xref: /src/sys/compat/freebsd/freebsd_exec_elf32.c

/*	$NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $	*/

/*
 * Copyright (c) 1993, 1994 Christopher G. Demetriou
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/exec.h>
#ifndef ELFSIZE
#  define ELFSIZE 32
#endif /* !ELFSIZE */
#include <sys/exec_elf.h>

#include <compat/freebsd/freebsd_exec.h>
#include <compat/common/compat_util.h>

#include <compat/freebsd/freebsd_machdep.h>

int
ELFNAME2(freebsd,probe)(struct lwp *l, struct exec_package *epp, void *veh,
    char *itp, vaddr_t *pos)
{
	int error;
	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
	static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
	static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;

	/*
	 * Insist that the executable have a brand, and that it be "FreeBSD".
	 * Newer FreeBSD binaries have OSABI set to ELFOSABI_FREEBSD. This
	 * is arguably broken, but they seem to think they need it, for
	 * whatever reason.
	 */
#ifndef EI_BRAND
#define EI_BRAND 8
#endif
	if ((eh->e_ident[EI_BRAND] == '\0' ||
	     strcmp(&eh->e_ident[EI_BRAND], wantBrand) != 0) &&
		eh->e_ident[EI_OSABI] != ELFOSABI_FREEBSD)
		return ENOEXEC;

	if (itp) {
		if (strncmp(itp, wantInterp, sizeof(wantInterp) - 1))
			return ENOEXEC;
		if ((error = emul_find_interp(l, epp, itp)))
			return error;
	}

	return 0;
}