1
2
3
4
5
6
7
8
9
10
11#include <linux/module.h>
12#include <linux/string.h>
13#include <linux/stat.h>
14#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
33 elf_ex = *((struct elfhdr *)bprm->buf);
34
35 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
36 return -ENOEXEC;
37
38
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
45 bprm->recursion_depth++;
46 allow_write_access(bprm->file);
47 fput(bprm->file);
48 bprm->file = NULL;
49
50
51
52
53 interp = EM86_INTERP;
54 i_name = EM86_I_NAME;
55 i_arg = NULL;
56
57
58
59
60
61
62
63
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
80
81
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");
114