xref: /dragonfly/sys/kern/imgact_elf.c (revision 9ddb8543)
1 /*-
2  * Copyright (c) 1995-1996 Søren 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 1.55 2008/08/17 17:21:36 nth 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 emulation 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 can_exec_dyn = 1;
529 SYSCTL_INT(_kern, OID_AUTO, elf_exec_dyn, CTLFLAG_RW,
530 		&can_exec_dyn, 1,
531 		"ELF: can exec shared libraries");
532 
533 static int
534 exec_elf_imgact(struct image_params *imgp)
535 {
536 	const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
537 	const Elf_Phdr *phdr;
538 	Elf_Auxargs *elf_auxargs = NULL;
539 	struct vmspace *vmspace;
540 	vm_prot_t prot;
541 	u_long text_size = 0, data_size = 0, total_size = 0;
542 	u_long text_addr = 0, data_addr = 0;
543 	u_long seg_size, seg_addr;
544 	u_long addr, entry = 0, proghdr = 0;
545 	int error, i;
546 	const char *interp = NULL;
547 	const Elf_Note *abi_note = NULL;
548 	Elf_Brandinfo *brand_info;
549 	char *path;
550 
551 	error = 0;
552 
553 	/*
554 	 * Do we have a valid ELF header ?
555 	 * We allow execution of ET_EXEC and, if kern.elf_exec_dyn is 1, ET_DYN.
556 	 */
557 	if (elf_check_header(hdr) != 0 ||
558 	    (hdr->e_type != ET_EXEC && (!can_exec_dyn || hdr->e_type != ET_DYN)))
559 		return -1;
560 
561 	/*
562 	 * From here on down, we return an errno, not -1, as we've
563 	 * detected an ELF file.
564 	 */
565 
566 	if ((hdr->e_phoff > PAGE_SIZE) ||
567 	    (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
568 		/* Only support headers in first page for now */
569 		return ENOEXEC;
570 	}
571 	phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff);
572 
573 	/*
574 	 * From this point on, we may have resources that need to be freed.
575 	 */
576 
577 	exec_new_vmspace(imgp, NULL);
578 
579 	/*
580 	 * Yeah, I'm paranoid.  There is every reason in the world to get
581 	 * VTEXT now since from here on out, there are places we can have
582 	 * a context switch.  Better safe than sorry; I really don't want
583 	 * the file to change while it's being loaded.
584 	 */
585 	vsetflags(imgp->vp, VTEXT);
586 
587 	vmspace = imgp->proc->p_vmspace;
588 
589 	for (i = 0; i < hdr->e_phnum; i++) {
590 		switch(phdr[i].p_type) {
591 
592 		case PT_LOAD:	/* Loadable segment */
593 			prot = 0;
594 			if (phdr[i].p_flags & PF_X)
595   				prot |= VM_PROT_EXECUTE;
596 			if (phdr[i].p_flags & PF_W)
597   				prot |= VM_PROT_WRITE;
598 			if (phdr[i].p_flags & PF_R)
599   				prot |= VM_PROT_READ;
600 
601 			if ((error = elf_load_section(imgp->proc,
602 						     vmspace, imgp->vp,
603   						     phdr[i].p_offset,
604   						     (caddr_t)phdr[i].p_vaddr,
605   						     phdr[i].p_memsz,
606   						     phdr[i].p_filesz, prot)) != 0)
607   				goto fail;
608 
609 			/*
610 			 * If this segment contains the program headers,
611 			 * remember their virtual address for the AT_PHDR
612 			 * aux entry. Static binaries don't usually include
613 			 * a PT_PHDR entry.
614 			 */
615 			if (phdr[i].p_offset == 0 &&
616 			    hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
617 				<= phdr[i].p_filesz)
618 				proghdr = phdr[i].p_vaddr + hdr->e_phoff;
619 
620 			seg_addr = trunc_page(phdr[i].p_vaddr);
621 			seg_size = round_page(phdr[i].p_memsz +
622 				phdr[i].p_vaddr - seg_addr);
623 
624 			/*
625 			 * Is this .text or .data?  We can't use
626 			 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
627 			 * alpha terribly and possibly does other bad
628 			 * things so we stick to the old way of figuring
629 			 * it out:  If the segment contains the program
630 			 * entry point, it's a text segment, otherwise it
631 			 * is a data segment.
632 			 *
633 			 * Note that obreak() assumes that data_addr +
634 			 * data_size == end of data load area, and the ELF
635 			 * file format expects segments to be sorted by
636 			 * address.  If multiple data segments exist, the
637 			 * last one will be used.
638 			 */
639 			if (hdr->e_entry >= phdr[i].p_vaddr &&
640 			    hdr->e_entry < (phdr[i].p_vaddr +
641 			    phdr[i].p_memsz)) {
642 				text_size = seg_size;
643 				text_addr = seg_addr;
644 				entry = (u_long)hdr->e_entry;
645 			} else {
646 				data_size = seg_size;
647 				data_addr = seg_addr;
648 			}
649 			total_size += seg_size;
650 
651 			/*
652 			 * Check limits.  It should be safe to check the
653 			 * limits after loading the segment since we do
654 			 * not actually fault in all the segment's pages.
