xref: /netbsd-src/sys/kern/exec_elf32.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: exec_elf32.c,v 1.99 2004/10/30 09:38:15 skrll 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 1.99 2004/10/30 09:38:15 skrll 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(load_file)(struct proc *, struct exec_package *, char *,
92 	    struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *);
93 void	ELFNAME(load_psection)(struct exec_vmcmd_set *, struct vnode *,
94 	    const Elf_Phdr *, Elf_Addr *, u_long *, int *, int);
95 
96 int ELFNAME2(netbsd,signature)(struct proc *, struct exec_package *,
97     Elf_Ehdr *);
98 int 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  */
111 int
112 ELFNAME(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  */
203 int
204 ELFNAME(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 > 1024 ||
226 	    eh->e_phnum > 128)
227 		return (ENOEXEC);
228 
229 	return (0);
230 }
231 
232 /*
233  * elf_load_psection():
234  *
235  * Load a psection at the appropriate address
236  */
237 void
238 ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
239     const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags)
240 {
241 	u_long msize, psize, rm, rf;
242 	long diff, offset;
243 
244 	/*
245 	 * If the user specified an address, then we load there.
246 	 */
247 	if (*addr == ELFDEFNNAME(NO_ADDR))
248 		*addr = ph->p_vaddr;
249 
250 	if (ph->p_align > 1) {
251 		/*
252 		 * Make sure we are virtually aligned as we are supposed to be.
253 		 */
254 		diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align);
255 		KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align));
256 		/*
257 		 * But make sure to not map any pages before the start of the
258 		 * psection by limiting the difference to within a page.
259 		 */
260 		diff &= PAGE_MASK;
261 	} else
262 		diff = 0;
263 
264 	*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
265 	*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
266 	*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
267 
268 	/*
269 	 * Adjust everything so it all starts on a page boundary.
270 	 */
271 	*addr -= diff;
272 	offset = ph->p_offset - diff;
273 	*size = ph->p_filesz + diff;
274 	msize = ph->p_memsz + diff;
275 
276 	if (ph->p_align >= PAGE_SIZE) {
277 		if ((ph->p_flags & PF_W) != 0) {
278 			/*
279 			 * Because the pagedvn pager can't handle zero fill
280 			 * of the last data page if it's not page aligned we
281 			 * map the last page readvn.
282 			 */
283 			psize = trunc_page(*size);
284 		} else {
285 			psize = round_page(*size);
286 		}
287 	} else {
288 		psize = *size;
289 	}
290 
291 	if (psize > 0) {
292 		NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
293 		    vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
294 		    offset, *prot, flags);
295 		flags &= VMCMD_RELATIVE;
296 	}
297 	if (psize < *size) {
298 		NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
299 		    *addr + psize, vp, offset + psize, *prot, flags);
300 	}
301 
302 	/*
303 	 * Check if we need to extend the size of the segment (does
304 	 * bss extend page the next page boundary)?
305 	 */
306 	rm = round_page(*addr + msize);
307 	rf = round_page(*addr + *size);
308 
309 	if (rm != rf) {
310 		NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP,
311 		    0, *prot, flags & VMCMD_RELATIVE);
312 		*size = msize;
313 	}
314 }
315 
316 /*
317  * elf_load_file():
318  *
319  * Load a file (interpreter/library) pointed to by path
320  * [stolen from coff_load_shlib()]. Made slightly generic
321  * so it might be used externally.
322  */
323 int
324 ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
325     struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap,
326     Elf_Addr *last)
327 {
328 	int error, i;
329 	struct nameidata nd;
330 	struct vnode *vp;
331 	struct vattr attr;
332 	Elf_Ehdr eh;
333 	Elf_Phdr *ph = NULL;
334 	const Elf_Phdr *ph0;
335 	const Elf_Phdr *base_ph;
336 	const Elf_Phdr *last_ph;
337 	u_long phsize;
338 	Elf_Addr addr = *last;
339 
340 	/*
341 	 * 1. open file
342 	 * 2. read filehdr
343 	 * 3. map text, data, and bss out of it using VM_*
344 	 */
345 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p);
346 	if ((error = namei(&nd)) != 0)
347 		return error;
348 	vp = nd.ni_vp;
349 
350 	/*
351 	 * Similarly, if it's not marked as executable, or it's not a regular
352 	 * file, we don't allow it to be used.
353 	 */
354 	if (vp->v_type != VREG) {
355 		error = EACCES;
356 		goto badunlock;
357 	}
358 	if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
359 		goto badunlock;
360 
361 	/* get attributes */
362 	if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0)
363 		goto badunlock;
364 
365 	/*
366 	 * Check mount point.  Though we're not trying to exec this binary,
367 	 * we will be executing code from it, so if the mount point
368 	 * disallows execution or set-id-ness, we punt or kill the set-id.
