exec_elf32.c revision 1.76
1/*	$NetBSD: exec_elf32.c,v 1.76 2002/10/05 22:34:05 chs Exp $	*/
2
3/*-
4 * Copyright (c) 1994, 2000 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#include <sys/cdefs.h>
67__KERNEL_RCSID(1, "$NetBSD: exec_elf32.c,v 1.76 2002/10/05 22:34:05 chs Exp $");
68
69/* If not included by exec_elf64.c, ELFSIZE won't be defined. */
70#ifndef ELFSIZE
71#define	ELFSIZE		32
72#endif
73
74#include <sys/param.h>
75#include <sys/proc.h>
76#include <sys/malloc.h>
77#include <sys/namei.h>
78#include <sys/vnode.h>
79#include <sys/exec.h>
80#include <sys/exec_elf.h>
81#include <sys/syscall.h>
82#include <sys/signalvar.h>
83#include <sys/mount.h>
84#include <sys/stat.h>
85
86#include <machine/cpu.h>
87#include <machine/reg.h>
88
89extern const struct emul emul_netbsd;
90
91int	ELFNAME(check_header)(Elf_Ehdr *, int);
92int	ELFNAME(load_file)(struct proc *, struct exec_package *, char *,
93	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *);
94void	ELFNAME(load_psection)(struct exec_vmcmd_set *, struct vnode *,
95	    const Elf_Phdr *, Elf_Addr *, u_long *, int *, int);
96
97int ELFNAME2(netbsd,signature)(struct proc *, struct exec_package *,
98    Elf_Ehdr *);
99int ELFNAME2(netbsd,probe)(struct proc *, struct exec_package *,
100    void *, char *, vaddr_t *);
101
102/* round up and down to page boundaries. */
103#define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
104#define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
105
106/*
107 * Copy arguments onto the stack in the normal way, but add some
108 * extra information in case of dynamic binding.
109 */
110int
111ELFNAME(copyargs)(struct proc *p, struct exec_package *pack,
112    struct ps_strings *arginfo, char **stackp, void *argp)
113{
114	size_t len;
115	AuxInfo ai[ELF_AUX_ENTRIES], *a;
116	struct elf_args *ap;
117	int error;
118
119	if ((error = copyargs(p, pack, arginfo, stackp, argp)) != 0)
120		return error;
121
122	a = ai;
123
124	/*
125	 * Push extra arguments on the stack needed by dynamically
126	 * linked binaries
127	 */
128	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
129
130		a->a_type = AT_PHDR;
131		a->a_v = ap->arg_phaddr;
132		a++;
133
134		a->a_type = AT_PHENT;
135		a->a_v = ap->arg_phentsize;
136		a++;
137
138		a->a_type = AT_PHNUM;
139		a->a_v = ap->arg_phnum;
140		a++;
141
142		a->a_type = AT_PAGESZ;
143		a->a_v = PAGE_SIZE;
144		a++;
145
146		a->a_type = AT_BASE;
147		a->a_v = ap->arg_interp;
148		a++;
149
150		a->a_type = AT_FLAGS;
151		a->a_v = 0;
152		a++;
153
154		a->a_type = AT_ENTRY;
155		a->a_v = ap->arg_entry;
156		a++;
157
158		a->a_type = AT_EUID;
159		a->a_v = p->p_ucred->cr_uid;
160		a++;
161
162		a->a_type = AT_RUID;
163		a->a_v = p->p_cred->p_ruid;
164		a++;
165
166		a->a_type = AT_EGID;
167		a->a_v = p->p_ucred->cr_gid;
168		a++;
169
170		a->a_type = AT_RGID;
171		a->a_v = p->p_cred->p_rgid;
172		a++;
173
174		free(ap, M_TEMP);
175		pack->ep_emul_arg = NULL;
176	}
177
178	a->a_type = AT_NULL;
179	a->a_v = 0;
180	a++;
181
182	len = (a - ai) * sizeof(AuxInfo);
183	if ((error = copyout(ai, *stackp, len)) != 0)
184		return error;
185	*stackp += len;
186
187	return 0;
188}
189
190/*
191 * elf_check_header():
192 *
193 * Check header for validity; return 0 of ok ENOEXEC if error
194 */
195int
196ELFNAME(check_header)(Elf_Ehdr *eh, int type)
197{
198
199	if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
200	    eh->e_ident[EI_CLASS] != ELFCLASS)
201		return (ENOEXEC);
202
203	switch (eh->e_machine) {
204
205	ELFDEFNNAME(MACHDEP_ID_CASES)
206
207	default:
208		return (ENOEXEC);
209	}
210
211	if (ELF_EHDR_FLAGS_OK(eh) == 0)
212		return (ENOEXEC);
213
214	if (eh->e_type != type)
215		return (ENOEXEC);
216
217	if (eh->e_shnum > 512 ||
218	    eh->e_phnum > 128)
219		return (ENOEXEC);
220
221	return (0);
222}
223
224/*
225 * elf_load_psection():
226 *
227 * Load a psection at the appropriate address
228 */
229void
230ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
231    const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags)
232{
233	u_long uaddr, msize, psize, rm, rf;
234	long diff, offset;
235
236	/*
237	 * If the user specified an address, then we load there.
