xref: /dragonfly/sys/kern/imgact_elf.c (revision 10cbe914)
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 without 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/eventhandler.h>
55 
56 #include <cpu/lwbuf.h>
57 
58 #include <vm/vm.h>
59 #include <vm/vm_kern.h>
60 #include <vm/vm_param.h>
61 #include <vm/pmap.h>
62 #include <sys/lock.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_object.h>
65 #include <vm/vm_extern.h>
66 
67 #include <machine/elf.h>
68 #include <machine/md_var.h>
69 #include <sys/mount.h>
70 #include <sys/ckpt.h>
71 #define OLD_EI_BRAND	8
72 
73 __ElfType(Brandinfo);
74 __ElfType(Auxargs);
75 
76 static int elf_check_header (const Elf_Ehdr *hdr);
77 static int elf_freebsd_fixup (register_t **stack_base,
78     struct image_params *imgp);
79 static int elf_load_file (struct proc *p, const char *file, u_long *addr,
80     u_long *entry);
81 static int elf_load_section (struct proc *p,
82     struct vmspace *vmspace, struct vnode *vp,
83     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
84     vm_prot_t prot);
85 static int exec_elf_imgact (struct image_params *imgp);
86 
87 static int elf_trace = 0;
88 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, "");
89 static int elf_legacy_coredump = 0;
90 SYSCTL_INT(_debug, OID_AUTO, elf_legacy_coredump, CTLFLAG_RW,
91     &elf_legacy_coredump, 0,
92     "Do not dump inaccessible mappings, legacy coredump mode");
93 
94 static int dragonfly_match_abi_note(const Elf_Note *);
95 static int freebsd_match_abi_note(const Elf_Note *);
96 
97 static struct sysentvec elf_freebsd_sysvec = {
98         SYS_MAXSYSCALL,
99         sysent,
100         -1,
101         0,
102         0,
103         0,
104         0,
105         0,
106         elf_freebsd_fixup,
107         sendsig,
108         sigcode,
109         &szsigcode,
110         0,
111 #if defined(__x86_64__)
112 	"FreeBSD ELF64",
113 #else
114 	"FreeBSD ELF32",
115 #endif
116 	elf_coredump,
117 	NULL,
118 	MINSIGSTKSZ
119 };
120 
121 static Elf_Brandinfo freebsd_brand_info = {
122 						ELFOSABI_FREEBSD,
123 						"FreeBSD",
124 						freebsd_match_abi_note,
125 						"",
126 						"/usr/libexec/ld-elf.so.1",
127 						&elf_freebsd_sysvec
128 					  };
129 
130 static Elf_Brandinfo dragonfly_brand_info = {
131 						ELFOSABI_NONE,
132 						"DragonFly",
133 						dragonfly_match_abi_note,
134 						"",
135 						"/usr/libexec/ld-elf.so.2",
136 						&elf_freebsd_sysvec
137 					  };
138 
139 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = {
140 							&dragonfly_brand_info,
141 							&freebsd_brand_info,
142 							NULL, NULL, NULL,
143 							NULL, NULL, NULL
144 						    };
145 
146 static int
147 freebsd_match_abi_note(const Elf_Note *abi_note)
148 {
149 	const char *abi_name = (const char *)
150 	    ((const uint8_t *)abi_note + sizeof(*abi_note));
151 
152 	if (abi_note->n_namesz != sizeof("FreeBSD"))
153 		return(FALSE);
154 	if (memcmp(abi_name, "FreeBSD", sizeof("FreeBSD")))
155 		return(FALSE);
156 	return(TRUE);
157 }
158 
159 static int
160 dragonfly_match_abi_note(const Elf_Note *abi_note)
161 {
162 	const char *abi_name = (const char *)
163 	    ((const uint8_t *)abi_note + sizeof(*abi_note));
164 
165 	if (abi_note->n_namesz != sizeof("DragonFly"))
166 		return(FALSE);
167 	if (memcmp(abi_name, "DragonFly", sizeof("DragonFly")))
168 		return(FALSE);
169 	return(TRUE);
170 }
171 
172 int
173 elf_insert_brand_entry(Elf_Brandinfo *entry)
174 {
175 	int i;
176 
177 	for (i=1; i<MAX_BRANDS; i++) {
178 		if (elf_brand_list[i] == NULL) {
179 			elf_brand_list[i] = entry;
180 			break;
181 		}
182 	}
183 	if (i == MAX_BRANDS)
184 		return -1;
185 	return 0;
186 }
187 
188 int
189 elf_remove_brand_entry(Elf_Brandinfo *entry)
190 {
191 	int i;
192 
193 	for (i=1; i<MAX_BRANDS; i++) {
194 		if (elf_brand_list[i] == entry) {
195 			elf_brand_list[i] = NULL;
196 			break;
197 		}
198 	}
199 	if (i == MAX_BRANDS)
200 		return -1;
201 	return 0;
202 }
203 
204 /*
205  * Check if an elf brand is being used anywhere in the system.
