xref: /netbsd-src/sys/compat/freebsd/freebsd_exec_elf32.c (revision 0f16c35db33af3a9ea169f0dc45cb13c5f13d2a2)
1 /*	$NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1994 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Christopher G. Demetriou.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: freebsd_exec_elf32.c,v 1.21 2017/08/08 08:04:06 maxv Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/proc.h>
39 #include <sys/vnode.h>
40 #include <sys/exec.h>
41 #ifndef ELFSIZE
42 #  define ELFSIZE 32
43 #endif /* !ELFSIZE */
44 #include <sys/exec_elf.h>
45 
46 #include <compat/freebsd/freebsd_exec.h>
47 #include <compat/common/compat_util.h>
48 
49 #include <compat/freebsd/freebsd_machdep.h>
50 
51 int
ELFNAME2(freebsd,probe)52 ELFNAME2(freebsd,probe)(struct lwp *l, struct exec_package *epp, void *veh,
53     char *itp, vaddr_t *pos)
54 {
55 	int error;
56 	Elf_Ehdr *eh = (Elf_Ehdr *) veh;
57 	static const char wantBrand[] = FREEBSD_ELF_BRAND_STRING;
58 	static const char wantInterp[] = FREEBSD_ELF_INTERP_PREFIX_STRING;
59 
60 	/*
61 	 * Insist that the executable have a brand, and that it be "FreeBSD".
62 	 * Newer FreeBSD binaries have OSABI set to ELFOSABI_FREEBSD. This
63 	 * is arguably broken, but they seem to think they need it, for
64 	 * whatever reason.
65 	 */
66 #ifndef EI_BRAND
67 #define EI_BRAND 8
68 #endif
69 	if ((eh->e_ident[EI_BRAND] == '\0' ||
70 	     strcmp(&eh->e_ident[EI_BRAND], wantBrand) != 0) &&
71 		eh->e_ident[EI_OSABI] != ELFOSABI_FREEBSD)
72 		return ENOEXEC;
73 
74 	if (itp) {
75 		if (strncmp(itp, wantInterp, sizeof(wantInterp) - 1))
76 			return ENOEXEC;
77 		if ((error = emul_find_interp(l, epp, itp)))
78 			return error;
79 	}
80 
81 	return 0;
82 }
83