exec_elf32.c revision 1.82
1/*	$NetBSD: exec_elf32.c,v 1.82 2003/02/26 21:18:22 matt 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 1.82 2003/02/26 21:18:22 matt 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 ((flags & (VMCMD_TOPDOWN|VMCMD_RELATIVE)) == VMCMD_TOPDOWN)
284		*addr -= round_page(msize);
285	if (psize > 0) {
286		NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
287		    vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
288		    offset, *prot, flags);
289	}
290	if (psize < *size) {
291		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
292		    *addr + psize, vp, offset + psize, *prot,
293		    psize > 0 ? flags & (VMCMD_RELATIVE | VMCMD_TOPDOWN) : flags);
294	}
295
296	/*
297	 * Check if we need to extend the size of the segment
298	 */
299	rm = round_page(*addr + msize);
300	rf = round_page(*addr + *size);
301
302	if (rm != rf) {
303		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
304		    0, *prot, flags & (VMCMD_RELATIVE | VMCMD_TOPDOWN));
305		*size = msize;
306	}
307}
308
309/*
310 * elf_load_file():
311 *
312 * Load a file (interpreter/library) pointed to by path
313 * [stolen from coff_load_shlib()]. Made slightly generic
314 * so it might be used externally.
315 */
316int
317ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
318    struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap,
319    Elf_Addr *last)
320{
321	int error, i, direction, end;
322	const int topdown =
323	    p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN ? VMCMD_TOPDOWN : 0;
324	struct nameidata nd;
325	struct vnode *vp;
326	struct vattr attr;
327	Elf_Ehdr eh;
328	Elf_Phdr *ph = NULL;
329	Elf_Phdr *base_ph = NULL;
330	u_long phsize;
331	Elf_Addr addr = *last;
332
333	/*
334	 * 1. open file
335	 * 2. read filehdr
336	 * 3. map text, data, and bss out of it using VM_*
337	 */
338	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
339	if ((error = namei(&nd)) != 0)
340		return error;
341	vp = nd.ni_vp;
342
343	/*
344	 * Similarly, if it's not marked as executable, or it's not a regular
345	 * file, we don't allow it to be used.
346	 */
347	if (vp->v_type != VREG) {
348		error = EACCES;
349		goto badunlock;
350	}
351	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
352		goto badunlock;
353
354	/* get attributes */
355	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
356		goto badunlock;
357
358	/*
359	 * Check mount point.  Though we're not trying to exec this binary,
360	 * we will be executing code from it, so if the mount point
361	 * disallows execution or set-id-ness, we punt or kill the set-id.
362	 */
363	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
364		error = EACCES;
365		goto badunlock;
366	}
367	if (vp->v_mount->mnt_flag & MNT_NOSUID)
368		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
369
370#ifdef notyet /* XXX cgd 960926 */
371	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
372#endif
373
374	error = vn_marktext(vp);
375	if (error)
376		goto badunlock;
377
378	VOP_UNLOCK(vp, 0);
379
380	if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0)
381		goto bad;
382
383	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
384		goto bad;
385
386	phsize = eh.e_phnum * sizeof(Elf_Phdr);
387	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
388
389	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
390		goto bad;
391
392	/*
393	 * Load all the necessary sections.  If TOPDOWN, load the
394	 * psections last to first to properly deal with spacing and
395	 * alignment between psections, if any.  Note that end is one
396	 * past the last (before or after) valid array index.
397	 */
398	if (topdown) {
399		i = eh.e_phnum - 1;
400		end = -1;
401		direction = -1;
402	} else {
403		i = 0;
404		end = eh.e_phnum;
405		direction = 1;
406	}
407	for (; i != end; i += direction) {
408		u_long size = 0;
409		int prot = 0;
410		int flags;
411
412		switch (ph[i].p_type) {
413		case PT_LOAD:
414			if (base_ph == NULL) {
415				/*
416				 * First encountered psection is always the
417				 * base psection.
418				 */
419				base_ph = &ph[i];
420				addr = *last;
421				flags = VMCMD_BASE;
422			} else {
423				/*
424				 * If TOPDOWN, the last psection may not be
425				 * page aligned.  Make sure that the address
426				 * we are using is page aligned.  If TOPDOWN
427				 * addr will be a "negative" offset.
