1 /*	$NetBSD: linux_exec_aout.c,v 1.47 2001/11/13 02:08:50 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas, Frank van der Linden and Eric Haszlakiewicz.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * based on exec_aout.c, sunos_exec.c and svr4_exec.c
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: linux_exec_aout.c,v 1.47 2001/11/13 02:08:50 lukem Exp $");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/proc.h>
50 #include <sys/malloc.h>
51 #include <sys/namei.h>
52 #include <sys/vnode.h>
53 #include <sys/mount.h>
54 #include <sys/exec.h>
55 #include <sys/exec_elf.h>
56 
57 #include <sys/mman.h>
58 #include <sys/syscallargs.h>
59 
60 #include <machine/cpu.h>
61 #include <machine/reg.h>
62 
63 #include <compat/linux/common/linux_types.h>
64 #include <compat/linux/common/linux_signal.h>
65 #include <compat/linux/common/linux_util.h>
66 #include <compat/linux/common/linux_exec.h>
67 #include <compat/linux/common/linux_machdep.h>
68 
69 #include <compat/linux/linux_syscallargs.h>
70 #include <compat/linux/linux_syscall.h>
71 
72 int linux_aout_copyargs __P((struct exec_package *, struct ps_strings *,
73     char **, void *));
74 
75 static int exec_linux_aout_prep_zmagic __P((struct proc *,
76     struct exec_package *));
77 static int exec_linux_aout_prep_nmagic __P((struct proc *,
78     struct exec_package *));
79 static int exec_linux_aout_prep_omagic __P((struct proc *,
80     struct exec_package *));
81 static int exec_linux_aout_prep_qmagic __P((struct proc *,
82     struct exec_package *));
83 
84 int
85 linux_aout_copyargs(pack, arginfo, stackp, argp)
86 	struct exec_package *pack;
87 	struct ps_strings *arginfo;
88 	char **stackp;
89 	void *argp;
90 {
91 	char **cpp = (char **)*stackp;
92 	char **stk = (char **)*stackp;
93 	char *dp, *sp;
94 	size_t len;
95 	void *nullp = NULL;
96 	int argc = arginfo->ps_nargvstr;
97 	int envc = arginfo->ps_nenvstr;
98 	int error;
99 
100 	if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0)
101 		return error;
102 
103 	/* leave room for envp and argv */
104 	cpp += 2;
105 	if ((error = copyout(&cpp, &stk[1], sizeof (cpp))) != 0)
106 		return error;
107 
108 	dp = (char *) (cpp + argc + envc + 2);
109 	sp = argp;
110 
111 	/* XXX don't copy them out, remap them! */
112 	arginfo->ps_argvstr = cpp; /* remember location of argv for later */
113 
114 	for (; --argc >= 0; sp += len, dp += len)
115 		if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 ||
116 		    (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0)
117 			return error;
118 
119 	if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0)
120 		return error;
121 
122 	if ((error = copyout(&cpp, &stk[2], sizeof (cpp))) != 0)
123 		return error;
124 
125 	arginfo->ps_envstr = cpp; /* remember location of envp for later */
126 
127 	for (; --envc >= 0; sp += len, dp += len)
128 		if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 ||
129 		    (error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0)
130 			return error;
131 
132 	if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0)
133 		return error;
134 
135 	*stackp = (char *)cpp;
136 	return 0;
137 }
138 
139 int
140 exec_linux_aout_makecmds(p, epp)
141 	struct proc *p;
142 	struct exec_package *epp;
143 {
144 	struct exec *linux_ep = epp->ep_hdr;
145 	int machtype, magic;
146 	int error = ENOEXEC;
147 
148 	magic = LINUX_N_MAGIC(linux_ep);
149 	machtype = LINUX_N_MACHTYPE(linux_ep);
150 
151 
152 	if (machtype != LINUX_MID_MACHINE)
153 		return (ENOEXEC);
154 
155 	switch (magic) {
156 	case QMAGIC:
157 		error = exec_linux_aout_prep_qmagic(p, epp);
158 		break;
159 	case ZMAGIC:
160 		error = exec_linux_aout_prep_zmagic(p, epp);
161 		break;
162 	case NMAGIC:
163 		error = exec_linux_aout_prep_nmagic(p, epp);
164 		break;
165 	case OMAGIC:
166 		error = exec_linux_aout_prep_omagic(p, epp);
167 		break;
168 	}
169 	return error;
170 }
171 
172 /*
173  * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400
174  * is very likely not page aligned on most architectures, it is treated
175  * as an NMAGIC here. XXX
176  */
177 
178 static int
179 exec_linux_aout_prep_zmagic(p, epp)
180 	struct proc *p;
181 	struct exec_package *epp;
182 {
183 	struct exec *execp = epp->ep_hdr;
184 
185 	epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC);
186 	epp->ep_tsize = execp->a_text;
187 	epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC);
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, LINUX_N_TXTOFF(*execp, ZMAGIC),
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, LINUX_N_DATOFF(*execp, ZMAGIC),
199 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
200 
201 	/* set up command for bss segment */
202 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
203 	    epp->ep_daddr + execp->a_data, NULLVP, 0,
204 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
205 
206 	return exec_aout_setup_stack(p, epp);
207 }
208 
209 /*
210  * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package.
