1 /* $NetBSD: linux_exec_powerpc.c,v 1.25 2021/09/07 11:43:04 riastradh 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 1.25 2021/09/07 11:43:04 riastradh 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 */
64 int
ELFNAME2(linux,copyargs)65 ELFNAME2(linux,copyargs)(struct lwp *l, struct exec_package *pack,
66 struct ps_strings *arginfo, char **stackp,
67 void *argp)
68 {
69 size_t len;
70 AuxInfo ai[LINUX_ELF_AUX_ENTRIES], *a;
71 struct elf_args *ap;
72 int error;
73
74 #ifdef LINUX_SHIFT
75 /*
76 * Seems that PowerPC Linux binaries expect argc to start on a 16 bytes
77 * aligned address. And we need one more 16 byte shift if it was already
78 * 16 bytes aligned,
79 */
80 *stackp = (char *)(((unsigned long)*stackp - 1) & ~LINUX_SHIFT);
81 #endif
82
83 if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0)
84 return error;
85
86 #ifdef LINUX_SHIFT
87 /*
88 * From Linux's arch/ppc/kernel/process.c:shove_aux_table(). GNU ld.so
89 * expects the ELF auxiliary table to start on a 16 bytes boundary on
90 * the PowerPC.
91 */
92 *stackp = (char *)(((unsigned long)(*stackp) + LINUX_SHIFT)
93 & ~LINUX_SHIFT);
94 #endif
95
96 memset(ai, 0, sizeof(ai));
97
98 a = ai;
99
100 /*
101 * Push extra arguments on the stack needed by dynamically
102 * linked binaries.
103 */
104 if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
105 #if 1
106 /*
107 * The exec_package doesn't have a proc pointer and it's not
108 * exactly trivial to add one since the credentials are
109 * changing. XXX Linux uses curlwp's credentials.
110 * Why can't we use them too? XXXad we do, what's different?
111 */
112 a->a_type = LINUX_AT_EGID;
113 a->a_v = kauth_cred_getegid(l->l_cred);
114 a++;
115
116 a->a_type = LINUX_AT_GID;
117 a->a_v = kauth_cred_getgid(l->l_cred);
118 a++;
119
120 a->a_type = LINUX_AT_EUID;
121 a->a_v = kauth_cred_geteuid(l->l_cred);
122 a++;
123
124 a->a_type = LINUX_AT_UID;
125 a->a_v = kauth_cred_getuid(l->l_cred);
126 a++;
127 #endif
128
129 a->a_type = AT_ENTRY;
130 a->a_v = ap->arg_entry;
131 a++;
132
133 a->a_type = AT_FLAGS;
134 a->a_v = 0;
135 a++;
136
137 a->a_type = AT_BASE;
138 a->a_v = ap->arg_interp;
139 a++;
140
141 a->a_type = AT_PHNUM;
142 a->a_v = ap->arg_phnum;
143 a++;
144
145 a->a_type = AT_PHENT;
146 a->a_v = ap->arg_phentsize;
147 a++;
148
149 a->a_type = AT_PHDR;
150 a->a_v = ap->arg_phaddr;
151 a++;
152
153 a->a_type = LINUX_AT_CLKTCK;
154 a->a_v = LINUX_CLOCKS_PER_SEC;
155 a++;
156
157 a->a_type = AT_PAGESZ;
158 a->a_v = PAGE_SIZE;
159 a++;
160
161 a->a_type = LINUX_AT_HWCAP;
162 a->a_v = LINUX_ELF_HWCAP;
163 a++;
164
165 exec_free_emul_arg(pack);
166 }
167
168 a->a_type = AT_NULL;
169 a->a_v = 0;
170 a++;
171
172 len = (a - ai) * sizeof(AuxInfo);
173
174 if ((error = copyout(ai, *stackp, len)) != 0)
175 return error;
176 *stackp += len;
177 return 0;
178 }
179