238	 */
239	if (*addr != ELFDEFNNAME(NO_ADDR)) {
240		if (ph->p_align > 1) {
241			*addr = ELF_TRUNC(*addr, ph->p_align);
242			uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
243		} else
244			uaddr = ph->p_vaddr;
245		diff = ph->p_vaddr - uaddr;
246	} else {
247		*addr = uaddr = ph->p_vaddr;
248		if (ph->p_align > 1)
249			*addr = ELF_TRUNC(uaddr, ph->p_align);
250		diff = uaddr - *addr;
251	}
252
253	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
254	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
255	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
256
257	offset = ph->p_offset - diff;
258	*size = ph->p_filesz + diff;
259	msize = ph->p_memsz + diff;
260
261	if (ph->p_align >= PAGE_SIZE) {
262		if ((ph->p_flags & PF_W) != 0) {
263			/*
264			 * Because the pagedvn pager can't handle zero fill
265			 * of the last data page if it's not page aligned we
266			 * map the last page readvn.
267			 */
268			psize = trunc_page(*size);
269		} else {
270			psize = round_page(*size);
271		}
272	} else {
273		psize = *size;
274	}
275
276	if (psize > 0) {
277		NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
278		    vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
279		    offset, *prot, flags);
280	}
281	if (psize < *size) {
282		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
283		    *addr + psize, vp, offset + psize, *prot,
284		    psize > 0 ? flags & VMCMD_RELATIVE : flags);
285	}
286
287	/*
288	 * Check if we need to extend the size of the segment
289	 */
290	rm = round_page(*addr + msize);
291	rf = round_page(*addr + *size);
292
293	if (rm != rf) {
294		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
295		    0, *prot, flags & VMCMD_RELATIVE);
296		*size = msize;
297	}
298}
299
300/*
301 * elf_load_file():
302 *
303 * Load a file (interpreter/library) pointed to by path
304 * [stolen from coff_load_shlib()]. Made slightly generic
305 * so it might be used externally.
306 */
307int
308ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
309    struct exec_vmcmd_set *vcset, u_long *entry, struct elf_args *ap,
310    Elf_Addr *last)
311{
312	int error, i;
313	struct nameidata nd;
314	struct vnode *vp;
315	struct vattr attr;
316	Elf_Ehdr eh;
317	Elf_Phdr *ph = NULL;
318	Elf_Phdr *base_ph = NULL;
319	u_long phsize;
320	char *bp = NULL;
321	Elf_Addr addr = *last;
322
323	bp = path;
324	/*
325	 * 1. open file
326	 * 2. read filehdr
327	 * 3. map text, data, and bss out of it using VM_*
328	 */
329	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
330	if ((error = namei(&nd)) != 0)
331		return error;
332	vp = nd.ni_vp;
333
334	/*
335	 * Similarly, if it's not marked as executable, or it's not a regular
336	 * file, we don't allow it to be used.
337	 */
338	if (vp->v_type != VREG) {
339		error = EACCES;
340		goto badunlock;
341	}
342	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
343		goto badunlock;
344
345	/* get attributes */
346	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
347		goto badunlock;
348
349	/*
350	 * Check mount point.  Though we're not trying to exec this binary,
351	 * we will be executing code from it, so if the mount point
352	 * disallows execution or set-id-ness, we punt or kill the set-id.