211  * Not different from the normal stuff.
212  */
213 
214 static int
215 exec_linux_aout_prep_nmagic(p, epp)
216 	struct proc *p;
217 	struct exec_package *epp;
218 {
219 	struct exec *execp = epp->ep_hdr;
220 	long bsize, baddr;
221 
222 	epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC);
223 	epp->ep_tsize = execp->a_text;
224 	epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC);
225 	epp->ep_dsize = execp->a_data + execp->a_bss;
226 	epp->ep_entry = execp->a_entry;
227 
228 	/* set up command for text segment */
229 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text,
230 	    epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC),
231 	    VM_PROT_READ|VM_PROT_EXECUTE);
232 
233 	/* set up command for data segment */
234 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data,
235 	    epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC),
236 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
237 
238 	/* set up command for bss segment */
239 	baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
240 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
241 	if (bsize > 0)
242 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
243 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
244 
245 	return exec_aout_setup_stack(p, epp);
246 }
247 
248 /*
249  * exec_aout_prep_omagic(): Prepare Linux OMAGIC package.
250  * Business as usual.
251  */
252 
253 static int
254 exec_linux_aout_prep_omagic(p, epp)
255 	struct proc *p;
256 	struct exec_package *epp;
257 {
258 	struct exec *execp = epp->ep_hdr;
259 	long dsize, bsize, baddr;
260 
261 	epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC);
262 	epp->ep_tsize = execp->a_text;
263 	epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC);
264 	epp->ep_dsize = execp->a_data + execp->a_bss;
265 	epp->ep_entry = execp->a_entry;
266 
267 	/* set up command for text and data segments */
268 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn,
269 	    execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp,
270 	    LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
271 
272 	/* set up command for bss segment */
273 	baddr = roundup(epp->ep_daddr + execp->a_data, NBPG);
274 	bsize = epp->ep_daddr + epp->ep_dsize - baddr;
275 	if (bsize > 0)
276 		NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr,
277 		    NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
278 
279 	/*
280 	 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize);
281 	 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are
282 	 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize'
283 	 * respectively to page boundaries.
284 	 * Compensate `ep_dsize' for the amount of data covered by the last
285 	 * text page.
286 	 */
287 	dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG);
288 	epp->ep_dsize = (dsize > 0) ? dsize : 0;
289 	return exec_aout_setup_stack(p, epp);
290 }
291 
292 static int
293 exec_linux_aout_prep_qmagic(p, epp)
294 	struct proc *p;
295 	struct exec_package *epp;
296 {
297 	struct exec *execp = epp->ep_hdr;
298 
299 	epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC);
300 	epp->ep_tsize = execp->a_text;
301 	epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC);
302 	epp->ep_dsize = execp->a_data + execp->a_bss;
303 	epp->ep_entry = execp->a_entry;
304 
305 	/*
306 	 * check if vnode is in open for writing, because we want to
307 	 * demand-page out of it.  if it is, don't do it, for various
308 	 * reasons
309 	 */
310 	if ((execp->a_text != 0 || execp->a_data != 0) &&
311 	    epp->ep_vp->v_writecount != 0) {
312 #ifdef DIAGNOSTIC
313 		if (epp->ep_vp->v_flag & VTEXT)
314 			panic("exec: a VTEXT vnode has writecount != 0\n");
315 #endif
316 		return ETXTBSY;
317 	}
318 	epp->ep_vp->v_flag |= VTEXT;
319 
320 	/* set up command for text segment */
321 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text,
322 	    epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC),
323 	    VM_PROT_READ|VM_PROT_EXECUTE);
324 
325 	/* set up command for data segment */
326 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data,
327 	    epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC),
328 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
329 
330 	/* set up command for bss segment */
331 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss,
332 	    epp->ep_daddr + execp->a_data, NULLVP, 0,
333 	    VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
334 
335 	return exec_aout_setup_stack(p, epp);
336 }
337