369 	 */
370 	if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
371 		error = EACCES;
372 		goto badunlock;
373 	}
374 	if (vp->v_mount->mnt_flag & MNT_NOSUID)
375 		epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
376 
377 #ifdef notyet /* XXX cgd 960926 */
378 	XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?)
379 #endif
380 
381 	error = vn_marktext(vp);
382 	if (error)
383 		goto badunlock;
384 
385 	VOP_UNLOCK(vp, 0);
386 
387 	if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0)
388 		goto bad;
389 
390 	if ((error = ELFNAME(check_header)(&eh, ET_DYN)) != 0)
391 		goto bad;
392 
393 	if (eh.e_phnum > MAXPHNUM)
394 		goto bad;
395 
396 	phsize = eh.e_phnum * sizeof(Elf_Phdr);
397 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
398 
399 	if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0)
400 		goto bad;
401 
402 	/*
403 	 * If no position to load the interpreter was set by a probe
404 	 * function, pick the same address that a non-fixed mmap(0, ..)
405 	 * would (i.e. something safely out of the way).
406 	 */
407 	if (*last == ELFDEFNNAME(NO_ADDR)) {
408 		u_long limit = 0;
409 		/*
410 		 * Find the start and ending addresses of the psections to
411 		 * be loaded.  This will give us the size.
412 		 */
413 		for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum;
414 		     i++, ph0++) {
415 			if (ph0->p_type == PT_LOAD) {
416 				u_long psize = ph0->p_vaddr + ph0->p_memsz;
417 				if (base_ph == NULL)
418 					base_ph = ph0;
419 				if (psize > limit)
420 					limit = psize;
421 			}
422 		}
423 
424 		/*
425 		 * Now compute the size and load address.
426 		 */
427 		addr = VM_DEFAULT_ADDRESS(epp->ep_daddr,
428 		    round_page(limit) - trunc_page(base_ph->p_vaddr));
429 	} else
430 		addr = *last; /* may be ELF_LINK_ADDR */
431 
432 	/*
433 	 * Load all the necessary sections
434 	 */
435 	for (i = 0, ph0 = ph, base_ph = NULL, last_ph = NULL;
436 	     i < eh.e_phnum; i++, ph0++) {
437 		switch (ph0->p_type) {
438 		case PT_LOAD: {
439 			u_long size;
440 			int prot = 0;
441 			int flags;
442 
443 			if (base_ph == NULL) {
444 				/*
445 				 * First encountered psection is always the
446 				 * base psection.  Make sure it's aligned
447 				 * properly (align down for topdown and align
448 				 * upwards for not topdown).
449 				 */
450 				base_ph = ph0;
451 				flags = VMCMD_BASE;
452 				if (addr == ELF_LINK_ADDR)
453 					addr = ph0->p_vaddr;
454 				if (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN)
455 					addr = ELF_TRUNC(addr, ph0->p_align);
456 				else
457 					addr = ELF_ROUND(addr, ph0->p_align);
458 			} else {
459 				u_long limit = round_page(last_ph->p_vaddr
460 				    + last_ph->p_memsz);
461 				u_long base = trunc_page(ph0->p_vaddr);
462 
463 				/*
464 				 * If there is a gap in between the psections,
465 				 * map it as inaccessible so nothing else
466 				 * mmap'ed will be placed there.
467 				 */
468 				if (limit != base) {
469 					NEW_VMCMD2(vcset, vmcmd_map_zero,
470 					    base - limit,
471 					    limit - base_ph->p_vaddr, NULLVP,
472 					    0, VM_PROT_NONE, VMCMD_RELATIVE);
473 				}
474 
475 				addr = ph0->p_vaddr - base_ph->p_vaddr;
476 				flags = VMCMD_RELATIVE;
477 			}
478 			last_ph = ph0;
479 			ELFNAME(load_psection)(vcset, vp, &ph[i], &addr,
480 			    &size, &prot, flags);
481 			/*
482 			 * If entry is within this psection then this
483 			 * must contain the .text section.  *entryoff is
484 			 * relative to the base psection.
485 			 */
486 			if (eh.e_entry >= ph0->p_vaddr &&
487 			    eh.e_entry < (ph0->p_vaddr + size)) {
488 				*entryoff = eh.e_entry - base_ph->p_vaddr;
489 			}
490 			addr += size;
491 			break;
492 		}
493 
494 		case PT_DYNAMIC:
495 		case PT_PHDR:
496 		case PT_NOTE:
497 			break;
498 
499 		default:
500 			break;
501 		}
502 	}
503 
504 	free(ph, M_TEMP);
505 	/*
506 	 * This value is ignored if TOPDOWN.
