exec_elf32.c revision 1.102
1/*	$NetBSD: exec_elf32.c,v 1.102 2005/03/02 11:05:34 mycroft Exp $	*/
2
3/*-
4 * Copyright (c) 1994, 2000, 2005 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 1.102 2005/03/02 11:05:34 mycroft 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(load_file)(struct proc *, struct exec_package *, char *,
92	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *);
93void	ELFNAME(load_psection)(struct exec_vmcmd_set *, struct vnode *,
94	    const Elf_Phdr *, Elf_Addr *, u_long *, int *, int);
95
96int ELFNAME2(netbsd,signature)(struct proc *, struct exec_package *,
97    Elf_Ehdr *);
98int ELFNAME2(netbsd,probe)(struct proc *, struct exec_package *,
99    void *, char *, vaddr_t *);
100
101/* round up and down to page boundaries. */
102#define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
103#define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
104
105#define MAXPHNUM	50
106
107/*
108 * Copy arguments onto the stack in the normal way, but add some
109 * extra information in case of dynamic binding.
110 */
111int
112ELFNAME(copyargs)(struct proc *p, struct exec_package *pack,
113    struct ps_strings *arginfo, char **stackp, void *argp)
114{
115	size_t len;
116	AuxInfo ai[ELF_AUX_ENTRIES], *a;
117	struct elf_args *ap;
118	int error;
119
120	if ((error = copyargs(p, pack, arginfo, stackp, argp)) != 0)
121		return error;
122
123	a = ai;
124
125	/*
126	 * Push extra arguments on the stack needed by dynamically
127	 * linked binaries
128	 */
129	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
130		struct vattr *vap = pack->ep_vap;
131
132		a->a_type = AT_PHDR;
133		a->a_v = ap->arg_phaddr;
134		a++;
135
136		a->a_type = AT_PHENT;
137		a->a_v = ap->arg_phentsize;
138		a++;
139
140		a->a_type = AT_PHNUM;
141		a->a_v = ap->arg_phnum;
142		a++;
143
144		a->a_type = AT_PAGESZ;
145		a->a_v = PAGE_SIZE;
146		a++;
147
148		a->a_type = AT_BASE;
149		a->a_v = ap->arg_interp;
150		a++;
151
152		a->a_type = AT_FLAGS;
153		a->a_v = 0;
154		a++;
155
156		a->a_type = AT_ENTRY;
157		a->a_v = ap->arg_entry;
158		a++;
159
160		a->a_type = AT_EUID;
161		if (vap->va_mode & S_ISUID)
162			a->a_v = vap->va_uid;
163		else
164			a->a_v = p->p_ucred->cr_uid;
165		a++;
166
167		a->a_type = AT_RUID;
168		a->a_v = p->p_cred->p_ruid;
169		a++;
170
171		a->a_type = AT_EGID;
172		if (vap->va_mode & S_ISGID)
173			a->a_v = vap->va_gid;
174		else
175			a->a_v = p->p_ucred->cr_gid;
176		a++;
177
178		a->a_type = AT_RGID;
179		a->a_v = p->p_cred->p_rgid;
180		a++;
181
182		free(ap, M_TEMP);
183		pack->ep_emul_arg = NULL;
184	}
185
186	a->a_type = AT_NULL;
187	a->a_v = 0;
188	a++;
189
190	len = (a - ai) * sizeof(AuxInfo);
191	if ((error = copyout(ai, *stackp, len)) != 0)
192		return error;
193	*stackp += len;
194
195	return 0;
196}
197
198/*
199 * elf_check_header():
200 *
201 * Check header for validity; return 0 of ok ENOEXEC if error
202 */
203int
204ELFNAME(check_header)(Elf_Ehdr *eh, int type)
205{
206
207	if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
208	    eh->e_ident[EI_CLASS] != ELFCLASS)
209		return (ENOEXEC);
210
211	switch (eh->e_machine) {
212
213	ELFDEFNNAME(MACHDEP_ID_CASES)
214
215	default:
216		return (ENOEXEC);
217	}
218
219	if (ELF_EHDR_FLAGS_OK(eh) == 0)
220		return (ENOEXEC);
221
222	if (eh->e_type != type)
223		return (ENOEXEC);
224
225	if (eh->e_shnum > 32768 || 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 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		*addr = ph->p_vaddr;
248
249	if (ph->p_align > 1) {
250		/*
251		 * Make sure we are virtually aligned as we are supposed to be.
252		 */
253		diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align);
254		KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align));
255		/*
256		 * But make sure to not map any pages before the start of the
257		 * psection by limiting the difference to within a page.
258		 */
259		diff &= PAGE_MASK;
260	} else
261		diff = 0;
262
263	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
264	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
265	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
266
267	/*
268	 * Adjust everything so it all starts on a page boundary.
