xref: /netbsd-src/sys/kern/exec_elf32.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: exec_elf32.c,v 1.48 2000/04/11 04:37:50 chs 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 
77 #include <sys/param.h>
78 #include <sys/systm.h>
79 #include <sys/kernel.h>
80 #include <sys/proc.h>
81 #include <sys/malloc.h>
82 #include <sys/namei.h>
83 #include <sys/vnode.h>
84 #include <sys/exec.h>
85 #include <sys/exec_elf.h>
86 #include <sys/fcntl.h>
87 #include <sys/syscall.h>
88 #include <sys/signalvar.h>
89 #include <sys/mount.h>
90 #include <sys/stat.h>
91 
92 #include <sys/mman.h>
93 #include <vm/vm.h>
94 #include <vm/vm_param.h>
95 #include <vm/vm_map.h>
96 
97 #include <machine/cpu.h>
98 #include <machine/reg.h>
99 
100 #ifdef COMPAT_NETBSD32
101 #include <compat/netbsd32/netbsd32_exec.h>
102 #endif
103 
104 #ifdef COMPAT_LINUX
105 #include <compat/linux/common/linux_exec.h>
106 #endif
107 
108 #ifdef COMPAT_SVR4
109 #include <compat/svr4/svr4_exec.h>
110 #endif
111 
112 #ifdef COMPAT_IBCS2
113 #include <compat/ibcs2/ibcs2_exec.h>
114 #endif
115 
116 #ifdef COMPAT_FREEBSD
117 #include <compat/freebsd/freebsd_exec.h>
118 #endif
119 
120 int	ELFNAME(check_header) __P((Elf_Ehdr *, int));
121 int	ELFNAME(load_file) __P((struct proc *, struct exec_package *, char *,
122 	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *));
123 void	ELFNAME(load_psection) __P((struct exec_vmcmd_set *, struct vnode *,
124 	    Elf_Phdr *, Elf_Addr *, u_long *, int *));
125 
126 int ELFNAME2(netbsd,signature) __P((struct proc *, struct exec_package *,
127     Elf_Ehdr *));
128 static int ELFNAME2(netbsd,probe) __P((struct proc *, struct exec_package *,
129     Elf_Ehdr *, char *, Elf_Addr *));
130 
131 extern char sigcode[], esigcode[];
132 #ifdef SYSCALL_DEBUG
133 extern char *syscallnames[];
134 #endif
135 
136 struct emul ELFNAMEEND(emul_netbsd) = {
137 	"netbsd",
138 	NULL,
139 	sendsig,
140 	SYS_syscall,
141 	SYS_MAXSYSCALL,
142 	sysent,
143 #ifdef SYSCALL_DEBUG
144 	syscallnames,
145 #else
146 	NULL,
147 #endif
148 	howmany(ELF_AUX_ENTRIES * sizeof(AuxInfo), sizeof (Elf_Addr)),
149 	ELFNAME(copyargs),
150 	setregs,
151 	sigcode,
152 	esigcode,
153 };
154 
155 int (*ELFNAME(probe_funcs)[]) __P((struct proc *, struct exec_package *,
156     Elf_Ehdr *, char *, Elf_Addr *)) = {
157 #if defined(COMPAT_NETBSD32) && (ELFSIZE == 32)
158 	    /* This one should go first so it matches instead of netbsd */
159 	ELFNAME2(netbsd32,probe),
160 #endif
161 	ELFNAME2(netbsd,probe),
162 #if defined(COMPAT_FREEBSD) && (ELFSIZE == 32)
163 	ELFNAME2(freebsd,probe),		/* XXX not 64-bit safe */
164 #endif
165 #if defined(COMPAT_LINUX)
166 	ELFNAME2(linux,probe),
167 #endif
168 #if defined(COMPAT_SVR4) && (ELFSIZE == 32)
169 	ELFNAME2(svr4,probe),			/* XXX not 64-bit safe */
170 #endif
171 #if defined(COMPAT_IBCS2) && (ELFSIZE == 32)
172 	ELFNAME2(ibcs2,probe),			/* XXX not 64-bit safe */
173 #endif
174 };
175 
176 /* round up and down to page boundaries. */
177 #define	ELF_ROUND(a, b)		(((a) + (b) - 1) & ~((b) - 1))
178 #define	ELF_TRUNC(a, b)		((a) & ~((b) - 1))
179 
180 /*
181  * Copy arguments onto the stack in the normal way, but add some
182  * extra information in case of dynamic binding.
