xref: /dragonfly/sys/kern/imgact_elf.c (revision c03f08f3)
1 /*-
2  * Copyright (c) 1995-1996 S�ren Schmidt
3  * Copyright (c) 1996 Peter Wemm
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer
11  *    in this position and unchanged.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software withough specific prior written permission
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD: src/sys/kern/imgact_elf.c,v 1.73.2.13 2002/12/28 19:49:41 dillon Exp $
30  * $DragonFly: src/sys/kern/imgact_elf.c,v 1.52 2007/06/29 23:40:00 dillon Exp $
31  */
32 
33 #include <sys/param.h>
34 #include <sys/exec.h>
35 #include <sys/fcntl.h>
36 #include <sys/file.h>
37 #include <sys/imgact.h>
38 #include <sys/imgact_elf.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mman.h>
42 #include <sys/systm.h>
43 #include <sys/proc.h>
44 #include <sys/nlookup.h>
45 #include <sys/pioctl.h>
46 #include <sys/procfs.h>
47 #include <sys/resourcevar.h>
48 #include <sys/signalvar.h>
49 #include <sys/stat.h>
50 #include <sys/syscall.h>
51 #include <sys/sysctl.h>
52 #include <sys/sysent.h>
53 #include <sys/vnode.h>
54 #include <sys/sfbuf.h>
55 
56 #include <vm/vm.h>
57 #include <vm/vm_kern.h>
58 #include <vm/vm_param.h>
59 #include <vm/pmap.h>
60 #include <sys/lock.h>
61 #include <vm/vm_map.h>
62 #include <vm/vm_object.h>
63 #include <vm/vm_extern.h>
64 
65 #include <machine/elf.h>
66 #include <machine/md_var.h>
67 #include <sys/mount.h>
68 #include <sys/ckpt.h>
69 #define OLD_EI_BRAND	8
70 
71 __ElfType(Brandinfo);
72 __ElfType(Auxargs);
73 
74 static int elf_check_header (const Elf_Ehdr *hdr);
75 static int elf_freebsd_fixup (register_t **stack_base,
76     struct image_params *imgp);
77 static int elf_load_file (struct proc *p, const char *file, u_long *addr,
78     u_long *entry);
79 static int elf_load_section (struct proc *p,
80     struct vmspace *vmspace, struct vnode *vp,
81     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
82     vm_prot_t prot);
83 static int exec_elf_imgact (struct image_params *imgp);
84 
85 static int elf_trace = 0;
86 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, "");
87 static int elf_legacy_coredump = 0;
88 SYSCTL_INT(_debug, OID_AUTO, elf_legacy_coredump, CTLFLAG_RW,
89     &elf_legacy_coredump, 0, "");
90 
91 static int dragonfly_match_abi_note(const Elf_Note *);
92 static int freebsd_match_abi_note(const Elf_Note *);
93 
94 static struct sysentvec elf_freebsd_sysvec = {
95         SYS_MAXSYSCALL,
96         sysent,
97         -1,
98         0,
99         0,
100         0,
101         0,
102         0,
103         elf_freebsd_fixup,
104         sendsig,
105         sigcode,
106         &szsigcode,
107         0,
108 	"FreeBSD ELF",
109 	elf_coredump,
110 	NULL,
111 	MINSIGSTKSZ
112 };
113 
114 static Elf_Brandinfo freebsd_brand_info = {
115 						ELFOSABI_FREEBSD,
116 						"FreeBSD",
117 						freebsd_match_abi_note,
118 						"",
119 						"/usr/libexec/ld-elf.so.1",
120 						&elf_freebsd_sysvec
121 					  };
122 
123 static Elf_Brandinfo dragonfly_brand_info = {
124 						ELFOSABI_NONE,
125 						"DragonFly",
126 						dragonfly_match_abi_note,
127 						"",
128 						"/usr/libexec/ld-elf.so.2",
129 						&elf_freebsd_sysvec
130 					  };
131 
132 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = {
133 							&dragonfly_brand_info,
134 							&freebsd_brand_info,
135 							NULL, NULL, NULL,
136 							NULL, NULL, NULL
137 						    };
138 
139 static int
140 freebsd_match_abi_note(const Elf_Note *abi_note)
141 {
142 	const char *abi_name = (const char *)
143 	    ((const uint8_t *)abi_note + sizeof(*abi_note));
144 
145 	if (abi_note->n_namesz != sizeof("FreeBSD"))
146 		return(FALSE);
147 	if (memcmp(abi_name, "FreeBSD", sizeof("FreeBSD")))
148 		return(FALSE);
149 	return(TRUE);
150 }
151 
152 static int
153 dragonfly_match_abi_note(const Elf_Note *abi_note)
154 {
155 	const char *abi_name = (const char *)
156 	    ((const uint8_t *)abi_note + sizeof(*abi_note));
157 
158 	if (abi_note->n_namesz != sizeof("DragonFly"))
159 		return(FALSE);
160 	if (memcmp(abi_name, "DragonFly", sizeof("DragonFly")))
161 		return(FALSE);
162 	return(TRUE);
163 }
164 
165 int
166 elf_insert_brand_entry(Elf_Brandinfo *entry)
167 {
168 	int i;
169 
170 	for (i=1; i<MAX_BRANDS; i++) {
171 		if (elf_brand_list[i] == NULL) {
172 			elf_brand_list[i] = entry;
173 			break;
174 		}
175 	}
176 	if (i == MAX_BRANDS)
177 		return -1;
178 	return 0;
179 }
180 
181 int
182 elf_remove_brand_entry(Elf_Brandinfo *entry)
183 {
184 	int i;
185 
186 	for (i=1; i<MAX_BRANDS; i++) {
187 		if (elf_brand_list[i] == entry) {
188 			elf_brand_list[i] = NULL;
189 			break;
190 		}
191 	}
192 	if (i == MAX_BRANDS)
193 		return -1;
194 	return 0;
195 }
196 
197 /*
198  * Check if an elf brand is being used anywhere in the system.
199  *
200  * Used by the linux emulatino module unloader.  This isn't safe from
201  * races.