269	 */
270	*addr -= diff;
271	offset = ph->p_offset - diff;
272	*size = ph->p_filesz + diff;
273	msize = ph->p_memsz + diff;
274
275	if (ph->p_align >= PAGE_SIZE) {
276		if ((ph->p_flags & PF_W) != 0) {
277			/*
278			 * Because the pagedvn pager can't handle zero fill
279			 * of the last data page if it's not page aligned we
280			 * map the last page readvn.
281			 */
282			psize = trunc_page(*size);
283		} else {
284			psize = round_page(*size);
285		}
286	} else {
287		psize = *size;
288	}
289
290	if (psize > 0) {
291		NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
292		    vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
293		    offset, *prot, flags);
294		flags &= VMCMD_RELATIVE;
295	}
296	if (psize < *size) {
297		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
298		    *addr + psize, vp, offset + psize, *prot, flags);
299	}
300
301	/*
302	 * Check if we need to extend the size of the segment (does
303	 * bss extend page the next page boundary)?
304	 */
305	rm = round_page(*addr + msize);
306	rf = round_page(*addr + *size);
307
308	if (rm != rf) {
309		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
310		    0, *prot, flags & VMCMD_RELATIVE);
311		*size = msize;
312	}
313}
314
315/*
316 * elf_load_file():
317 *
318 * Load a file (interpreter/library) pointed to by path
319 * [stolen from coff_load_shlib()]. Made slightly generic
320 * so it might be used externally.
321 */
322int
323ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
324    struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap,
325    Elf_Addr *last)
326{
327	int error, i;
328	struct nameidata nd;
329	struct vnode *vp;
330	struct vattr attr;
331	Elf_Ehdr eh;
332	Elf_Phdr *ph = NULL;
333	const Elf_Phdr *ph0;
334	const Elf_Phdr *base_ph;
335	const Elf_Phdr *last_ph;
336	u_long phsize;
337	Elf_Addr addr = *last;
338
339	/*
340	 * 1. open file
341	 * 2. read filehdr
342	 * 3. map text, data, and bss out of it using VM_*
343	 */
344	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
345	if ((error = namei(&nd)) != 0)
346		return error;
347	vp = nd.ni_vp;
348
349	/*
350	 * Similarly, if it's not marked as executable, or it's not a regular
351	 * file, we don't allow it to be used.
352	 */
353	if (vp->v_type != VREG) {
354		error = EACCES;
355		goto badunlock;
356	}
357	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
358		goto badunlock;
359
360	/* get attributes */
361	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
362		goto badunlock;
363
364	/*
365	 * Check mount point.  Though we're not trying to exec this binary,
366	 * we will be executing code from it, so if the mount point
367	 * disallows execution or set-id-ness, we punt or kill the set-id.
368	 */
369	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
370		error = EACCES;
371		goto badunlock;
372	}
373	if (vp->v_mount->mnt_flag & MNT_NOSUID)
374		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
375
376#ifdef notyet /* XXX cgd 960926 */
377	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
378#endif
379
380	error = vn_marktext(vp);
381	if (error)
382		goto badunlock;
383
384	VOP_UNLOCK(vp, 0);
385
386	if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0)
387		goto bad;
388
389	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
390		goto bad;
391
392	if (eh.e_phnum > MAXPHNUM)
393		goto bad;
394
395	phsize = eh.e_phnum * sizeof(Elf_Phdr);
396	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
397
398	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
399		goto bad;
400
401	/*
402	 * If no position to load the interpreter was set by a probe
403	 * function, pick the same address that a non-fixed mmap(0, ..)
404	 * would (i.e. something safely out of the way).
405	 */
406	if (*last == ELFDEFNNAME(NO_ADDR)) {
407		u_long limit = 0;
408		/*
409		 * Find the start and ending addresses of the psections to
410		 * be loaded.  This will give us the size.
411		 */
412		for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum;
413		     i++, ph0++) {
414			if (ph0->p_type == PT_LOAD) {
415				u_long psize = ph0->p_vaddr + ph0->p_memsz;
416				if (base_ph == NULL)
417					base_ph = ph0;
418				if (psize > limit)
419					limit = psize;
420			}
421		}
422
423		/*
424		 * Now compute the size and load address.
425		 */
426		addr = VM_DEFAULT_ADDRESS(epp->ep_daddr,
427		    round_page(limit) - trunc_page(base_ph->p_vaddr));
428	} else
429		addr = *last; /* may be ELF_LINK_ADDR */
430
431	/*
432	 * Load all the necessary sections
433	 */
434	for (i = 0, ph0 = ph, base_ph = NULL, last_ph = NULL;
435	     i < eh.e_phnum; i++, ph0++) {
436		switch (ph0->p_type) {
437		case PT_LOAD: {
438			u_long size;
439			int prot = 0;
440			int flags;
441
442			if (base_ph == NULL) {
443				/*
444				 * First encountered psection is always the
445				 * base psection.  Make sure it's aligned
446				 * properly (align down for topdown and align
447				 * upwards for not topdown).