206  *
207  * Used by the linux emulation module unloader.  This isn't safe from
208  * races.
209  */
210 struct elf_brand_inuse_info {
211 	int rval;
212 	Elf_Brandinfo *entry;
213 };
214 
215 static int elf_brand_inuse_callback(struct proc *p, void *data);
216 
217 int
218 elf_brand_inuse(Elf_Brandinfo *entry)
219 {
220 	struct elf_brand_inuse_info info;
221 
222 	info.rval = FALSE;
223 	info.entry = entry;
224 	allproc_scan(elf_brand_inuse_callback, entry);
225 	return (info.rval);
226 }
227 
228 static
229 int
230 elf_brand_inuse_callback(struct proc *p, void *data)
231 {
232 	struct elf_brand_inuse_info *info = data;
233 
234 	if (p->p_sysent == info->entry->sysvec) {
235 		info->rval = TRUE;
236 		return(-1);
237 	}
238 	return(0);
239 }
240 
241 static int
242 elf_check_header(const Elf_Ehdr *hdr)
243 {
244 	if (!IS_ELF(*hdr) ||
245 	    hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
246 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
247 	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||
248 	    hdr->e_phentsize != sizeof(Elf_Phdr) ||
249 	    hdr->e_ehsize != sizeof(Elf_Ehdr) ||
250 	    hdr->e_version != ELF_TARG_VER)
251 		return ENOEXEC;
252 
253 	if (!ELF_MACHINE_OK(hdr->e_machine))
254 		return ENOEXEC;
255 
256 	return 0;
257 }
258 
259 static Elf_Brandinfo *
260 elf_check_abi_note(struct image_params *imgp, const Elf_Phdr *ph)
261 {
262 	Elf_Brandinfo *match = NULL;
263 	const Elf_Note *tmp_note;
264 	struct lwbuf *lwb;
265 	const char *page;
266 	char *data = NULL;
267 	Elf_Off off;
268 	size_t firstoff;
269 	size_t len;
270 	size_t firstlen;
271 
272 	len = ph->p_filesz;
273 	off = ph->p_offset;
274 
275 	firstoff = off & PAGE_MASK;
276 	firstlen = PAGE_SIZE - firstoff;
277 
278 	if (len < sizeof(Elf_Note) || len > PAGE_SIZE)
279 		return NULL; /* ENOEXEC? */
280 
281 	if (exec_map_page(imgp, off >> PAGE_SHIFT, &lwb, &page))
282 		return NULL;
283 
284 	/*
285 	 * Crosses page boundary?  Is that allowed?
