1 /* $NetBSD: m68k4k_exec.c,v 1.25 2019/11/20 19:37:53 pgoyette 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 m68k4k exectuables.
35 *
36 * Taken directly from kern/exec_aout.c and frobbed to map text and
37 * data as m68k4k executables expect.
38 *
39 * This module only works on machines with PAGE_SIZE == 4096. It's not clear
40 * that making it work on other machines is worth the trouble.
41 */
42
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: m68k4k_exec.c,v 1.25 2019/11/20 19:37:53 pgoyette Exp $");
45
46 #if !defined(__m68k__)
47 #error YOU GOTTA BE KIDDING!
48 #endif
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/proc.h>
53 #include <sys/malloc.h>
54 #include <sys/module.h>
55 #include <sys/vnode.h>
56 #include <sys/exec.h>
57 #include <sys/exec_aout.h>
58 #include <sys/resourcevar.h>
59
60 #include <compat/m68k4k/m68k4k_exec.h>
61
62 MODULE(MODULE_CLASS_EXEC, exec_m68k4k, NULL);
63
64 static struct execsw exec_m68k4k_execsw = {
65 .es_hdrsz = sizeof(struct exec),
66 .es_makecmds = exec_m68k4k_makecmds,
67 .u = {
68 .elf_probe_func = NULL,
69 },
70 .es_emul = &emul_netbsd,
71 .es_prio = EXECSW_PRIO_ANY,
72 .es_arglen = 0,
73 .es_copyargs = copyargs,
74 .es_setregs = NULL,
75 .es_coredump = coredump_netbsd,
76 .es_setup_stack = exec_setup_stack,
77 };
78
79 static int
exec_m68k4k_modcmd(modcmd_t cmd,void * arg)80 exec_m68k4k_modcmd(modcmd_t cmd, void *arg)
81 {
82
83 switch (cmd) {
84 case MODULE_CMD_INIT:
85 return exec_add(&exec_m68k4k_execsw, 1);
86
87 case MODULE_CMD_FINI:
88 return exec_remove(&exec_m68k4k_execsw, 1);
89
90 default:
91 return ENOTTY;
92 }
93 }
94
95 int exec_m68k4k_prep_zmagic(struct lwp *, struct exec_package *);
96 int exec_m68k4k_prep_nmagic(struct lwp *, struct exec_package *);
97 int exec_m68k4k_prep_omagic(struct lwp *, struct exec_package *);
98
99 /*
100 * exec_m68k4k_makecmds(): Check if it's an a.out-format executable
101 * with an m68k4k magic number.
102 *
103 * Given a proc pointer and an exec package pointer, see if the referent
104 * of the epp is in a.out format. Just check 'standard' magic numbers for
105 * this architecture.
106 *
107 * This function, in the former case, or the hook, in the latter, is
108 * responsible for creating a set of vmcmds which can be used to build
109 * the process's vm space and inserting them into the exec package.
110 */
111
112 int
exec_m68k4k_makecmds(struct lwp * l,struct exec_package * epp)113 exec_m68k4k_makecmds(struct lwp *l, struct exec_package *epp)
114 {
115 u_long midmag, magic;
116 u_short mid;
117 int error;
118 struct exec *execp = epp->ep_hdr;
119
120 /* See note above... */
121 if (M68K4K_LDPGSZ != PAGE_SIZE)
122 return ENOEXEC;
123
124 if (epp->ep_hdrvalid < sizeof(struct exec))
125 return ENOEXEC;
126
127 midmag = ntohl(execp->a_midmag);
128 mid = (midmag >> 16) & 0x3ff;
129 magic = midmag & 0xffff;
130
131 midmag = mid << 16 | magic;
132
133 switch (midmag) {
134 case (MID_M68K4K << 16) | ZMAGIC:
135 error = exec_m68k4k_prep_zmagic(l, epp);
136 break;
137 case (MID_M68K4K << 16) | NMAGIC:
138 error = exec_m68k4k_prep_nmagic(l, epp);
139 break;
140 case (MID_M68K4K << 16) | OMAGIC:
141 error = exec_m68k4k_prep_omagic(l, epp);
142 break;
143 default:
144 error = ENOEXEC;
145 }
146
147 if (error)
148 kill_vmcmds(&epp->ep_vmcmds);
149
150 return error;
151 }
152
153 /*
154 * exec_m68k4k_prep_zmagic(): Prepare an m68k4k ZMAGIC binary's exec package
155 *
156 * First, set of the various offsets/lengths in the exec package.