202  */
203 struct elf_brand_inuse_info {
204 	int rval;
205 	Elf_Brandinfo *entry;
206 };
207 
208 static int elf_brand_inuse_callback(struct proc *p, void *data);
209 
210 int
211 elf_brand_inuse(Elf_Brandinfo *entry)
212 {
213 	struct elf_brand_inuse_info info;
214 
215 	info.rval = FALSE;
216 	info.entry = entry;
217 	allproc_scan(elf_brand_inuse_callback, entry);
218 	return (info.rval);
219 }
220 
221 static
222 int
223 elf_brand_inuse_callback(struct proc *p, void *data)
224 {
225 	struct elf_brand_inuse_info *info = data;
226 
227 	if (p->p_sysent == info->entry->sysvec) {
228 		info->rval = TRUE;
229 		return(-1);
230 	}
231 	return(0);
232 }
233 
234 static int
235 elf_check_header(const Elf_Ehdr *hdr)
236 {
237 	if (!IS_ELF(*hdr) ||
238 	    hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
239 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
240 	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||
241 	    hdr->e_phentsize != sizeof(Elf_Phdr) ||
242 	    hdr->e_ehsize != sizeof(Elf_Ehdr) ||
243 	    hdr->e_version != ELF_TARG_VER)
244 		return ENOEXEC;
245 
246 	if (!ELF_MACHINE_OK(hdr->e_machine))
247 		return ENOEXEC;
248 
249 	return 0;
250 }
251 
252 static int
253 elf_load_section(struct proc *p, struct vmspace *vmspace, struct vnode *vp,
254 		 vm_offset_t offset, caddr_t vmaddr, size_t memsz,
255 		 size_t filsz, vm_prot_t prot)
256 {
257 	size_t map_len;
258 	vm_offset_t map_addr;
259 	int error, rv, cow;
260 	int count;
261 	size_t copy_len;
262 	vm_object_t object;
263 	vm_offset_t file_addr;
264 
265 	object = vp->v_object;
266 	error = 0;
267 
268 	/*
269 	 * It's necessary to fail if the filsz + offset taken from the
270 	 * header is greater than the actual file pager object's size.
271 	 * If we were to allow this, then the vm_map_find() below would
272 	 * walk right off the end of the file object and into the ether.
273 	 *
274 	 * While I'm here, might as well check for something else that
275 	 * is invalid: filsz cannot be greater than memsz.
276 	 */
277 	if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) {
278 		uprintf("elf_load_section: truncated ELF file\n");
279 		return (ENOEXEC);
280 	}
281 
282 	map_addr = trunc_page((vm_offset_t)vmaddr);
283 	file_addr = trunc_page(offset);
284 
285 	/*
286 	 * We have two choices.  We can either clear the data in the last page
287 	 * of an oversized mapping, or we can start the anon mapping a page
288 	 * early and copy the initialized data into that first page.  We
289 	 * choose the second..
290 	 */
291 	if (memsz > filsz)
292 		map_len = trunc_page(offset+filsz) - file_addr;
293 	else
294 		map_len = round_page(offset+filsz) - file_addr;
295 
296 	if (map_len != 0) {
297 		vm_object_reference(object);
298 
299 		/* cow flags: don't dump readonly sections in core */
300 		cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
301 		    (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
302 
303 		count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
304 		vm_map_lock(&vmspace->vm_map);
305 		rv = vm_map_insert(&vmspace->vm_map, &count,
306 				      object,
307 				      file_addr,	/* file offset */
308 				      map_addr,		/* virtual start */
309 				      map_addr + map_len,/* virtual end */
310 				      VM_MAPTYPE_NORMAL,
311 				      prot, VM_PROT_ALL,
312 				      cow);
313 		vm_map_unlock(&vmspace->vm_map);
314 		vm_map_entry_release(count);
315 		if (rv != KERN_SUCCESS) {
316 			vm_object_deallocate(object);
317 			return EINVAL;
318 		}
319 
320 		/* we can stop now if we've covered it all */
321 		if (memsz == filsz) {
322 			return 0;
323 		}
324 	}
325 
326 
327 	/*
328 	 * We have to get the remaining bit of the file into the first part
329 	 * of the oversized map segment.  This is normally because the .data
330 	 * segment in the file is extended to provide bss.  It's a neat idea
331 	 * to try and save a page, but it's a pain in the behind to implement.
332 	 */
333 	copy_len = (offset + filsz) - trunc_page(offset + filsz);
334 	map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
335 	map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
336 
337 	/* This had damn well better be true! */
338         if (map_len != 0) {
339 		count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
340 		vm_map_lock(&vmspace->vm_map);
341 		rv = vm_map_insert(&vmspace->vm_map, &count,
342 					NULL, 0,
343 					map_addr, map_addr + map_len,
344 					VM_MAPTYPE_NORMAL,
345 					VM_PROT_ALL, VM_PROT_ALL,
346 					0);
347 		vm_map_unlock(&vmspace->vm_map);
348 		vm_map_entry_release(count);
349 		if (rv != KERN_SUCCESS) {
350 			return EINVAL;
351 		}
352 	}
353 
354 	if (copy_len != 0) {
355 		vm_page_t m;
356 		struct sf_buf *sf;
357 
358 		m = vm_fault_object_page(object, trunc_page(offset + filsz),
359 					 VM_PROT_READ, 0, &error);
360 		if (m) {
361 			sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
362 			error = copyout((caddr_t)sf_buf_kva(sf),
363 					(caddr_t)map_addr, copy_len);
364 			sf_buf_free(sf);
365 			vm_page_unhold(m);
366 		}
367 		if (error) {
368 			return (error);
369 		}
370 	}
371 
372 	/*
373 	 * set it to the specified protection
374 	 */
375 	vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len,  prot,
376 		       FALSE);
377 
378 	return error;
379 }
380 
381 /*
382  * Load the file "file" into memory.  It may be either a shared object
383  * or an executable.
384  *
385  * The "addr" reference parameter is in/out.  On entry, it specifies
386  * the address where a shared object should be loaded.  If the file is
387  * an executable, this value is ignored.  On exit, "addr" specifies
388  * where the file was actually loaded.
389  *
390  * The "entry" reference parameter is out only.  On exit, it specifies
391  * the entry point for the loaded file.
392  */
393 static int
394 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry)
395 {
396 	struct {
397 		struct nlookupdata nd;
398 		struct vattr attr;
399 		struct image_params image_params;
400 	} *tempdata;
401 	const Elf_Ehdr *hdr = NULL;
402 	const Elf_Phdr *phdr = NULL;
403 	struct nlookupdata *nd;
404 	struct vmspace *vmspace = p->p_vmspace;
405 	struct vattr *attr;
406 	struct image_params *imgp;
407 	vm_prot_t prot;
408 	u_long rbase;
409 	u_long base_addr = 0;
410 	int error, i, numsegs;
411 
412 	tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
413 	nd = &tempdata->nd;
414 	attr = &tempdata->attr;
415 	imgp = &tempdata->image_params;
416 
417 	/*
418 	 * Initialize part of the common data
419 	 */
420 	imgp->proc = p;
421 	imgp->attr = attr;
422 	imgp->firstpage = NULL;
423 	imgp->image_header = NULL;
424 	imgp->vp = NULL;
425 
426 	error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
427 	if (error == 0)
428 		error = nlookup(nd);
429 	if (error == 0)
430 		error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp);
431 	nlookup_done(nd);
432 	if (error)
433 		goto fail;
434 
435 	/*
436 	 * Check permissions, modes, uid, etc on the file, and "open" it.
