exec_elf32.c revision 1.41
1/*	$NetBSD: exec_elf32.c,v 1.41 1999/01/06 11:52:53 christos Exp $	*/
2
3/*-
4 * Copyright (c) 1994 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.
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 * Copyright (c) 1996 Christopher G. Demetriou
41 * All rights reserved.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 *    notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 *    notice, this list of conditions and the following disclaimer in the
50 *    documentation and/or other materials provided with the distribution.
51 * 3. The name of the author may not be used to endorse or promote products
52 *    derived from this software without specific prior written permission
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
55 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
56 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
57 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
58 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
59 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
60 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
61 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
62 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
63 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64 */
65
66/* If not included by exec_elf64.c, ELFSIZE won't be defined. */
67#ifndef ELFSIZE
68#define	ELFSIZE		32
69#endif
70
71#include "opt_compat_linux.h"
72#include "opt_compat_ibcs2.h"
73#include "opt_compat_svr4.h"
74
75#include <sys/param.h>
76#include <sys/systm.h>
77#include <sys/kernel.h>
78#include <sys/proc.h>
79#include <sys/malloc.h>
80#include <sys/namei.h>
81#include <sys/vnode.h>
82#include <sys/exec.h>
83#include <sys/exec_elf.h>
84#include <sys/fcntl.h>
85#include <sys/syscall.h>
86#include <sys/signalvar.h>
87#include <sys/mount.h>
88#include <sys/stat.h>
89
90#include <sys/mman.h>
91#include <vm/vm.h>
92#include <vm/vm_param.h>
93#include <vm/vm_map.h>
94
95#include <machine/cpu.h>
96#include <machine/reg.h>
97
98#ifdef COMPAT_LINUX
99#include <compat/linux/common/linux_exec.h>
100#endif
101
102#ifdef COMPAT_SVR4
103#include <compat/svr4/svr4_exec.h>
104#endif
105
106#ifdef COMPAT_IBCS2
107#include <compat/ibcs2/ibcs2_exec.h>
108#endif
109
110int	ELFNAME(check_header) __P((Elf_Ehdr *, int));
111int	ELFNAME(load_file) __P((struct proc *, struct exec_package *, char *,
112	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *));
113void	ELFNAME(load_psection) __P((struct exec_vmcmd_set *, struct vnode *,
114	    Elf_Phdr *, Elf_Addr *, u_long *, int *));
115
116static int ELFNAME2(netbsd,signature) __P((struct proc *, struct exec_package *,
117    Elf_Ehdr *));
118static int ELFNAME2(netbsd,probe) __P((struct proc *, struct exec_package *,
119    Elf_Ehdr *, char *, Elf_Addr *));
120
121extern char sigcode[], esigcode[];
122#ifdef SYSCALL_DEBUG
123extern char *syscallnames[];
124#endif
125
126struct emul ELFNAMEEND(emul_netbsd) = {
127	"netbsd",
128	NULL,
129	sendsig,
130	SYS_syscall,
131	SYS_MAXSYSCALL,
132	sysent,
133#ifdef SYSCALL_DEBUG
134	syscallnames,
135#else
136	NULL,
137#endif
138	ELF_AUX_ENTRIES * sizeof(AuxInfo),
139	ELFNAME(copyargs),
140	setregs,
141	sigcode,
142	esigcode,
143};
144
145int (*ELFNAME(probe_funcs)[]) __P((struct proc *, struct exec_package *,
146    Elf_Ehdr *, char *, Elf_Addr *)) = {
147	ELFNAME2(netbsd,probe),
148#if defined(COMPAT_LINUX)
149	ELFNAME2(linux,probe),
150#endif
151#if defined(COMPAT_SVR4) && (ELFSIZE == 32)
152	ELFNAME2(svr4,probe),			/* XXX not 64-bit safe */
153#endif
154#if defined(COMPAT_IBCS2) && (ELFSIZE == 32)
155	ELFNAME2(ibcs2,probe),			/* XXX not 64-bit safe */
156#endif
157};
158
159/* round up and down to page boundaries. */
160#define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
161#define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
162
163/*
164 * Copy arguments onto the stack in the normal way, but add some
165 * extra information in case of dynamic binding.