655 			 */
656 			if (data_size >
657 			    imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
658 			    text_size > maxtsiz ||
659 			    total_size >
660 			    imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
661 				error = ENOMEM;
662 				goto fail;
663 			}
664 			break;
665 	  	case PT_INTERP:	/* Path to interpreter */
666 			if (phdr[i].p_filesz > MAXPATHLEN ||
667 			    phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
668 				error = ENOEXEC;
669 				goto fail;
670 			}
671 			interp = imgp->image_header + phdr[i].p_offset;
672 			break;
673 		case PT_NOTE:	/* Check for .note.ABI-tag */
674 		{
675 			const Elf_Note *tmp_note;
676 			/* XXX handle anything outside the first page */
677 			if (phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
678 				continue;
679 			if (phdr[i].p_filesz < sizeof(Elf_Note))
680 				continue; /* ENOEXEC? */
681 			tmp_note = (const Elf_Note *)(imgp->image_header + phdr[i].p_offset);
682 			if (tmp_note->n_type != 1)
683 				continue;
684 			if (tmp_note->n_namesz + sizeof(Elf_Note) +
685 			    tmp_note->n_descsz > phdr[i].p_filesz)
686 				continue; /* ENOEXEC? */
687 			abi_note = tmp_note;
688 		}
689 			break;
690 		case PT_PHDR: 	/* Program header table info */
691 			proghdr = phdr[i].p_vaddr;
692 			break;
693 		default:
694 			break;
695 		}
696 	}
697 
698 	vmspace->vm_tsize = text_size >> PAGE_SHIFT;
699 	vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
700 	vmspace->vm_dsize = data_size >> PAGE_SHIFT;
701 	vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
702 
703 	addr = ELF_RTLD_ADDR(vmspace);
704 
705 	imgp->entry_addr = entry;
706 
707 	brand_info = NULL;
708 
709 	/* We support three types of branding -- (1) the ELF EI_OSABI field
710 	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
711 	 * branding w/in the ELF header, and (3) path of the `interp_path'
712 	 * field.  We should also look for an ".note.ABI-tag" ELF section now
713 	 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
714 	 */
715 
716 	/* If the executable has a brand, search for it in the brand list. */
717 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] != ELFOSABI_NONE) {
718 		for (i = 0;  i < MAX_BRANDS;  i++) {
719 			Elf_Brandinfo *bi = elf_brand_list[i];
720 
721 			if (bi != NULL &&
722 			    (hdr->e_ident[EI_OSABI] == bi->brand
723 			    || 0 ==
724 			    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
725 			    bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
726 				brand_info = bi;
727 				break;
728 			}
729 		}
730 	}
731 
732 	/* Search for a recognized ABI. */
733 	if (brand_info == NULL && abi_note != NULL) {
734 		for (i = 0; i < MAX_BRANDS; i++) {
735 			Elf_Brandinfo *bi = elf_brand_list[i];
736 
737 			if (bi != NULL && bi->match_abi_note != NULL &&
738 			    (*bi->match_abi_note)(abi_note)) {
739 				brand_info = bi;
740 				break;
741 			}
742 		}
743 	}
744 
745 	/*
746 	 * ELFOSABI_NONE == ELFOSABI_SYSV, so a SYSV binary misses all
747 	 * checks so far, since it is neither branded nor does it have
748 	 * an ABI note.  If the EI_OSABI field is ELFOSABI_NONE, assume
749 	 * it is svr4 and look for an entry in the elf_brand_list with
750 	 * match_abi_note == NULL.