507 	 */
508 	*last = addr;
509 	vrele(vp);
510 	return 0;
511 
512 badunlock:
513 	VOP_UNLOCK(vp, 0);
514 
515 bad:
516 	if (ph != NULL)
517 		free(ph, M_TEMP);
518 #ifdef notyet /* XXX cgd 960926 */
519 	(maybe) VOP_CLOSE it
520 #endif
521 	vrele(vp);
522 	return error;
523 }
524 
525 /*
526  * exec_elf_makecmds(): Prepare an Elf binary's exec package
527  *
528  * First, set of the various offsets/lengths in the exec package.
529  *
530  * Then, mark the text image busy (so it can be demand paged) or error
531  * out if this is not possible.  Finally, set up vmcmds for the
532  * text, data, bss, and stack segments.
533  */
534 int
535 ELFNAME2(exec,makecmds)(struct proc *p, struct exec_package *epp)
536 {
537 	Elf_Ehdr *eh = epp->ep_hdr;
538 	Elf_Phdr *ph, *pp;
539 	Elf_Addr phdr = 0, pos = 0;
540 	int error, i, nload;
541 	char *interp = NULL;
542 	u_long phsize;
543 
544 	if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
545 		return ENOEXEC;
546 
547 	/*
548 	 * XXX allow for executing shared objects. It seems silly
549 	 * but other ELF-based systems allow it as well.
550 	 */
551 	if (ELFNAME(check_header)(eh, ET_EXEC) != 0 &&
552 	    ELFNAME(check_header)(eh, ET_DYN) != 0)
553 		return ENOEXEC;
554 
555 	if (eh->e_phnum > MAXPHNUM)
556 		return ENOEXEC;
557 
558 	error = vn_marktext(epp->ep_vp);
559 	if (error)
560 		return (error);
561 
562 	/*
563 	 * Allocate space to hold all the program headers, and read them
564 	 * from the file
565 	 */
566 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
567 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
568 
569 	if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) !=
570 	    0)
571 		goto bad;
572 
573 	epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR);
574 	epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR);
575 
576 	for (i = 0; i < eh->e_phnum; i++) {
577 		pp = &ph[i];
578 		if (pp->p_type == PT_INTERP) {
579 			if (pp->p_filesz >= MAXPATHLEN)
580 				goto bad;
581 			MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK);
582 			interp[0] = '\0';
583 			if ((error = exec_read_from(p, epp->ep_vp,
584 			    pp->p_offset, interp, pp->p_filesz)) != 0)
585 				goto bad;
586 			break;
587 		}
588 	}
589 
590 	/*
591 	 * On the same architecture, we may be emulating different systems.
592 	 * See which one will accept this executable.
593 	 *
594 	 * Probe functions would normally see if the interpreter (if any)
595 	 * exists. Emulation packages may possibly replace the interpreter in
596 	 * interp[] with a changed path (/emul/xxx/<path>).
597 	 */
598 	pos = ELFDEFNNAME(NO_ADDR);
599 	if (epp->ep_esch->u.elf_probe_func) {
600 		vaddr_t startp = (vaddr_t)pos;
601 
602 		error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp,
603 							  &startp);
604 		if (error)
605 			goto bad;
606 		pos = (Elf_Addr)startp;
607 	}
608 
609 	/*
610 	 * Load all the necessary sections
611 	 */
612 	for (i = nload = 0; i < eh->e_phnum; i++) {
613 		Elf_Addr  addr = ELFDEFNNAME(NO_ADDR);
614 		u_long size = 0;
615 		int prot = 0;
616 
617 		pp = &ph[i];
618 
619 		switch (ph[i].p_type) {
620 		case PT_LOAD:
621 			/*
622 			 * XXX
623 			 * Can handle only 2 sections: text and data
624 			 */
625 			if (nload++ == 2)
626 				goto bad;
627 			ELFNAME(load_psection)(&epp->ep_vmcmds, epp->ep_vp,
628 			    &ph[i], &addr, &size, &prot, VMCMD_FIXED);
629 
630 			/*
631 			 * Decide whether it's text or data by looking
632 			 * at the entry point.
