linux_exec_powerpc.c revision 1.23
1/* $NetBSD: linux_exec_powerpc.c,v 1.23 2012/02/03 20:11:53 matt Exp $ */
2
3/*-
4 * Copyright (c) 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Emmanuel Dreyfus.
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/*
33 * From NetBSD's sys/compat/arch/alpha/linux_exec_alpha.c, with some
34 * powerpc add-ons (ifdef LINUX_SHIFT).
35 *
36 * This code is to be common to alpha and powerpc. If it works on alpha, it
37 * should be moved to common/linux_exec_elf32.c. Beware that it needs
38 * LINUX_ELF_AUX_ENTRIES in arch/<arch>/linux_exec.h to also be moved to common
39 *
40 * Emmanuel Dreyfus <p99dreyf@criens.u-psud.fr>
41 */
42
43#include <sys/cdefs.h>
44__KERNEL_RCSID(0, "$NetBSD: linux_exec_powerpc.c,v 1.23 2012/02/03 20:11:53 matt Exp $");
45
46#define ELFSIZE 32
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/kernel.h>
51#include <sys/proc.h>
52#include <sys/exec.h>
53#include <sys/exec_elf.h>
54#include <sys/resourcevar.h>
55#include <sys/kauth.h>
56
57#include <uvm/uvm_extern.h>
58
59#include <compat/linux/common/linux_exec.h>
60
61/*
62 * Alpha and PowerPC specific linux copyargs function.
63 */
64int
65ELFNAME2(linux,copyargs)(l, pack, arginfo, stackp, argp)
66	struct lwp *l;
67	struct exec_package *pack;
68	struct ps_strings *arginfo;
69	char **stackp;
70	void *argp;
71{
72	size_t len;
73	AuxInfo ai[LINUX_ELF_AUX_ENTRIES], *a;
74	struct elf_args *ap;
75	int error;
76
77#ifdef LINUX_SHIFT
78	/*
79	 * Seems that PowerPC Linux binaries expect argc to start on a 16 bytes
80	 * aligned address. And we need one more 16 byte shift if it was already
81	 * 16 bytes aligned,
82	 */
83	*stackp = (char *)(((unsigned long)*stackp - 1) & ~LINUX_SHIFT);
84#endif
85
86	if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0)
87		return error;
88
89#ifdef LINUX_SHIFT
90	/*
91	 * From Linux's arch/ppc/kernel/process.c:shove_aux_table(). GNU ld.so
92	 * expects the ELF auxiliary table to start on a 16 bytes boundary on
93	 * the PowerPC.
94	 */
95	*stackp = (char *)(((unsigned long)(*stackp) + LINUX_SHIFT)
96	    & ~LINUX_SHIFT);
97#endif
98
99	memset(ai, 0, sizeof(AuxInfo) * LINUX_ELF_AUX_ENTRIES);
100
101	a = ai;
102
103	/*
104	 * Push extra arguments on the stack needed by dynamically
105	 * linked binaries.
106	 */
107	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
108#if 1
109		/*
110		 * The exec_package doesn't have a proc pointer and it's not
111		 * exactly trivial to add one since the credentials are
112		 * changing. XXX Linux uses curlwp's credentials.
113		 * Why can't we use them too? XXXad we do, what's different?
114		 */
115		a->a_type = LINUX_AT_EGID;
116		a->a_v = kauth_cred_getegid(l->l_cred);
117		a++;
118
119		a->a_type = LINUX_AT_GID;
120		a->a_v = kauth_cred_getgid(l->l_cred);
121		a++;
122
123		a->a_type = LINUX_AT_EUID;
124		a->a_v = kauth_cred_geteuid(l->l_cred);
125		a++;
126
127		a->a_type = LINUX_AT_UID;
128		a->a_v = kauth_cred_getuid(l->l_cred);
129		a++;
130#endif
131
132		a->a_type = AT_ENTRY;
133		a->a_v = ap->arg_entry;
134		a++;
135
136		a->a_type = AT_FLAGS;
137		a->a_v = 0;
138		a++;
139
140		a->a_type = AT_BASE;
141		a->a_v = ap->arg_interp;
142		a++;
143
144		a->a_type = AT_PHNUM;
145		a->a_v = ap->arg_phnum;
146		a++;
147
148		a->a_type = AT_PHENT;
149		a->a_v = ap->arg_phentsize;
150		a++;
151
152		a->a_type = AT_PHDR;
153		a->a_v = ap->arg_phaddr;
154		a++;
155
156		a->a_type = LINUX_AT_CLKTCK;
157		a->a_v = LINUX_CLOCKS_PER_SEC;
158		a++;
159
160		a->a_type = AT_PAGESZ;
161		a->a_v = PAGE_SIZE;
162		a++;
163
164		a->a_type = LINUX_AT_HWCAP;
165		a->a_v = LINUX_ELF_HWCAP;
166		a++;
167
168		exec_free_emul_arg(pack);
169	}
170
171	a->a_type = AT_NULL;
172	a->a_v = 0;
173	a++;
174
175	len = (a - ai) * sizeof(AuxInfo);
176
177	if ((error = copyout(ai, *stackp, len)) != 0)
178		return error;
179	*stackp += len;
180	return 0;
181}
182