xref: /netbsd-src/sys/kern/exec_elf32.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: exec_elf32.c,v 1.89 2003/03/01 05:55:51 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 1.89 2003/03/01 05:55:51 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 
89 extern const struct emul emul_netbsd;
90 
91 int	ELFNAME(check_header)(Elf_Ehdr *, int);
92 int	ELFNAME(load_file)(struct proc *, struct exec_package *, char *,
93 	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *);
94 void	ELFNAME(load_psection)(struct exec_vmcmd_set *, struct vnode *,
95 	    const Elf_Phdr *, Elf_Addr *, u_long *, int *, int);
96 
97 int ELFNAME2(netbsd,signature)(struct proc *, struct exec_package *,
98     Elf_Ehdr *);
99 int 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  */
110 int
111 ELFNAME(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  */
202 int
203 ELFNAME(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  */
236 void
237 ELFNAME(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  */
322 int
323 ELFNAME(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.  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 (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN)
452 					addr = ELF_TRUNC(addr, ph0->p_align);
453 				else
454 					addr = ELF_ROUND(addr, ph0->p_align);
455 			} else {
456 				u_long limit = round_page(last_ph->p_vaddr
457 				    + last_ph->p_memsz);
458 				u_long base = trunc_page(ph0->p_vaddr);
459 
460 				/*
461 				 * If there is a gap in between the psections,
462 				 * map it as inaccessible so nothing else
463 				 * mmap'ed will be placed there.
464 				 */
465 				if (limit != base) {
466 					NEW_VMCMD2(vcset, vmcmd_map_zero,
467 					    base - limit,
468 					    limit - base_ph->p_vaddr, NULLVP,
469 					    0, VM_PROT_NONE, VMCMD_RELATIVE);
470 				}
471 
472 				addr = ph0->p_vaddr - base_ph->p_vaddr;
473 				flags = VMCMD_RELATIVE;
474 			}
475 			last_ph = ph0;
476 			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
477 			    &size, &prot, flags);
478 			/*
479 			 * If entry is within this psection then this
480 			 * must contain the .text section.  *entryoff is
481 			 * relative to the base psection.
482 			 */
483 			if (eh.e_entry >= ph0->p_vaddr &&
484 			    eh.e_entry < (ph0->p_vaddr + size)) {
485 				*entryoff = eh.e_entry - base_ph->p_vaddr;
486 			}
487 			addr += size;
488 			break;
489 		}
490 
491 		case PT_DYNAMIC:
492 		case PT_PHDR:
493 		case PT_NOTE:
494 			break;
495 
496 		default:
497 			break;
498 		}
499 	}
500 
501 	free(ph, M_TEMP);
502 	/*
503 	 * This value is ignored if TOPDOWN.
504 	 */
505 	*last = addr;
506 	vrele(vp);
507 	return 0;
508 
509 badunlock:
510 	VOP_UNLOCK(vp, 0);
511 
512 bad:
513 	if (ph != NULL)
514 		free(ph, M_TEMP);
515 #ifdef notyet /* XXX cgd 960926 */
516 	(maybe) VOP_CLOSE it
517 #endif
518 	vrele(vp);
519 	return error;
520 }
521 
522 /*
523  * exec_elf_makecmds(): Prepare an Elf binary's exec package
524  *
525  * First, set of the various offsets/lengths in the exec package.
526  *
527  * Then, mark the text image busy (so it can be demand paged) or error
528  * out if this is not possible.  Finally, set up vmcmds for the
529  * text, data, bss, and stack segments.
530  */
531 int
532 ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
533 {
534 	Elf_Ehdr *eh = epp->ep_hdr;
535 	Elf_Phdr *ph, *pp;
536 	Elf_Addr phdr = 0, pos = 0;
537 	int error, i, nload;
538 	char *interp = NULL;
539 	u_long phsize;
540 
541 	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
542 		return ENOEXEC;
543 
544 	/*
545 	 * XXX allow for executing shared objects. It seems silly
546 	 * but other ELF-based systems allow it as well.
547 	 */
548 	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
549 	    ELFNAME(check_header)(eh, ET_DYN) != 0)
550 		return ENOEXEC;
551 
552 	error = vn_marktext(epp->ep_vp);
553 	if (error)
554 		return (error);
555 
556 	/*
557 	 * Allocate space to hold all the program headers, and read them
558 	 * from the file
559 	 */
560 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
561 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
562 
563 	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
564 	    0)
565 		goto bad;
566 
567 	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
568 	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
569 
570 	MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
571 	interp[0] = '\0';
572 
573 	for (i = 0; i < eh->e_phnum; i++) {
574 		pp = &ph[i];
575 		if (pp->p_type == PT_INTERP) {
576 			if (pp->p_filesz >= MAXPATHLEN)
577 				goto bad;
578 			if ((error = exec_read_from(p, epp->ep_vp,
579 			    pp->p_offset, interp, pp->p_filesz)) != 0)
580 				goto bad;
581 			break;
582 		}
583 	}
584 
585 	/*
586 	 * On the same architecture, we may be emulating different systems.
587 	 * See which one will accept this executable. This currently only
588 	 * applies to SVR4, and IBCS2 on the i386 and Linux on the i386
589 	 * and the Alpha.
