binfmt_em86.c
上传用户:lgb322
上传日期:2013-02-24
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文件大小:3k
- /*
- * linux/fs/binfmt_em86.c
- *
- * Based on linux/fs/binfmt_script.c
- * Copyright (C) 1996 Martin von L鰓is
- * original #!-checking implemented by tytso.
- *
- * em86 changes Copyright (C) 1997 Jim Paradis
- */
- #include <linux/module.h>
- #include <linux/string.h>
- #include <linux/stat.h>
- #include <linux/slab.h>
- #include <linux/locks.h>
- #include <linux/smp_lock.h>
- #include <linux/binfmts.h>
- #include <linux/elf.h>
- #include <linux/init.h>
- #include <linux/file.h>
- #define EM86_INTERP "/usr/bin/em86"
- #define EM86_I_NAME "em86"
- static int load_em86(struct linux_binprm *bprm,struct pt_regs *regs)
- {
- char *interp, *i_name, *i_arg;
- struct file * file;
- int retval;
- struct elfhdr elf_ex;
- /* Make sure this is a Linux/Intel ELF executable... */
- elf_ex = *((struct elfhdr *)bprm->buf);
- if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
- return -ENOEXEC;
- /* First of all, some simple consistency checks */
- if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
- (!((elf_ex.e_machine == EM_386) || (elf_ex.e_machine == EM_486))) ||
- (!bprm->file->f_op || !bprm->file->f_op->mmap)) {
- return -ENOEXEC;
- }
- bprm->sh_bang++; /* Well, the bang-shell is implicit... */
- allow_write_access(bprm->file);
- fput(bprm->file);
- bprm->file = NULL;
- /* Unlike in the script case, we don't have to do any hairy
- * parsing to find our interpreter... it's hardcoded!
- */
- interp = EM86_INTERP;
- i_name = EM86_I_NAME;
- i_arg = NULL; /* We reserve the right to add an arg later */
- /*
- * Splice in (1) the interpreter's name for argv[0]
- * (2) (optional) argument to interpreter
- * (3) filename of emulated file (replace argv[0])
- *
- * This is done in reverse order, because of how the
- * user environment and arguments are stored.
- */
- remove_arg_zero(bprm);
- retval = copy_strings_kernel(1, &bprm->filename, bprm);
- if (retval < 0) return retval;
- bprm->argc++;
- if (i_arg) {
- retval = copy_strings_kernel(1, &i_arg, bprm);
- if (retval < 0) return retval;
- bprm->argc++;
- }
- retval = copy_strings_kernel(1, &i_name, bprm);
- if (retval < 0) return retval;
- bprm->argc++;
- /*
- * OK, now restart the process with the interpreter's inode.
- * Note that we use open_exec() as the name is now in kernel
- * space, and we don't need to copy it.
- */
- file = open_exec(interp);
- if (IS_ERR(file))
- return PTR_ERR(file);
- bprm->file = file;
- retval = prepare_binprm(bprm);
- if (retval < 0)
- return retval;
- return search_binary_handler(bprm, regs);
- }
- struct linux_binfmt em86_format = {
- NULL, THIS_MODULE, load_em86, NULL, NULL, 0
- };
- static int __init init_em86_binfmt(void)
- {
- return register_binfmt(&em86_format);
- }
- static void __exit exit_em86_binfmt(void)
- {
- unregister_binfmt(&em86_format);
- }
- module_init(init_em86_binfmt)
- module_exit(exit_em86_binfmt)