428				 */
429				addr = ph[i].p_vaddr -
430				    trunc_page(base_ph->p_vaddr);
431				flags = VMCMD_RELATIVE;
432			}
433			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
434			    &size, &prot, flags|topdown);
435			/*
436			 * If entry is within this psection then this
437			 * must contain the .text section.  *entryoff is
438			 * relative to the (page aligned) base psection.
439			 * If TOPDOWN, entryoff may be backwards.
440			 */
441			if (eh.e_entry >= ph[i].p_vaddr &&
442			    eh.e_entry < (ph[i].p_vaddr + size)) {
443				*entryoff = eh.e_entry -
444				    trunc_page(base_ph->p_vaddr);
445			}
446			/*
447			 * This value is ignored if TOPDOWN.
448			 */
449			if (ph[i].p_vaddr != 0)
450				addr += size;
451			break;
452
453		case PT_DYNAMIC:
454		case PT_PHDR:
455		case PT_NOTE:
456			break;
457
458		default:
459			break;
460		}
461	}
462
463	free(ph, M_TEMP);
464	/*
465	 * This value is ignored if TOPDOWN.
466	 */
467	*last = addr;
468	vrele(vp);
469	return 0;
470
471badunlock:
472	VOP_UNLOCK(vp, 0);
473
474bad:
475	if (ph != NULL)
476		free(ph, M_TEMP);
477#ifdef notyet /* XXX cgd 960926 */
478	(maybe) VOP_CLOSE it
479#endif
480	vrele(vp);
481	return error;
482}
483
484/*
485 * exec_elf_makecmds(): Prepare an Elf binary's exec package
486 *
487 * First, set of the various offsets/lengths in the exec package.
488 *
489 * Then, mark the text image busy (so it can be demand paged) or error
490 * out if this is not possible.  Finally, set up vmcmds for the
491 * text, data, bss, and stack segments.
492 */
493int
494ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
495{
496	Elf_Ehdr *eh = epp->ep_hdr;
497	Elf_Phdr *ph, *pp;
498	Elf_Addr phdr = 0, pos = 0;
499	int error, i, nload;
500	char *interp = NULL;
501	u_long phsize;
502
503	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
504		return ENOEXEC;
505
506	/*
507	 * XXX allow for executing shared objects. It seems silly
508	 * but other ELF-based systems allow it as well.
509	 */
510	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
511	    ELFNAME(check_header)(eh, ET_DYN) != 0)
512		return ENOEXEC;
513
514	error = vn_marktext(epp->ep_vp);
515	if (error)
516		return (error);
517
518	/*
519	 * Allocate space to hold all the program headers, and read them
520	 * from the file
521	 */
522	phsize = eh->e_phnum * sizeof(Elf_Phdr);
523	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
524
525	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
526	    0)
527		goto bad;
528
529	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
530	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
531
532	MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
533	interp[0] = '\0';
534
535	for (i = 0; i < eh->e_phnum; i++) {
536		pp = &ph[i];
537		if (pp->p_type == PT_INTERP) {
538			if (pp->p_filesz >= MAXPATHLEN)
539				goto bad;
540			if ((error = exec_read_from(p, epp->ep_vp,
541			    pp->p_offset, interp, pp->p_filesz)) != 0)
542				goto bad;
543			break;
544		}
545	}
546
547	/*
548	 * On the same architecture, we may be emulating different systems.
549	 * See which one will accept this executable. This currently only
550	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
551	 * and the Alpha.
552	 *
553	 * Probe functions would normally see if the interpreter (if any)
554	 * exists. Emulation packages may possibly replace the interpreter in
555	 * interp[] with a changed path (/emul/xxx/<path>).
556	 */
557	if (!epp->ep_esch->u.elf_probe_func) {
558		pos = ELFDEFNNAME(NO_ADDR);
559	} else {
560		vaddr_t startp = 0;
561
562		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
563							  &startp);
564		pos = (Elf_Addr)startp;
565		if (error)
566			goto bad;
567	}
568
569	/*
570	 * Load all the necessary sections
571	 */
572	for (i = nload = 0; i < eh->e_phnum; i++) {
573		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
574		u_long size = 0;
575		int prot = 0;
576
577		pp = &ph[i];
578
579		switch (ph[i].p_type) {
580		case PT_LOAD:
581			/*
582			 * XXX
583			 * Can handle only 2 sections: text and data
584			 */
585			if (nload++ == 2)
586				goto bad;
587			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
588			    &ph[i], &addr, &size, &prot, VMCMD_FIXED);
589
590			/*
591			 * Decide whether it's text or data by looking
592			 * at the entry point.