590 	 *
591 	 * Probe functions would normally see if the interpreter (if any)
592 	 * exists. Emulation packages may possibly replace the interpreter in
593 	 * interp[] with a changed path (/emul/xxx/<path>).
594 	 */
595 	if (!epp->ep_esch->u.elf_probe_func) {
596 		pos = ELFDEFNNAME(NO_ADDR);
597 	} else {
598 		vaddr_t startp = 0;
599 
600 		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
601 							  &startp);
602 		pos = (Elf_Addr)startp;
603 		if (error)
604 			goto bad;
605 	}
606 
607 	/*
608 	 * Load all the necessary sections
609 	 */
610 	for (i = nload = 0; i < eh->e_phnum; i++) {
611 		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
612 		u_long size = 0;
613 		int prot = 0;
614 
615 		pp = &ph[i];
616 
617 		switch (ph[i].p_type) {
618 		case PT_LOAD:
619 			/*
620 			 * XXX
621 			 * Can handle only 2 sections: text and data
622 			 */
623 			if (nload++ == 2)
624 				goto bad;
625 			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
626 			    &ph[i], &addr, &size, &prot, VMCMD_FIXED);
627 
628 			/*
629 			 * Decide whether it's text or data by looking
630 			 * at the entry point.
631 			 */
632 			if (eh->e_entry >= addr &&
633 			    eh->e_entry < (addr + size)) {
634 				epp->ep_taddr = addr;
635 				epp->ep_tsize = size;
636 				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
637 					epp->ep_daddr = addr;
638 					epp->ep_dsize = size;
639 				}
640 			} else {
641 				epp->ep_daddr = addr;
642 				epp->ep_dsize = size;
643 			}
644 			break;
645 
646 		case PT_SHLIB:
647 			/* SCO has these sections. */
648 		case PT_INTERP:
649 			/* Already did this one. */
650 		case PT_DYNAMIC:
651 		case PT_NOTE:
652 			break;
653 
654 		case PT_PHDR:
655 			/* Note address of program headers (in text segment) */
656 			phdr = pp->p_vaddr;
657 			break;
658 
659 		default:
660 			/*
661 			 * Not fatal; we don't need to understand everything.
662 			 */
663 			break;
664 		}
665 	}
666 
667 	/*
668 	 * Check if we found a dynamically linked binary and arrange to load
669 	 * its interpreter
670 	 */
671 	if (interp[0]) {
672 		struct elf_args *ap;
673 		int i = epp->ep_vmcmds.evs_used;
674 		u_long interp_offset;
675 
676 		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
677 		    M_TEMP, M_WAITOK);
678 		if ((error = ELFNAME(load_file)(p, epp, interp,
679 		    &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) {
680 			FREE(ap, M_TEMP);
681 			goto bad;
682 		}
683 		ap->arg_interp = epp->ep_vmcmds.evs_cmds[i].ev_addr;
684 		epp->ep_entry = ap->arg_interp + interp_offset;
685 		ap->arg_phaddr = phdr;
686 
687 		ap->arg_phentsize = eh->e_phentsize;
688 		ap->arg_phnum = eh->e_phnum;
689 		ap->arg_entry = eh->e_entry;
690 
691 		epp->ep_emul_arg = ap;
692 	} else
693 		epp->ep_entry = eh->e_entry;
694 
695 #ifdef ELF_MAP_PAGE_ZERO
696 	/* Dell SVR4 maps page zero, yeuch! */
697 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
698 	    epp->ep_vp, 0, VM_PROT_READ);
699 #endif
700 	FREE(interp, M_TEMP);
701 	free(ph, M_TEMP);
702 	return exec_elf_setup_stack(p, epp);
703 
704 bad:
705 	if (interp)
706 		FREE(interp, M_TEMP);
707 	free(ph, M_TEMP);
708 	kill_vmcmds(&epp->ep_vmcmds);
709 	return ENOEXEC;
710 }
711 
712 int
713 ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
714     Elf_Ehdr *eh)
715 {
716 	size_t i;
717 	Elf_Phdr *ph;
718 	size_t phsize;
719 	int error;
720 
721 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
722 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
723 	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
724 	if (error)
725 		goto out;
726 
727 	for (i = 0; i < eh->e_phnum; i++) {
728 		Elf_Phdr *ephp = &ph[i];
729 		Elf_Nhdr *np;
730 
731 		if (ephp->p_type != PT_NOTE ||
732 		    ephp->p_filesz > 1024 ||
733 		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
734 			continue;
735 
736 		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
737 		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
738 		    ephp->p_filesz);
739 		if (error)
740 			goto next;
741 
742 		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
743 		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
744 		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
745 		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
746 		    ELF_NOTE_NETBSD_NAMESZ))
747 			goto next;
748 
749 		error = 0;
750 		free(np, M_TEMP);
751 		goto out;
752 
753 	next:
754 		free(np, M_TEMP);
755 		continue;
756 	}
757 
758 	error = ENOEXEC;
759 out:
760 	free(ph, M_TEMP);
761 	return (error);
762 }
763 
764 int
765 ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
766     void *eh, char *itp, vaddr_t *pos)
767 {
768 	int error;
769 
770 	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
771 		return error;
772 	*pos = ELFDEFNNAME(NO_ADDR);
773 	return 0;
774 }
775