xref: /netbsd-src/sys/arch/arm/arm/cpu_exec.c (revision 0d06f9660b11de556f8d07cfc56993a2465a69eb)
1 /*	$NetBSD: cpu_exec.c,v 1.6 2013/10/21 20:05:50 joerg Exp $	*/
2 
3 /*-
4  * Copyright (c) 2012 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: cpu_exec.c,v 1.6 2013/10/21 20:05:50 joerg Exp $");
34 
35 #include "opt_compat_netbsd.h"
36 #include "opt_compat_netbsd32.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/proc.h>
41 #include <sys/exec.h>
42 
43 #include <uvm/uvm_extern.h>
44 
45 #include <compat/common/compat_util.h>
46 #include <sys/exec_elf.h>			/* mandatory */
47 
48 #ifdef COMPAT_NETBSD32
49 #include <compat/netbsd32/netbsd32_exec.h>
50 #endif
51 
52 #if EXEC_ELF32
53 int
54 arm_netbsd_elf32_probe(struct lwp *l, struct exec_package *epp, void *eh0,
55 	char *itp, vaddr_t *start_p)
56 {
57 	const char *itp_suffix = NULL;
58 	const Elf_Ehdr * const eh = eh0;
59 	const bool elf_aapcs_p =
60 	    (eh->e_flags & EF_ARM_EABIMASK) >= EF_ARM_EABI_VER4;
61 #ifdef COMPAT_NETBSD32
62 	const bool netbsd32_p = (epp->ep_esch->es_emul == &emul_netbsd32);
63 #else
64 	const bool netbsd32_p = false;
65 #endif
66 #ifdef __ARM_EABI__
67 	const bool aapcs_p = true;
68 #else
69 	const bool aapcs_p = false;
70 #endif
71 #ifdef __ARMEB__
72 	const bool be8_p = (eh->e_flags & EF_ARM_BE8) != 0;
73 
74 	/*
75 	 * If the BE-8 model is supported, CPSR[7] will be clear.
76 	 * If the BE-32 model is supported, CPSR[7] will be set.
77 	 */
78 	register_t cpsr;
79 	__asm("mrs\t%0, cpsr" : "=r"(cpsr));
80 	if ((cpsr & CPU_CONTROL_BEND_ENABLE) == be8_p)
81 		return ENOEXEC;
82 #endif /* __ARMEB__ */
83 
84 	/*
85 	 * This is subtle.  If we are netbsd32, then we don't want to match the
86 	 * same ABI as the kernel.  If we aren't (netbsd32 == false), then we
87 	 * don't want to be different from the kernel's ABI.
88 	 *    true   true   true  ENOEXEC
89 	 *    true   false  true  0
90 	 *    true   true   false 0
91 	 *    true   false  false ENOEXEC
92 	 *    false  true   true  0
93 	 *    false  false  true  ENOEXEC
94 	 *    false  true   false ENOEXEC
95 	 *    false  false  false 0
96 	 */
97 	if (netbsd32_p ^ elf_aapcs_p ^ aapcs_p)
98 		return ENOEXEC;
99 
100 	if (netbsd32_p)
101 		itp_suffix = (elf_aapcs_p) ? "eabi" : "oabi";
102 
103 	if (itp_suffix != NULL)
104 		(void)compat_elf_check_interp(epp, itp, itp_suffix);
105 
106 	/*
107 	 * Copy (if any) the machine_arch of the executable to the proc.
108 	 */
109 	if (epp->ep_machine_arch[0] != 0) {
110 		strlcpy(l->l_proc->p_md.md_march, epp->ep_machine_arch,
111 		    sizeof(l->l_proc->p_md.md_march));
112 	}
113 	return 0;
114 }
115 #endif
116