xref: /netbsd-src/sys/kern/exec_ecoff.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: exec_ecoff.c,v 1.14 2000/11/21 00:37:55 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Adam Glass
5  * Copyright (c) 1993, 1994, 1996, 1999 Christopher G. Demetriou
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Christopher G. Demetriou
19  *      for the NetBSD Project.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/proc.h>
38 #include <sys/malloc.h>
39 #include <sys/vnode.h>
40 #include <sys/exec.h>
41 #include <sys/resourcevar.h>
42 
43 #include <sys/exec_ecoff.h>
44 
45 /*
46  * exec_ecoff_makecmds(): Check if it's an ecoff-format executable.
47  *
48  * Given a proc pointer and an exec package pointer, see if the referent
49  * of the epp is in ecoff format.  Check 'standard' magic numbers for
50  * this architecture.  If that fails, return failure.
51  *
52  * This function is  responsible for creating a set of vmcmds which can be
53  * used to build the process's vm space and inserting them into the exec
54  * package.
55  */
56 int
57 exec_ecoff_makecmds(struct proc *p, struct exec_package *epp)
58 {
59 	int error;
60 	struct ecoff_exechdr *execp = epp->ep_hdr;
61 
62 	if (epp->ep_hdrvalid < ECOFF_HDR_SIZE)
63 		return ENOEXEC;
64 
65 	if (ECOFF_BADMAG(execp))
66 		return ENOEXEC;
67 
68 	error = (*epp->ep_esch->u.ecoff_probe_func)(p, epp);
69 
70 	/*
71 	 * if there was an error or there are already vmcmds set up,
72 	 * we return.  (the latter can happen if cpu_exec_ecoff_hook()
73 	 * recursively invokes check_exec() to handle loading of a
74 	 * dynamically linked binary's shared loader.
75 	 */
76 	if (error || epp->ep_vmcmds.evs_cnt)
77 		return (error);
78 
79 	/*
80 	 * prepare the exec package to map the executable.
81 	 */
82 	switch (execp->a.magic) {
83 	case ECOFF_OMAGIC:
84 		error = exec_ecoff_prep_omagic(p, epp, epp->ep_hdr,
85 		   epp->ep_vp);
86 		break;
87 	case ECOFF_NMAGIC:
88 		error = exec_ecoff_prep_nmagic(p, epp, epp->ep_hdr,
89 		   epp->ep_vp);
90 		break;
91 	case ECOFF_ZMAGIC:
92 		error = exec_ecoff_prep_zmagic(p, epp, epp->ep_hdr,
93 		   epp->ep_vp);
94 		break;
95 	default:
96 		return ENOEXEC;
97 	}
98 
99 	/* set up the stack */
100 	if (!error)
101 		error = exec_ecoff_setup_stack(p, epp);
102 
103 	if (error)
104 		kill_vmcmds(&epp->ep_vmcmds);
105 
106 	return error;
107 }
108 
109 /*
110  * exec_ecoff_setup_stack(): Set up the stack segment for an ecoff
111  * executable.
112  *
113  * Note that the ep_ssize parameter must be set to be the current stack
114  * limit; this is adjusted in the body of execve() to yield the
115  * appropriate stack segment usage once the argument length is
116  * calculated.
117  *
118  * This function returns an int for uniformity with other (future) formats'
119  * stack setup functions.  They might have errors to return.
120  */
121 int
122 exec_ecoff_setup_stack(struct proc *p, struct exec_package *epp)
123 {
124 
125 	epp->ep_maxsaddr = USRSTACK - MAXSSIZ;
126 	epp->ep_minsaddr = USRSTACK;
127 	epp->ep_ssize = p->p_rlimit[RLIMIT_STACK].rlim_cur;
128 
129 	/*
130 	 * set up commands for stack.  note that this takes *two*, one to
131 	 * map the part of the stack which we can access, and one to map
132 	 * the part which we can't.
