diff options
Diffstat (limited to 'fs/binfmt_em86.c')
| -rw-r--r-- | fs/binfmt_em86.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/fs/binfmt_em86.c b/fs/binfmt_em86.c new file mode 100644 index 000000000000..1f2d1ad63319 --- /dev/null +++ b/fs/binfmt_em86.c @@ -0,0 +1,115 @@ +/* + * linux/fs/binfmt_em86.c + * + * Based on linux/fs/binfmt_script.c + * Copyright (C) 1996 Martin von Lwis + * 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/smp_lock.h> +#include <linux/binfmts.h> +#include <linux/elf.h> +#include <linux/init.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/errno.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); +} + +static struct linux_binfmt em86_format = { + .module = THIS_MODULE, + .load_binary = load_em86, +}; + +static int __init init_em86_binfmt(void) +{ + return register_binfmt(&em86_format); +} + +static void __exit exit_em86_binfmt(void) +{ + unregister_binfmt(&em86_format); +} + +core_initcall(init_em86_binfmt); +module_exit(exit_em86_binfmt); +MODULE_LICENSE("GPL"); |