286 	 */
287 	if (firstlen < len) {
288 		data = kmalloc(len, M_TEMP, M_WAITOK);
289 
290 		bcopy(page + firstoff, data, firstlen);
291 
292 		exec_unmap_page(lwb);
293 		if (exec_map_page(imgp, (off >> PAGE_SHIFT) + 1, &lwb, &page)) {
294 			kfree(data, M_TEMP);
295 			return NULL;
296 		}
297 		bcopy(page, data + firstlen, len - firstlen);
298 		tmp_note = (void *)data;
299 	} else {
300 		tmp_note = (const void *)(page + firstoff);
301 	}
302 
303 	while (len >= sizeof(Elf_Note)) {
304 		int i;
305 		size_t nlen = roundup(tmp_note->n_namesz, sizeof(Elf_Word)) +
306 			      roundup(tmp_note->n_descsz, sizeof(Elf_Word)) +
307 			      sizeof(Elf_Note);
308 
309 		if (nlen > len)
310 			break;
311 
312 		if (tmp_note->n_type != 1)
313 			goto next;
314 
315 		for (i = 0; i < MAX_BRANDS; i++) {
316 			Elf_Brandinfo *bi = elf_brand_list[i];
317 
318 			if (bi != NULL && bi->match_abi_note != NULL &&
319 			    bi->match_abi_note(tmp_note)) {
320 				match = bi;
321 				break;
322 			}
323 		}
324 
325 		if (match != NULL)
326 			break;
327 
328 next:
329 		len -= nlen;
330 		tmp_note += nlen;
331 	}
332 
333 	if (data != NULL)
334 		kfree(data, M_TEMP);
335 	exec_unmap_page(lwb);
336 
337 	return (match);
338 }
339 
340 static int
341 elf_load_section(struct proc *p, struct vmspace *vmspace, struct vnode *vp,
342 		 vm_offset_t offset, caddr_t vmaddr, size_t memsz,
343 		 size_t filsz, vm_prot_t prot)
344 {
345 	size_t map_len;
346 	vm_offset_t map_addr;
347 	int error, rv, cow;
348 	int count;
349 	size_t copy_len;
350 	vm_object_t object;
351 	vm_offset_t file_addr;
352 
353 	object = vp->v_object;
354 	error = 0;
355 
356 	/*
357 	 * It's necessary to fail if the filsz + offset taken from the
358 	 * header is greater than the actual file pager object's size.
359 	 * If we were to allow this, then the vm_map_find() below would
360 	 * walk right off the end of the file object and into the ether.
361 	 *
362 	 * While I'm here, might as well check for something else that
363 	 * is invalid: filsz cannot be greater than memsz.
364 	 */
365 	if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) {
366 		uprintf("elf_load_section: truncated ELF file\n");
367 		return (ENOEXEC);
368 	}
369 
370 	map_addr = trunc_page((vm_offset_t)vmaddr);
371 	file_addr = trunc_page(offset);
372 
373 	/*
374 	 * We have two choices.  We can either clear the data in the last page
375 	 * of an oversized mapping, or we can start the anon mapping a page
376 	 * early and copy the initialized data into that first page.  We
377 	 * choose the second..
378 	 */
379 	if (memsz > filsz)
380 		map_len = trunc_page(offset+filsz) - file_addr;
381 	else
382 		map_len = round_page(offset+filsz) - file_addr;
383 
384 	if (map_len != 0) {
385 		vm_object_reference(object);
386 
387 		/* cow flags: don't dump readonly sections in core */
388 		cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
389 		    (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
390 
391 		count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
392 		vm_map_lock(&vmspace->vm_map);
393 		rv = vm_map_insert(&vmspace->vm_map, &count,
394 				      object,
395 				      file_addr,	/* file offset */
396 				      map_addr,		/* virtual start */
397 				      map_addr + map_len,/* virtual end */
398 				      VM_MAPTYPE_NORMAL,
399 				      prot, VM_PROT_ALL,
400 				      cow);
401 		vm_map_unlock(&vmspace->vm_map);
402 		vm_map_entry_release(count);
403 		if (rv != KERN_SUCCESS) {
404 			vm_object_deallocate(object);
405 			return EINVAL;
406 		}
407 
408 		/* we can stop now if we've covered it all */
409 		if (memsz == filsz) {
410 			return 0;
411 		}
412 	}
413 
414 
415 	/*
416 	 * We have to get the remaining bit of the file into the first part
417 	 * of the oversized map segment.  This is normally because the .data
418 	 * segment in the file is extended to provide bss.  It's a neat idea
419 	 * to try and save a page, but it's a pain in the behind to implement.