437 	 */
438 	error = exec_check_permissions(imgp);
439 	if (error) {
440 		vn_unlock(imgp->vp);
441 		goto fail;
442 	}
443 
444 	error = exec_map_first_page(imgp);
445 	/*
446 	 * Also make certain that the interpreter stays the same, so set
447 	 * its VTEXT flag, too.
448 	 */
449 	if (error == 0)
450 		imgp->vp->v_flag |= VTEXT;
451 	vn_unlock(imgp->vp);
452 	if (error)
453                 goto fail;
454 
455 	hdr = (const Elf_Ehdr *)imgp->image_header;
456 	if ((error = elf_check_header(hdr)) != 0)
457 		goto fail;
458 	if (hdr->e_type == ET_DYN)
459 		rbase = *addr;
460 	else if (hdr->e_type == ET_EXEC)
461 		rbase = 0;
462 	else {
463 		error = ENOEXEC;
464 		goto fail;
465 	}
466 
467 	/* Only support headers that fit within first page for now
468 	 * (multiplication of two Elf_Half fields will not overflow) */
469 	if ((hdr->e_phoff > PAGE_SIZE) ||
470 	    (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
471 		error = ENOEXEC;
472 		goto fail;
473 	}
474 
475 	phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
476 
477 	for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
478 		if (phdr[i].p_type == PT_LOAD) {	/* Loadable segment */
479 			prot = 0;
480 			if (phdr[i].p_flags & PF_X)
481   				prot |= VM_PROT_EXECUTE;
482 			if (phdr[i].p_flags & PF_W)
483   				prot |= VM_PROT_WRITE;
484 			if (phdr[i].p_flags & PF_R)
485   				prot |= VM_PROT_READ;
486 
487 			error = elf_load_section(
488 				    p, vmspace, imgp->vp,
489 				    phdr[i].p_offset,
490 				    (caddr_t)phdr[i].p_vaddr +
491 				    rbase,
492 				    phdr[i].p_memsz,
493 				    phdr[i].p_filesz, prot);
494 			if (error != 0)
495 				goto fail;
496 			/*
497 			 * Establish the base address if this is the
498 			 * first segment.
499 			 */
500 			if (numsegs == 0)
501   				base_addr = trunc_page(phdr[i].p_vaddr + rbase);
502 			numsegs++;
503 		}
504 	}
505 	*addr = base_addr;
506 	*entry=(unsigned long)hdr->e_entry + rbase;
507 
508 fail:
509 	if (imgp->firstpage)
510 		exec_unmap_first_page(imgp);
511 	if (imgp->vp) {
512 		vrele(imgp->vp);
513 		imgp->vp = NULL;
514 	}
515 	kfree(tempdata, M_TEMP);
516 
517 	return error;
518 }
519 
520 /*
521  * non static, as it can be overridden by start_init()
522  */
523 int fallback_elf_brand = -1;
524 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
525 		&fallback_elf_brand, -1,
526 		"ELF brand of last resort");
527 
528 static int
529 exec_elf_imgact(struct image_params *imgp)
530 {
531 	const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
532 	const Elf_Phdr *phdr;
533 	Elf_Auxargs *elf_auxargs = NULL;
534 	struct vmspace *vmspace;
535 	vm_prot_t prot;
536 	u_long text_size = 0, data_size = 0, total_size = 0;
537 	u_long text_addr = 0, data_addr = 0;
538 	u_long seg_size, seg_addr;
539 	u_long addr, entry = 0, proghdr = 0;
540 	int error, i;
541 	const char *interp = NULL;
542 	const Elf_Note *abi_note = NULL;
543 	Elf_Brandinfo *brand_info;
544 	char *path;
545 
546 	error = 0;
547 
548 	/*
549 	 * Do we have a valid ELF header ?
550 	 */
551 	if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC)
552 		return -1;
553 
554 	/*
555 	 * From here on down, we return an errno, not -1, as we've
556 	 * detected an ELF file.
557 	 */
558 
559 	if ((hdr->e_phoff > PAGE_SIZE) ||
560 	    (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
561 		/* Only support headers in first page for now */
562 		return ENOEXEC;
563 	}
564 	phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff);
565 
566 	/*
567 	 * From this point on, we may have resources that need to be freed.
568 	 */
569 
570 	exec_new_vmspace(imgp, NULL);
571 
572 	/*
573 	 * Yeah, I'm paranoid.  There is every reason in the world to get
574 	 * VTEXT now since from here on out, there are places we can have
575 	 * a context switch.  Better safe than sorry; I really don't want
576 	 * the file to change while it's being loaded.
577 	 */
578 	vsetflags(imgp->vp, VTEXT);
579 
580 	vmspace = imgp->proc->p_vmspace;
581 
582 	for (i = 0; i < hdr->e_phnum; i++) {
583 		switch(phdr[i].p_type) {
584 
585 		case PT_LOAD:	/* Loadable segment */
586 			prot = 0;
587 			if (phdr[i].p_flags & PF_X)
588   				prot |= VM_PROT_EXECUTE;
589 			if (phdr[i].p_flags & PF_W)
590   				prot |= VM_PROT_WRITE;
591 			if (phdr[i].p_flags & PF_R)
592   				prot |= VM_PROT_READ;
593 
594 			if ((error = elf_load_section(imgp->proc,
595 						     vmspace, imgp->vp,
596   						     phdr[i].p_offset,
597   						     (caddr_t)phdr[i].p_vaddr,
598   						     phdr[i].p_memsz,
599   						     phdr[i].p_filesz, prot)) != 0)
600   				goto fail;
601 
602 			/*
603 			 * If this segment contains the program headers,
604 			 * remember their virtual address for the AT_PHDR
605 			 * aux entry. Static binaries don't usually include
606 			 * a PT_PHDR entry.
