
99
100static struct linux_binfmt em86_format = {
101 .module = THIS_MODULE,
102 .load_binary = load_em86,
103};
104
105static int __init init_em86_binfmt(void)
106{
Al Viro8fc3dc52012-03-17 03:05:16 -0400107 register_binfmt(&em86_format);
108 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109}
110
111static void __exit exit_em86_binfmt(void)
112{
113 unregister_binfmt(&em86_format);
114}
115
116core_initcall(init_em86_binfmt);
117module_exit(exit_em86_binfmt);
118MODULE_LICENSE("GPL");