420 	 */
421 	copy_len = (offset + filsz) - trunc_page(offset + filsz);
422 	map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
423 	map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
424 
425 	/* This had damn well better be true! */
426         if (map_len != 0) {
427 		count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
428 		vm_map_lock(&vmspace->vm_map);
429 		rv = vm_map_insert(&vmspace->vm_map, &count,
430 					NULL, 0,
431 					map_addr, map_addr + map_len,
432 					VM_MAPTYPE_NORMAL,
433 					VM_PROT_ALL, VM_PROT_ALL,
434 					0);
435 		vm_map_unlock(&vmspace->vm_map);
436 		vm_map_entry_release(count);
437 		if (rv != KERN_SUCCESS) {
438 			return EINVAL;
439 		}
440 	}
441 
442 	if (copy_len != 0) {
443 		vm_page_t m;
444 		struct lwbuf *lwb;
445 
446 		m = vm_fault_object_page(object, trunc_page(offset + filsz),
447 					 VM_PROT_READ, 0, &error);
448 		if (m) {
449 			lwb = lwbuf_alloc(m);
450 			error = copyout((caddr_t)lwbuf_kva(lwb),
451 					(caddr_t)map_addr, copy_len);
452 			lwbuf_free(lwb);
453 			vm_page_unhold(m);
454 		}
455 		if (error) {
456 			return (error);
457 		}
458 	}
459 
460 	/*
461 	 * set it to the specified protection
462 	 */
463 	vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len,  prot,
464 		       FALSE);
465 
466 	return error;
467 }
468 
469 /*
470  * Load the file "file" into memory.  It may be either a shared object
471  * or an executable.
472  *
473  * The "addr" reference parameter is in/out.  On entry, it specifies
474  * the address where a shared object should be loaded.  If the file is
475  * an executable, this value is ignored.  On exit, "addr" specifies
476  * where the file was actually loaded.
477  *
478  * The "entry" reference parameter is out only.  On exit, it specifies
479  * the entry point for the loaded file.
480  */
481 static int
482 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry)
483 {
484 	struct {
485 		struct nlookupdata nd;
486 		struct vattr attr;
487 		struct image_params image_params;
488 	} *tempdata;
489 	const Elf_Ehdr *hdr = NULL;
490 	const Elf_Phdr *phdr = NULL;
491 	struct nlookupdata *nd;
492 	struct vmspace *vmspace = p->p_vmspace;
493 	struct vattr *attr;
494 	struct image_params *imgp;
495 	struct mount *topmnt;
496 	vm_prot_t prot;
497 	u_long rbase;
498 	u_long base_addr = 0;
499 	int error, i, numsegs;
500 
501 	tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
502 	nd = &tempdata->nd;
503 	attr = &tempdata->attr;
504 	imgp = &tempdata->image_params;
505 
506 	/*
507 	 * Initialize part of the common data
508 	 */
509 	imgp->proc = p;
510 	imgp->attr = attr;
511 	imgp->firstpage = NULL;
512 	imgp->image_header = NULL;
513 	imgp->vp = NULL;
514 
515 	error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
516 	if (error == 0)
517 		error = nlookup(nd);
518 	if (error == 0)
519 		error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp);
520 	topmnt = nd->nl_nch.mount;
521 	nlookup_done(nd);
522 	if (error)
523 		goto fail;
524 
525 	/*
526 	 * Check permissions, modes, uid, etc on the file, and "open" it.