353	 */
354	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
355		error = EACCES;
356		goto badunlock;
357	}
358	if (vp->v_mount->mnt_flag & MNT_NOSUID)
359		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
360
361#ifdef notyet /* XXX cgd 960926 */
362	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
363#endif
364
365	error = vn_marktext(vp);
366	if (error)
367		goto badunlock;
368
369	VOP_UNLOCK(vp, 0);
370
371	if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0)
372		goto bad;
373
374	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
375		goto bad;
376
377	phsize = eh.e_phnum * sizeof(Elf_Phdr);
378	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
379
380	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
381		goto bad;
382
383	/*
384	 * Load all the necessary sections
385	 */
386	for (i = 0; i < eh.e_phnum; i++) {
387		u_long size = 0;
388		int prot = 0;
389		int flags;
390
391		switch (ph[i].p_type) {
392		case PT_LOAD:
393			if (base_ph == NULL) {
394				addr = *last;
395				flags = VMCMD_BASE;
396			} else {
397				addr = ph[i].p_vaddr - base_ph->p_vaddr;
398				flags = VMCMD_RELATIVE;
399			}
400			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
401			    &size, &prot, flags);
402			/* If entry is within this section it must be text */
403			if (eh.e_entry >= ph[i].p_vaddr &&
404			    eh.e_entry < (ph[i].p_vaddr + size)) {
405				*entry = addr + eh.e_entry - ph[i].p_vaddr;
406				ap->arg_interp = addr;
407			}
408			if (base_ph == NULL)
409				base_ph = &ph[i];
410			addr += size;
411			break;
412
413		case PT_DYNAMIC:
414		case PT_PHDR:
415		case PT_NOTE:
416			break;
417
418		default:
419			break;
420		}
421	}
422
423	free(ph, M_TEMP);
424	*last = addr;
425	vrele(vp);
426	return 0;
427
428badunlock:
429	VOP_UNLOCK(vp, 0);
430
431bad:
432	if (ph != NULL)
433		free(ph, M_TEMP);
434#ifdef notyet /* XXX cgd 960926 */
435	(maybe) VOP_CLOSE it
436#endif
437	vrele(vp);
438	return error;
439}
440
441/*
442 * exec_elf_makecmds(): Prepare an Elf binary's exec package
443 *
444 * First, set of the various offsets/lengths in the exec package.
445 *
446 * Then, mark the text image busy (so it can be demand paged) or error
447 * out if this is not possible.  Finally, set up vmcmds for the
448 * text, data, bss, and stack segments.
449 */
450int
451ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
452{
453	Elf_Ehdr *eh = epp->ep_hdr;
454	Elf_Phdr *ph, *pp;
455	Elf_Addr phdr = 0, pos = 0;
456	int error, i, nload;
457	char *interp = NULL;
458	u_long phsize;
459
460	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
461		return ENOEXEC;
462
463	/*
464	 * XXX allow for executing shared objects. It seems silly
465	 * but other ELF-based systems allow it as well.
466	 */
467	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
468	    ELFNAME(check_header)(eh, ET_DYN) != 0)
469		return ENOEXEC;
470
471	error = vn_marktext(epp->ep_vp);
472	if (error)
473		return (error);
474
475	/*
476	 * Allocate space to hold all the program headers, and read them
477	 * from the file
478	 */
479	phsize = eh->e_phnum * sizeof(Elf_Phdr);
480	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
481
482	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
483	    0)
484		goto bad;
485
486	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
487	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
488
489	MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
490	interp[0] = '\0';
491
492	for (i = 0; i < eh->e_phnum; i++) {
493		pp = &ph[i];
494		if (pp->p_type == PT_INTERP) {
495			if (pp->p_filesz >= MAXPATHLEN)
496				goto bad;
497			if ((error = exec_read_from(p, epp->ep_vp,
498			    pp->p_offset, interp, pp->p_filesz)) != 0)
499				goto bad;
500			break;
501		}
502	}
503
504	/*
505	 * On the same architecture, we may be emulating different systems.
506	 * See which one will accept this executable. This currently only
507	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
508	 * and the Alpha.
509	 *
510	 * Probe functions would normally see if the interpreter (if any)
511	 * exists. Emulation packages may possibly replace the interpreter in
512	 * interp[] with a changed path (/emul/xxx/<path>).
513	 */
514	if (!epp->ep_esch->u.elf_probe_func) {
515		pos = ELFDEFNNAME(NO_ADDR);
516	} else {
517		vaddr_t startp = 0;
518
519		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
520							  &startp);
521		pos = (Elf_Addr)startp;
522		if (error)
523			goto bad;
524	}
525
526	/*
527	 * Load all the necessary sections
528	 */
529	for (i = nload = 0; i < eh->e_phnum; i++) {
530		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
531		u_long size = 0;
532		int prot = 0;
533
534		pp = &ph[i];
535
536		switch (ph[i].p_type) {
537		case PT_LOAD:
538			/*
539			 * XXX
540			 * Can handle only 2 sections: text and data
541			 */
542			if (nload++ == 2)
543				goto bad;
544			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
545			    &ph[i], &addr, &size, &prot, 0);
546
547			/*
548			 * Decide whether it's text or data by looking
549			 * at the entry point.