183  */
184 void *
185 ELFNAME(copyargs)(pack, arginfo, stack, argp)
186 	struct exec_package *pack;
187 	struct ps_strings *arginfo;
188 	void *stack;
189 	void *argp;
190 {
191 	size_t len;
192 	AuxInfo ai[ELF_AUX_ENTRIES], *a;
193 	struct elf_args *ap;
194 
195 	stack = copyargs(pack, arginfo, stack, argp);
196 	if (!stack)
197 		return NULL;
198 
199 	a = ai;
200 
201 	/*
202 	 * Push extra arguments on the stack needed by dynamically
203 	 * linked binaries
204 	 */
205 	if ((ap = (struct elf_args *)pack->ep_emul_arg)) {
206 
207 		a->a_type = AT_PHDR;
208 		a->a_v = ap->arg_phaddr;
209 		a++;
210 
211 		a->a_type = AT_PHENT;
212 		a->a_v = ap->arg_phentsize;
213 		a++;
214 
215 		a->a_type = AT_PHNUM;
216 		a->a_v = ap->arg_phnum;
217 		a++;
218 
219 		a->a_type = AT_PAGESZ;
220 		a->a_v = NBPG;
221 		a++;
222 
223 		a->a_type = AT_BASE;
224 		a->a_v = ap->arg_interp;
225 		a++;
226 
227 		a->a_type = AT_FLAGS;
228 		a->a_v = 0;
229 		a++;
230 
231 		a->a_type = AT_ENTRY;
232 		a->a_v = ap->arg_entry;
233 		a++;
234 
235 		free((char *)ap, M_TEMP);
236 		pack->ep_emul_arg = NULL;
237 	}
238 
239 	a->a_type = AT_NULL;
240 	a->a_v = 0;
241 	a++;
242 
243 	len = (a - ai) * sizeof(AuxInfo);
244 	if (copyout(ai, stack, len))
245 		return NULL;
246 	stack = (caddr_t)stack + len;
247 
248 	return stack;
249 }
250 
251 /*
252  * elf_check_header():
253  *
254  * Check header for validity; return 0 of ok ENOEXEC if error
255  */
256 int
257 ELFNAME(check_header)(eh, type)
258 	Elf_Ehdr *eh;
259 	int type;
260 {
261 
262 	if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
263 	    eh->e_ident[EI_CLASS] != ELFCLASS)
264 
265 	switch (eh->e_machine) {
266 
267 	ELFDEFNNAME(MACHDEP_ID_CASES)
268 
269 	default:
270 		return ENOEXEC;
271 	}
272 
273 	if (eh->e_type != type)
274 		return ENOEXEC;
275 
276 	return 0;
277 }
278 
279 /*
280  * elf_load_psection():
281  *
282  * Load a psection at the appropriate address
283  */
284 void
285 ELFNAME(load_psection)(vcset, vp, ph, addr, size, prot)
286 	struct exec_vmcmd_set *vcset;
287 	struct vnode *vp;
288 	Elf_Phdr *ph;
289 	Elf_Addr *addr;
290 	u_long *size;
291 	int *prot;
292 {
293 	u_long uaddr, msize, psize, rm, rf;
294 	long diff, offset;
295 
296 	/*
297 	 * If the user specified an address, then we load there.
