exec_elf32.c revision 1.54
1/*	$NetBSD: exec_elf32.c,v 1.54 2000/08/01 04:57:28 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 1994 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/* If not included by exec_elf64.c, ELFSIZE won't be defined. */
67#ifndef ELFSIZE
68#define	ELFSIZE		32
69#endif
70
71#include "opt_compat_linux.h"
72#include "opt_compat_ibcs2.h"
73#include "opt_compat_svr4.h"
74#include "opt_compat_freebsd.h"
75#include "opt_compat_netbsd32.h"
76#include "opt_syscall_debug.h"
77
78#include <sys/param.h>
79#include <sys/systm.h>
80#include <sys/kernel.h>
81#include <sys/proc.h>
82#include <sys/malloc.h>
83#include <sys/namei.h>
84#include <sys/vnode.h>
85#include <sys/exec.h>
86#include <sys/exec_elf.h>
87#include <sys/fcntl.h>
88#include <sys/syscall.h>
89#include <sys/signalvar.h>
90#include <sys/mount.h>
91#include <sys/stat.h>
92
93#include <sys/mman.h>
94
95#include <machine/cpu.h>
96#include <machine/reg.h>
97
98#ifdef COMPAT_NETBSD32
99#include <compat/netbsd32/netbsd32_exec.h>
100#endif
101
102#ifdef COMPAT_LINUX
103#include <compat/linux/common/linux_exec.h>
104#endif
105
106#ifdef COMPAT_SVR4
107#include <compat/svr4/svr4_exec.h>
108#endif
109
110#ifdef COMPAT_IBCS2
111#include <compat/ibcs2/ibcs2_exec.h>
112#endif
113
114#ifdef COMPAT_FREEBSD
115#include <compat/freebsd/freebsd_exec.h>
116#endif
117
118int	ELFNAME(check_header)(Elf_Ehdr *, int);
119int	ELFNAME(load_file)(struct proc *, struct exec_package *, char *,
120	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *);
121void	ELFNAME(load_psection)(struct exec_vmcmd_set *, struct vnode *,
122	    const Elf_Phdr *, Elf_Addr *, u_long *, int *, int);
123
124int ELFNAME2(netbsd,signature)(struct proc *, struct exec_package *,
125    Elf_Ehdr *);
126static int ELFNAME2(netbsd,probe)(struct proc *, struct exec_package *,
127    Elf_Ehdr *, char *, Elf_Addr *);
128
129extern char sigcode[], esigcode[];
130#ifdef SYSCALL_DEBUG
131extern char *syscallnames[];
132#endif
133
134struct emul ELFNAMEEND(emul_netbsd) = {
135	"netbsd",
136	NULL,
137	sendsig,
138	SYS_syscall,
139	SYS_MAXSYSCALL,
140	sysent,
141#ifdef SYSCALL_DEBUG
142	syscallnames,
143#else
144	NULL,
145#endif
146	howmany(ELF_AUX_ENTRIES * sizeof(AuxInfo), sizeof (Elf_Addr)),
147	ELFNAME(copyargs),
148	setregs,
149	sigcode,
150	esigcode,
151};
152
153int (*ELFNAME(probe_funcs)[])(struct proc *, struct exec_package *,
154    Elf_Ehdr *, char *, Elf_Addr *) = {
155#if defined(COMPAT_NETBSD32) && (ELFSIZE == 32)
156	    /* This one should go first so it matches instead of netbsd */
157	ELFNAME2(netbsd32,probe),
158#endif
159	ELFNAME2(netbsd,probe),
160#if defined(COMPAT_FREEBSD) && (ELFSIZE == 32)
161	ELFNAME2(freebsd,probe),		/* XXX not 64-bit safe */
162#endif
163#if defined(COMPAT_LINUX)
164	ELFNAME2(linux,probe),
165#endif
166#if defined(COMPAT_SVR4) && (ELFSIZE == 32)
167	ELFNAME2(svr4,probe),			/* XXX not 64-bit safe */
168#endif
169#if defined(COMPAT_IBCS2) && (ELFSIZE == 32)
170	ELFNAME2(ibcs2,probe),			/* XXX not 64-bit safe */
171#endif
172};
173
174/* round up and down to page boundaries. */
175#define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
176#define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
177
178/*
179 * Copy arguments onto the stack in the normal way, but add some
180 * extra information in case of dynamic binding.
