1/* 2 * linux/fs/binfmt_em86.c 3 * 4 * Based on linux/fs/binfmt_script.c 5 * Copyright (C) 1996 Martin von L��wis 6 * 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> 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 /* 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 45 bprm->recursion_depth++; /* Well, the bang-shell is implicit... */ 46 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"); 114