157 *
158 * Then, mark the text image busy (so it can be demand paged) or error
159 * out if this is not possible. Finally, set up vmcmds for the
160 * text, data, bss, and stack segments.
161 */
162
163 int
exec_m68k4k_prep_zmagic(struct lwp * l,struct exec_package * epp)164 exec_m68k4k_prep_zmagic(struct lwp *l, struct exec_package *epp)
165 {
166 struct exec *execp = epp->ep_hdr;
167 int error;
168
169 epp->ep_taddr = M68K4K_USRTEXT;
170 epp->ep_tsize = execp->a_text;
171 epp->ep_daddr = epp->ep_taddr + execp->a_text;
172 epp->ep_dsize = execp->a_data + execp->a_bss;
173 epp->ep_entry = execp->a_entry;
174
175 error = vn_marktext(epp->ep_vp);
176 if (error)
177 return (error);
178
179 /* set up command for text segment */
180 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
181 epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
182
183 /* set up command for data segment */
184 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
185 epp->ep_daddr, epp->ep_vp, execp->a_text,
186 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
187
188 /* set up command for bss segment */
189 if (execp->a_bss)
190 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
191 epp->ep_daddr + execp->a_data, NULLVP, 0,
192 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
193
194 return (*epp->ep_esch->es_setup_stack)(l, epp);
195 }
196
197 /*
198 * exec_m68k4k_prep_nmagic(): Prepare a m68k4k NMAGIC binary's exec package
199 */
200
201 int
exec_m68k4k_prep_nmagic(struct lwp * l,struct exec_package * epp)202 exec_m68k4k_prep_nmagic(struct lwp *l, struct exec_package *epp)
203 {
204 struct exec *execp = epp->ep_hdr;
205 long bsize, baddr;
206
207 epp->ep_taddr = M68K4K_USRTEXT;
208 epp->ep_tsize = execp->a_text;
209 epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text,
210 M68K4K_LDPGSZ);
211 epp->ep_dsize = execp->a_data + execp->a_bss;
212 epp->ep_entry = execp->a_entry;
213
214 /* set up command for text segment */
215 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
216 epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
217 VM_PROT_READ|VM_PROT_EXECUTE);
218
219 /* set up command for data segment */
220 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
221 epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
222 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
223
224 /* set up command for bss segment */
225 baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
226 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
227 if (bsize > 0)
228 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
229 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
230
231 return (*epp->ep_esch->es_setup_stack)(l, epp);
232 }
233
234 /*
235 * exec_m68k4k_prep_omagic(): Prepare a m68k4k OMAGIC binary's exec package
236 */
237
238 int
exec_m68k4k_prep_omagic(struct lwp * l,struct exec_package * epp)239 exec_m68k4k_prep_omagic(struct lwp *l, struct exec_package *epp)
240 {
241 struct exec *execp = epp->ep_hdr;
242 long dsize, bsize, baddr;
243
244 epp->ep_taddr = M68K4K_USRTEXT;
245 epp->ep_tsize = execp->a_text;
246 epp->ep_daddr = epp->ep_taddr + execp->a_text;
247 epp->ep_dsize = execp->a_data + execp->a_bss;
248 epp->ep_entry = execp->a_entry;
249
250 /* set up command for text and data segments */
251 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
252 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
253 sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
254
255 /* set up command for bss segment */
256 baddr = roundup(epp->ep_daddr + execp->a_data, PAGE_SIZE);
257 bsize = epp->ep_daddr + epp->ep_dsize - baddr;
258 if (bsize > 0)
259 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
260 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
261
262 /*
263 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
264 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
265 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
266 * respectively to page boundaries.
267 * Compensate `ep_dsize' for the amount of data covered by the last
268 * text page.
269 */
270 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text,
271 PAGE_SIZE);
272 epp->ep_dsize = (dsize > 0) ? dsize : 0;
273 return (*epp->ep_esch->es_setup_stack)(l, epp);
274 }
275