181 */
182void *
183ELFNAME(copyargs)(struct exec_package *pack, struct ps_strings *arginfo,
184    void *stack, void *argp)
185{
186	size_t len;
187	AuxInfo ai[ELF_AUX_ENTRIES], *a;
188	struct elf_args *ap;
189
190	stack = copyargs(pack, arginfo, stack, argp);
191	if (!stack)
192		return NULL;
193
194	a = ai;
195
196	/*
197	 * Push extra arguments on the stack needed by dynamically
198	 * linked binaries
199	 */
200	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
201
202		a->a_type = AT_PHDR;
203		a->a_v = ap->arg_phaddr;
204		a++;
205
206		a->a_type = AT_PHENT;
207		a->a_v = ap->arg_phentsize;
208		a++;
209
210		a->a_type = AT_PHNUM;
211		a->a_v = ap->arg_phnum;
212		a++;
213
214		a->a_type = AT_PAGESZ;
215		a->a_v = NBPG;
216		a++;
217
218		a->a_type = AT_BASE;
219		a->a_v = ap->arg_interp;
220		a++;
221
222		a->a_type = AT_FLAGS;
223		a->a_v = 0;
224		a++;
225
226		a->a_type = AT_ENTRY;
227		a->a_v = ap->arg_entry;
228		a++;
229
230		free((char *)ap, M_TEMP);
231		pack->ep_emul_arg = NULL;
232	}
233
234	a->a_type = AT_NULL;
235	a->a_v = 0;
236	a++;
237
238	len = (a - ai) * sizeof(AuxInfo);
239	if (copyout(ai, stack, len))
240		return NULL;
241	stack = (caddr_t)stack + len;
242
243	return stack;
244}
245
246/*
247 * elf_check_header():
248 *
249 * Check header for validity; return 0 of ok ENOEXEC if error
250 */
251int
252ELFNAME(check_header)(Elf_Ehdr *eh, int type)
253{
254
255	if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
256	    eh->e_ident[EI_CLASS] != ELFCLASS)
257		return ENOEXEC;
258
259	switch (eh->e_machine) {
260
261	ELFDEFNNAME(MACHDEP_ID_CASES)
262
263	default:
264		return ENOEXEC;
265	}
266
267	if (eh->e_type != type)
268		return ENOEXEC;
269
270	return 0;
271}
272
273/*
274 * elf_load_psection():
275 *
276 * Load a psection at the appropriate address
277 */
278void
279ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
280    const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags)
281{
282	u_long uaddr, msize, psize, rm, rf;
283	long diff, offset;
284
285	/*
286	 * If the user specified an address, then we load there.
287	 */
288	if (*addr != ELFDEFNNAME(NO_ADDR)) {
289		if (ph->p_align > 1) {
290			*addr = ELF_TRUNC(*addr, ph->p_align);
291			uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
292		} else
293			uaddr = ph->p_vaddr;
294		diff = ph->p_vaddr - uaddr;
295	} else {
296		*addr = uaddr = ph->p_vaddr;
297		if (ph->p_align > 1)
298			*addr = ELF_TRUNC(uaddr, ph->p_align);
299		diff = uaddr - *addr;
300	}
301
302	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
303	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
304	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
305
306	offset = ph->p_offset - diff;
307	*size = ph->p_filesz + diff;
308	msize = ph->p_memsz + diff;
309	psize = round_page(*size);
310
311	if ((ph->p_flags & PF_W) != 0) {
312		/*
313		 * Because the pagedvn pager can't handle zero fill of the last
314		 * data page if it's not page aligned we map the last page
315		 * readvn.
316		 */
317		psize = trunc_page(*size);
318	}
319	if (psize > 0) {
320		NEW_VMCMD2(vcset, vmcmd_map_pagedvn, psize, *addr, vp,
321		    offset, *prot, flags);
322	}
323	if (psize < *size) {
324		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
325		    *addr + psize, vp, offset + psize, *prot,
326		    psize > 0 ? flags & VMCMD_RELATIVE : flags);
327	}
328
329	/*
330	 * Check if we need to extend the size of the segment
331	 */
332	rm = round_page(*addr + msize);
333	rf = round_page(*addr + *size);
334
335	if (rm != rf) {
336		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
337		    0, *prot, flags & VMCMD_RELATIVE);
338		*size = msize;
339	}
340}
341
342/*
343 * elf_read_from():
344 *
345 *	Read from vnode into buffer at offset.