607 			 */
608 			if (phdr[i].p_offset == 0 &&
609 			    hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
610 				<= phdr[i].p_filesz)
611 				proghdr = phdr[i].p_vaddr + hdr->e_phoff;
612 
613 			seg_addr = trunc_page(phdr[i].p_vaddr);
614 			seg_size = round_page(phdr[i].p_memsz +
615 				phdr[i].p_vaddr - seg_addr);
616 
617 			/*
618 			 * Is this .text or .data?  We can't use
619 			 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
620 			 * alpha terribly and possibly does other bad
621 			 * things so we stick to the old way of figuring
622 			 * it out:  If the segment contains the program
623 			 * entry point, it's a text segment, otherwise it
624 			 * is a data segment.
625 			 *
626 			 * Note that obreak() assumes that data_addr +
627 			 * data_size == end of data load area, and the ELF
628 			 * file format expects segments to be sorted by
629 			 * address.  If multiple data segments exist, the
630 			 * last one will be used.
631 			 */
632 			if (hdr->e_entry >= phdr[i].p_vaddr &&
633 			    hdr->e_entry < (phdr[i].p_vaddr +
634 			    phdr[i].p_memsz)) {
635 				text_size = seg_size;
636 				text_addr = seg_addr;
637 				entry = (u_long)hdr->e_entry;
638 			} else {
639 				data_size = seg_size;
640 				data_addr = seg_addr;
641 			}
642 			total_size += seg_size;
643 
644 			/*
645 			 * Check limits.  It should be safe to check the
646 			 * limits after loading the segment since we do
647 			 * not actually fault in all the segment's pages.
648 			 */
649 			if (data_size >
650 			    imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
651 			    text_size > maxtsiz ||
652 			    total_size >
653 			    imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
654 				error = ENOMEM;
655 				goto fail;
656 			}
657 			break;
658 	  	case PT_INTERP:	/* Path to interpreter */
659 			if (phdr[i].p_filesz > MAXPATHLEN ||
660 			    phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
661 				error = ENOEXEC;
662 				goto fail;
663 			}
664 			interp = imgp->image_header + phdr[i].p_offset;
665 			break;
666 		case PT_NOTE:	/* Check for .note.ABI-tag */
667 		{
668 			const Elf_Note *tmp_note;
669 			/* XXX handle anything outside the first page */
670 			if (phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
671 				continue;
672 			if (phdr[i].p_filesz < sizeof(Elf_Note))
673 				continue; /* ENOEXEC? */
674 			tmp_note = (const Elf_Note *)(imgp->image_header + phdr[i].p_offset);
675 			if (tmp_note->n_type != 1)
676 				continue;
677 			if (tmp_note->n_namesz + sizeof(Elf_Note) +
678 			    tmp_note->n_descsz > phdr[i].p_filesz)
679 				continue; /* ENOEXEC? */
680 			abi_note = tmp_note;
681 		}
682 			break;
683 		case PT_PHDR: 	/* Program header table info */
684 			proghdr = phdr[i].p_vaddr;
685 			break;
686 		default:
687 			break;
688 		}
689 	}
690 
691 	vmspace->vm_tsize = text_size >> PAGE_SHIFT;
692 	vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
693 	vmspace->vm_dsize = data_size >> PAGE_SHIFT;
694 	vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
695 
696 	addr = ELF_RTLD_ADDR(vmspace);
697 
698 	imgp->entry_addr = entry;
699 
700 	brand_info = NULL;
701 
702 	/* We support three types of branding -- (1) the ELF EI_OSABI field
703 	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
704 	 * branding w/in the ELF header, and (3) path of the `interp_path'
705 	 * field.  We should also look for an ".note.ABI-tag" ELF section now
706 	 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
707 	 */
708 
709 	/* If the executable has a brand, search for it in the brand list. */
710 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] != ELFOSABI_NONE) {
711 		for (i = 0;  i < MAX_BRANDS;  i++) {
712 			Elf_Brandinfo *bi = elf_brand_list[i];
713 
714 			if (bi != NULL &&
715 			    (hdr->e_ident[EI_OSABI] == bi->brand
716 			    || 0 ==
717 			    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
718 			    bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
719 				brand_info = bi;
720 				break;
721 			}
722 		}
723 	}
724 
725 	/* Search for a recognized ABI. */
726 	if (brand_info == NULL && abi_note != NULL) {
727 		for (i = 0; i < MAX_BRANDS; i++) {
728 			Elf_Brandinfo *bi = elf_brand_list[i];
729 
730 			if (bi != NULL && bi->match_abi_note != NULL &&
731 			    (*bi->match_abi_note)(abi_note)) {
732 				brand_info = bi;
733 				break;
734 			}
735 		}
736 	}
737 
738 	/*
739 	 * ELFOSABI_NONE == ELFOSABI_SYSV, so a SYSV binary misses all
740 	 * checks so far, since it is neither branded nor does it have
741 	 * an ABI note.  If the EI_OSABI field is ELFOSABI_NONE, assume
742 	 * it is svr4 and look for an entry in the elf_brand_list with
743 	 * match_abi_note == NULL.