593			 */
594			if (eh->e_entry >= addr &&
595			    eh->e_entry < (addr + size)) {
596				epp->ep_taddr = addr;
597				epp->ep_tsize = size;
598				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
599					epp->ep_daddr = addr;
600					epp->ep_dsize = size;
601				}
602			} else {
603				epp->ep_daddr = addr;
604				epp->ep_dsize = size;
605			}
606			break;
607
608		case PT_SHLIB:
609			/* SCO has these sections. */
610		case PT_INTERP:
611			/* Already did this one. */
612		case PT_DYNAMIC:
613		case PT_NOTE:
614			break;
615
616		case PT_PHDR:
617			/* Note address of program headers (in text segment) */
618			phdr = pp->p_vaddr;
619			break;
620
621		default:
622			/*
623			 * Not fatal; we don't need to understand everything.
624			 */
625			break;
626		}
627	}
628
629	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
630#ifndef ELF_INTERP_NON_RELOCATABLE
631	/*
632	 * If no position to load the interpreter was set by a probe
633	 * function, pick the same address that a non-fixed mmap(0, ..)
634	 * would (i.e. something safely out of the way).
635	 */
636	if (pos == ELFDEFNNAME(NO_ADDR))
637		/* XXX size will be accounted for in load_psection */
638		pos = VM_DEFAULT_ADDRESS(epp->ep_daddr, 0);
639#endif	/* !ELF_INTERP_NON_RELOCATABLE */
640
641	/*
642	 * Check if we found a dynamically linked binary and arrange to load
643	 * its interpreter
644	 */
645	if (interp[0]) {
646		struct elf_args *ap;
647		int i = epp->ep_vmcmds.evs_used;
648		u_long interp_offset;
649
650		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
651		    M_TEMP, M_WAITOK);
652		if ((error = ELFNAME(load_file)(p, epp, interp,
653		    &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) {
654			FREE(ap, M_TEMP);
655			goto bad;
656		}
657		ap->arg_interp = epp->ep_vmcmds.evs_cmds[i].ev_addr;
658		epp->ep_entry = ap->arg_interp + interp_offset;
659		ap->arg_phaddr = phdr;
660
661		ap->arg_phentsize = eh->e_phentsize;
662		ap->arg_phnum = eh->e_phnum;
663		ap->arg_entry = eh->e_entry;
664
665		epp->ep_emul_arg = ap;
666	} else
667		epp->ep_entry = eh->e_entry;
668
669#ifdef ELF_MAP_PAGE_ZERO
670	/* Dell SVR4 maps page zero, yeuch! */
671	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
672	    epp->ep_vp, 0, VM_PROT_READ);
673#endif
674	FREE(interp, M_TEMP);
675	free(ph, M_TEMP);
676	return exec_elf_setup_stack(p, epp);
677
678bad:
679	if (interp)
680		FREE(interp, M_TEMP);
681	free(ph, M_TEMP);
682	kill_vmcmds(&epp->ep_vmcmds);
683	return ENOEXEC;
684}
685
686int
687ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
688    Elf_Ehdr *eh)
689{
690	size_t i;
691	Elf_Phdr *ph;
692	size_t phsize;
693	int error;
694
695	phsize = eh->e_phnum * sizeof(Elf_Phdr);
696	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
697	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
698	if (error)
699		goto out;
700
701	for (i = 0; i < eh->e_phnum; i++) {
702		Elf_Phdr *ephp = &ph[i];
703		Elf_Nhdr *np;
704
705		if (ephp->p_type != PT_NOTE ||
706		    ephp->p_filesz > 1024 ||
707		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
708			continue;
709
710		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
711		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
712		    ephp->p_filesz);
713		if (error)
714			goto next;
715
716		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
717		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
718		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
719		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
720		    ELF_NOTE_NETBSD_NAMESZ))
721			goto next;
722
723		error = 0;
724		free(np, M_TEMP);
725		goto out;
726
727	next:
728		free(np, M_TEMP);
729		continue;
730	}
731
732	error = ENOEXEC;
733out:
734	free(ph, M_TEMP);
735	return (error);
736}
737
738int
739ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
740    void *eh, char *itp, vaddr_t *pos)
741{
742	int error;
743
744	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
745		return error;
746	*pos = ELFDEFNNAME(NO_ADDR);
747	return 0;
748}
749