298 	 */
299 	if (*addr != ELFDEFNNAME(NO_ADDR)) {
300 		if (ph->p_align > 1) {
301 			*addr = ELF_ROUND(*addr, ph->p_align);
302 			uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
303 		} else
304 			uaddr = ph->p_vaddr;
305 		diff = ph->p_vaddr - uaddr;
306 	} else {
307 		*addr = uaddr = ph->p_vaddr;
308 		if (ph->p_align > 1)
309 			*addr = ELF_TRUNC(uaddr, ph->p_align);
310 		diff = uaddr - *addr;
311 	}
312 
313 	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
314 	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
315 	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
316 
317 	offset = ph->p_offset - diff;
318 	*size = ph->p_filesz + diff;
319 	msize = ph->p_memsz + diff;
320 	psize = round_page(*size);
321 
322 	if ((ph->p_flags & PF_W) != 0) {
323 		/*
324 		 * Because the pagedvn pager can't handle zero fill of the last
325 		 * data page if it's not page aligned we map the last page
326 		 * readvn.
327 		 */
328 		psize = trunc_page(*size);
329 		NEW_VMCMD(vcset, vmcmd_map_pagedvn, psize, *addr, vp,
330 		    offset, *prot);
331 		if(psize != *size)
332 			NEW_VMCMD(vcset, vmcmd_map_readvn, *size - psize,
333 			    *addr + psize, vp, offset + psize, *prot);
334 	} else
335 		NEW_VMCMD(vcset, vmcmd_map_pagedvn, psize, *addr, vp,
336 		    offset, *prot);
337 
338 	/*
339 	 * Check if we need to extend the size of the segment
340 	 */
341 	rm = round_page(*addr + msize);
342 	rf = round_page(*addr + *size);
343 
344 	if (rm != rf) {
345 		NEW_VMCMD(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
346 		    0, *prot);
347 		*size = msize;
348 	}
349 }
350 
351 /*
352  * elf_read_from():
353  *
354  *	Read from vnode into buffer at offset.
355  */
356 int
357 ELFNAME(read_from)(p, vp, off, buf, size)
358 	struct vnode *vp;
359 	u_long off;
360 	struct proc *p;
361 	caddr_t buf;
362 	int size;
363 {
364 	int error;
365 	size_t resid;
366 
367 	if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE,
368 	    0, p->p_ucred, &resid, p)) != 0)
369 		return error;
370 	/*
371 	 * See if we got all of it
372 	 */
373 	if (resid != 0)
374 		return ENOEXEC;
375 	return 0;
376 }
377 
378 /*
379  * elf_load_file():
380  *
381  * Load a file (interpreter/library) pointed to by path
382  * [stolen from coff_load_shlib()]. Made slightly generic
383  * so it might be used externally.
384  */
385 int
386 ELFNAME(load_file)(p, epp, path, vcset, entry, ap, last)
387 	struct proc *p;
388 	struct exec_package *epp;
389 	char *path;
390 	struct exec_vmcmd_set *vcset;
391 	u_long *entry;
392 	struct elf_args	*ap;
393 	Elf_Addr *last;
394 {
395 	int error, i;
396 	struct nameidata nd;
397 	struct vnode *vp;
398 	struct vattr attr;
399 	Elf_Ehdr eh;
400 	Elf_Phdr *ph = NULL;
401 	u_long phsize;
402 	char *bp = NULL;
403 	Elf_Addr addr = *last;
404 
405 	bp = path;
406 	/*
407 	 * 1. open file
408 	 * 2. read filehdr
409 	 * 3. map text, data, and bss out of it using VM_*
410 	 */
411 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
412 	if ((error = namei(&nd)) != 0)
413 		return error;
414 	vp = nd.ni_vp;
415 
416 	/*
417 	 * Similarly, if it's not marked as executable, or it's not a regular
418 	 * file, we don't allow it to be used.
419 	 */
420 	if (vp->v_type != VREG) {
421 		error = EACCES;
422 		goto badunlock;
423 	}
424 	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
425 		goto badunlock;
426 
427 	/* get attributes */
428 	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
429 		goto badunlock;
430 
431 	/*
432 	 * Check mount point.  Though we're not trying to exec this binary,
433 	 * we will be executing code from it, so if the mount point
434 	 * disallows execution or set-id-ness, we punt or kill the set-id.