744 	 */
745 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] == ELFOSABI_NONE) {
746 		for (i = 0; i < MAX_BRANDS; i++) {
747 			Elf_Brandinfo *bi = elf_brand_list[i];
748 
749 			if (bi != NULL && bi->match_abi_note == NULL &&
750 			    ELFOSABI_SYSV == bi->brand) {
751 				brand_info = bi;
752 				break;
753 			}
754 		}
755 	}
756 
757 	/* Lacking a recognized ABI, search for a recognized interpreter. */
758 	if (brand_info == NULL && interp != NULL) {
759 		for (i = 0;  i < MAX_BRANDS;  i++) {
760 			Elf_Brandinfo *bi = elf_brand_list[i];
761 
762 			if (bi != NULL &&
763 			    strcmp(interp, bi->interp_path) == 0) {
764 				brand_info = bi;
765 				break;
766 			}
767 		}
768 	}
769 
770 	/* Lacking a recognized interpreter, try the default brand */
771 	if (brand_info == NULL) {
772 		for (i = 0; i < MAX_BRANDS; i++) {
773 			Elf_Brandinfo *bi = elf_brand_list[i];
774 
775 			if (bi != NULL && fallback_elf_brand == bi->brand) {
776 				brand_info = bi;
777 				break;
778 			}
779 		}
780 	}
781 
782 	if (brand_info == NULL) {
783 		uprintf("ELF binary type \"%u\" not known.\n",
784 		    hdr->e_ident[EI_OSABI]);
785 		error = ENOEXEC;
786 		goto fail;
787 	}
788 
789 	imgp->proc->p_sysent = brand_info->sysvec;
790 	if (interp != NULL) {
791 		path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
792 	        ksnprintf(path, MAXPATHLEN, "%s%s",
793 			 brand_info->emul_path, interp);
794 		if ((error = elf_load_file(imgp->proc, path, &addr,
795 					   &imgp->entry_addr)) != 0) {
796 		        if ((error = elf_load_file(imgp->proc, interp, &addr,
797 						   &imgp->entry_addr)) != 0) {
798 			        uprintf("ELF interpreter %s not found\n", path);
799 				kfree(path, M_TEMP);
800 				goto fail;
801 			}
802                 }
803 		kfree(path, M_TEMP);
804 	}
805 
806 	/*
807 	 * Construct auxargs table (used by the fixup routine)
808 	 */
809 	elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
810 	elf_auxargs->execfd = -1;
811 	elf_auxargs->phdr = proghdr;
812 	elf_auxargs->phent = hdr->e_phentsize;
813 	elf_auxargs->phnum = hdr->e_phnum;
814 	elf_auxargs->pagesz = PAGE_SIZE;
815 	elf_auxargs->base = addr;
816 	elf_auxargs->flags = 0;
817 	elf_auxargs->entry = entry;
818 	elf_auxargs->trace = elf_trace;
819 
820 	imgp->auxargs = elf_auxargs;
821 	imgp->interpreted = 0;
822 
823 fail:
824 	return error;
825 }
826 
827 static int
828 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp)
829 {
830 	Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
831 	register_t *pos;
832 
833 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
834 
835 	if (args->trace) {
836 		AUXARGS_ENTRY(pos, AT_DEBUG, 1);
837 	}
838 	if (args->execfd != -1) {
839 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
840 	}
841 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
842 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
843 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
844 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
845 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
846 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
847 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
848 	AUXARGS_ENTRY(pos, AT_NULL, 0);
849 
850 	kfree(imgp->auxargs, M_TEMP);
851 	imgp->auxargs = NULL;
852 
853 	(*stack_base)--;
854 	suword(*stack_base, (long) imgp->args->argc);
855 	return 0;
856 }
857 
858 /*
859  * Code for generating ELF core dumps.
860  */
861 
862 typedef int (*segment_callback) (vm_map_entry_t, void *);
863 
864 /* Closure for cb_put_phdr(). */
865 struct phdr_closure {
866 	Elf_Phdr *phdr;		/* Program header to fill in (incremented) */
867 	Elf_Phdr *phdr_max;	/* Pointer bound for error check */
868 	Elf_Off offset;		/* Offset of segment in core file */
869 };
870 
871 /* Closure for cb_size_segment(). */
872 struct sseg_closure {
873 	int count;		/* Count of writable segments. */
874 	size_t vsize;		/* Total size of all writable segments. */
875 };
876 
877 /* Closure for cb_put_fp(). */
878 struct fp_closure {
879 	struct vn_hdr *vnh;
880 	struct vn_hdr *vnh_max;
881 	int count;
882 	struct stat *sb;
883 };
884 
885 typedef struct elf_buf {
886 	char	*buf;
887 	size_t	off;
888 	size_t	off_max;
889 } *elf_buf_t;
890 
891 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
892 
893 static int cb_put_phdr (vm_map_entry_t, void *);
894 static int cb_size_segment (vm_map_entry_t, void *);
895 static int cb_fpcount_segment(vm_map_entry_t, void *);
896 static int cb_put_fp(vm_map_entry_t, void *);
897 
898 
899 static int each_segment (struct proc *, segment_callback, void *, int);
900 static int elf_corehdr (struct lwp *, int, struct file *, struct ucred *,
901 			int, elf_buf_t);
902 static int elf_puthdr (struct lwp *, elf_buf_t, const prstatus_t *,
903 			const prfpregset_t *, const prpsinfo_t *, int,
904 			struct file *);
905 static int elf_putnote (elf_buf_t, const char *, int, const void *, size_t);
906 
907 static int elf_putsigs(struct lwp *, elf_buf_t);
908 static int elf_puttextvp(struct proc *, elf_buf_t);
909 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
910 
911 extern int osreldate;
912 
913 int
914 elf_coredump(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
915 {
916 	struct file *fp;
917 	int error;
918 
919 	if ((error = falloc(NULL, &fp, NULL)) != 0)
920 		return (error);
921 	fsetcred(fp, lp->lwp_proc->p_ucred);
922 
923 	/*
924 	 * XXX fixme.
925 	 */
926 	fp->f_type = DTYPE_VNODE;
927 	fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
928 	fp->f_ops = &vnode_fileops;
929 	fp->f_data = vp;
930 	vn_unlock(vp);
931 
932 	error = generic_elf_coredump(lp, sig, fp, limit);
933 
934 	fp->f_type = 0;
935 	fp->f_flag = 0;
936 	fp->f_ops = &badfileops;
937 	fp->f_data = NULL;
938 	fdrop(fp);
939 	return (error);
940 }
941 
942 int
943 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
944 {
945 	struct proc *p = lp->lwp_proc;
946 	struct ucred *cred = p->p_ucred;
947 	int error = 0;
948 	struct sseg_closure seginfo;
949 	struct elf_buf target;
950 
951 	if (!fp)
952 		kprintf("can't dump core - null fp\n");
953 
954 	/*
955 	 * Size the program segments
956 	 */
957 	seginfo.count = 0;
958 	seginfo.vsize = 0;
959 	each_segment(p, cb_size_segment, &seginfo, 1);
960 
961 	/*
962 	 * Calculate the size of the core file header area by making
963 	 * a dry run of generating it.  Nothing is written, but the
964 	 * size is calculated.
965 	 */
966 	bzero(&target, sizeof(target));
967 	elf_puthdr(lp, &target, NULL, NULL, NULL, seginfo.count, fp);
968 
969 	if (target.off + seginfo.vsize >= limit)
970 		return (EFAULT);
971 
972 	/*
973 	 * Allocate memory for building the header, fill it up,
974 	 * and write it out.
975 	 */
976 	target.off_max = target.off;
977 	target.off = 0;
978 	target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
979 
980 	if (target.buf == NULL)
981 		return EINVAL;
982 	error = elf_corehdr(lp, sig, fp, cred, seginfo.count, &target);
983 
984 	/* Write the contents of all of the writable segments. */
985 	if (error == 0) {
986 		Elf_Phdr *php;
987 		int i;
988 		int nbytes;
989 
990 		php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
991 		for (i = 0; i < seginfo.count; i++) {
992 			error = fp_write(fp, (caddr_t)php->p_vaddr,
993 					php->p_filesz, &nbytes, UIO_USERSPACE);
994 			if (error != 0)
995 				break;
996 			php++;
997 		}
998 	}
999 	kfree(target.buf, M_TEMP);
1000 
1001 	return error;
1002 }
1003 
1004 /*
1005  * A callback for each_segment() to write out the segment's
1006  * program header entry.