550			 */
551			if (eh->e_entry >= addr &&
552			    eh->e_entry < (addr + size)) {
553				epp->ep_taddr = addr;
554				epp->ep_tsize = size;
555				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
556					epp->ep_daddr = addr;
557					epp->ep_dsize = size;
558				}
559			} else {
560				epp->ep_daddr = addr;
561				epp->ep_dsize = size;
562			}
563			break;
564
565		case PT_SHLIB:
566			/* SCO has these sections. */
567		case PT_INTERP:
568			/* Already did this one. */
569		case PT_DYNAMIC:
570		case PT_NOTE:
571			break;
572
573		case PT_PHDR:
574			/* Note address of program headers (in text segment) */
575			phdr = pp->p_vaddr;
576			break;
577
578		default:
579			/*
580			 * Not fatal; we don't need to understand everything.
581			 */
582			break;
583		}
584	}
585
586	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
587#ifndef ELF_INTERP_NON_RELOCATABLE
588	/*
589	 * If no position to load the interpreter was set by a probe
590	 * function, pick the same address that a non-fixed mmap(0, ..)
591	 * would (i.e. something safely out of the way).
592	 */
593	if (pos == ELFDEFNNAME(NO_ADDR))
594		pos = round_page(epp->ep_daddr + MAXDSIZ);
595#endif	/* !ELF_INTERP_NON_RELOCATABLE */
596
597	/*
598	 * Check if we found a dynamically linked binary and arrange to load
599	 * it's interpreter
600	 */
601	if (interp[0]) {
602		struct elf_args *ap;
603
604		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
605		    M_TEMP, M_WAITOK);
606		if ((error = ELFNAME(load_file)(p, epp, interp,
607		    &epp->ep_vmcmds, &epp->ep_entry, ap, &pos)) != 0) {
608			FREE(ap, M_TEMP);
609			goto bad;
610		}
611		ap->arg_phaddr = phdr;
612
613		ap->arg_phentsize = eh->e_phentsize;
614		ap->arg_phnum = eh->e_phnum;
615		ap->arg_entry = eh->e_entry;
616
617		epp->ep_emul_arg = ap;
618	} else
619		epp->ep_entry = eh->e_entry;
620
621#ifdef ELF_MAP_PAGE_ZERO
622	/* Dell SVR4 maps page zero, yeuch! */
623	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
624	    epp->ep_vp, 0, VM_PROT_READ);
625#endif
626	FREE(interp, M_TEMP);
627	free(ph, M_TEMP);
628	return exec_elf_setup_stack(p, epp);
629
630bad:
631	if (interp)
632		FREE(interp, M_TEMP);
633	free(ph, M_TEMP);
634	kill_vmcmds(&epp->ep_vmcmds);
635	return ENOEXEC;
636}
637
638int
639ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
640    Elf_Ehdr *eh)
641{
642	size_t i;
643	Elf_Phdr *ph;
644	size_t phsize;
645	int error;
646
647	phsize = eh->e_phnum * sizeof(Elf_Phdr);
648	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
649	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
650	if (error)
651		goto out;
652
653	for (i = 0; i < eh->e_phnum; i++) {
654		Elf_Phdr *ephp = &ph[i];
655		Elf_Nhdr *np;
656
657		if (ephp->p_type != PT_NOTE ||
658		    ephp->p_filesz > 1024 ||
659		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
660			continue;
661
662		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
663		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
664		    ephp->p_filesz);
665		if (error)
666			goto next;
667
668		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
669		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
670		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
671		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
672		    ELF_NOTE_NETBSD_NAMESZ))
673			goto next;
674
675		error = 0;
676		free(np, M_TEMP);
677		goto out;
678
679	next:
680		free(np, M_TEMP);
681		continue;
682	}
683
684	error = ENOEXEC;
685out:
686	free(ph, M_TEMP);
687	return (error);
688}
689
690int
691ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
692    void *eh, char *itp, vaddr_t *pos)
693{
694	int error;
695
696	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
697		return error;
698	*pos = ELFDEFNNAME(NO_ADDR);
699	return 0;
700}
701