435 	 */
436 	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
437 		error = EACCES;
438 		goto badunlock;
439 	}
440 	if (vp->v_mount->mnt_flag & MNT_NOSUID)
441 		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
442 
443 #ifdef notyet /* XXX cgd 960926 */
444 	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
445 #endif
446 	VOP_UNLOCK(vp, 0);
447 
448 	if ((error = ELFNAME(read_from)(p, vp, 0, (caddr_t) &eh,
449 	    sizeof(eh))) != 0)
450 		goto bad;
451 
452 	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
453 		goto bad;
454 
455 	phsize = eh.e_phnum * sizeof(Elf_Phdr);
456 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
457 
458 	if ((error = ELFNAME(read_from)(p, vp, eh.e_phoff,
459 	    (caddr_t) ph, phsize)) != 0)
460 		goto bad;
461 
462 	/*
463 	 * Load all the necessary sections
464 	 */
465 	for (i = 0; i < eh.e_phnum; i++) {
466 		u_long size = 0;
467 		int prot = 0;
468 
469 		switch (ph[i].p_type) {
470 		case PT_LOAD:
471 			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
472 			    &size, &prot);
473 			/* If entry is within this section it must be text */
474 			if (eh.e_entry >= ph[i].p_vaddr &&
475 			    eh.e_entry < (ph[i].p_vaddr + size)) {
476 				/* XXX */
477 				*entry = addr + eh.e_entry;
478 #ifdef mips
479 				*entry -= ph[i].p_vaddr;
480 #endif
481 				ap->arg_interp = addr;
482 			}
483 			addr += size;
484 			break;
485 
486 		case PT_DYNAMIC:
487 		case PT_PHDR:
488 		case PT_NOTE:
489 			break;
490 
491 		default:
492 			break;
493 		}
494 	}
495 
496 	free((char *)ph, M_TEMP);
497 	*last = addr;
498 	vrele(vp);
499 	return 0;
500 
501 badunlock:
502 	VOP_UNLOCK(vp, 0);
503 
504 bad:
505 	if (ph != NULL)
506 		free((char *)ph, M_TEMP);
507 #ifdef notyet /* XXX cgd 960926 */
508 	(maybe) VOP_CLOSE it
509 #endif
510 	vrele(vp);
511 	return error;
512 }
513 
514 /*
515  * exec_elf_makecmds(): Prepare an Elf binary's exec package
516  *
517  * First, set of the various offsets/lengths in the exec package.
518  *
519  * Then, mark the text image busy (so it can be demand paged) or error
520  * out if this is not possible.  Finally, set up vmcmds for the
521  * text, data, bss, and stack segments.
522  */
523 int
524 ELFNAME2(exec,makecmds)(p, epp)
525 	struct proc *p;
526 	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, n, nload;
532 	char interp[MAXPATHLEN];
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 	/*
547 	 * check if vnode is in open for writing, because we want to
548 	 * demand-page out of it.  if it is, don't do it, for various
549 	 * reasons
550 	 */
551 	if (epp->ep_vp->v_writecount != 0) {
552 #ifdef DIAGNOSTIC
553 		if (epp->ep_vp->v_flag & VTEXT)
554 			panic("exec: a VTEXT vnode has writecount != 0\n");
555 #endif
556 		return ETXTBSY;
557 	}
558 	/*
559 	 * Allocate space to hold all the program headers, and read them
560 	 * from the file
561 	 */
562 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
563 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
564 
565 	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
566 	    (caddr_t) ph, phsize)) != 0)
567 		goto bad;
568 
569 	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
570 	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
571 
572 	interp[0] = '\0';
573 
574 	for (i = 0; i < eh->e_phnum; i++) {
575 		pp = &ph[i];
576 		if (pp->p_type == PT_INTERP) {
577 			if (pp->p_filesz >= sizeof(interp))
578 				goto bad;
579 			if ((error = ELFNAME(read_from)(p, epp->ep_vp,
580 			    pp->p_offset, (caddr_t) interp,
581 			    pp->p_filesz)) != 0)
582 				goto bad;
583 			break;
584 		}
585 	}
586 
587 	/*
588 	 * Setup things for native emulation.