527 	 */
528 	error = exec_check_permissions(imgp, topmnt);
529 	if (error) {
530 		vn_unlock(imgp->vp);
531 		goto fail;
532 	}
533 
534 	error = exec_map_first_page(imgp);
535 	/*
536 	 * Also make certain that the interpreter stays the same, so set
537 	 * its VTEXT flag, too.
538 	 */
539 	if (error == 0)
540 		vsetflags(imgp->vp, VTEXT);
541 	vn_unlock(imgp->vp);
542 	if (error)
543                 goto fail;
544 
545 	hdr = (const Elf_Ehdr *)imgp->image_header;
546 	if ((error = elf_check_header(hdr)) != 0)
547 		goto fail;
548 	if (hdr->e_type == ET_DYN)
549 		rbase = *addr;
550 	else if (hdr->e_type == ET_EXEC)
551 		rbase = 0;
552 	else {
553 		error = ENOEXEC;
554 		goto fail;
555 	}
556 
557 	/* Only support headers that fit within first page for now
558 	 * (multiplication of two Elf_Half fields will not overflow) */
559 	if ((hdr->e_phoff > PAGE_SIZE) ||
560 	    (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
561 		error = ENOEXEC;
562 		goto fail;
563 	}
564 
565 	phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
566 
567 	for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
568 		if (phdr[i].p_type == PT_LOAD) {	/* Loadable segment */
569 			prot = 0;
570 			if (phdr[i].p_flags & PF_X)
571   				prot |= VM_PROT_EXECUTE;
572 			if (phdr[i].p_flags & PF_W)
573   				prot |= VM_PROT_WRITE;
574 			if (phdr[i].p_flags & PF_R)
575   				prot |= VM_PROT_READ;
576 
577 			error = elf_load_section(
578 				    p, vmspace, imgp->vp,
579 				    phdr[i].p_offset,
580 				    (caddr_t)phdr[i].p_vaddr +
581 				    rbase,
582 				    phdr[i].p_memsz,
583 				    phdr[i].p_filesz, prot);
584 			if (error != 0)
585 				goto fail;
586 			/*
587 			 * Establish the base address if this is the
588 			 * first segment.
589 			 */
590 			if (numsegs == 0)
591   				base_addr = trunc_page(phdr[i].p_vaddr + rbase);
592 			numsegs++;
593 		}
594 	}
595 	*addr = base_addr;
596 	*entry=(unsigned long)hdr->e_entry + rbase;
597 
598 fail:
599 	if (imgp->firstpage)
600 		exec_unmap_first_page(imgp);
601 	if (imgp->vp) {
602 		vrele(imgp->vp);
603 		imgp->vp = NULL;
604 	}
605 	kfree(tempdata, M_TEMP);
606 
607 	return error;
608 }
609 
610 /*
611  * non static, as it can be overridden by start_init()
612  */
613 int fallback_elf_brand = -1;
614 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
615 		&fallback_elf_brand, -1,
616 		"ELF brand of last resort");
617 
618 static int can_exec_dyn = 1;
619 SYSCTL_INT(_kern, OID_AUTO, elf_exec_dyn, CTLFLAG_RW,
620 		&can_exec_dyn, 1,
621 		"ELF: can exec shared libraries");
622 
623 static int
624 exec_elf_imgact(struct image_params *imgp)
625 {
626 	const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
627 	const Elf_Phdr *phdr;
628 	Elf_Auxargs *elf_auxargs = NULL;
629 	struct vmspace *vmspace;
630 	vm_prot_t prot;
631 	u_long text_size = 0, data_size = 0, total_size = 0;
632 	u_long text_addr = 0, data_addr = 0;
633 	u_long seg_size, seg_addr;
634 	u_long addr, entry = 0, proghdr = 0;
635 	int error, i;
636 	const char *interp = NULL;
637 	const Elf_Note *abi_note = NULL;
638 	Elf_Brandinfo *brand_info = NULL;
639 	char *path;
640 
641 	error = 0;
642 
643 	/*
644 	 * Do we have a valid ELF header ?