751 	 */
752 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] == ELFOSABI_NONE) {
753 		for (i = 0; i < MAX_BRANDS; i++) {
754 			Elf_Brandinfo *bi = elf_brand_list[i];
755 
756 			if (bi != NULL && bi->match_abi_note == NULL &&
757 			    ELFOSABI_SYSV == bi->brand) {
758 				brand_info = bi;
759 				break;
760 			}
761 		}
762 	}
763 
764 	/* Lacking a recognized ABI, search for a recognized interpreter. */
765 	if (brand_info == NULL && interp != NULL) {
766 		for (i = 0;  i < MAX_BRANDS;  i++) {
767 			Elf_Brandinfo *bi = elf_brand_list[i];
768 
769 			if (bi != NULL &&
770 			    strcmp(interp, bi->interp_path) == 0) {
771 				brand_info = bi;
772 				break;
773 			}
774 		}
775 	}
776 
777 	/* Lacking a recognized interpreter, try the default brand */
778 	if (brand_info == NULL) {
779 		for (i = 0; i < MAX_BRANDS; i++) {
780 			Elf_Brandinfo *bi = elf_brand_list[i];
781 
782 			if (bi != NULL && fallback_elf_brand == bi->brand) {
783 				brand_info = bi;
784 				break;
785 			}
786 		}
787 	}
788 
789 	if (brand_info == NULL) {
790 		uprintf("ELF binary type \"%u\" not known.\n",
791 		    hdr->e_ident[EI_OSABI]);
792 		error = ENOEXEC;
793 		goto fail;
794 	}
795 
796 	imgp->proc->p_sysent = brand_info->sysvec;
797 	if (interp != NULL) {
798 		path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
799 	        ksnprintf(path, MAXPATHLEN, "%s%s",
800 			 brand_info->emul_path, interp);
801 		if ((error = elf_load_file(imgp->proc, path, &addr,
802 					   &imgp->entry_addr)) != 0) {
803 		        if ((error = elf_load_file(imgp->proc, interp, &addr,
804 						   &imgp->entry_addr)) != 0) {
805 			        uprintf("ELF interpreter %s not found\n", path);
806 				kfree(path, M_TEMP);
807 				goto fail;
808 			}
809                 }
810 		kfree(path, M_TEMP);
811 	} else {
812 		addr = 0;
813 	}
814 
815 	/*
816 	 * Construct auxargs table (used by the fixup routine)
817 	 */
818 	elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
819 	elf_auxargs->execfd = -1;
820 	elf_auxargs->phdr = proghdr;
821 	elf_auxargs->phent = hdr->e_phentsize;
822 	elf_auxargs->phnum = hdr->e_phnum;
823 	elf_auxargs->pagesz = PAGE_SIZE;
824 	elf_auxargs->base = addr;
825 	elf_auxargs->flags = 0;
826 	elf_auxargs->entry = entry;
827 	elf_auxargs->trace = elf_trace;
828 
829 	imgp->auxargs = elf_auxargs;
830 	imgp->interpreted = 0;
831 
832 fail:
833 	return error;
834 }
835 
836 static int
837 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp)
838 {
839 	Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
840 	register_t *pos;
841 
842 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
843 
844 	if (args->trace) {
845 		AUXARGS_ENTRY(pos, AT_DEBUG, 1);
846 	}
847 	if (args->execfd != -1) {
848 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
849 	}
850 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
851 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
852 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
853 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
854 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
855 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
856 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
857 	AUXARGS_ENTRY(pos, AT_NULL, 0);
858 
859 	kfree(imgp->auxargs, M_TEMP);
860 	imgp->auxargs = NULL;
861 
862 	(*stack_base)--;
863 	suword(*stack_base, (long) imgp->args->argc);
864 	return 0;
865 }
866 
867 /*
868  * Code for generating ELF core dumps.
869  */
870 
871 typedef int (*segment_callback) (vm_map_entry_t, void *);
872 
873 /* Closure for cb_put_phdr(). */
874 struct phdr_closure {
875 	Elf_Phdr *phdr;		/* Program header to fill in (incremented) */
876 	Elf_Phdr *phdr_max;	/* Pointer bound for error check */
877 	Elf_Off offset;		/* Offset of segment in core file */
878 };
879 
880 /* Closure for cb_size_segment(). */
881 struct sseg_closure {
882 	int count;		/* Count of writable segments. */
883 	size_t vsize;		/* Total size of all writable segments. */
884 };
885 
886 /* Closure for cb_put_fp(). */
887 struct fp_closure {
888 	struct vn_hdr *vnh;
889 	struct vn_hdr *vnh_max;
890 	int count;
891 	struct stat *sb;
892 };
893 
894 typedef struct elf_buf {
895 	char	*buf;
896 	size_t	off;
897 	size_t	off_max;
898 } *elf_buf_t;
899 
900 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
901 
902 static int cb_put_phdr (vm_map_entry_t, void *);
903 static int cb_size_segment (vm_map_entry_t, void *);
904 static int cb_fpcount_segment(vm_map_entry_t, void *);
905 static int cb_put_fp(vm_map_entry_t, void *);
906 
907 
908 static int each_segment (struct proc *, segment_callback, void *, int);
909 static int elf_corehdr (struct lwp *, int, struct file *, struct ucred *,
910 			int, elf_buf_t);
911 enum putmode { WRITE, DRYRUN };
912 static int elf_puthdr (struct lwp *, elf_buf_t, int sig, enum putmode,
913 			int, struct file *);
914 static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
915 static int elf_putnote (elf_buf_t, const char *, int, const void *, size_t);
916 
917 static int elf_putsigs(struct lwp *, elf_buf_t);
918 static int elf_puttextvp(struct proc *, elf_buf_t);
919 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
920 
921 extern int osreldate;
922 
923 int
924 elf_coredump(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
925 {
926 	struct file *fp;
927 	int error;
928 
929 	if ((error = falloc(NULL, &fp, NULL)) != 0)
930 		return (error);
931 	fsetcred(fp, lp->lwp_proc->p_ucred);
932 
933 	/*
934 	 * XXX fixme.