589 	 */
590 	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
591 	pos = ELFDEFNNAME(NO_ADDR);
592 
593 	/*
594 	 * On the same architecture, we may be emulating different systems.
595 	 * See which one will accept this executable. This currently only
596 	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
597 	 * and the Alpha.
598 	 *
599 	 * Probe functions would normally see if the interpreter (if any)
600 	 * exists. Emulation packages may possibly replace the interpreter in
601 	 * interp[] with a changed path (/emul/xxx/<path>), and also
602 	 * set the ep_emul field in the exec package structure.
603 	 */
604 	n = sizeof(ELFNAME(probe_funcs)) / sizeof(ELFNAME(probe_funcs)[0]);
605 	if (n != 0) {
606 		error = ENOEXEC;
607 		for (i = 0; i < n && error; i++)
608 			error = ELFNAME(probe_funcs)[i](p, epp, eh,
609 			    interp, &pos);
610 #ifdef notyet
611 		/*
612 		 * We should really use a signature in our native binaries
613 		 * and have our own probe function for matching binaries,
614 		 * before trying the emulations. For now, if the emulation
615 		 * probes failed we default to native.
616 		 */
617 		if (error)
618 			goto bad;
619 #endif
620 	}
621 
622 	/*
623 	 * Load all the necessary sections
624 	 */
625 	for (i = nload = 0; i < eh->e_phnum; i++) {
626 		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
627 		u_long size = 0;
628 		int prot = 0;
629 
630 		pp = &ph[i];
631 
632 		switch (ph[i].p_type) {
633 		case PT_LOAD:
634 			/*
635 			 * XXX
636 			 * Can handle only 2 sections: text and data
637 			 */
638 			if (nload++ == 2)
639 				goto bad;
640 			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
641 			    &ph[i], &addr, &size, &prot);
642 
643 			/*
644 			 * Decide whether it's text or data by looking
645 			 * at the entry point.
646 			 */
647 			if (eh->e_entry >= addr &&
648 			    eh->e_entry < (addr + size)) {
649 				epp->ep_taddr = addr;
650 				epp->ep_tsize = size;
651 				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
652 					epp->ep_daddr = addr;
653 					epp->ep_dsize = size;
654 				}
655 			} else {
656 				epp->ep_daddr = addr;
657 				epp->ep_dsize = size;
658 			}
659 			break;
660 
661 		case PT_SHLIB:
662 #ifndef COMPAT_IBCS2			/* SCO has these sections */
663 			error = ENOEXEC;
664 			goto bad;
665 #endif
666 
667 		case PT_INTERP:
668 			/* Already did this one */
669 		case PT_DYNAMIC:
670 		case PT_NOTE:
671 			break;
672 
673 		case PT_PHDR:
674 			/* Note address of program headers (in text segment) */
675 			phdr = pp->p_vaddr;
676 			break;
677 
678 		default:
679 			/*
680 			 * Not fatal; we don't need to understand everything.
681 			 */
682 			break;
683 		}
684 	}
685 
686 	/* this breaks on, e.g., OpenBSD-compatible mips shared binaries. */
687 #ifndef ELF_INTERP_NON_RELOCATABLE
688 	/*
689 	 * If no position to load the interpreter was set by a probe
690 	 * function, pick the same address that a non-fixed mmap(0, ..)
691 	 * would (i.e. something safely out of the way).