1007  */
1008 static int
1009 cb_put_phdr(vm_map_entry_t entry, void *closure)
1010 {
1011 	struct phdr_closure *phc = closure;
1012 	Elf_Phdr *phdr = phc->phdr;
1013 
1014 	if (phc->phdr == phc->phdr_max)
1015 		return EINVAL;
1016 
1017 	phc->offset = round_page(phc->offset);
1018 
1019 	phdr->p_type = PT_LOAD;
1020 	phdr->p_offset = phc->offset;
1021 	phdr->p_vaddr = entry->start;
1022 	phdr->p_paddr = 0;
1023 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1024 	phdr->p_align = PAGE_SIZE;
1025 	phdr->p_flags = 0;
1026 	if (entry->protection & VM_PROT_READ)
1027 		phdr->p_flags |= PF_R;
1028 	if (entry->protection & VM_PROT_WRITE)
1029 		phdr->p_flags |= PF_W;
1030 	if (entry->protection & VM_PROT_EXECUTE)
1031 		phdr->p_flags |= PF_X;
1032 
1033 	phc->offset += phdr->p_filesz;
1034 	++phc->phdr;
1035 	return 0;
1036 }
1037 
1038 /*
1039  * A callback for each_writable_segment() to gather information about
1040  * the number of segments and their total size.
1041  */
1042 static int
1043 cb_size_segment(vm_map_entry_t entry, void *closure)
1044 {
1045 	struct sseg_closure *ssc = closure;
1046 
1047 	++ssc->count;
1048 	ssc->vsize += entry->end - entry->start;
1049 	return 0;
1050 }
1051 
1052 /*
1053  * A callback for each_segment() to gather information about
1054  * the number of text segments.
1055  */
1056 static int
1057 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
1058 {
1059 	int *count = closure;
1060 	struct vnode *vp;
1061 
1062 	if (entry->object.vm_object->type == OBJT_VNODE) {
1063 		vp = (struct vnode *)entry->object.vm_object->handle;
1064 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1065 			return 0;
1066 		++*count;
1067 	}
1068 	return 0;
1069 }
1070 
1071 static int
1072 cb_put_fp(vm_map_entry_t entry, void *closure)
1073 {
1074 	struct fp_closure *fpc = closure;
1075 	struct vn_hdr *vnh = fpc->vnh;
1076 	Elf_Phdr *phdr = &vnh->vnh_phdr;
1077 	struct vnode *vp;
1078 	int error;
1079 
1080 	/*
1081 	 * If an entry represents a vnode then write out a file handle.
1082 	 *
1083 	 * If we are checkpointing a checkpoint-restored program we do
1084 	 * NOT record the filehandle for the old checkpoint vnode (which
1085 	 * is mapped all over the place).  Instead we rely on the fact
1086 	 * that a checkpoint-restored program does not mmap() the checkpt
1087 	 * vnode NOCORE, so its contents will be written out to the
1088 	 * new checkpoint file.  This is necessary because the 'old'
1089 	 * checkpoint file is typically destroyed when a new one is created
1090 	 * and thus cannot be used to restore the new checkpoint.
1091 	 *
1092 	 * Theoretically we could create a chain of checkpoint files and
1093 	 * operate the checkpointing operation kinda like an incremental
1094 	 * checkpoint, but a checkpoint restore would then likely wind up
1095 	 * referencing many prior checkpoint files and that is a bit over
1096 	 * the top for the purpose of the checkpoint API.
1097 	 */
1098 	if (entry->object.vm_object->type == OBJT_VNODE) {
1099 		vp = (struct vnode *)entry->object.vm_object->handle;
1100 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1101 			return 0;
1102 		if (vnh == fpc->vnh_max)
1103 			return EINVAL;
1104 
1105 		if (vp->v_mount)
1106 			vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1107 		error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
1108 		if (error) {
1109 			char *freepath, *fullpath;
1110 
1111 			if (vn_fullpath(curproc, vp, &fullpath, &freepath)) {
1112 				kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
1113 			} else {
1114 				kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
1115 				kfree(freepath, M_TEMP);
1116 			}
1117 			error = 0;
1118 		}
1119 
1120 		phdr->p_type = PT_LOAD;
1121 		phdr->p_offset = 0;        /* not written to core */
1122 		phdr->p_vaddr = entry->start;
1123 		phdr->p_paddr = 0;
1124 		phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1125 		phdr->p_align = PAGE_SIZE;
1126 		phdr->p_flags = 0;
1127 		if (entry->protection & VM_PROT_READ)
1128 			phdr->p_flags |= PF_R;
1129 		if (entry->protection & VM_PROT_WRITE)
1130 			phdr->p_flags |= PF_W;
1131 		if (entry->protection & VM_PROT_EXECUTE)
1132 			phdr->p_flags |= PF_X;
1133 		++fpc->vnh;
1134 		++fpc->count;
1135 	}
1136 	return 0;
1137 }
1138 
1139 /*
1140  * For each writable segment in the process's memory map, call the given
1141  * function with a pointer to the map entry and some arbitrary
1142  * caller-supplied data.
1143  */
1144 static int
1145 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
1146 {
1147 	int error = 0;
1148 	vm_map_t map = &p->p_vmspace->vm_map;
1149 	vm_map_entry_t entry;
1150 
1151 	for (entry = map->header.next; error == 0 && entry != &map->header;
1152 	    entry = entry->next) {
1153 		vm_object_t obj;
1154 
1155 		/*
1156 		 * Don't dump inaccessible mappings, deal with legacy
1157 		 * coredump mode.
1158 		 *
1159 		 * Note that read-only segments related to the elf binary
1160 		 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1161 		 * need to arbitrarily ignore such segments.
1162 		 */
1163 		if (elf_legacy_coredump) {
1164 			if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
1165 				continue;
1166 		} else {
1167 			if (writable && (entry->protection & VM_PROT_ALL) == 0)
1168 				continue;
1169 		}
1170 
1171 		/*
1172 		 * Dont include memory segment in the coredump if
1173 		 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1174 		 * madvise(2).
1175 		 *
1176 		 * Currently we only dump normal VM object maps.  We do
1177 		 * not dump submaps or virtual page tables.
