xref: /netbsd-src/sys/compat/m68k4k/m68k4k_exec.c (revision 7cc2f76925f078d01ddc9e640a98f4ccfc9f8c3b)
1 /*	$NetBSD: m68k4k_exec.c,v 1.6 2000/11/21 00:37:54 jdolecek 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 NBPG == 4096.  It's not clear
40  * that making it work on other machines is worth the trouble.
41  */
42 
43 #if !defined(__m68k__)
44 #error YOU GOTTA BE KIDDING!
45 #endif
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/proc.h>
50 #include <sys/malloc.h>
51 #include <sys/vnode.h>
52 #include <sys/exec.h>
53 #include <sys/resourcevar.h>
54 
55 #include <compat/m68k4k/m68k4k_exec.h>
56 
57 int	exec_m68k4k_prep_zmagic __P((struct proc *, struct exec_package *));
58 int	exec_m68k4k_prep_nmagic __P((struct proc *, struct exec_package *));
59 int	exec_m68k4k_prep_omagic __P((struct proc *, struct exec_package *));
60 
61 /*
62  * exec_m68k4k_makecmds(): Check if it's an a.out-format executable
63  * with an m68k4k magic number.
64  *
65  * Given a proc pointer and an exec package pointer, see if the referent
66  * of the epp is in a.out format.  Just check 'standard' magic numbers for
67  * this architecture.
68  *
69  * This function, in the former case, or the hook, in the latter, is
70  * responsible for creating a set of vmcmds which can be used to build
71  * the process's vm space and inserting them into the exec package.
72  */
73 
74 int
75 exec_m68k4k_makecmds(p, epp)
76 	struct proc *p;
77 	struct exec_package *epp;
78 {
79 	u_long midmag, magic;
80 	u_short mid;
81 	int error;
82 	struct exec *execp = epp->ep_hdr;
83 
84 	/* See note above... */
85 	if (M68K4K_LDPGSZ != NBPG)
86 		return ENOEXEC;
87 
88 	if (epp->ep_hdrvalid < sizeof(struct exec))
89 		return ENOEXEC;
90 
91 	midmag = ntohl(execp->a_midmag);
92 	mid = (midmag >> 16) & 0x3ff;
93 	magic = midmag & 0xffff;
94 
95 	midmag = mid << 16 | magic;
96 
97 	switch (midmag) {
98 	case (MID_M68K4K << 16) | ZMAGIC:
99 		error = exec_m68k4k_prep_zmagic(p, epp);
100 		break;
101 	case (MID_M68K4K << 16) | NMAGIC:
102 		error = exec_m68k4k_prep_nmagic(p, epp);
103 		break;
104 	case (MID_M68K4K << 16) | OMAGIC:
105 		error = exec_m68k4k_prep_omagic(p, epp);
106 		break;
107 	default:
108 		error = ENOEXEC;
109 	}
110 
111 	if (error)
112 		kill_vmcmds(&epp->ep_vmcmds);
113 
114 	return error;
115 }
116 
117 /*
118  * exec_m68k4k_prep_zmagic(): Prepare an m68k4k ZMAGIC binary's exec package
119  *
120  * First, set of the various offsets/lengths in the exec package.
121  *
122  * Then, mark the text image busy (so it can be demand paged) or error
123  * out if this is not possible.  Finally, set up vmcmds for the
124  * text, data, bss, and stack segments.