346 */
347int
348ELFNAME(read_from)(struct proc *p, struct vnode *vp, u_long off,
349    caddr_t buf, int size)
350{
351	int error;
352	size_t resid;
353
354	if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE,
355	    0, p->p_ucred, &resid, p)) != 0)
356		return error;
357	/*
358	 * See if we got all of it
359	 */
360	if (resid != 0)
361		return ENOEXEC;
362	return 0;
363}
364
365/*
366 * elf_load_file():
367 *
368 * Load a file (interpreter/library) pointed to by path
369 * [stolen from coff_load_shlib()]. Made slightly generic
370 * so it might be used externally.
371 */
372int
373ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
374    struct exec_vmcmd_set *vcset, u_long *entry, struct elf_args *ap,
375    Elf_Addr *last)
376{
377	int error, i;
378	struct nameidata nd;
379	struct vnode *vp;
380	struct vattr attr;
381	Elf_Ehdr eh;
382	Elf_Phdr *ph = NULL;
383	Elf_Phdr *base_ph = NULL;
384	u_long phsize;
385	char *bp = NULL;
386	Elf_Addr addr = *last;
387
388	bp = path;
389	/*
390	 * 1. open file
391	 * 2. read filehdr
392	 * 3. map text, data, and bss out of it using VM_*
393	 */
394	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
395	if ((error = namei(&nd)) != 0)
396		return error;
397	vp = nd.ni_vp;
398
399	/*
400	 * Similarly, if it's not marked as executable, or it's not a regular
401	 * file, we don't allow it to be used.
402	 */
403	if (vp->v_type != VREG) {
404		error = EACCES;
405		goto badunlock;
406	}
407	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
408		goto badunlock;
409
410	/* get attributes */
411	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
412		goto badunlock;
413
414	/*
415	 * Check mount point.  Though we're not trying to exec this binary,
416	 * we will be executing code from it, so if the mount point
417	 * disallows execution or set-id-ness, we punt or kill the set-id.
418	 */
419	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
420		error = EACCES;
421		goto badunlock;
422	}
423	if (vp->v_mount->mnt_flag & MNT_NOSUID)
424		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
425
426#ifdef notyet /* XXX cgd 960926 */
427	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
428#endif
429	VOP_UNLOCK(vp, 0);
430
431	if ((error = ELFNAME(read_from)(p, vp, 0, (caddr_t) &eh,
432	    sizeof(eh))) != 0)
433		goto bad;
434
435	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
436		goto bad;
437
438	phsize = eh.e_phnum * sizeof(Elf_Phdr);
439	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
440
441	if ((error = ELFNAME(read_from)(p, vp, eh.e_phoff,
442	    (caddr_t) ph, phsize)) != 0)
443		goto bad;
444
445	/*
446	 * Load all the necessary sections
447	 */
448	for (i = 0; i < eh.e_phnum; i++) {
449		u_long size = 0;
450		int prot = 0;
451		int flags;
452
453		switch (ph[i].p_type) {
454		case PT_LOAD:
455			if (base_ph == NULL) {
456				addr = *last;
457				flags = VMCMD_BASE;
458			} else {
459				addr = ph[i].p_vaddr - base_ph->p_vaddr;
460				flags = VMCMD_RELATIVE;
461			}
462			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
463			    &size, &prot, flags);
464			/* If entry is within this section it must be text */
465			if (eh.e_entry >= ph[i].p_vaddr &&
466			    eh.e_entry < (ph[i].p_vaddr + size)) {
467				/* XXX */
468				*entry = addr + eh.e_entry;
469#ifdef mips
470				*entry -= ph[i].p_vaddr;
471#endif
472				ap->arg_interp = addr;
473			}
474			if (base_ph == NULL)
475				base_ph = &ph[i];
476			addr += size;
477			break;
478
479		case PT_DYNAMIC:
480		case PT_PHDR:
481		case PT_NOTE:
482			break;
483
484		default:
485			break;
486		}
487	}
488
489	free((char *)ph, M_TEMP);
490	*last = addr;
491	vrele(vp);
492	return 0;
493
494badunlock:
495	VOP_UNLOCK(vp, 0);
496
497bad:
498	if (ph != NULL)
499		free((char *)ph, M_TEMP);
500#ifdef notyet /* XXX cgd 960926 */
501	(maybe) VOP_CLOSE it
502#endif
503	vrele(vp);
504	return error;
505}
506
507/*
508 * exec_elf_makecmds(): Prepare an Elf binary's exec package
509 *
510 * First, set of the various offsets/lengths in the exec package.