935 	 */
936 	fp->f_type = DTYPE_VNODE;
937 	fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
938 	fp->f_ops = &vnode_fileops;
939 	fp->f_data = vp;
940 	vn_unlock(vp);
941 
942 	error = generic_elf_coredump(lp, sig, fp, limit);
943 
944 	fp->f_type = 0;
945 	fp->f_flag = 0;
946 	fp->f_ops = &badfileops;
947 	fp->f_data = NULL;
948 	fdrop(fp);
949 	return (error);
950 }
951 
952 int
953 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
954 {
955 	struct proc *p = lp->lwp_proc;
956 	struct ucred *cred = p->p_ucred;
957 	int error = 0;
958 	struct sseg_closure seginfo;
959 	struct elf_buf target;
960 
961 	if (!fp)
962 		kprintf("can't dump core - null fp\n");
963 
964 	/*
965 	 * Size the program segments
966 	 */
967 	seginfo.count = 0;
968 	seginfo.vsize = 0;
969 	each_segment(p, cb_size_segment, &seginfo, 1);
970 
971 	/*
972 	 * Calculate the size of the core file header area by making
973 	 * a dry run of generating it.  Nothing is written, but the
974 	 * size is calculated.
975 	 */
976 	bzero(&target, sizeof(target));
977 	elf_puthdr(lp, &target, sig, DRYRUN, seginfo.count, fp);
978 
979 	if (target.off + seginfo.vsize >= limit)
980 		return (EFAULT);
981 
982 	/*
983 	 * Allocate memory for building the header, fill it up,
984 	 * and write it out.
985 	 */
986 	target.off_max = target.off;
987 	target.off = 0;
988 	target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
989 
990 	error = elf_corehdr(lp, sig, fp, cred, seginfo.count, &target);
991 
992 	/* Write the contents of all of the writable segments. */
993 	if (error == 0) {
994 		Elf_Phdr *php;
995 		int i;
996 		ssize_t nbytes;
997 
998 		php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
999 		for (i = 0; i < seginfo.count; i++) {
1000 			error = fp_write(fp, (caddr_t)php->p_vaddr,
1001 					php->p_filesz, &nbytes, UIO_USERSPACE);
1002 			if (error != 0)
1003 				break;
1004 			php++;
1005 		}
1006 	}
1007 	kfree(target.buf, M_TEMP);
1008 
1009 	return error;
1010 }
1011 
1012 /*
1013  * A callback for each_segment() to write out the segment's
1014  * program header entry.
1015  */
1016 static int
1017 cb_put_phdr(vm_map_entry_t entry, void *closure)
1018 {
1019 	struct phdr_closure *phc = closure;
1020 	Elf_Phdr *phdr = phc->phdr;
1021 
1022 	if (phc->phdr == phc->phdr_max)
1023 		return EINVAL;
1024 
1025 	phc->offset = round_page(phc->offset);
1026 
1027 	phdr->p_type = PT_LOAD;
1028 	phdr->p_offset = phc->offset;
1029 	phdr->p_vaddr = entry->start;
1030 	phdr->p_paddr = 0;
1031 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1032 	phdr->p_align = PAGE_SIZE;
1033 	phdr->p_flags = 0;
1034 	if (entry->protection & VM_PROT_READ)
1035 		phdr->p_flags |= PF_R;
1036 	if (entry->protection & VM_PROT_WRITE)
1037 		phdr->p_flags |= PF_W;
1038 	if (entry->protection & VM_PROT_EXECUTE)
1039 		phdr->p_flags |= PF_X;
1040 
1041 	phc->offset += phdr->p_filesz;
1042 	++phc->phdr;
1043 	return 0;
1044 }
1045 
1046 /*
1047  * A callback for each_writable_segment() to gather information about
1048  * the number of segments and their total size.
1049  */
1050 static int
1051 cb_size_segment(vm_map_entry_t entry, void *closure)
1052 {
1053 	struct sseg_closure *ssc = closure;
1054 
1055 	++ssc->count;
1056 	ssc->vsize += entry->end - entry->start;
1057 	return 0;
1058 }
1059 
1060 /*
1061  * A callback for each_segment() to gather information about
1062  * the number of text segments.
1063  */
1064 static int
1065 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
1066 {
1067 	int *count = closure;
1068 	struct vnode *vp;
1069 
1070 	if (entry->object.vm_object->type == OBJT_VNODE) {
1071 		vp = (struct vnode *)entry->object.vm_object->handle;
1072 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1073 			return 0;
1074 		++*count;
1075 	}
1076 	return 0;
1077 }
1078 
1079 static int
1080 cb_put_fp(vm_map_entry_t entry, void *closure)
1081 {
1082 	struct fp_closure *fpc = closure;
1083 	struct vn_hdr *vnh = fpc->vnh;
1084 	Elf_Phdr *phdr = &vnh->vnh_phdr;
1085 	struct vnode *vp;
1086 	int error;
1087 
1088 	/*
1089 	 * If an entry represents a vnode then write out a file handle.