1178 		 */
1179 		if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
1180 			continue;
1181 		if (entry->maptype != VM_MAPTYPE_NORMAL)
1182 			continue;
1183 		if ((obj = entry->object.vm_object) == NULL)
1184 			continue;
1185 
1186 		/* Find the deepest backing object. */
1187 		while (obj->backing_object != NULL)
1188 			obj = obj->backing_object;
1189 
1190 		/* Ignore memory-mapped devices and such things. */
1191 		if (obj->type != OBJT_DEFAULT &&
1192 		    obj->type != OBJT_SWAP &&
1193 		    obj->type != OBJT_VNODE)
1194 			continue;
1195 
1196 		error = (*func)(entry, closure);
1197 	}
1198 	return error;
1199 }
1200 
1201 static
1202 void *
1203 target_reserve(elf_buf_t target, size_t bytes, int *error)
1204 {
1205     void *res = NULL;
1206 
1207     if (target->buf) {
1208 	    if (target->off + bytes > target->off_max)
1209 		    *error = EINVAL;
1210 	    else
1211 		    res = target->buf + target->off;
1212     }
1213     target->off += bytes;
1214     return (res);
1215 }
1216 
1217 /*
1218  * Write the core file header to the file, including padding up to
1219  * the page boundary.
1220  */
1221 static int
1222 elf_corehdr(struct lwp *lp, int sig, struct file *fp, struct ucred *cred, int numsegs,
1223 	    elf_buf_t target)
1224 {
1225 	/* XXX lwp handle more than one lwp */
1226 	struct proc *p = lp->lwp_proc;
1227 	struct {
1228 		prstatus_t status;
1229 		prfpregset_t fpregset;
1230 		prpsinfo_t psinfo;
1231 	} *tempdata;
1232 	int error;
1233 	prstatus_t *status;
1234 	prfpregset_t *fpregset;
1235 	prpsinfo_t *psinfo;
1236 	int nbytes;
1237 
1238 	tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_ZERO | M_WAITOK);
1239 	status = &tempdata->status;
1240 	fpregset = &tempdata->fpregset;
1241 	psinfo = &tempdata->psinfo;
1242 
1243 	/* Gather the information for the header. */
1244 	status->pr_version = PRSTATUS_VERSION;
1245 	status->pr_statussz = sizeof(prstatus_t);
1246 	status->pr_gregsetsz = sizeof(gregset_t);
1247 	status->pr_fpregsetsz = sizeof(fpregset_t);
1248 	status->pr_osreldate = osreldate;
1249 	status->pr_cursig = sig;
1250 	status->pr_pid = p->p_pid;
1251 	fill_regs(lp, &status->pr_reg);
1252 
1253 	fill_fpregs(lp, fpregset);
1254 
1255 	psinfo->pr_version = PRPSINFO_VERSION;
1256 	psinfo->pr_psinfosz = sizeof(prpsinfo_t);
1257 	strncpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname) - 1);
1258 
1259 	/* XXX - We don't fill in the command line arguments properly yet. */
1260 	strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ);
1261 
1262 	/*
1263 	 * Fill in the header.  The fp is passed so we can detect and flag
1264 	 * a checkpoint file pointer within the core file itself, because
1265 	 * it may not be restored from the same file handle.
1266 	 */
1267 	error = elf_puthdr(lp, target, status, fpregset, psinfo, numsegs, fp);
1268 
1269 	kfree(tempdata, M_TEMP);
1270 
1271 	/* Write it to the core file. */
1272 	if (error == 0) {
1273 		error = fp_write(fp, target->buf, target->off, &nbytes,
1274 				 UIO_SYSSPACE);
1275 	}
1276 	return error;
1277 }
1278 
1279 static int
1280 elf_puthdr(struct lwp *lp, elf_buf_t target, const prstatus_t *status,
1281 	const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs,
1282 	struct file *fp)
1283 {
1284 	struct proc *p = lp->lwp_proc;
1285 	int error = 0;
1286 	size_t phoff;
1287 	size_t noteoff;
1288 	size_t notesz;
1289 	Elf_Ehdr *ehdr;
1290 	Elf_Phdr *phdr;
1291 
1292 	ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
1293 
1294 	phoff = target->off;
1295 	phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
1296 
1297 	noteoff = target->off;
1298 	if (error == 0) {
1299 		error = elf_putnote(target, "FreeBSD", NT_PRSTATUS,
1300 					status, sizeof *status);
1301 	}
1302 	if (error == 0) {
1303 		error = elf_putnote(target, "FreeBSD", NT_FPREGSET,
1304 					fpregset, sizeof *fpregset);
1305 	}
1306 	if (error == 0) {
1307 		error = elf_putnote(target, "FreeBSD", NT_PRPSINFO,
1308 					psinfo, sizeof *psinfo);
1309 	}
1310 	notesz = target->off - noteoff;
1311 
1312 	/*
1313 	 * put extra cruft for dumping process state here
1314 	 *  - we really want it be before all the program
1315 	 *    mappings
1316 	 *  - we just need to update the offset accordingly
1317 	 *    and GDB will be none the wiser.
1318 	 */
1319 	if (error == 0)
1320 		error = elf_puttextvp(p, target);
1321 	if (error == 0)
1322 		error = elf_putsigs(lp, target);
1323 	if (error == 0)
1324 		error = elf_putfiles(p, target, fp);
1325 
1326 	/*
1327 	 * Align up to a page boundary for the program segments.  The
1328 	 * actual data will be written to the outptu file, not to elf_buf_t,
1329 	 * so we do not have to do any further bounds checking.
1330 	 */
1331 	target->off = round_page(target->off);
1332 	if (error == 0 && ehdr != NULL) {
1333 		/*
1334 		 * Fill in the ELF header.
1335 		 */
1336 		ehdr->e_ident[EI_MAG0] = ELFMAG0;
1337 		ehdr->e_ident[EI_MAG1] = ELFMAG1;
1338 		ehdr->e_ident[EI_MAG2] = ELFMAG2;
1339 		ehdr->e_ident[EI_MAG3] = ELFMAG3;
1340 		ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1341 		ehdr->e_ident[EI_DATA] = ELF_DATA;
1342 		ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1343 		ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
1344 		ehdr->e_ident[EI_ABIVERSION] = 0;
1345 		ehdr->e_ident[EI_PAD] = 0;
1346 		ehdr->e_type = ET_CORE;
1347 		ehdr->e_machine = ELF_ARCH;
1348 		ehdr->e_version = EV_CURRENT;
1349 		ehdr->e_entry = 0;
1350 		ehdr->e_phoff = phoff;
1351 		ehdr->e_flags = 0;
1352 		ehdr->e_ehsize = sizeof(Elf_Ehdr);
1353 		ehdr->e_phentsize = sizeof(Elf_Phdr);
1354 		ehdr->e_phnum = numsegs + 1;
1355 		ehdr->e_shentsize = sizeof(Elf_Shdr);
1356 		ehdr->e_shnum = 0;
1357 		ehdr->e_shstrndx = SHN_UNDEF;
1358 	}
1359 	if (error == 0 && phdr != NULL) {
1360 		/*
1361 		 * Fill in the program header entries.