166 */
167void *
168ELFNAME(copyargs)(pack, arginfo, stack, argp)
169	struct exec_package *pack;
170	struct ps_strings *arginfo;
171	void *stack;
172	void *argp;
173{
174	size_t len;
175	AuxInfo ai[ELF_AUX_ENTRIES], *a;
176	struct elf_args *ap;
177
178	stack = copyargs(pack, arginfo, stack, argp);
179	if (!stack)
180		return NULL;
181
182	a = ai;
183
184	/*
185	 * Push extra arguments on the stack needed by dynamically
186	 * linked binaries
187	 */
188	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
189
190		a->au_id = AUX_phdr;
191		a->au_v = ap->arg_phaddr;
192		a++;
193
194		a->au_id = AUX_phent;
195		a->au_v = ap->arg_phentsize;
196		a++;
197
198		a->au_id = AUX_phnum;
199		a->au_v = ap->arg_phnum;
200		a++;
201
202		a->au_id = AUX_pagesz;
203		a->au_v = NBPG;
204		a++;
205
206		a->au_id = AUX_base;
207		a->au_v = ap->arg_interp;
208		a++;
209
210		a->au_id = AUX_flags;
211		a->au_v = 0;
212		a++;
213
214		a->au_id = AUX_entry;
215		a->au_v = ap->arg_entry;
216		a++;
217
218		free((char *)ap, M_TEMP);
219		pack->ep_emul_arg = NULL;
220	}
221
222	a->au_id = AUX_null;
223	a->au_v = 0;
224	a++;
225
226	len = (a - ai) * sizeof(AuxInfo);
227	if (copyout(ai, stack, len))
228		return NULL;
229	(caddr_t)stack += len;
230
231	return stack;
232}
233
234/*
235 * elf_check_header():
236 *
237 * Check header for validity; return 0 of ok ENOEXEC if error
238 */
239int
240ELFNAME(check_header)(eh, type)
241	Elf_Ehdr *eh;
242	int type;
243{
244
245	if (memcmp(eh->e_ident, Elf_e_ident, Elf_e_siz) != 0)
246		return ENOEXEC;
247
248	switch (eh->e_machine) {
249
250	ELFDEFNNAME(MACHDEP_ID_CASES)
251
252	default:
253		return ENOEXEC;
254	}
255
256	if (eh->e_type != type)
257		return ENOEXEC;
258
259	return 0;
260}
261
262/*
263 * elf_load_psection():
264 *
265 * Load a psection at the appropriate address
266 */
267void
268ELFNAME(load_psection)(vcset, vp, ph, addr, size, prot)
269	struct exec_vmcmd_set *vcset;
270	struct vnode *vp;
271	Elf_Phdr *ph;
272	Elf_Addr *addr;
273	u_long *size;
274	int *prot;
275{
276	u_long uaddr, msize, psize, rm, rf;
277	long diff, offset;
278
279	/*
280	 * If the user specified an address, then we load there.
281	 */
282	if (*addr != ELFDEFNNAME(NO_ADDR)) {
283		if (ph->p_align > 1) {
284			*addr = ELF_ROUND(*addr, ph->p_align);
285			uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
286		} else
287			uaddr = ph->p_vaddr;
288		diff = ph->p_vaddr - uaddr;
289	} else {
290		*addr = uaddr = ph->p_vaddr;
291		if (ph->p_align > 1)
292			*addr = ELF_TRUNC(uaddr, ph->p_align);
293		diff = uaddr - *addr;
294	}
295
296	*prot |= (ph->p_flags & Elf_pf_r) ? VM_PROT_READ : 0;
297	*prot |= (ph->p_flags & Elf_pf_w) ? VM_PROT_WRITE : 0;
298	*prot |= (ph->p_flags & Elf_pf_x) ? VM_PROT_EXECUTE : 0;
299
300	offset = ph->p_offset - diff;
301	*size = ph->p_filesz + diff;
302	msize = ph->p_memsz + diff;
303	psize = round_page(*size);
304
305	if ((ph->p_flags & Elf_pf_w) != 0) {
306		/*
307		 * Because the pagedvn pager can't handle zero fill of the last
308		 * data page if it's not page aligned we map the last page
309		 * readvn.
310		 */
311		psize = trunc_page(*size);
312		NEW_VMCMD(vcset, vmcmd_map_pagedvn, psize, *addr, vp,
313		    offset, *prot);
314		if(psize != *size)
315			NEW_VMCMD(vcset, vmcmd_map_readvn, *size - psize,
316			    *addr + psize, vp, offset + psize, *prot);
317	} else
318		NEW_VMCMD(vcset, vmcmd_map_pagedvn, psize, *addr, vp,
319		    offset, *prot);
320
321	/*
322	 * Check if we need to extend the size of the segment
323	 */
324	rm = round_page(*addr + msize);
325	rf = round_page(*addr + *size);
326
327	if (rm != rf) {
328		NEW_VMCMD(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
329		    0, *prot);
330		*size = msize;
331	}
332}
333
334/*
335 * elf_read_from():
336 *
337 *	Read from vnode into buffer at offset.