511 *
512 * Then, mark the text image busy (so it can be demand paged) or error
513 * out if this is not possible.  Finally, set up vmcmds for the
514 * text, data, bss, and stack segments.
515 */
516int
517ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
518{
519	Elf_Ehdr *eh = epp->ep_hdr;
520	Elf_Phdr *ph, *pp;
521	Elf_Addr phdr = 0, pos = 0;
522	int error, i, n, nload;
523	char interp[MAXPATHLEN];
524	u_long phsize;
525
526	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
527		return ENOEXEC;
528
529	/*
530	 * XXX allow for executing shared objects. It seems silly
531	 * but other ELF-based systems allow it as well.
532	 */
533	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
534	    ELFNAME(check_header)(eh, ET_DYN) != 0)
535		return ENOEXEC;
536
537	/*
538	 * check if vnode is in open for writing, because we want to
539	 * demand-page out of it.  if it is, don't do it, for various
540	 * reasons
541	 */
542	if (epp->ep_vp->v_writecount != 0) {
543#ifdef DIAGNOSTIC
544		if (epp->ep_vp->v_flag & VTEXT)
545			panic("exec: a VTEXT vnode has writecount != 0\n");
546#endif
547		return ETXTBSY;
548	}
549	/*
550	 * Allocate space to hold all the program headers, and read them
551	 * from the file
552	 */
553	phsize = eh->e_phnum * sizeof(Elf_Phdr);
554	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
555
556	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
557	    (caddr_t) ph, phsize)) != 0)
558		goto bad;
559
560	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
561	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
562
563	interp[0] = '\0';
564
565	for (i = 0; i < eh->e_phnum; i++) {
566		pp = &ph[i];
567		if (pp->p_type == PT_INTERP) {
568			if (pp->p_filesz >= sizeof(interp))
569				goto bad;
570			if ((error = ELFNAME(read_from)(p, epp->ep_vp,
571			    pp->p_offset, (caddr_t) interp,
572			    pp->p_filesz)) != 0)
573				goto bad;
574			break;
575		}
576	}
577
578	/*
579	 * Setup things for native emulation.
580	 */
581	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
582	pos = ELFDEFNNAME(NO_ADDR);
583
584	/*
585	 * On the same architecture, we may be emulating different systems.
586	 * See which one will accept this executable. This currently only
587	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
588	 * and the Alpha.
589	 *
590	 * Probe functions would normally see if the interpreter (if any)
591	 * exists. Emulation packages may possibly replace the interpreter in
592	 * interp[] with a changed path (/emul/xxx/<path>), and also
593	 * set the ep_emul field in the exec package structure.
594	 */
595	n = sizeof(ELFNAME(probe_funcs)) / sizeof(ELFNAME(probe_funcs)[0]);
596	if (n != 0) {
597		error = ENOEXEC;
598		for (i = 0; i < n && error; i++)
599			error = ELFNAME(probe_funcs)[i](p, epp, eh,
600			    interp, &pos);
601#ifdef notyet
602		/*
603		 * We should really use a signature in our native binaries
604		 * and have our own probe function for matching binaries,
605		 * before trying the emulations. For now, if the emulation
606		 * probes failed we default to native.
607		 */
608		if (error)
609			goto bad;
610#endif
611	}
612
613	/*
614	 * Load all the necessary sections
615	 */
616	for (i = nload = 0; i < eh->e_phnum; i++) {
617		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
618		u_long size = 0;
619		int prot = 0;
620
621		pp = &ph[i];
622
623		switch (ph[i].p_type) {
624		case PT_LOAD:
625			/*
626			 * XXX
627			 * Can handle only 2 sections: text and data
628			 */
629			if (nload++ == 2)
630				goto bad;
631			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
632			    &ph[i], &addr, &size, &prot, 0);
633
634			/*
635			 * Decide whether it's text or data by looking
636			 * at the entry point.
637			 */
638			if (eh->e_entry >= addr &&
639			    eh->e_entry < (addr + size)) {
640				epp->ep_taddr = addr;
641				epp->ep_tsize = size;
642				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
643					epp->ep_daddr = addr;
644					epp->ep_dsize = size;
645				}
646			} else {
647				epp->ep_daddr = addr;
648				epp->ep_dsize = size;
649			}
650			break;
651
652		case PT_SHLIB:
653#ifndef COMPAT_IBCS2			/* SCO has these sections */
654			error = ENOEXEC;
655			goto bad;
656#endif
657
658		case PT_INTERP:
659			/* Already did this one */
660		case PT_DYNAMIC:
661		case PT_NOTE:
662			break;
663
664		case PT_PHDR:
665			/* Note address of program headers (in text segment) */
666			phdr = pp->p_vaddr;
667			break;
668
669		default:
670			/*
671			 * Not fatal; we don't need to understand everything.