633 			 */
634 			if (eh->e_entry >= addr &&
635 			    eh->e_entry < (addr + size)) {
636 				epp->ep_taddr = addr;
637 				epp->ep_tsize = size;
638 				if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) {
639 					epp->ep_daddr = addr;
640 					epp->ep_dsize = size;
641 				}
642 			} else {
643 				epp->ep_daddr = addr;
644 				epp->ep_dsize = size;
645 			}
646 			break;
647 
648 		case PT_SHLIB:
649 			/* SCO has these sections. */
650 		case PT_INTERP:
651 			/* Already did this one. */
652 		case PT_DYNAMIC:
653 		case PT_NOTE:
654 			break;
655 
656 		case PT_PHDR:
657 			/* Note address of program headers (in text segment) */
658 			phdr = pp->p_vaddr;
659 			break;
660 
661 		default:
662 			/*
663 			 * Not fatal; we don't need to understand everything.
664 			 */
665 			break;
666 		}
667 	}
668 
669 	/*
670 	 * Check if we found a dynamically linked binary and arrange to load
671 	 * its interpreter
672 	 */
673 	if (interp) {
674 		struct elf_args *ap;
675 		int i = epp->ep_vmcmds.evs_used;
676 		u_long interp_offset;
677 
678 		MALLOC(ap, struct elf_args *, sizeof(struct elf_args),
679 		    M_TEMP, M_WAITOK);
680 		if ((error = ELFNAME(load_file)(p, epp, interp,
681 		    &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) {
682 			FREE(ap, M_TEMP);
683 			goto bad;
684 		}
685 		ap->arg_interp = epp->ep_vmcmds.evs_cmds[i].ev_addr;
686 		epp->ep_entry = ap->arg_interp + interp_offset;
687 		ap->arg_phaddr = phdr;
688 
689 		ap->arg_phentsize = eh->e_phentsize;
690 		ap->arg_phnum = eh->e_phnum;
691 		ap->arg_entry = eh->e_entry;
692 
693 		epp->ep_emul_arg = ap;
694 
695 		FREE(interp, M_TEMP);
696 	} else
697 		epp->ep_entry = eh->e_entry;
698 
699 #ifdef ELF_MAP_PAGE_ZERO
700 	/* Dell SVR4 maps page zero, yeuch! */
701 	NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0,
702 	    epp->ep_vp, 0, VM_PROT_READ);
703 #endif
704 	free(ph, M_TEMP);
705 	return (*epp->ep_esch->es_setup_stack)(p, epp);
706 
707 bad:
708 	if (interp)
709 		FREE(interp, M_TEMP);
710 	free(ph, M_TEMP);
711 	kill_vmcmds(&epp->ep_vmcmds);
712 	return ENOEXEC;
713 }
714 
715 int
716 ELFNAME2(netbsd,signature)(struct proc *p, struct exec_package *epp,
717     Elf_Ehdr *eh)
718 {
719 	size_t i;
720 	Elf_Phdr *ph;
721 	size_t phsize;
722 	int error;
723 
724 	if (eh->e_phnum > MAXPHNUM)
725 		return ENOEXEC;
726 
727 	phsize = eh->e_phnum * sizeof(Elf_Phdr);
728 	ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK);
729 	error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize);
730 	if (error)
731 		goto out;
732 
733 	for (i = 0; i < eh->e_phnum; i++) {
734 		Elf_Phdr *ephp = &ph[i];
735 		Elf_Nhdr *np;
736 
737 		if (ephp->p_type != PT_NOTE ||
738 		    ephp->p_filesz > 1024 ||
739 		    ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ)
740 			continue;
741 
742 		np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK);
743 		error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np,
744 		    ephp->p_filesz);
745 		if (error)
746 			goto next;
747 
748 		if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG ||
749 		    np->n_namesz != ELF_NOTE_NETBSD_NAMESZ ||
750 		    np->n_descsz != ELF_NOTE_NETBSD_DESCSZ ||
751 		    memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME,
752 		    ELF_NOTE_NETBSD_NAMESZ))
753 			goto next;
754 
755 		error = 0;
756 		free(np, M_TEMP);
757 		goto out;
758 
759 	next:
760 		free(np, M_TEMP);
761 		continue;
762 	}
763 
764 	error = ENOEXEC;
765 out:
766 	free(ph, M_TEMP);
767 	return (error);
768 }
769 
770 int
771 ELFNAME2(netbsd,probe)(struct proc *p, struct exec_package *epp,
772     void *eh, char *itp, vaddr_t *pos)
773 {
774 	int error;
775 
776 	if ((error = ELFNAME2(netbsd,signature)(p, epp, eh)) != 0)
777 		return error;
778 #ifdef ELF_INTERP_NON_RELOCATABLE
779 	*pos = ELF_LINK_ADDR;
780 #endif
781 	return 0;
782 }
783