1090 	 *
1091 	 * If we are checkpointing a checkpoint-restored program we do
1092 	 * NOT record the filehandle for the old checkpoint vnode (which
1093 	 * is mapped all over the place).  Instead we rely on the fact
1094 	 * that a checkpoint-restored program does not mmap() the checkpt
1095 	 * vnode NOCORE, so its contents will be written out to the
1096 	 * new checkpoint file.  This is necessary because the 'old'
1097 	 * checkpoint file is typically destroyed when a new one is created
1098 	 * and thus cannot be used to restore the new checkpoint.
1099 	 *
1100 	 * Theoretically we could create a chain of checkpoint files and
1101 	 * operate the checkpointing operation kinda like an incremental
1102 	 * checkpoint, but a checkpoint restore would then likely wind up
1103 	 * referencing many prior checkpoint files and that is a bit over
1104 	 * the top for the purpose of the checkpoint API.
1105 	 */
1106 	if (entry->object.vm_object->type == OBJT_VNODE) {
1107 		vp = (struct vnode *)entry->object.vm_object->handle;
1108 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1109 			return 0;
1110 		if (vnh == fpc->vnh_max)
1111 			return EINVAL;
1112 
1113 		if (vp->v_mount)
1114 			vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1115 		error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
1116 		if (error) {
1117 			char *freepath, *fullpath;
1118 
1119 			if (vn_fullpath(curproc, vp, &fullpath, &freepath)) {
1120 				kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
1121 			} else {
1122 				kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
1123 				kfree(freepath, M_TEMP);
1124 			}
1125 			error = 0;
1126 		}
1127 
1128 		phdr->p_type = PT_LOAD;
1129 		phdr->p_offset = 0;        /* not written to core */
1130 		phdr->p_vaddr = entry->start;
1131 		phdr->p_paddr = 0;
1132 		phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1133 		phdr->p_align = PAGE_SIZE;
1134 		phdr->p_flags = 0;
1135 		if (entry->protection & VM_PROT_READ)
1136 			phdr->p_flags |= PF_R;
1137 		if (entry->protection & VM_PROT_WRITE)
1138 			phdr->p_flags |= PF_W;
1139 		if (entry->protection & VM_PROT_EXECUTE)
1140 			phdr->p_flags |= PF_X;
1141 		++fpc->vnh;
1142 		++fpc->count;
1143 	}
1144 	return 0;
1145 }
1146 
1147 /*
1148  * For each writable segment in the process's memory map, call the given
1149  * function with a pointer to the map entry and some arbitrary
1150  * caller-supplied data.
1151  */
1152 static int
1153 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
1154 {
1155 	int error = 0;
1156 	vm_map_t map = &p->p_vmspace->vm_map;
1157 	vm_map_entry_t entry;
1158 
1159 	for (entry = map->header.next; error == 0 && entry != &map->header;
1160 	    entry = entry->next) {
1161 		vm_object_t obj;
1162 
1163 		/*
1164 		 * Don't dump inaccessible mappings, deal with legacy
1165 		 * coredump mode.
1166 		 *
1167 		 * Note that read-only segments related to the elf binary
1168 		 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1169 		 * need to arbitrarily ignore such segments.
1170 		 */
1171 		if (elf_legacy_coredump) {
1172 			if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
1173 				continue;
1174 		} else {
1175 			if (writable && (entry->protection & VM_PROT_ALL) == 0)
1176 				continue;
1177 		}
1178 
1179 		/*
1180 		 * Dont include memory segment in the coredump if
1181 		 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1182 		 * madvise(2).
1183 		 *
1184 		 * Currently we only dump normal VM object maps.  We do
1185 		 * not dump submaps or virtual page tables.
1186 		 */
1187 		if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
1188 			continue;
1189 		if (entry->maptype != VM_MAPTYPE_NORMAL)
1190 			continue;
1191 		if ((obj = entry->object.vm_object) == NULL)
1192 			continue;
1193 
1194 		/* Find the deepest backing object. */
1195 		while (obj->backing_object != NULL)
1196 			obj = obj->backing_object;
1197 
1198 		/* Ignore memory-mapped devices and such things. */
1199 		if (obj->type != OBJT_DEFAULT &&
1200 		    obj->type != OBJT_SWAP &&
1201 		    obj->type != OBJT_VNODE)
1202 			continue;
1203 
1204 		error = (*func)(entry, closure);
1205 	}
1206 	return error;
1207 }
1208 
1209 static
1210 void *
1211 target_reserve(elf_buf_t target, size_t bytes, int *error)
1212 {
1213     void *res = NULL;
1214 
1215     if (target->buf) {
1216 	    if (target->off + bytes > target->off_max)
1217 		    *error = EINVAL;
1218 	    else
1219 		    res = target->buf + target->off;
1220     }
1221     target->off += bytes;
1222     return (res);
1223 }
1224 
1225 /*
1226  * Write the core file header to the file, including padding up to
1227  * the page boundary.