338 */
339int
340ELFNAME(read_from)(p, vp, off, buf, size)
341	struct vnode *vp;
342	u_long off;
343	struct proc *p;
344	caddr_t buf;
345	int size;
346{
347	int error;
348	size_t resid;
349
350	if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE,
351	    0, p->p_ucred, &resid, p)) != 0)
352		return error;
353	/*
354	 * See if we got all of it
355	 */
356	if (resid != 0)
357		return ENOEXEC;
358	return 0;
359}
360
361/*
362 * elf_load_file():
363 *
364 * Load a file (interpreter/library) pointed to by path
365 * [stolen from coff_load_shlib()]. Made slightly generic
366 * so it might be used externally.
367 */
368int
369ELFNAME(load_file)(p, epp, path, vcset, entry, ap, last)
370	struct proc *p;
371	struct exec_package *epp;
372	char *path;
373	struct exec_vmcmd_set *vcset;
374	u_long *entry;
375	struct elf_args	*ap;
376	Elf_Addr *last;
377{
378	int error, i;
379	struct nameidata nd;
380	struct vnode *vp;
381	struct vattr attr;
382	Elf_Ehdr eh;
383	Elf_Phdr *ph = NULL;
384	u_long phsize;
385	char *bp = NULL;
386	Elf_Addr addr = *last;
387
388	bp = path;
389	/*
390	 * 1. open file
391	 * 2. read filehdr
392	 * 3. map text, data, and bss out of it using VM_*
393	 */
394	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
395	if ((error = namei(&nd)) != 0)
396		return error;
397	vp = nd.ni_vp;
398
399	/*
400	 * Similarly, if it's not marked as executable, or it's not a regular
401	 * file, we don't allow it to be used.
402	 */
403	if (vp->v_type != VREG) {
404		error = EACCES;
405		goto badunlock;
406	}
407	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
408		goto badunlock;
409
410	/* get attributes */
411	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
412		goto badunlock;
413
414	/*
415	 * Check mount point.  Though we're not trying to exec this binary,
416	 * we will be executing code from it, so if the mount point
417	 * disallows execution or set-id-ness, we punt or kill the set-id.
418	 */
419	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
420		error = EACCES;
421		goto badunlock;
422	}
423	if (vp->v_mount->mnt_flag & MNT_NOSUID)
424		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
425
426#ifdef notyet /* XXX cgd 960926 */
427	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
428#endif
429	VOP_UNLOCK(vp, 0);
430
431	if ((error = ELFNAME(read_from)(p, vp, 0, (caddr_t) &eh,
432	    sizeof(eh))) != 0)
433		goto bad;
434
435	if ((error = ELFNAME(check_header)(&eh, Elf_et_dyn)) != 0)
436		goto bad;
437
438	phsize = eh.e_phnum * sizeof(Elf_Phdr);
439	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
440
441	if ((error = ELFNAME(read_from)(p, vp, eh.e_phoff,
442	    (caddr_t) ph, phsize)) != 0)
443		goto bad;
444
445	/*
446	 * Load all the necessary sections
447	 */
448	for (i = 0; i < eh.e_phnum; i++) {
449		u_long size = 0;
450		int prot = 0;
451
452		switch (ph[i].p_type) {
453		case Elf_pt_load:
454			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
455			    &size, &prot);
456			/* If entry is within this section it must be text */
457			if (eh.e_entry >= ph[i].p_vaddr &&
458			    eh.e_entry < (ph[i].p_vaddr + size)) {
459				/* XXX */
460				*entry = addr + eh.e_entry;
461#ifdef mips
462				*entry -= ph[i].p_vaddr;
463#endif
464				ap->arg_interp = addr;
465			}
466			addr += size;
467			break;
468
469		case Elf_pt_dynamic:
470		case Elf_pt_phdr:
471		case Elf_pt_note:
472			break;
473
474		default:
475			break;
476		}
477	}
478
479	free((char *)ph, M_TEMP);
480	*last = addr;
481	vrele(vp);
482	return 0;
483
484badunlock:
485	VOP_UNLOCK(vp, 0);
486
487bad:
488	if (ph != NULL)
489		free((char *)ph, M_TEMP);
490#ifdef notyet /* XXX cgd 960926 */
491	(maybe) VOP_CLOSE it
492#endif
493	vrele(vp);
494	return error;
495}
496
497/*
498 * exec_elf_makecmds(): Prepare an Elf binary's exec package
499 *
500 * First, set of the various offsets/lengths in the exec package.