125  */
126 
127 int
128 exec_m68k4k_prep_zmagic(p, epp)
129 	struct proc *p;
130 	struct exec_package *epp;
131 {
132 	struct exec *execp = epp->ep_hdr;
133 
134 	epp->ep_taddr = M68K4K_USRTEXT;
135 	epp->ep_tsize = execp->a_text;
136 	epp->ep_daddr = epp->ep_taddr + execp->a_text;
137 	epp->ep_dsize = execp->a_data + execp->a_bss;
138 	epp->ep_entry = execp->a_entry;
139 
140 	/*
141 	 * check if vnode is in open for writing, because we want to
142 	 * demand-page out of it.  if it is, don't do it, for various
143 	 * reasons
144 	 */
145 	if ((execp->a_text != 0 || execp->a_data != 0) &&
146 	    epp->ep_vp->v_writecount != 0) {
147 #ifdef DIAGNOSTIC
148 		if (epp->ep_vp->v_flag & VTEXT)
149 			panic("exec: a VTEXT vnode has writecount != 0\n");
150 #endif
151 		return ETXTBSY;
152 	}
153 	vn_marktext(epp->ep_vp);
154 
155 	/* set up command for text segment */
156 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
157 	    epp->ep_taddr, epp->ep_vp, 0, VM_PROT_READ|VM_PROT_EXECUTE);
158 
159 	/* set up command for data segment */
160 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
161 	    epp->ep_daddr, epp->ep_vp, execp->a_text,
162 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
163 
164 	/* set up command for bss segment */
165 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
166 	    epp->ep_daddr + execp->a_data, NULLVP, 0,
167 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
168 
169 	return exec_aout_setup_stack(p, epp);
170 }
171 
172 /*
173  * exec_m68k4k_prep_nmagic(): Prepare a m68k4k NMAGIC binary's exec package
174  */
175 
176 int
177 exec_m68k4k_prep_nmagic(p, epp)
178 	struct proc *p;
179 	struct exec_package *epp;
180 {
181 	struct exec *execp = epp->ep_hdr;
182 	long bsize, baddr;
183 
184 	epp->ep_taddr = M68K4K_USRTEXT;
185 	epp->ep_tsize = execp->a_text;
186 	epp->ep_daddr = roundup(epp->ep_taddr + execp->a_text,
187 	    M68K4K_LDPGSZ);
188 	epp->ep_dsize = execp->a_data + execp->a_bss;
189 	epp->ep_entry = execp->a_entry;
190 
191 	/* set up command for text segment */
192 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
193 	    epp->ep_taddr, epp->ep_vp, sizeof(struct exec),
194 	    VM_PROT_READ|VM_PROT_EXECUTE);
195 
196 	/* set up command for data segment */
197 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
198 	    epp->ep_daddr, epp->ep_vp, execp->a_text + sizeof(struct exec),
199 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
200 
201 	/* set up command for bss segment */
202 	baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
203 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
204 	if (bsize > 0)
205 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
206 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
207 
208 	return exec_aout_setup_stack(p, epp);
209 }
210 
211 /*
212  * exec_m68k4k_prep_omagic(): Prepare a m68k4k OMAGIC binary's exec package
213  */
214 
215 int
216 exec_m68k4k_prep_omagic(p, epp)
217 	struct proc *p;
218 	struct exec_package *epp;
219 {
220 	struct exec *execp = epp->ep_hdr;
221 	long dsize, bsize, baddr;
222 
223 	epp->ep_taddr = M68K4K_USRTEXT;
224 	epp->ep_tsize = execp->a_text;
225 	epp->ep_daddr = epp->ep_taddr + execp->a_text;
226 	epp->ep_dsize = execp->a_data + execp->a_bss;
227 	epp->ep_entry = execp->a_entry;
228 
229 	/* set up command for text and data segments */
230 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
231 	    execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
232 	    sizeof(struct exec), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
233 
234 	/* set up command for bss segment */
235 	baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
236 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
237 	if (bsize > 0)
238 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
239 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
240 
241 	/*
242 	 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
243 	 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
244 	 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
245 	 * respectively to page boundaries.
246 	 * Compensate `ep_dsize' for the amount of data covered by the last
247 	 * text page.
248 	 */
249 	dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG);
250 	epp->ep_dsize = (dsize > 0) ? dsize : 0;
251 	return exec_aout_setup_stack(p, epp);
252 }
253