1228  */
1229 static int
1230 elf_corehdr(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
1231 	    int numsegs, elf_buf_t target)
1232 {
1233 	int error;
1234 	ssize_t nbytes;
1235 
1236 	/*
1237 	 * Fill in the header.  The fp is passed so we can detect and flag
1238 	 * a checkpoint file pointer within the core file itself, because
1239 	 * it may not be restored from the same file handle.
1240 	 */
1241 	error = elf_puthdr(lp, target, sig, WRITE, numsegs, fp);
1242 
1243 	/* Write it to the core file. */
1244 	if (error == 0) {
1245 		error = fp_write(fp, target->buf, target->off, &nbytes,
1246 				 UIO_SYSSPACE);
1247 	}
1248 	return error;
1249 }
1250 
1251 static int
1252 elf_puthdr(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
1253     int numsegs, struct file *fp)
1254 {
1255 	struct proc *p = lp->lwp_proc;
1256 	int error = 0;
1257 	size_t phoff;
1258 	size_t noteoff;
1259 	size_t notesz;
1260 	Elf_Ehdr *ehdr;
1261 	Elf_Phdr *phdr;
1262 
1263 	ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
1264 
1265 	phoff = target->off;
1266 	phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
1267 
1268 	noteoff = target->off;
1269 	if (error == 0)
1270 		elf_putallnotes(lp, target, sig, mode);
1271 	notesz = target->off - noteoff;
1272 
1273 	/*
1274 	 * put extra cruft for dumping process state here
1275 	 *  - we really want it be before all the program
1276 	 *    mappings
1277 	 *  - we just need to update the offset accordingly
1278 	 *    and GDB will be none the wiser.
1279 	 */
1280 	if (error == 0)
1281 		error = elf_puttextvp(p, target);
1282 	if (error == 0)
1283 		error = elf_putsigs(lp, target);
1284 	if (error == 0)
1285 		error = elf_putfiles(p, target, fp);
1286 
1287 	/*
1288 	 * Align up to a page boundary for the program segments.  The
1289 	 * actual data will be written to the outptu file, not to elf_buf_t,
1290 	 * so we do not have to do any further bounds checking.
1291 	 */
1292 	target->off = round_page(target->off);
1293 	if (error == 0 && ehdr != NULL) {
1294 		/*
1295 		 * Fill in the ELF header.
1296 		 */
1297 		ehdr->e_ident[EI_MAG0] = ELFMAG0;
1298 		ehdr->e_ident[EI_MAG1] = ELFMAG1;
1299 		ehdr->e_ident[EI_MAG2] = ELFMAG2;
1300 		ehdr->e_ident[EI_MAG3] = ELFMAG3;
1301 		ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1302 		ehdr->e_ident[EI_DATA] = ELF_DATA;
1303 		ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1304 		ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
1305 		ehdr->e_ident[EI_ABIVERSION] = 0;
1306 		ehdr->e_ident[EI_PAD] = 0;
1307 		ehdr->e_type = ET_CORE;
1308 		ehdr->e_machine = ELF_ARCH;
1309 		ehdr->e_version = EV_CURRENT;
1310 		ehdr->e_entry = 0;
1311 		ehdr->e_phoff = phoff;
1312 		ehdr->e_flags = 0;
1313 		ehdr->e_ehsize = sizeof(Elf_Ehdr);
1314 		ehdr->e_phentsize = sizeof(Elf_Phdr);
1315 		ehdr->e_phnum = numsegs + 1;
1316 		ehdr->e_shentsize = sizeof(Elf_Shdr);
1317 		ehdr->e_shnum = 0;
1318 		ehdr->e_shstrndx = SHN_UNDEF;
1319 	}
1320 	if (error == 0 && phdr != NULL) {
1321 		/*
1322 		 * Fill in the program header entries.
1323 		 */
1324 		struct phdr_closure phc;
1325 
1326 		/* The note segement. */
1327 		phdr->p_type = PT_NOTE;
1328 		phdr->p_offset = noteoff;
1329 		phdr->p_vaddr = 0;
1330 		phdr->p_paddr = 0;
1331 		phdr->p_filesz = notesz;
1332 		phdr->p_memsz = 0;
1333 		phdr->p_flags = 0;
1334 		phdr->p_align = 0;
1335 		++phdr;
1336 
1337 		/* All the writable segments from the program. */
1338 		phc.phdr = phdr;
1339 		phc.phdr_max = phdr + numsegs;
1340 		phc.offset = target->off;
1341 		each_segment(p, cb_put_phdr, &phc, 1);
1342 	}
1343 	return (error);
1344 }
1345 
1346 /*
1347  * Append core dump notes to target ELF buffer or simply update target size
1348  * if dryrun selected.