501 *
502 * Then, mark the text image busy (so it can be demand paged) or error
503 * out if this is not possible.  Finally, set up vmcmds for the
504 * text, data, bss, and stack segments.
505 */
506int
507ELFNAME2(exec,makecmds)(p, epp)
508	struct proc *p;
509	struct exec_package *epp;
510{
511	Elf_Ehdr *eh = epp->ep_hdr;
512	Elf_Phdr *ph, *pp;
513	Elf_Addr phdr = 0, pos = 0;
514	int error, i, n, nload;
515	char interp[MAXPATHLEN];
516	u_long phsize;
517
518	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
519		return ENOEXEC;
520
521	if (ELFNAME(check_header)(eh, Elf_et_exec))
522		return ENOEXEC;
523
524	/*
525	 * check if vnode is in open for writing, because we want to
526	 * demand-page out of it.  if it is, don't do it, for various
527	 * reasons
528	 */
529	if (epp->ep_vp->v_writecount != 0) {
530#ifdef DIAGNOSTIC
531		if (epp->ep_vp->v_flag & VTEXT)
532			panic("exec: a VTEXT vnode has writecount != 0\n");
533#endif
534		return ETXTBSY;
535	}
536	/*
537	 * Allocate space to hold all the program headers, and read them
538	 * from the file
539	 */
540	phsize = eh->e_phnum * sizeof(Elf_Phdr);
541	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
542
543	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
544	    (caddr_t) ph, phsize)) != 0)
545		goto bad;
546
547	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
548	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
549
550	interp[0] = '\0';
551
552	for (i = 0; i < eh->e_phnum; i++) {
553		pp = &ph[i];
554		if (pp->p_type == Elf_pt_interp) {
555			if (pp->p_filesz >= sizeof(interp))
556				goto bad;
557			if ((error = ELFNAME(read_from)(p, epp->ep_vp,
558			    pp->p_offset, (caddr_t) interp,
559			    pp->p_filesz)) != 0)
560				goto bad;
561			break;
562		}
563	}
564
565	/*
566	 * Setup things for native emulation.
567	 */
568	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
569	pos = ELFDEFNNAME(NO_ADDR);
570
571	/*
572	 * On the same architecture, we may be emulating different systems.
573	 * See which one will accept this executable. This currently only
574	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
575	 * and the Alpha.
576	 *
577	 * Probe functions would normally see if the interpreter (if any)
578	 * exists. Emulation packages may possibly replace the interpreter in
579	 * interp[] with a changed path (/emul/xxx/<path>), and also
580	 * set the ep_emul field in the exec package structure.
581	 */
582	n = sizeof(ELFNAME(probe_funcs)) / sizeof(ELFNAME(probe_funcs)[0]);
583	if (n != 0) {
584		error = ENOEXEC;
585		for (i = 0; i < n && error; i++)
586			error = ELFNAME(probe_funcs)[i](p, epp, eh,
587			    interp, &pos);
588#ifdef notyet
589		/*
590		 * We should really use a signature in our native binaries
591		 * and have our own probe function for matching binaries,
592		 * before trying the emulations. For now, if the emulation
593		 * probes failed we default to native.
594		 */
595		if (error)
596			goto bad;
597#endif
598	}
599
600	/*
601	 * Load all the necessary sections
602	 */
603	for (i = nload = 0; i < eh->e_phnum; i++) {
604		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
605		u_long size = 0;
606		int prot = 0;
607
608		pp = &ph[i];
609
610		switch (ph[i].p_type) {
611		case Elf_pt_load:
612			/*
613			 * XXX
614			 * Can handle only 2 sections: text and data
615			 */
616			if (nload++ == 2)
617				goto bad;
618			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
619			    &ph[i], &addr, &size, &prot);
620
621			/*
622			 * Decide whether it's text or data by looking
623			 * at the entry point.
624			 */
625			if (eh->e_entry >= addr &&
626			    eh->e_entry < (addr + size)) {
627				epp->ep_taddr = addr;
628				epp->ep_tsize = size;
629				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
630					epp->ep_daddr = addr;
631					epp->ep_dsize = size;
632				}
633			} else {
634				epp->ep_daddr = addr;
635				epp->ep_dsize = size;
636			}
637			break;
638
639		case Elf_pt_shlib:
640#ifndef COMPAT_IBCS2			/* SCO has these sections */
641			error = ENOEXEC;
642			goto bad;
643#endif
644
645		case Elf_pt_interp:
646			/* Already did this one */
647		case Elf_pt_dynamic:
648		case Elf_pt_note:
649			break;
650
651		case Elf_pt_phdr:
652			/* Note address of program headers (in text segment) */
653			phdr = pp->p_vaddr;
654			break;
655
656		default:
657			/*
658			 * Not fatal; we don't need to understand everything.