1362 		 */
1363 		struct phdr_closure phc;
1364 
1365 		/* The note segement. */
1366 		phdr->p_type = PT_NOTE;
1367 		phdr->p_offset = noteoff;
1368 		phdr->p_vaddr = 0;
1369 		phdr->p_paddr = 0;
1370 		phdr->p_filesz = notesz;
1371 		phdr->p_memsz = 0;
1372 		phdr->p_flags = 0;
1373 		phdr->p_align = 0;
1374 		++phdr;
1375 
1376 		/* All the writable segments from the program. */
1377 		phc.phdr = phdr;
1378 		phc.phdr_max = phdr + numsegs;
1379 		phc.offset = target->off;
1380 		each_segment(p, cb_put_phdr, &phc, 1);
1381 	}
1382 	return (error);
1383 }
1384 
1385 static int
1386 elf_putnote(elf_buf_t target, const char *name, int type,
1387 	    const void *desc, size_t descsz)
1388 {
1389 	int error = 0;
1390 	char *dst;
1391 	Elf_Note note;
1392 
1393 	note.n_namesz = strlen(name) + 1;
1394 	note.n_descsz = descsz;
1395 	note.n_type = type;
1396 	dst = target_reserve(target, sizeof(note), &error);
1397 	if (dst != NULL)
1398 		bcopy(&note, dst, sizeof note);
1399 	dst = target_reserve(target, note.n_namesz, &error);
1400 	if (dst != NULL)
1401 		bcopy(name, dst, note.n_namesz);
1402 	target->off = roundup2(target->off, sizeof(Elf_Size));
1403 	dst = target_reserve(target, note.n_descsz, &error);
1404 	if (dst != NULL)
1405 		bcopy(desc, dst, note.n_descsz);
1406 	target->off = roundup2(target->off, sizeof(Elf_Size));
1407 	return(error);
1408 }
1409 
1410 
1411 static int
1412 elf_putsigs(struct lwp *lp, elf_buf_t target)
1413 {
1414 	/* XXX lwp handle more than one lwp */
1415 	struct proc *p = lp->lwp_proc;
1416 	int error = 0;
1417 	struct ckpt_siginfo *csi;
1418 
1419 	csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
1420 	if (csi) {
1421 		csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
1422 		bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
1423 		bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
1424 		bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
1425 			sizeof(sigset_t));
1426 		csi->csi_sigparent = p->p_sigparent;
1427 	}
1428 	return(error);
1429 }
1430 
1431 static int
1432 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
1433 {
1434 	int error = 0;
1435 	int i;
1436 	struct ckpt_filehdr *cfh = NULL;
1437 	struct ckpt_fileinfo *cfi;
1438 	struct file *fp;
1439 	struct vnode *vp;
1440 	/*
1441 	 * the duplicated loop is gross, but it was the only way
1442 	 * to eliminate uninitialized variable warnings
1443 	 */
1444 	cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
1445 	if (cfh) {
1446 		cfh->cfh_nfiles = 0;
1447 	}
1448 
1449 	/*
1450 	 * ignore STDIN/STDERR/STDOUT.
1451 	 */
1452 	for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
1453 		fp = holdfp(p->p_fd, i, -1);
1454 		if (fp == NULL)
1455 			continue;
1456 		/*
1457 		 * XXX Only checkpoint vnodes for now.
1458 		 */
1459 		if (fp->f_type != DTYPE_VNODE) {
1460 			fdrop(fp);
1461 			continue;
1462 		}
1463 		cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
1464 					&error);
1465 		if (cfi == NULL) {
1466 			fdrop(fp);
1467 			continue;
1468 		}
1469 		cfi->cfi_index = -1;
1470 		cfi->cfi_type = fp->f_type;
1471 		cfi->cfi_flags = fp->f_flag;
1472 		cfi->cfi_offset = fp->f_offset;
1473 		cfi->cfi_ckflags = 0;
1474 
1475 		if (fp == ckfp)
1476 			cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
1477 		/* f_count and f_msgcount should not be saved/restored */
1478 		/* XXX save cred info */
1479 
1480 		switch(fp->f_type) {
1481 		case DTYPE_VNODE:
1482 			vp = (struct vnode *)fp->f_data;
1483 			/*
1484 			 * it looks like a bug in ptrace is marking
1485 			 * a non-vnode as a vnode - until we find the
1486 			 * root cause this will at least prevent
1487 			 * further panics from truss
1488 			 */
1489 			if (vp == NULL || vp->v_mount == NULL)
1490 				break;
1491 			cfh->cfh_nfiles++;
1492 			cfi->cfi_index = i;
1493 			cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1494 			error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
1495 			break;
1496 		default:
1497 			break;
1498 		}
1499 		fdrop(fp);
1500 	}
1501 	return(error);
1502 }
1503 
1504 static int
1505 elf_puttextvp(struct proc *p, elf_buf_t target)
1506 {
1507 	int error = 0;
1508 	int *vn_count;
1509 	struct fp_closure fpc;
1510 	struct ckpt_vminfo *vminfo;
1511 
1512 	vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
1513 	if (vminfo != NULL) {
1514 		vminfo->cvm_dsize = p->p_vmspace->vm_dsize;
1515 		vminfo->cvm_tsize = p->p_vmspace->vm_tsize;
1516 		vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
1517 		vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
1518 	}
1519 
1520 	fpc.count = 0;
1521 	vn_count = target_reserve(target, sizeof(int), &error);
1522 	if (target->buf != NULL) {
1523 		fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
1524 		fpc.vnh_max = fpc.vnh +
1525 			(target->off_max - target->off) / sizeof(struct vn_hdr);
1526 		error = each_segment(p, cb_put_fp, &fpc, 0);
1527 		if (vn_count)
1528 			*vn_count = fpc.count;
1529 	} else {
1530 		error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
1531 	}
1532 	target->off += fpc.count * sizeof(struct vn_hdr);
1533 	return(error);
1534 }
1535 
1536 
1537 /*
1538  * Tell kern_execve.c about it, with a little help from the linker.
1539  */
1540 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"};
1541 EXEC_SET_ORDERED(elf, elf_execsw, SI_ORDER_FIRST);
1542