133 	 *
134 	 * arguably, it could be made into one, but that would require the
135 	 * addition of another mapping proc, which is unnecessary
136 	 *
137 	 * note that in memory, things assumed to be: 0 ... ep_maxsaddr
138 	 * <stack> ep_minsaddr
139 	 */
140 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero,
141 	    ((epp->ep_minsaddr - epp->ep_ssize) - epp->ep_maxsaddr),
142 	    epp->ep_maxsaddr, NULLVP, 0, VM_PROT_NONE);
143 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, epp->ep_ssize,
144 	    (epp->ep_minsaddr - epp->ep_ssize), NULLVP, 0,
145 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
146 
147 	return 0;
148 }
149 
150 /*
151  * exec_ecoff_prep_omagic(): Prepare a ECOFF OMAGIC binary's exec package
152  */
153 int
154 exec_ecoff_prep_omagic(struct proc *p, struct exec_package *epp,
155     struct ecoff_exechdr *execp, struct vnode *vp)
156 {
157 	struct ecoff_aouthdr *eap = &execp->a;
158 
159 	epp->ep_taddr = ECOFF_SEGMENT_ALIGN(execp, eap->text_start);
160 	epp->ep_tsize = eap->tsize;
161 	epp->ep_daddr = ECOFF_SEGMENT_ALIGN(execp, eap->data_start);
162 	epp->ep_dsize = eap->dsize + eap->bsize;
163 	epp->ep_entry = eap->entry;
164 
165 	/* set up command for text and data segments */
166 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
167 	    eap->tsize + eap->dsize, epp->ep_taddr, vp,
168 	    ECOFF_TXTOFF(execp),
169 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
170 
171 	/* set up command for bss segment */
172 	if (eap->bsize > 0)
173 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, eap->bsize,
174 		    ECOFF_SEGMENT_ALIGN(execp, eap->bss_start), NULLVP, 0,
175 		    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
176 
177 	return 0;
178 }
179 
180 /*
181  * exec_ecoff_prep_nmagic(): Prepare a 'native' NMAGIC ECOFF binary's exec
182  *                           package.
183  */
184 int
185 exec_ecoff_prep_nmagic(struct proc *p, struct exec_package *epp,
186     struct ecoff_exechdr *execp, struct vnode *vp)
187 {
188 	struct ecoff_aouthdr *eap = &execp->a;
189 
190 	epp->ep_taddr = ECOFF_SEGMENT_ALIGN(execp, eap->text_start);
191 	epp->ep_tsize = eap->tsize;
192 	epp->ep_daddr = ECOFF_ROUND(eap->data_start, ECOFF_LDPGSZ);
193 	epp->ep_dsize = eap->dsize + eap->bsize;
194 	epp->ep_entry = eap->entry;
195 
196 	/* set up command for text segment */
197 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, epp->ep_tsize,
198 	    epp->ep_taddr, vp, ECOFF_TXTOFF(execp),
199 	    VM_PROT_READ|VM_PROT_EXECUTE);
200 
201 	/* set up command for data segment */
202 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, epp->ep_dsize,
203 	    epp->ep_daddr, vp, ECOFF_DATOFF(execp),
204 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
205 
206 	/* set up command for bss segment */
207 	if (eap->bsize > 0)
208 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, eap->bsize,
209 		    ECOFF_SEGMENT_ALIGN(execp, eap->bss_start), NULLVP, 0,
210 		    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
211 
212 	return 0;
213 }
214 
215 /*
216  * exec_ecoff_prep_zmagic(): Prepare a ECOFF ZMAGIC binary's exec package
217  *
218  * First, set the various offsets/lengths in the exec package.
219  *
220  * Then, mark the text image busy (so it can be demand paged) or error
221  * out if this is not possible.  Finally, set up vmcmds for the
222  * text, data, bss, and stack segments.
223  */
224 int
225 exec_ecoff_prep_zmagic(struct proc *p, struct exec_package *epp,
226     struct ecoff_exechdr *execp, struct vnode *vp)
227 {
228 	struct ecoff_aouthdr *eap = &execp->a;
229 
230 	epp->ep_taddr = ECOFF_SEGMENT_ALIGN(execp, eap->text_start);
231 	epp->ep_tsize = eap->tsize;
232 	epp->ep_daddr = ECOFF_SEGMENT_ALIGN(execp, eap->data_start);
233 	epp->ep_dsize = eap->dsize + eap->bsize;
234 	epp->ep_entry = eap->entry;
235 
236 	/*
237 	 * check if vnode is in open for writing, because we want to
238 	 * demand-page out of it.  if it is, don't do it, for various
239 	 * reasons
240 	 */
241 	if ((eap->tsize != 0 || eap->dsize != 0) &&
242 	    vp->v_writecount != 0) {
243 #ifdef DIAGNOSTIC
244 		if (vp->v_flag & VTEXT)
245 			panic("exec: a VTEXT vnode has writecount != 0\n");
246 #endif
247 		return ETXTBSY;
248 	}
249 	vn_marktext(vp);
250 
251 	/* set up command for text segment */
252 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, eap->tsize,
253 	    epp->ep_taddr, vp, ECOFF_TXTOFF(execp),
254 	    VM_PROT_READ|VM_PROT_EXECUTE);
255 
256 	/* set up command for data segment */
257 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, eap->dsize,
258 	    epp->ep_daddr, vp, ECOFF_DATOFF(execp),
259 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
260 
261 	/* set up command for bss segment */
262 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, eap->bsize,
263 	    ECOFF_SEGMENT_ALIGN(execp, eap->bss_start), NULLVP, 0,
264 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
265 
266 	return 0;
267 }
268