exec_elf32.c revision 1.87
1/*	$NetBSD: exec_elf32.c,v 1.87 2003/02/28 19:09:08 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 1.87 2003/02/28 19:09:08 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 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	phsize = eh.e_phnum * sizeof(Elf_Phdr);
393	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
394
395	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
396		goto bad;
397
398	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
399#ifndef ELF_INTERP_NON_RELOCATABLE
400	/*
401	 * If no position to load the interpreter was set by a probe
402	 * function, pick the same address that a non-fixed mmap(0, ..)
403	 * would (i.e. something safely out of the way).
404	 */
405	if (*last == ELFDEFNNAME(NO_ADDR)) {
406		u_long limit = 0;
407		/*
408		 * Find the start and ending addresses of the psections to
409		 * be loaded.  This will give us the size.
410		 */
411		for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum;
412		     i++, ph0++) {
413			if (ph0->p_type == PT_LOAD) {
414				u_long psize = ph0->p_vaddr + ph0->p_memsz;
415				if (base_ph == NULL)
416					base_ph = ph0;
417				if (psize > limit)
418					limit = psize;
419			}
420		}
421
422		/*
423		 * Now compute the size and load address.
424		 */
425		addr = VM_DEFAULT_ADDRESS(epp->ep_daddr,
426		    round_page(limit) - trunc_page(base_ph->p_vaddr));
427	} else
428#endif	/* !ELF_INTERP_NON_RELOCATABLE */
429		addr = *last;
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.
446				 */
447				base_ph = ph0;
448				flags = VMCMD_BASE;
449			} else {
450				u_long limit = round_page(last_ph->p_vaddr
451				    + last_ph->p_memsz);
452				u_long base = trunc_page(ph0->p_vaddr);
453
454				/*
455				 * If there is a gap in between the psections,
456				 * map it as inaccessible so nothing else
457				 * mmap'ed will be placed there.
458				 */
459				if (limit != base) {
460					NEW_VMCMD2(vcset, vmcmd_map_zero,
461					    base - limit,
462					    limit - base_ph->p_vaddr, NULLVP,
463					    0, VM_PROT_NONE, VMCMD_RELATIVE);
464				}
465
466				addr = ph0->p_vaddr - base_ph->p_vaddr;
467				flags = VMCMD_RELATIVE;
468			}
469			last_ph = ph0;
470			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
471			    &size, &prot, flags);
472			/*
473			 * If entry is within this psection then this
474			 * must contain the .text section.  *entryoff is
475			 * relative to the base psection.
476			 */
477			if (eh.e_entry >= ph0->p_vaddr &&
478			    eh.e_entry < (ph0->p_vaddr + size)) {
479				*entryoff = eh.e_entry - base_ph->p_vaddr;
480			}
481			addr += size;
482			break;
483		}
484
485		case PT_DYNAMIC:
486		case PT_PHDR:
487		case PT_NOTE:
488			break;
489
490		default:
491			break;
492		}
493	}
494
495	free(ph, M_TEMP);
496	/*
497	 * This value is ignored if TOPDOWN.
498	 */
499	*last = addr;
500	vrele(vp);
501	return 0;
502
503badunlock:
504	VOP_UNLOCK(vp, 0);
505
506bad:
507	if (ph != NULL)
508		free(ph, M_TEMP);
509#ifdef notyet /* XXX cgd 960926 */
510	(maybe) VOP_CLOSE it
511#endif
512	vrele(vp);
513	return error;
514}
515
516/*
517 * exec_elf_makecmds(): Prepare an Elf binary's exec package
518 *
519 * First, set of the various offsets/lengths in the exec package.
520 *
521 * Then, mark the text image busy (so it can be demand paged) or error
522 * out if this is not possible.  Finally, set up vmcmds for the
523 * text, data, bss, and stack segments.
524 */
525int
526ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
527{
528	Elf_Ehdr *eh = epp->ep_hdr;
529	Elf_Phdr *ph, *pp;
530	Elf_Addr phdr = 0, pos = 0;
531	int error, i, nload;
532	char *interp = NULL;
533	u_long phsize;
534
535	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
536		return ENOEXEC;
537
538	/*
539	 * XXX allow for executing shared objects. It seems silly
540	 * but other ELF-based systems allow it as well.
541	 */
542	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
543	    ELFNAME(check_header)(eh, ET_DYN) != 0)
544		return ENOEXEC;
545
546	error = vn_marktext(epp->ep_vp);
547	if (error)
548		return (error);
549
550	/*
551	 * Allocate space to hold all the program headers, and read them
552	 * from the file
553	 */
554	phsize = eh->e_phnum * sizeof(Elf_Phdr);
555	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
556
557	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
558	    0)
559		goto bad;
560
561	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
562	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
563
564	MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
565	interp[0] = '\0';
566
567	for (i = 0; i < eh->e_phnum; i++) {
568		pp = &ph[i];
569		if (pp->p_type == PT_INTERP) {
570			if (pp->p_filesz >= MAXPATHLEN)
571				goto bad;
572			if ((error = exec_read_from(p, epp->ep_vp,
573			    pp->p_offset, interp, pp->p_filesz)) != 0)
574				goto bad;
575			break;
576		}
577	}
578
579	/*
580	 * On the same architecture, we may be emulating different systems.
