patch-2.0.34 linux/fs/binfmt_em86.c

• Lines: 132
• Date: Wed Jun 3 15:17:49 1998
• Orig file: v2.0.33/linux/fs/binfmt_em86.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.0.33/linux/fs/binfmt_em86.c linux/fs/binfmt_em86.c
@@ -0,0 +1,131 @@
+/*
+ *  linux/fs/binfmt_em86.c
+ *
+ *  Based on linux/fs/binfmt_script.c
+ *  Copyright (C) 1996  Martin von Löwis
+ *  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/malloc.h>
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+
+#define EM86_INTERP	"/usr/bin/em86"
+#define EM86_I_NAME	"em86"
+
+static int do_load_em86(struct linux_binprm *bprm,struct pt_regs *regs)
+{
+	char *cp, *interp, *i_name, *i_arg;
+	int retval;
+	struct elfhdr	elf_ex;
+	uid_t		x86_uid;
+	gid_t		x86_gid;
+
+	/* Make sure this is a Linux/Intel ELF executable... */
+	elf_ex = *((struct elfhdr *)bprm->buf);
+	
+        if (elf_ex.e_ident[0] != 0x7f ||
+            strncmp(&elf_ex.e_ident[1], "ELF",3) != 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->inode->i_op || !bprm->inode->i_op->default_file_ops ||
+            !bprm->inode->i_op->default_file_ops->mmap)){
+                return -ENOEXEC;
+        }
+
+	bprm->sh_bang++;	/* Well, the bang-shell is implicit... */
+	iput(bprm->inode);
+	bprm->dont_iput = 1;
+
+	/* 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);
+	bprm->p = copy_strings(1, &bprm->filename, bprm->page, bprm->p, 2);
+	bprm->argc++;
+	if (i_arg) {
+		bprm->p = copy_strings(1, &i_arg, bprm->page, bprm->p, 2);
+		bprm->argc++;
+	}
+	bprm->p = copy_strings(1, &i_name, bprm->page, bprm->p, 2);
+	bprm->argc++;
+	if (!bprm->p) 
+		return -E2BIG;
+	/*
+	 * OK, now restart the process with the interpreter's inode.
+	 * Note that we use open_namei() as the name is now in kernel
+	 * space, and we don't need to copy it.
+	 */
+	retval = open_namei(interp, 0, 0, &bprm->inode, NULL);
+	if (retval)
+		return retval;
+	bprm->dont_iput=0;
+
+	/* Remember the uid/gid that was set by this executable */
+	x86_uid = bprm->e_uid;
+	x86_gid = bprm->e_gid;
+	retval=prepare_binprm(bprm);
+	if(retval<0)
+		return retval;
+
+	/* ...so that we may propagate them to em86 */
+	bprm->e_uid = x86_uid;
+	bprm->e_gid = x86_gid;
+	current->personality = PER_LINUX_EM86;
+	return search_binary_handler(bprm,regs);
+}
+
+static int load_em86(struct linux_binprm *bprm,struct pt_regs *regs)
+{
+	int retval;
+	MOD_INC_USE_COUNT;
+	retval = do_load_em86(bprm,regs);
+	MOD_DEC_USE_COUNT;
+	return retval;
+}
+
+struct linux_binfmt em86_format = {
+#ifndef MODULE
+	NULL, 0, load_em86, NULL, NULL
+#else
+	NULL, &mod_use_count_, load_em86, NULL, NULL
+#endif
+};
+
+int init_em86_binfmt(void) {
+	return register_binfmt(&em86_format);
+}
+
+#ifdef MODULE
+int init_module(void)
+{
+	return init_em86_binfmt();
+}
+
+void cleanup_module( void) {
+	unregister_binfmt(&em86_format);
+}
+#endif