exec_elf32.c revision 1.77
1/*	$NetBSD: exec_elf32.c,v 1.77 2002/11/13 15:49:44 jdolecek 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 1.77 2002/11/13 15:49:44 jdolecek 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		struct vattr *vap = pack->ep_vap;
130
131		a->a_type = AT_PHDR;
132		a->a_v = ap->arg_phaddr;
133		a++;
134
135		a->a_type = AT_PHENT;
136		a->a_v = ap->arg_phentsize;
137		a++;
138
139		a->a_type = AT_PHNUM;
140		a->a_v = ap->arg_phnum;
141		a++;
142
143		a->a_type = AT_PAGESZ;
144		a->a_v = PAGE_SIZE;
145		a++;
146
147		a->a_type = AT_BASE;
148		a->a_v = ap->arg_interp;
149		a++;
150
151		a->a_type = AT_FLAGS;
152		a->a_v = 0;
153		a++;
154
155		a->a_type = AT_ENTRY;
156		a->a_v = ap->arg_entry;
157		a++;
158
159		a->a_type = AT_EUID;
160		if (vap->va_mode & S_ISUID)
161			a->a_v = vap->va_uid;
162		else
163			a->a_v = p->p_ucred->cr_uid;
164		a++;
165
166		a->a_type = AT_RUID;
167		a->a_v = p->p_cred->p_ruid;
168		a++;
169
170		a->a_type = AT_EGID;
171		if (vap->va_mode & S_ISGID)
172			a->a_v = vap->va_gid;
173		else
174			a->a_v = p->p_ucred->cr_gid;
175		a++;
176
177		a->a_type = AT_RGID;
178		a->a_v = p->p_cred->p_rgid;
179		a++;
180
181		free(ap, M_TEMP);
182		pack->ep_emul_arg = NULL;
183	}
184
185	a->a_type = AT_NULL;
186	a->a_v = 0;
187	a++;
188
189	len = (a - ai) * sizeof(AuxInfo);
190	if ((error = copyout(ai, *stackp, len)) != 0)
191		return error;
192	*stackp += len;
193
194	return 0;
195}
196
197/*
198 * elf_check_header():
199 *
200 * Check header for validity; return 0 of ok ENOEXEC if error
201 */
202int
203ELFNAME(check_header)(Elf_Ehdr *eh, int type)
204{
205
206	if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
207	    eh->e_ident[EI_CLASS] != ELFCLASS)
208		return (ENOEXEC);
209
210	switch (eh->e_machine) {
211
212	ELFDEFNNAME(MACHDEP_ID_CASES)
213
214	default:
215		return (ENOEXEC);
216	}
217
218	if (ELF_EHDR_FLAGS_OK(eh) == 0)
219		return (ENOEXEC);
220
221	if (eh->e_type != type)
222		return (ENOEXEC);
223
224	if (eh->e_shnum > 512 ||
225	    eh->e_phnum > 128)
226		return (ENOEXEC);
227
228	return (0);
229}
230
231/*
232 * elf_load_psection():
233 *
234 * Load a psection at the appropriate address
235 */
236void
237ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
238    const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags)
239{
240	u_long uaddr, msize, psize, rm, rf;
241	long diff, offset;
242
243	/*
244	 * If the user specified an address, then we load there.
245	 */
246	if (*addr != ELFDEFNNAME(NO_ADDR)) {
247		if (ph->p_align > 1) {
248			*addr = ELF_TRUNC(*addr, ph->p_align);
249			uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
250		} else
251			uaddr = ph->p_vaddr;
252		diff = ph->p_vaddr - uaddr;
253	} else {
254		*addr = uaddr = ph->p_vaddr;
255		if (ph->p_align > 1)
256			*addr = ELF_TRUNC(uaddr, ph->p_align);
257		diff = uaddr - *addr;
258	}
259
260	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
261	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
262	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
263
264	offset = ph->p_offset - diff;
265	*size = ph->p_filesz + diff;
266	msize = ph->p_memsz + diff;
267
268	if (ph->p_align >= PAGE_SIZE) {
269		if ((ph->p_flags & PF_W) != 0) {
270			/*
271			 * Because the pagedvn pager can't handle zero fill
272			 * of the last data page if it's not page aligned we
273			 * map the last page readvn.