581	 * See which one will accept this executable. This currently only
582	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
583	 * and the Alpha.
584	 *
585	 * Probe functions would normally see if the interpreter (if any)
586	 * exists. Emulation packages may possibly replace the interpreter in
587	 * interp[] with a changed path (/emul/xxx/<path>).
588	 */
589	if (!epp->ep_esch->u.elf_probe_func) {
590		pos = ELFDEFNNAME(NO_ADDR);
591	} else {
592		vaddr_t startp = 0;
593
594		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
595							  &startp);
596		pos = (Elf_Addr)startp;
597		if (error)
598			goto bad;
599	}
600
601	/*
602	 * Load all the necessary sections
603	 */
604	for (i = nload = 0; i < eh->e_phnum; i++) {
605		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
606		u_long size = 0;
607		int prot = 0;
608
609		pp = &ph[i];
610
611		switch (ph[i].p_type) {
612		case PT_LOAD:
613			/*
614			 * XXX
615			 * Can handle only 2 sections: text and data
616			 */
617			if (nload++ == 2)
618				goto bad;
619			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
620			    &ph[i], &addr, &size, &prot, VMCMD_FIXED);
621
622			/*
623			 * Decide whether it's text or data by looking
624			 * at the entry point.
625			 */
626			if (eh->e_entry >= addr &&
627			    eh->e_entry < (addr + size)) {
628				epp->ep_taddr = addr;
629				epp->ep_tsize = size;
630				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
631					epp->ep_daddr = addr;
632					epp->ep_dsize = size;
633				}
634			} else {
635				epp->ep_daddr = addr;
636				epp->ep_dsize = size;
637			}
638			break;
639
640		case PT_SHLIB:
641			/* SCO has these sections. */
642		case PT_INTERP:
643			/* Already did this one. */
644		case PT_DYNAMIC:
645		case PT_NOTE:
646			break;
647
648		case PT_PHDR:
649			/* Note address of program headers (in text segment) */
650			phdr = pp->p_vaddr;
651			break;
652
653		default:
654			/*
655			 * Not fatal; we don't need to understand everything.
656			 */
657			break;
658		}
659	}
660
661	/*
662	 * Check if we found a dynamically linked binary and arrange to load
663	 * its interpreter
664	 */
665	if (interp[0]) {
666		struct elf_args *ap;
667		int i = epp->ep_vmcmds.evs_used;
668		u_long interp_offset;
669
670		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
671		    M_TEMP, M_WAITOK);
672		if ((error = ELFNAME(load_file)(p, epp, interp,
673		    &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) {
674			FREE(ap, M_TEMP);
675			goto bad;
676		}
677		ap->arg_interp = epp->ep_vmcmds.evs_cmds[i].ev_addr;
678		epp->ep_entry = ap->arg_interp + interp_offset;
679		ap->arg_phaddr = phdr;
680
681		ap->arg_phentsize = eh->e_phentsize;
682		ap->arg_phnum = eh->e_phnum;
683		ap->arg_entry = eh->e_entry;
684
685		epp->ep_emul_arg = ap;
686	} else
687		epp->ep_entry = eh->e_entry;
688
689#ifdef ELF_MAP_PAGE_ZERO
690	/* Dell SVR4 maps page zero, yeuch! */
691	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
692	    epp->ep_vp, 0, VM_PROT_READ);
693#endif
694	FREE(interp, M_TEMP);
695	free(ph, M_TEMP);
696	return exec_elf_setup_stack(p, epp);
697
698bad:
699	if (interp)
700		FREE(interp, M_TEMP);
701	free(ph, M_TEMP);
702	kill_vmcmds(&epp->ep_vmcmds);
703	return ENOEXEC;
704}
705
706int
707ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
708    Elf_Ehdr *eh)
709{
710	size_t i;
711	Elf_Phdr *ph;
712	size_t phsize;
713	int error;
714
715	phsize = eh->e_phnum * sizeof(Elf_Phdr);
716	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
717	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
718	if (error)
719		goto out;
720
721	for (i = 0; i < eh->e_phnum; i++) {
722		Elf_Phdr *ephp = &ph[i];
723		Elf_Nhdr *np;
724
725		if (ephp->p_type != PT_NOTE ||
726		    ephp->p_filesz > 1024 ||
727		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
728			continue;
729
730		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
731		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
732		    ephp->p_filesz);
733		if (error)
734			goto next;
735
736		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
737		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
738		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
739		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
740		    ELF_NOTE_NETBSD_NAMESZ))
741			goto next;
742
743		error = 0;
744		free(np, M_TEMP);
745		goto out;
746
747	next:
748		free(np, M_TEMP);
749		continue;
750	}
751
752	error = ENOEXEC;
753out:
754	free(ph, M_TEMP);
755	return (error);
756}
757
758int
759ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
760    void *eh, char *itp, vaddr_t *pos)
761{
762	int error;
763
764	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
765		return error;
766	*pos = ELFDEFNNAME(NO_ADDR);
767	return 0;
768}
769