645 	 * We allow execution of ET_EXEC and, if kern.elf_exec_dyn is 1, ET_DYN.
646 	 */
647 	if (elf_check_header(hdr) != 0 ||
648 	    (hdr->e_type != ET_EXEC && (!can_exec_dyn || hdr->e_type != ET_DYN)))
649 		return -1;
650 
651 	/*
652 	 * From here on down, we return an errno, not -1, as we've
653 	 * detected an ELF file.
654 	 */
655 
656 	if ((hdr->e_phoff > PAGE_SIZE) ||
657 	    (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
658 		/* Only support headers in first page for now */
659 		return ENOEXEC;
660 	}
661 	phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff);
662 
663 	/*
664 	 * From this point on, we may have resources that need to be freed.
665 	 */
666 
667 	exec_new_vmspace(imgp, NULL);
668 
669 	/*
670 	 * Yeah, I'm paranoid.  There is every reason in the world to get
671 	 * VTEXT now since from here on out, there are places we can have
672 	 * a context switch.  Better safe than sorry; I really don't want
673 	 * the file to change while it's being loaded.
674 	 */
675 	vsetflags(imgp->vp, VTEXT);
676 
677 	vmspace = imgp->proc->p_vmspace;
678 
679 	for (i = 0; i < hdr->e_phnum; i++) {
680 		switch(phdr[i].p_type) {
681 
682 		case PT_LOAD:	/* Loadable segment */
683 			prot = 0;
684 			if (phdr[i].p_flags & PF_X)
685   				prot |= VM_PROT_EXECUTE;
686 			if (phdr[i].p_flags & PF_W)
687   				prot |= VM_PROT_WRITE;
688 			if (phdr[i].p_flags & PF_R)
689   				prot |= VM_PROT_READ;
690 
691 			if ((error = elf_load_section(imgp->proc,
692 						     vmspace, imgp->vp,
693   						     phdr[i].p_offset,
694   						     (caddr_t)phdr[i].p_vaddr,
695   						     phdr[i].p_memsz,
696   						     phdr[i].p_filesz, prot)) != 0)
697   				goto fail;
698 
699 			/*
700 			 * If this segment contains the program headers,
701 			 * remember their virtual address for the AT_PHDR
702 			 * aux entry. Static binaries don't usually include
703 			 * a PT_PHDR entry.
704 			 */
705 			if (phdr[i].p_offset == 0 &&
706 			    hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
707 				<= phdr[i].p_filesz)
708 				proghdr = phdr[i].p_vaddr + hdr->e_phoff;
709 
710 			seg_addr = trunc_page(phdr[i].p_vaddr);
711 			seg_size = round_page(phdr[i].p_memsz +
712 				phdr[i].p_vaddr - seg_addr);
713 
714 			/*
715 			 * Is this .text or .data?  We can't use
716 			 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
717 			 * alpha terribly and possibly does other bad
718 			 * things so we stick to the old way of figuring
719 			 * it out:  If the segment contains the program
720 			 * entry point, it's a text segment, otherwise it
721 			 * is a data segment.
722 			 *
723 			 * Note that obreak() assumes that data_addr +
724 			 * data_size == end of data load area, and the ELF
725 			 * file format expects segments to be sorted by
726 			 * address.  If multiple data segments exist, the
727 			 * last one will be used.
728 			 */
729 			if (hdr->e_entry >= phdr[i].p_vaddr &&
730 			    hdr->e_entry < (phdr[i].p_vaddr +
731 			    phdr[i].p_memsz)) {
732 				text_size = seg_size;
733 				text_addr = seg_addr;
734 				entry = (u_long)hdr->e_entry;
735 			} else {
736 				data_size = seg_size;
737 				data_addr = seg_addr;
738 			}
739 			total_size += seg_size;
740 
741 			/*
742 			 * Check limits.  It should be safe to check the
743 			 * limits after loading the segment since we do
744 			 * not actually fault in all the segment's pages.