274			 */
275			psize = trunc_page(*size);
276		} else {
277			psize = round_page(*size);
278		}
279	} else {
280		psize = *size;
281	}
282
283	if (psize > 0) {
284		NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
285		    vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
286		    offset, *prot, flags);
287	}
288	if (psize < *size) {
289		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
290		    *addr + psize, vp, offset + psize, *prot,
291		    psize > 0 ? flags & VMCMD_RELATIVE : flags);
292	}
293
294	/*
295	 * Check if we need to extend the size of the segment
296	 */
297	rm = round_page(*addr + msize);
298	rf = round_page(*addr + *size);
299
300	if (rm != rf) {
301		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
302		    0, *prot, flags & VMCMD_RELATIVE);
303		*size = msize;
304	}
305}
306
307/*
308 * elf_load_file():
309 *
310 * Load a file (interpreter/library) pointed to by path
311 * [stolen from coff_load_shlib()]. Made slightly generic
312 * so it might be used externally.
313 */
314int
315ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
316    struct exec_vmcmd_set *vcset, u_long *entry, struct elf_args *ap,
317    Elf_Addr *last)
318{
319	int error, i;
320	struct nameidata nd;
321	struct vnode *vp;
322	struct vattr attr;
323	Elf_Ehdr eh;
324	Elf_Phdr *ph = NULL;
325	Elf_Phdr *base_ph = NULL;
326	u_long phsize;
327	char *bp = NULL;
328	Elf_Addr addr = *last;
329
330	bp = path;
331	/*
332	 * 1. open file
333	 * 2. read filehdr
334	 * 3. map text, data, and bss out of it using VM_*
335	 */
336	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
337	if ((error = namei(&nd)) != 0)
338		return error;
339	vp = nd.ni_vp;
340
341	/*
342	 * Similarly, if it's not marked as executable, or it's not a regular
343	 * file, we don't allow it to be used.
344	 */
345	if (vp->v_type != VREG) {
346		error = EACCES;
347		goto badunlock;
348	}
349	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
350		goto badunlock;
351
352	/* get attributes */
353	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
354		goto badunlock;
355
356	/*
357	 * Check mount point.  Though we're not trying to exec this binary,
358	 * we will be executing code from it, so if the mount point
359	 * disallows execution or set-id-ness, we punt or kill the set-id.
360	 */
361	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
362		error = EACCES;
363		goto badunlock;
364	}
365	if (vp->v_mount->mnt_flag & MNT_NOSUID)
366		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
367
368#ifdef notyet /* XXX cgd 960926 */
369	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
370#endif
371
372	error = vn_marktext(vp);
373	if (error)
374		goto badunlock;
375
376	VOP_UNLOCK(vp, 0);
377
378	if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0)
379		goto bad;
380
381	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
382		goto bad;
383
384	phsize = eh.e_phnum * sizeof(Elf_Phdr);
385	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
386
387	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
388		goto bad;
389
390	/*
391	 * Load all the necessary sections
392	 */
393	for (i = 0; i < eh.e_phnum; i++) {
394		u_long size = 0;
395		int prot = 0;
396		int flags;
397
398		switch (ph[i].p_type) {
399		case PT_LOAD:
400			if (base_ph == NULL) {
401				addr = *last;
402				flags = VMCMD_BASE;
403			} else {
404				addr = ph[i].p_vaddr - base_ph->p_vaddr;
405				flags = VMCMD_RELATIVE;
406			}
407			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
408			    &size, &prot, flags);
409			/* If entry is within this section it must be text */
410			if (eh.e_entry >= ph[i].p_vaddr &&
411			    eh.e_entry < (ph[i].p_vaddr + size)) {
412				*entry = addr + eh.e_entry - ph[i].p_vaddr;
413				ap->arg_interp = addr;
414			}
415			if (base_ph == NULL)
416				base_ph = &ph[i];
417			addr += size;
418			break;
419
420		case PT_DYNAMIC:
421		case PT_PHDR:
422		case PT_NOTE:
423			break;
424
425		default:
426			break;
427		}
428	}
429
430	free(ph, M_TEMP);
431	*last = addr;
432	vrele(vp);
433	return 0;
434
435badunlock:
436	VOP_UNLOCK(vp, 0);
437
438bad:
439	if (ph != NULL)
440		free(ph, M_TEMP);
441#ifdef notyet /* XXX cgd 960926 */
442	(maybe) VOP_CLOSE it
443#endif
444	vrele(vp);
445	return error;
446}
447
448/*
449 * exec_elf_makecmds(): Prepare an Elf binary's exec package
450 *
451 * First, set of the various offsets/lengths in the exec package.