448				 */
449				base_ph = ph0;
450				flags = VMCMD_BASE;
451				if (addr == ELF_LINK_ADDR)
452					addr = ph0->p_vaddr;
453				if (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN)
454					addr = ELF_TRUNC(addr, ph0->p_align);
455				else
456					addr = ELF_ROUND(addr, ph0->p_align);
457			} else {
458				u_long limit = round_page(last_ph->p_vaddr
459				    + last_ph->p_memsz);
460				u_long base = trunc_page(ph0->p_vaddr);
461
462				/*
463				 * If there is a gap in between the psections,
464				 * map it as inaccessible so nothing else
465				 * mmap'ed will be placed there.
466				 */
467				if (limit != base) {
468					NEW_VMCMD2(vcset, vmcmd_map_zero,
469					    base - limit,
470					    limit - base_ph->p_vaddr, NULLVP,
471					    0, VM_PROT_NONE, VMCMD_RELATIVE);
472				}
473
474				addr = ph0->p_vaddr - base_ph->p_vaddr;
475				flags = VMCMD_RELATIVE;
476			}
477			last_ph = ph0;
478			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
479			    &size, &prot, flags);
480			/*
481			 * If entry is within this psection then this
482			 * must contain the .text section.  *entryoff is
483			 * relative to the base psection.
484			 */
485			if (eh.e_entry >= ph0->p_vaddr &&
486			    eh.e_entry < (ph0->p_vaddr + size)) {
487				*entryoff = eh.e_entry - base_ph->p_vaddr;
488			}
489			addr += size;
490			break;
491		}
492
493		case PT_DYNAMIC:
494		case PT_PHDR:
495		case PT_NOTE:
496			break;
497
498		default:
499			break;
500		}
501	}
502
503	free(ph, M_TEMP);
504	/*
505	 * This value is ignored if TOPDOWN.
506	 */
507	*last = addr;
508	vrele(vp);
509	return 0;
510
511badunlock:
512	VOP_UNLOCK(vp, 0);
513
514bad:
515	if (ph != NULL)
516		free(ph, M_TEMP);
517#ifdef notyet /* XXX cgd 960926 */
518	(maybe) VOP_CLOSE it
519#endif
520	vrele(vp);
521	return error;
522}
523
524/*
525 * exec_elf_makecmds(): Prepare an Elf binary's exec package
526 *
527 * First, set of the various offsets/lengths in the exec package.
528 *
529 * Then, mark the text image busy (so it can be demand paged) or error
530 * out if this is not possible.  Finally, set up vmcmds for the
531 * text, data, bss, and stack segments.
532 */
533int
534ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
535{
536	Elf_Ehdr *eh = epp->ep_hdr;
537	Elf_Phdr *ph, *pp;
538	Elf_Addr phdr = 0, pos = 0;
539	int error, i, nload;
540	char *interp = NULL;
541	u_long phsize;
542
543	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
544		return ENOEXEC;
545
546	/*
547	 * XXX allow for executing shared objects. It seems silly
548	 * but other ELF-based systems allow it as well.
549	 */
550	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
551	    ELFNAME(check_header)(eh, ET_DYN) != 0)
552		return ENOEXEC;
553
554	if (eh->e_phnum > MAXPHNUM)
555		return ENOEXEC;
556
557	error = vn_marktext(epp->ep_vp);
558	if (error)
559		return (error);
560
561	/*
562	 * Allocate space to hold all the program headers, and read them
563	 * from the file
564	 */
565	phsize = eh->e_phnum * sizeof(Elf_Phdr);
566	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
567
568	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
569	    0)
570		goto bad;
571
572	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
573	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
574
575	for (i = 0; i < eh->e_phnum; i++) {
576		pp = &ph[i];
577		if (pp->p_type == PT_INTERP) {
578			if (pp->p_filesz >= MAXPATHLEN)
579				goto bad;
580			MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
581			interp[0] = '\0';
582			if ((error = exec_read_from(p, epp->ep_vp,
583			    pp->p_offset, interp, pp->p_filesz)) != 0)
584				goto bad;
585			break;
586		}
587	}
588
589	/*
590	 * On the same architecture, we may be emulating different systems.
591	 * See which one will accept this executable.
592	 *
593	 * Probe functions would normally see if the interpreter (if any)
594	 * exists. Emulation packages may possibly replace the interpreter in
595	 * interp[] with a changed path (/emul/xxx/<path>).