672			 */
673			break;
674		}
675	}
676
677	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
678#ifndef ELF_INTERP_NON_RELOCATABLE
679	/*
680	 * If no position to load the interpreter was set by a probe
681	 * function, pick the same address that a non-fixed mmap(0, ..)
682	 * would (i.e. something safely out of the way).
683	 */
684	if (pos == ELFDEFNNAME(NO_ADDR))
685		pos = round_page(epp->ep_daddr + MAXDSIZ);
686#endif	/* !ELF_INTERP_NON_RELOCATABLE */
687
688	/*
689	 * Check if we found a dynamically linked binary and arrange to load
690	 * it's interpreter
691	 */
692	if (interp[0]) {
693		struct elf_args *ap;
694
695		ap = (struct elf_args *)malloc(sizeof(struct elf_args),
696		    M_TEMP, M_WAITOK);
697		if ((error = ELFNAME(load_file)(p, epp, interp,
698		    &epp->ep_vmcmds, &epp->ep_entry, ap, &pos)) != 0) {
699			free((char *)ap, M_TEMP);
700			goto bad;
701		}
702		pos += phsize;
703		ap->arg_phaddr = phdr;
704
705		ap->arg_phentsize = eh->e_phentsize;
706		ap->arg_phnum = eh->e_phnum;
707		ap->arg_entry = eh->e_entry;
708
709		epp->ep_emul_arg = ap;
710	} else
711		epp->ep_entry = eh->e_entry;
712
713#ifdef ELF_MAP_PAGE_ZERO
714	/* Dell SVR4 maps page zero, yeuch! */
715	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, NBPG, 0, epp->ep_vp, 0,
716	    VM_PROT_READ);
717#endif
718	free((char *)ph, M_TEMP);
719	vn_marktext(epp->ep_vp);
720	return exec_elf_setup_stack(p, epp);
721
722bad:
723	free((char *)ph, M_TEMP);
724	kill_vmcmds(&epp->ep_vmcmds);
725	return ENOEXEC;
726}
727
728int
729ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
730    Elf_Ehdr *eh)
731{
732	Elf_Phdr *hph, *ph;
733	Elf_Nhdr *np = NULL;
734	size_t phsize;
735	int error;
736
737	phsize = eh->e_phnum * sizeof(Elf_Phdr);
738	hph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
739	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
740	    (caddr_t)hph, phsize)) != 0)
741		goto out1;
742
743	for (ph = hph;  ph < &hph[eh->e_phnum]; ph++) {
744		if (ph->p_type != PT_NOTE ||
745		    ph->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
746			continue;
747
748		np = (Elf_Nhdr *)malloc(ph->p_filesz, M_TEMP, M_WAITOK);
749		if ((error = ELFNAME(read_from)(p, epp->ep_vp, ph->p_offset,
750		    (caddr_t)np, ph->p_filesz)) != 0)
751			goto out2;
752
753		if (np->n_type != ELF_NOTE_TYPE_OSVERSION) {
754			free(np, M_TEMP);
755			np = NULL;
756			continue;
757		}
758
759		/* Check the name and description sizes. */
760		if (np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
761		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ)
762			goto out3;
763
764		/* Is the name "NetBSD\0\0"? */
765		if (memcmp((np + 1), ELF_NOTE_NETBSD_NAME,
766		    ELF_NOTE_NETBSD_NAMESZ))
767			goto out3;
768
769		/* XXX: We could check for the specific emulation here */
770		/* All checks succeeded. */
771		error = 0;
772		goto out2;
773	}
774
775out3:
776	error = ENOEXEC;
777out2:
778	if (np)
779		free(np, M_TEMP);
780out1:
781	free(hph, M_TEMP);
782	return error;
783}
784
785static int
786ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
787    Elf_Ehdr *eh, char *itp, Elf_Addr *pos)
788{
789	int error;
790
791	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
792		return error;
793	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
794	*pos = ELFDEFNNAME(NO_ADDR);
795	return 0;
796}
797