452 *
453 * Then, mark the text image busy (so it can be demand paged) or error
454 * out if this is not possible.  Finally, set up vmcmds for the
455 * text, data, bss, and stack segments.
456 */
457int
458ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
459{
460	Elf_Ehdr *eh = epp->ep_hdr;
461	Elf_Phdr *ph, *pp;
462	Elf_Addr phdr = 0, pos = 0;
463	int error, i, nload;
464	char *interp = NULL;
465	u_long phsize;
466
467	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
468		return ENOEXEC;
469
470	/*
471	 * XXX allow for executing shared objects. It seems silly
472	 * but other ELF-based systems allow it as well.
473	 */
474	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
475	    ELFNAME(check_header)(eh, ET_DYN) != 0)
476		return ENOEXEC;
477
478	error = vn_marktext(epp->ep_vp);
479	if (error)
480		return (error);
481
482	/*
483	 * Allocate space to hold all the program headers, and read them
484	 * from the file
485	 */
486	phsize = eh->e_phnum * sizeof(Elf_Phdr);
487	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
488
489	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
490	    0)
491		goto bad;
492
493	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
494	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
495
496	MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
497	interp[0] = '\0';
498
499	for (i = 0; i < eh->e_phnum; i++) {
500		pp = &ph[i];
501		if (pp->p_type == PT_INTERP) {
502			if (pp->p_filesz >= MAXPATHLEN)
503				goto bad;
504			if ((error = exec_read_from(p, epp->ep_vp,
505			    pp->p_offset, interp, pp->p_filesz)) != 0)
506				goto bad;
507			break;
508		}
509	}
510
511	/*
512	 * On the same architecture, we may be emulating different systems.
513	 * See which one will accept this executable. This currently only
514	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
515	 * and the Alpha.
516	 *
517	 * Probe functions would normally see if the interpreter (if any)
518	 * exists. Emulation packages may possibly replace the interpreter in
519	 * interp[] with a changed path (/emul/xxx/<path>).
520	 */
521	if (!epp->ep_esch->u.elf_probe_func) {
522		pos = ELFDEFNNAME(NO_ADDR);
523	} else {
524		vaddr_t startp = 0;
525
526		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
527							  &startp);
528		pos = (Elf_Addr)startp;
529		if (error)
530			goto bad;
531	}
532
533	/*
534	 * Load all the necessary sections
535	 */
536	for (i = nload = 0; i < eh->e_phnum; i++) {
537		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
538		u_long size = 0;
539		int prot = 0;
540
541		pp = &ph[i];
542
543		switch (ph[i].p_type) {
544		case PT_LOAD:
545			/*
546			 * XXX
547			 * Can handle only 2 sections: text and data
548			 */
549			if (nload++ == 2)
550				goto bad;
551			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
552			    &ph[i], &addr, &size, &prot, 0);
553
554			/*
555			 * Decide whether it's text or data by looking
556			 * at the entry point.