1349  */
1350 static int
1351 elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
1352     enum putmode mode)
1353 {
1354 	struct proc *p = corelp->lwp_proc;
1355 	int error;
1356 	struct {
1357 		prstatus_t status;
1358 		prfpregset_t fpregs;
1359 		prpsinfo_t psinfo;
1360 	} *tmpdata;
1361 	prstatus_t *status;
1362 	prfpregset_t *fpregs;
1363 	prpsinfo_t *psinfo;
1364 	struct lwp *lp;
1365 
1366 	/*
1367 	 * Allocate temporary storage for notes on heap to avoid stack overflow.
1368 	 */
1369 	if (mode != DRYRUN) {
1370 		tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
1371 		status = &tmpdata->status;
1372 		fpregs = &tmpdata->fpregs;
1373 		psinfo = &tmpdata->psinfo;
1374 	} else {
1375 		tmpdata = NULL;
1376 		status = NULL;
1377 		fpregs = NULL;
1378 		psinfo = NULL;
1379 	}
1380 
1381 	/*
1382 	 * Append LWP-agnostic note.
1383 	 */
1384 	if (mode != DRYRUN) {
1385 		psinfo->pr_version = PRPSINFO_VERSION;
1386 		psinfo->pr_psinfosz = sizeof(prpsinfo_t);
1387 		strncpy(psinfo->pr_fname, p->p_comm,
1388 			sizeof(psinfo->pr_fname) - 1);
1389 		/*
1390 		 * XXX - We don't fill in the command line arguments
1391 		 * properly yet.
1392 		 */
1393 		strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ);
1394 	}
1395 	error =
1396 	    elf_putnote(target, "FreeBSD", NT_PRPSINFO, psinfo, sizeof *psinfo);
1397 	if (error)
1398 		goto exit;
1399 
1400 	/*
1401 	 * Append first note for LWP that triggered core so that it is
1402 	 * the selected one when the debugger starts.
1403 	 */
1404 	if (mode != DRYRUN) {
1405 		status->pr_version = PRSTATUS_VERSION;
1406 		status->pr_statussz = sizeof(prstatus_t);
1407 		status->pr_gregsetsz = sizeof(gregset_t);
1408 		status->pr_fpregsetsz = sizeof(fpregset_t);
1409 		status->pr_osreldate = osreldate;
1410 		status->pr_cursig = sig;
1411 		/*
1412 		 * XXX GDB needs unique pr_pid for each LWP and does not
1413 		 * not support pr_pid==0 but lwp_tid can be 0, so hack unique
1414 		 * value.
1415 		 */
1416 		status->pr_pid = p->p_pid + corelp->lwp_tid;
1417 		fill_regs(corelp, &status->pr_reg);
1418 		fill_fpregs(corelp, fpregs);
1419 	}
1420 	error =
1421 	    elf_putnote(target, "FreeBSD", NT_PRSTATUS, status, sizeof *status);
1422 	if (error)
1423 		goto exit;
1424 	error =
1425 	    elf_putnote(target, "FreeBSD", NT_FPREGSET, fpregs, sizeof *fpregs);
1426 	if (error)
1427 		goto exit;
1428 
1429 	/*
1430 	 * Then append notes for other LWPs.
1431 	 */
1432 	FOREACH_LWP_IN_PROC(lp, p) {
1433 		if (lp == corelp)
1434 			continue;
1435 		/* skip lwps being created */
1436 		if (lp->lwp_thread == NULL)
1437 			continue;
1438 		if (mode != DRYRUN) {
1439 			status->pr_pid = p->p_pid + lp->lwp_tid;
1440 			fill_regs(lp, &status->pr_reg);
1441 			fill_fpregs(lp, fpregs);
1442 		}
1443 		error = elf_putnote(target, "FreeBSD", NT_PRSTATUS,
1444 					status, sizeof *status);
1445 		if (error)
1446 			goto exit;
1447 		error = elf_putnote(target, "FreeBSD", NT_FPREGSET,
1448 					fpregs, sizeof *fpregs);
1449 		if (error)
1450 			goto exit;
1451 	}
1452 
1453 exit:
1454 	if (tmpdata != NULL)
1455 		kfree(tmpdata, M_TEMP);
1456 	return (error);
1457 }
1458 
1459 /*
1460  * Generate a note sub-structure.
1461  *
1462  * NOTE: 4-byte alignment.