659			 */
660			break;
661		}
662	}
663
664	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
665#ifndef ELF_INTERP_NON_RELOCATABLE
666	/*
667	 * If no position to load the interpreter was set by a probe
668	 * function, pick the same address that a non-fixed mmap(0, ..)
669	 * would (i.e. something safely out of the way).
670	 */
671	if (pos == ELFDEFNNAME(NO_ADDR))
672		pos = round_page(epp->ep_daddr + MAXDSIZ);
673#endif	/* !ELF_INTERP_NON_RELOCATABLE */
674
675	/*
676	 * Check if we found a dynamically linked binary and arrange to load
677	 * it's interpreter
678	 */
679	if (interp[0]) {
680		struct elf_args *ap;
681
682		ap = (struct elf_args *)malloc(sizeof(struct elf_args),
683		    M_TEMP, M_WAITOK);
684		if ((error = ELFNAME(load_file)(p, epp, interp,
685		    &epp->ep_vmcmds, &epp->ep_entry, ap, &pos)) != 0) {
686			free((char *)ap, M_TEMP);
687			goto bad;
688		}
689		pos += phsize;
690		ap->arg_phaddr = phdr;
691
692		ap->arg_phentsize = eh->e_phentsize;
693		ap->arg_phnum = eh->e_phnum;
694		ap->arg_entry = eh->e_entry;
695
696		epp->ep_emul_arg = ap;
697	} else
698		epp->ep_entry = eh->e_entry;
699
700#ifdef ELF_MAP_PAGE_ZERO
701	/* Dell SVR4 maps page zero, yeuch! */
702	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, NBPG, 0, epp->ep_vp, 0,
703	    VM_PROT_READ);
704#endif
705	free((char *)ph, M_TEMP);
706	epp->ep_vp->v_flag |= VTEXT;
707	return exec_elf_setup_stack(p, epp);
708
709bad:
710	free((char *)ph, M_TEMP);
711	kill_vmcmds(&epp->ep_vmcmds);
712	return ENOEXEC;
713}
714
715static int
716ELFNAME2(netbsd,signature)(p, epp, eh)
717	struct proc *p;
718	struct exec_package *epp;
719	Elf_Ehdr *eh;
720{
721	Elf_Phdr *hph, *ph;
722	Elf_Note *np = NULL;
723	size_t phsize;
724	int error;
725
726	phsize = eh->e_phnum * sizeof(Elf_Phdr);
727	hph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
728	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
729	    (caddr_t)hph, phsize)) != 0)
730		goto out1;
731
732	for (ph = hph;  ph < &hph[eh->e_phnum]; ph++) {
733		if (ph->p_type != Elf_pt_note ||
734		    ph->p_filesz < sizeof(Elf_Note) + ELF_NOTE_NETBSD_NAMESZ)
735			continue;
736
737		np = (Elf_Note *)malloc(ph->p_filesz, M_TEMP, M_WAITOK);
738		if ((error = ELFNAME(read_from)(p, epp->ep_vp, ph->p_offset,
739		    (caddr_t)np, ph->p_filesz)) != 0)
740			goto out2;
741
742		if (np->type != ELF_NOTE_TYPE_OSVERSION) {
743			free(np, M_TEMP);
744			np = NULL;
745			continue;
746		}
747
748		/* Check the name and description sizes. */
749		if (np->namesz != ELF_NOTE_NETBSD_NAMESZ ||
750		    np->descsz != ELF_NOTE_NETBSD_DESCSZ)
751			goto out3;
752
753		/* Is the name "NetBSD\0\0"? */
754		if (memcmp((np + 1), ELF_NOTE_NETBSD_NAME,
755		    ELF_NOTE_NETBSD_NAMESZ))
756			goto out3;
757
758		/* XXX: We could check for the specific emulation here */
759		/* All checks succeeded. */
760		error = 0;
761		goto out2;
762	}
763
764out3:
765	error = ENOEXEC;
766out2:
767	if (np)
768		free(np, M_TEMP);
769out1:
770	free(hph, M_TEMP);
771	return error;
772}
773
774static int
775ELFNAME2(netbsd,probe)(p, epp, eh, itp, pos)
776	struct proc *p;
777	struct exec_package *epp;
778	Elf_Ehdr *eh;
779	char *itp;
780	Elf_Addr *pos;
781{
782	int error;
783
784	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
785		return error;
786
787	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
788	*pos = ELFDEFNNAME(NO_ADDR);
789	return 0;
790}
791