1 /* $NetBSD: vax1k_exec.c,v 1.18 2014/03/07 01:33:44 christos 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 /*
34 * Exec glue to provide compatibility with older NetBSD vax1k exectuables.
35 *
36 * Because NetBSD/vax now uses 4k page size, older binaries (that started
37 * on an 1k boundary) cannot be mmap'ed. Therefore they are read in
38 * (via vn_rdwr) as OMAGIC binaries and executed. This will use a little
39 * bit more memory, but otherwise won't affect the execution speed.
40 */
41
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(0, "$NetBSD: vax1k_exec.c,v 1.18 2014/03/07 01:33:44 christos Exp $");
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/proc.h>
48 #include <sys/malloc.h>
49 #include <sys/vnode.h>
50 #include <sys/exec.h>
51 #include <sys/resourcevar.h>
52 #include <sys/module.h>
53
54 #include <compat/vax1k/vax1k_exec.h>
55
56 #if defined(_KERNEL_OPT)
57 #include "opt_compat_43.h"
58 #include "opt_coredump.h"
59 #else
60 #define COMPAT_43 /* enable 4.3BSD binaries for lkm */
61 #endif
62
63 #ifdef COREDUMP
64 MODULE(MODULE_CLASS_EXEC, exec_vax1k, "coredump");
65 #else
66 MODULE(MODULE_CLASS_EXEC, exec_vax1k, NULL);
67 #endif
68
69 int exec_vax1k_prep_anymagic(struct lwp *, struct exec_package *,
70 size_t, bool);
71
72 static struct execsw exec_vax1k_execsw = {
73 /* NetBSD vax1k a.out */
74 .es_hdrsz = sizeof(struct exec),
75 .es_makecmds = exec_vax1k_makecmds,
76 .u = {
77 .elf_probe_func = NULL,
78 },
79 .es_emul = &emul_netbsd,
80 .es_prio = EXECSW_PRIO_ANY,
81 .es_arglen = 0,
82 .es_copyargs = copyargs,
83 .es_setregs = NULL,
84 .es_coredump = coredump_netbsd,
85 .es_setup_stack = exec_setup_stack,
86 };
87
88 static int
exec_vax1k_modcmd(modcmd_t cmd,void * arg)89 exec_vax1k_modcmd(modcmd_t cmd, void *arg)
90 {
91
92 switch (cmd) {
93 case MODULE_CMD_INIT:
94 return exec_add(&exec_vax1k_execsw, 1);
95
96 case MODULE_CMD_FINI:
97 return exec_remove(&exec_vax1k_execsw, 1);
98
99 default:
100 return ENOTTY;
101 }
102 }
103
104 /*
105 * exec_vax1k_makecmds(): Check if it's an a.out-format executable
106 * with an vax1k magic number.
107 *
108 * Given a proc pointer and an exec package pointer, see if the referent
109 * of the epp is in a.out format. Just check 'standard' magic numbers for
110 * this architecture.
111 *
112 * This function, in the former case, or the hook, in the latter, is
113 * responsible for creating a set of vmcmds which can be used to build
114 * the process's vm space and inserting them into the exec package.
115 */
116
117 int
exec_vax1k_makecmds(struct lwp * l,struct exec_package * epp)118 exec_vax1k_makecmds(struct lwp *l, struct exec_package *epp)
119 {
120 u_long midmag, magic;
121 u_short mid;
122 int error;
123 struct exec *execp = epp->ep_hdr;
124
125 if (epp->ep_hdrvalid < sizeof(struct exec))
126 return ENOEXEC;
127
128 midmag = ntohl(execp->a_midmag);
129 mid = (midmag >> 16) & 0x3ff;
130 magic = midmag & 0xffff;
131
132 midmag = mid << 16 | magic;
133
134 switch (midmag) {
135 case (MID_VAX1K << 16) | ZMAGIC:
136 error = exec_vax1k_prep_anymagic(l, epp, 0, false);
137 goto done;
138
139 case (MID_VAX1K << 16) | NMAGIC:
140 error = exec_vax1k_prep_anymagic(l, epp,
141 sizeof(struct exec), true);
142 goto done;
143
144 case (MID_VAX1K << 16) | OMAGIC:
145 error = exec_vax1k_prep_anymagic(l, epp,
146 sizeof(struct exec), false);
147 goto done;
148 }
149
150 #ifdef COMPAT_43
151 /*
152 * 4.3BSD pre-dates CPU midmag (e.g. MID_VAX1K). instead, we
153 * expect a magic number in native byte order.
154 */
155 switch (execp->a_midmag) {
156 case ZMAGIC:
157 error = exec_vax1k_prep_anymagic(l, epp, VAX1K_LDPGSZ, false);
158 goto done;
159
160 case NMAGIC:
161 error = exec_vax1k_prep_anymagic(l, epp,
162 sizeof(struct exec), true);
163 goto done;
164
165 case OMAGIC:
166 error = exec_vax1k_prep_anymagic(l, epp,
167 sizeof(struct exec), false);
168 goto done;
169 }
170 #endif
171
172 /* failed... */
173 error = ENOEXEC;
174
175 done:
176 if (error)
177 kill_vmcmds(&epp->ep_vmcmds);
178
179 return error;
180 }
181
182 /*
183 * exec_vax1k_prep_anymagic(): Prepare an vax1k ?MAGIC binary's exec package
184 *
185 * First, set of the various offsets/lengths in the exec package.
186 * Note that all code is mapped RW; no protection, but because it is
187 * only used for compatibility it won't hurt.
188 *
189 */
190 int
exec_vax1k_prep_anymagic(struct lwp * l,struct exec_package * epp,size_t text_foffset,bool textpad)191 exec_vax1k_prep_anymagic(struct lwp *l, struct exec_package *epp,
192 size_t text_foffset, bool textpad)
193 {
194 struct exec *execp = epp->ep_hdr;
195
196 epp->ep_taddr = execp->a_entry & ~(VAX1K_USRTEXT - 1);
197 epp->ep_tsize = execp->a_text;
198 epp->ep_daddr = epp->ep_taddr + epp->ep_tsize;
199 if (textpad) /* pad for NMAGIC? */
200 epp->ep_daddr = (epp->ep_daddr + (VAX1K_LDPGSZ - 1)) &
201 ~(VAX1K_LDPGSZ - 1);
202 epp->ep_dsize = execp->a_data;
203 epp->ep_entry = execp->a_entry;
204
205 /* first allocate memory for text+data+bss */
206 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero,
207 round_page(epp->ep_daddr + epp->ep_dsize + execp->a_bss) -
208 trunc_page(epp->ep_taddr), /* size */
209 trunc_page(epp->ep_taddr), NULLVP, /* addr, vnode */
210 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
211
212 /* then read the text in the area we just allocated */
213 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_readvn,
214 epp->ep_tsize, epp->ep_taddr, epp->ep_vp, text_foffset,
215 VM_PROT_WRITE|VM_PROT_READ|VM_PROT_EXECUTE);
216
217 /* next read the data */
218 if (epp->ep_dsize) {
219 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_readvn,
220 epp->ep_dsize, epp->ep_daddr, epp->ep_vp,
221 text_foffset + epp->ep_tsize,
222 VM_PROT_WRITE|VM_PROT_READ|VM_PROT_EXECUTE);
223 }
224
225 /* now bump up the dsize to include the bss so that sbrk works */
226 epp->ep_dsize += execp->a_bss;
227
228 /* finally, setup the stack ... */
229 return (*epp->ep_esch->es_setup_stack)(l, epp);
230 }
231