1463  */
1464 static int
1465 elf_putnote(elf_buf_t target, const char *name, int type,
1466 	    const void *desc, size_t descsz)
1467 {
1468 	int error = 0;
1469 	char *dst;
1470 	Elf_Note note;
1471 
1472 	note.n_namesz = strlen(name) + 1;
1473 	note.n_descsz = descsz;
1474 	note.n_type = type;
1475 	dst = target_reserve(target, sizeof(note), &error);
1476 	if (dst != NULL)
1477 		bcopy(&note, dst, sizeof note);
1478 	dst = target_reserve(target, note.n_namesz, &error);
1479 	if (dst != NULL)
1480 		bcopy(name, dst, note.n_namesz);
1481 	target->off = roundup2(target->off, sizeof(Elf_Word));
1482 	dst = target_reserve(target, note.n_descsz, &error);
1483 	if (dst != NULL)
1484 		bcopy(desc, dst, note.n_descsz);
1485 	target->off = roundup2(target->off, sizeof(Elf_Word));
1486 	return(error);
1487 }
1488 
1489 
1490 static int
1491 elf_putsigs(struct lwp *lp, elf_buf_t target)
1492 {
1493 	/* XXX lwp handle more than one lwp */
1494 	struct proc *p = lp->lwp_proc;
1495 	int error = 0;
1496 	struct ckpt_siginfo *csi;
1497 
1498 	csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
1499 	if (csi) {
1500 		csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
1501 		bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
1502 		bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
1503 		bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
1504 			sizeof(sigset_t));
1505 		csi->csi_sigparent = p->p_sigparent;
1506 	}
1507 	return(error);
1508 }
1509 
1510 static int
1511 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
1512 {
1513 	int error = 0;
1514 	int i;
1515 	struct ckpt_filehdr *cfh = NULL;
1516 	struct ckpt_fileinfo *cfi;
1517 	struct file *fp;
1518 	struct vnode *vp;
1519 	/*
1520 	 * the duplicated loop is gross, but it was the only way
1521 	 * to eliminate uninitialized variable warnings
1522 	 */
1523 	cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
1524 	if (cfh) {
1525 		cfh->cfh_nfiles = 0;
1526 	}
1527 
1528 	/*
1529 	 * ignore STDIN/STDERR/STDOUT.
1530 	 */
1531 	for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
1532 		fp = holdfp(p->p_fd, i, -1);
1533 		if (fp == NULL)
1534 			continue;
1535 		/*
1536 		 * XXX Only checkpoint vnodes for now.
1537 		 */
1538 		if (fp->f_type != DTYPE_VNODE) {
1539 			fdrop(fp);
1540 			continue;
1541 		}
1542 		cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
1543 					&error);
1544 		if (cfi == NULL) {
1545 			fdrop(fp);
1546 			continue;
1547 		}
1548 		cfi->cfi_index = -1;
1549 		cfi->cfi_type = fp->f_type;
1550 		cfi->cfi_flags = fp->f_flag;
1551 		cfi->cfi_offset = fp->f_offset;
1552 		cfi->cfi_ckflags = 0;
1553 
1554 		if (fp == ckfp)
1555 			cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
1556 		/* f_count and f_msgcount should not be saved/restored */
1557 		/* XXX save cred info */
1558 
1559 		switch(fp->f_type) {
1560 		case DTYPE_VNODE:
1561 			vp = (struct vnode *)fp->f_data;
1562 			/*
1563 			 * it looks like a bug in ptrace is marking
1564 			 * a non-vnode as a vnode - until we find the
1565 			 * root cause this will at least prevent
1566 			 * further panics from truss
1567 			 */
1568 			if (vp == NULL || vp->v_mount == NULL)
1569 				break;
1570 			cfh->cfh_nfiles++;
1571 			cfi->cfi_index = i;
1572 			cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1573 			error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
1574 			break;
1575 		default:
1576 			break;
1577 		}
1578 		fdrop(fp);
1579 	}
1580 	return(error);
1581 }
1582 
1583 static int
1584 elf_puttextvp(struct proc *p, elf_buf_t target)
1585 {
1586 	int error = 0;
1587 	int *vn_count;
1588 	struct fp_closure fpc;
1589 	struct ckpt_vminfo *vminfo;
1590 
1591 	vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
1592 	if (vminfo != NULL) {
1593 		vminfo->cvm_dsize = p->p_vmspace->vm_dsize;
1594 		vminfo->cvm_tsize = p->p_vmspace->vm_tsize;
1595 		vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
1596 		vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
1597 	}
1598 
1599 	fpc.count = 0;
1600 	vn_count = target_reserve(target, sizeof(int), &error);
1601 	if (target->buf != NULL) {
1602 		fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
1603 		fpc.vnh_max = fpc.vnh +
1604 			(target->off_max - target->off) / sizeof(struct vn_hdr);
1605 		error = each_segment(p, cb_put_fp, &fpc, 0);
1606 		if (vn_count)
1607 			*vn_count = fpc.count;
1608 	} else {
1609 		error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
1610 	}
1611 	target->off += fpc.count * sizeof(struct vn_hdr);
1612 	return(error);
1613 }
1614 
1615 
1616 /*
1617  * Tell kern_execve.c about it, with a little help from the linker.
1618  */
1619 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"};
1620 EXEC_SET_ORDERED(elf, elf_execsw, SI_ORDER_FIRST);
1621