596	 */
597	pos = ELFDEFNNAME(NO_ADDR);
598	if (epp->ep_esch->u.elf_probe_func) {
599		vaddr_t startp = (vaddr_t)pos;
600
601		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
602							  &startp);
603		if (error)
604			goto bad;
605		pos = (Elf_Addr)startp;
606	}
607
608	/*
609	 * Load all the necessary sections
610	 */
611	for (i = nload = 0; i < eh->e_phnum; i++) {
612		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
613		u_long size = 0;
614		int prot = 0;
615
616		pp = &ph[i];
617
618		switch (ph[i].p_type) {
619		case PT_LOAD:
620			/*
621			 * XXX
622			 * Can handle only 2 sections: text and data
623			 */
624			if (nload++ == 2)
625				goto bad;
626			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
627			    &ph[i], &addr, &size, &prot, VMCMD_FIXED);
628
629			/*
630			 * Decide whether it's text or data by looking
631			 * at the entry point.
632			 */
633			if (eh->e_entry >= addr &&
634			    eh->e_entry < (addr + size)) {
635				epp->ep_taddr = addr;
636				epp->ep_tsize = size;
637				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
638					epp->ep_daddr = addr;
639					epp->ep_dsize = size;
640				}
641			} else {
642				epp->ep_daddr = addr;
643				epp->ep_dsize = size;
644			}
645			break;
646
647		case PT_SHLIB:
648			/* SCO has these sections. */
649		case PT_INTERP:
650			/* Already did this one. */
651		case PT_DYNAMIC:
652		case PT_NOTE:
653			break;
654
655		case PT_PHDR:
656			/* Note address of program headers (in text segment) */
657			phdr = pp->p_vaddr;
658			break;
659
660		default:
661			/*
662			 * Not fatal; we don't need to understand everything.
663			 */
664			break;
665		}
666	}
667
668	/*
669	 * Check if we found a dynamically linked binary and arrange to load
670	 * its interpreter
671	 */
672	if (interp) {
673		struct elf_args *ap;
674		int i = epp->ep_vmcmds.evs_used;
675		u_long interp_offset;
676
677		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
678		    M_TEMP, M_WAITOK);
679		if ((error = ELFNAME(load_file)(p, epp, interp,
680		    &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) {
681			FREE(ap, M_TEMP);
682			goto bad;
683		}
684		ap->arg_interp = epp->ep_vmcmds.evs_cmds[i].ev_addr;
685		epp->ep_entry = ap->arg_interp + interp_offset;
686		ap->arg_phaddr = phdr;
687
688		ap->arg_phentsize = eh->e_phentsize;
689		ap->arg_phnum = eh->e_phnum;
690		ap->arg_entry = eh->e_entry;
691
692		epp->ep_emul_arg = ap;
693
694		FREE(interp, M_TEMP);
695	} else
696		epp->ep_entry = eh->e_entry;
697
698#ifdef ELF_MAP_PAGE_ZERO
699	/* Dell SVR4 maps page zero, yeuch! */
700	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
701	    epp->ep_vp, 0, VM_PROT_READ);
702#endif
703	free(ph, M_TEMP);
704	return (*epp->ep_esch->es_setup_stack)(p, epp);
705
706bad:
707	if (interp)
708		FREE(interp, M_TEMP);
709	free(ph, M_TEMP);
710	kill_vmcmds(&epp->ep_vmcmds);
711	return ENOEXEC;
712}
713
714int
715ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
716    Elf_Ehdr *eh)
717{
718	size_t i;
719	Elf_Phdr *ph;
720	size_t phsize;
721	int error;
722
723	if (eh->e_phnum > MAXPHNUM)
724		return ENOEXEC;
725
726	phsize = eh->e_phnum * sizeof(Elf_Phdr);
727	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
728	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
729	if (error)
730		goto out;
731
732	for (i = 0; i < eh->e_phnum; i++) {
733		Elf_Phdr *ephp = &ph[i];
734		Elf_Nhdr *np;
735
736		if (ephp->p_type != PT_NOTE ||
737		    ephp->p_filesz > 1024 ||
738		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
739			continue;
740
741		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
742		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
743		    ephp->p_filesz);
744		if (error)
745			goto next;
746
747		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
748		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
749		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
750		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
751		    ELF_NOTE_NETBSD_NAMESZ))
752			goto next;
753
754		error = 0;
755		free(np, M_TEMP);
756		goto out;
757
758	next:
759		free(np, M_TEMP);
760		continue;
761	}
762
763	error = ENOEXEC;
764out:
765	free(ph, M_TEMP);
766	return (error);
767}
768
769int
770ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
771    void *eh, char *itp, vaddr_t *pos)
772{
773	int error;
774
775	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
776		return error;
777#ifdef ELF_INTERP_NON_RELOCATABLE
778	*pos = ELF_LINK_ADDR;
779#endif
780	return 0;
781}
782