692 	 */
693 	if (pos == ELFDEFNNAME(NO_ADDR))
694 		pos = round_page(epp->ep_daddr + MAXDSIZ);
695 #endif	/* !ELF_INTERP_NON_RELOCATABLE */
696 
697 	/*
698 	 * Check if we found a dynamically linked binary and arrange to load
699 	 * it's interpreter
700 	 */
701 	if (interp[0]) {
702 		struct elf_args *ap;
703 
704 		ap = (struct elf_args *)malloc(sizeof(struct elf_args),
705 		    M_TEMP, M_WAITOK);
706 		if ((error = ELFNAME(load_file)(p, epp, interp,
707 		    &epp->ep_vmcmds, &epp->ep_entry, ap, &pos)) != 0) {
708 			free((char *)ap, M_TEMP);
709 			goto bad;
710 		}
711 		pos += phsize;
712 		ap->arg_phaddr = phdr;
713 
714 		ap->arg_phentsize = eh->e_phentsize;
715 		ap->arg_phnum = eh->e_phnum;
716 		ap->arg_entry = eh->e_entry;
717 
718 		epp->ep_emul_arg = ap;
719 	} else
720 		epp->ep_entry = eh->e_entry;
721 
722 #ifdef ELF_MAP_PAGE_ZERO
723 	/* Dell SVR4 maps page zero, yeuch! */
724 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, NBPG, 0, epp->ep_vp, 0,
725 	    VM_PROT_READ);
726 #endif
727 	free((char *)ph, M_TEMP);
728 	vn_marktext(epp->ep_vp);
729 	return exec_elf_setup_stack(p, epp);
730 
731 bad:
732 	free((char *)ph, M_TEMP);
733 	kill_vmcmds(&epp->ep_vmcmds);
734 	return ENOEXEC;
735 }
736 
737 int
738 ELFNAME2(netbsd,signature)(p, epp, eh)
739 	struct proc *p;
740 	struct exec_package *epp;
741 	Elf_Ehdr *eh;
742 {
743 	Elf_Phdr *hph, *ph;
744 	Elf_Nhdr *np = NULL;
745 	size_t phsize;
746 	int error;
747 
748 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
749 	hph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
750 	if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff,
751 	    (caddr_t)hph, phsize)) != 0)
752 		goto out1;
753 
754 	for (ph = hph;  ph < &hph[eh->e_phnum]; ph++) {
755 		if (ph->p_type != PT_NOTE ||
756 		    ph->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
757 			continue;
758 
759 		np = (Elf_Nhdr *)malloc(ph->p_filesz, M_TEMP, M_WAITOK);
760 		if ((error = ELFNAME(read_from)(p, epp->ep_vp, ph->p_offset,
761 		    (caddr_t)np, ph->p_filesz)) != 0)
762 			goto out2;
763 
764 		if (np->n_type != ELF_NOTE_TYPE_OSVERSION) {
765 			free(np, M_TEMP);
766 			np = NULL;
767 			continue;
768 		}
769 
770 		/* Check the name and description sizes. */
771 		if (np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
772 		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ)
773 			goto out3;
774 
775 		/* Is the name "NetBSD\0\0"? */
776 		if (memcmp((np + 1), ELF_NOTE_NETBSD_NAME,
777 		    ELF_NOTE_NETBSD_NAMESZ))
778 			goto out3;
779 
780 		/* XXX: We could check for the specific emulation here */
781 		/* All checks succeeded. */
782 		error = 0;
783 		goto out2;
784 	}
785 
786 out3:
787 	error = ENOEXEC;
788 out2:
789 	if (np)
790 		free(np, M_TEMP);
791 out1:
792 	free(hph, M_TEMP);
793 	return error;
794 }
795 
796 static int
797 ELFNAME2(netbsd,probe)(p, epp, eh, itp, pos)
798 	struct proc *p;
799 	struct exec_package *epp;
800 	Elf_Ehdr *eh;
801 	char *itp;
802 	Elf_Addr *pos;
803 {
804 	int error;
805 
806 	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
807 		return error;
808 	epp->ep_emul = &ELFNAMEEND(emul_netbsd);
809 	*pos = ELFDEFNNAME(NO_ADDR);
810 	return 0;
811 }
812