557			 */
558			if (eh->e_entry >= addr &&
559			    eh->e_entry < (addr + size)) {
560				epp->ep_taddr = addr;
561				epp->ep_tsize = size;
562				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
563					epp->ep_daddr = addr;
564					epp->ep_dsize = size;
565				}
566			} else {
567				epp->ep_daddr = addr;
568				epp->ep_dsize = size;
569			}
570			break;
571
572		case PT_SHLIB:
573			/* SCO has these sections. */
574		case PT_INTERP:
575			/* Already did this one. */
576		case PT_DYNAMIC:
577		case PT_NOTE:
578			break;
579
580		case PT_PHDR:
581			/* Note address of program headers (in text segment) */
582			phdr = pp->p_vaddr;
583			break;
584
585		default:
586			/*
587			 * Not fatal; we don't need to understand everything.
588			 */
589			break;
590		}
591	}
592
593	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
594#ifndef ELF_INTERP_NON_RELOCATABLE
595	/*
596	 * If no position to load the interpreter was set by a probe
597	 * function, pick the same address that a non-fixed mmap(0, ..)
598	 * would (i.e. something safely out of the way).
599	 */
600	if (pos == ELFDEFNNAME(NO_ADDR))
601		pos = round_page(epp->ep_daddr + MAXDSIZ);
602#endif	/* !ELF_INTERP_NON_RELOCATABLE */
603
604	/*
605	 * Check if we found a dynamically linked binary and arrange to load
606	 * it's interpreter
607	 */
608	if (interp[0]) {
609		struct elf_args *ap;
610
611		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
612		    M_TEMP, M_WAITOK);
613		if ((error = ELFNAME(load_file)(p, epp, interp,
614		    &epp->ep_vmcmds, &epp->ep_entry, ap, &pos)) != 0) {
615			FREE(ap, M_TEMP);
616			goto bad;
617		}
618		ap->arg_phaddr = phdr;
619
620		ap->arg_phentsize = eh->e_phentsize;
621		ap->arg_phnum = eh->e_phnum;
622		ap->arg_entry = eh->e_entry;
623
624		epp->ep_emul_arg = ap;
625	} else
626		epp->ep_entry = eh->e_entry;
627
628#ifdef ELF_MAP_PAGE_ZERO
629	/* Dell SVR4 maps page zero, yeuch! */
630	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
631	    epp->ep_vp, 0, VM_PROT_READ);
632#endif
633	FREE(interp, M_TEMP);
634	free(ph, M_TEMP);
635	return exec_elf_setup_stack(p, epp);
636
637bad:
638	if (interp)
639		FREE(interp, M_TEMP);
640	free(ph, M_TEMP);
641	kill_vmcmds(&epp->ep_vmcmds);
642	return ENOEXEC;
643}
644
645int
646ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
647    Elf_Ehdr *eh)
648{
649	size_t i;
650	Elf_Phdr *ph;
651	size_t phsize;
652	int error;
653
654	phsize = eh->e_phnum * sizeof(Elf_Phdr);
655	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
656	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
657	if (error)
658		goto out;
659
660	for (i = 0; i < eh->e_phnum; i++) {
661		Elf_Phdr *ephp = &ph[i];
662		Elf_Nhdr *np;
663
664		if (ephp->p_type != PT_NOTE ||
665		    ephp->p_filesz > 1024 ||
666		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
667			continue;
668
669		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
670		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
671		    ephp->p_filesz);
672		if (error)
673			goto next;
674
675		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
676		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
677		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
678		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
679		    ELF_NOTE_NETBSD_NAMESZ))
680			goto next;
681
682		error = 0;
683		free(np, M_TEMP);
684		goto out;
685
686	next:
687		free(np, M_TEMP);
688		continue;
689	}
690
691	error = ENOEXEC;
692out:
693	free(ph, M_TEMP);
694	return (error);
695}
696
697int
698ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
699    void *eh, char *itp, vaddr_t *pos)
700{
701	int error;
702
703	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
704		return error;
705	*pos = ELFDEFNNAME(NO_ADDR);
706	return 0;
707}
708