745 			 */
746 			if (data_size >
747 			    imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
748 			    text_size > maxtsiz ||
749 			    total_size >
750 			    imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
751 				error = ENOMEM;
752 				goto fail;
753 			}
754 			break;
755 	  	case PT_INTERP:	/* Path to interpreter */
756 			if (phdr[i].p_filesz > MAXPATHLEN ||
757 			    phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
758 				error = ENOEXEC;
759 				goto fail;
760 			}
761 			interp = imgp->image_header + phdr[i].p_offset;
762 			break;
763 		case PT_NOTE:	/* Check for .note.ABI-tag */
764 			if (brand_info == NULL)
765 				brand_info = elf_check_abi_note(imgp, &phdr[i]);
766 			break;
767 		case PT_PHDR: 	/* Program header table info */
768 			proghdr = phdr[i].p_vaddr;
769 			break;
770 		default:
771 			break;
772 		}
773 	}
774 
775 	vmspace->vm_tsize = text_size >> PAGE_SHIFT;
776 	vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
777 	vmspace->vm_dsize = data_size >> PAGE_SHIFT;
778 	vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
779 
780 	addr = ELF_RTLD_ADDR(vmspace);
781 
782 	imgp->entry_addr = entry;
783 
784 	/* We support three types of branding -- (1) the ELF EI_OSABI field
785 	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
786 	 * branding w/in the ELF header, and (3) path of the `interp_path'
787 	 * field.  We should also look for an ".note.ABI-tag" ELF section now
788 	 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
789 	 */
790 
791 	/* If the executable has a brand, search for it in the brand list. */
792 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] != ELFOSABI_NONE) {
793 		for (i = 0;  i < MAX_BRANDS;  i++) {
794 			Elf_Brandinfo *bi = elf_brand_list[i];
795 
796 			if (bi != NULL &&
797 			    (hdr->e_ident[EI_OSABI] == bi->brand
798 			    || 0 ==
799 			    strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
800 			    bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
801 				brand_info = bi;
802 				break;
803 			}
804 		}
805 	}
806 
807 	/* Search for a recognized ABI. */
808 	if (brand_info == NULL && abi_note != NULL) {
809 	}
810 
811 	/*
812 	 * ELFOSABI_NONE == ELFOSABI_SYSV, so a SYSV binary misses all
813 	 * checks so far, since it is neither branded nor does it have
814 	 * an ABI note.  If the EI_OSABI field is ELFOSABI_NONE, assume
815 	 * it is svr4 and look for an entry in the elf_brand_list with
816 	 * match_abi_note == NULL.
817 	 */
818 	if (brand_info == NULL && hdr->e_ident[EI_OSABI] == ELFOSABI_NONE) {
819 		for (i = 0; i < MAX_BRANDS; i++) {
820 			Elf_Brandinfo *bi = elf_brand_list[i];
821 
822 			if (bi != NULL && bi->match_abi_note == NULL &&
823 			    ELFOSABI_SYSV == bi->brand) {
824 				brand_info = bi;
825 				break;
826 			}
827 		}
828 	}
829 
830 	/* Lacking a recognized ABI, search for a recognized interpreter. */
831 	if (brand_info == NULL && interp != NULL) {
832 		for (i = 0;  i < MAX_BRANDS;  i++) {
833 			Elf_Brandinfo *bi = elf_brand_list[i];
834 
835 			if (bi != NULL &&
836 			    strcmp(interp, bi->interp_path) == 0) {
837 				brand_info = bi;
838 				break;
839 			}
840 		}
841 	}
842 
843 	/* Lacking a recognized interpreter, try the default brand */
844 	if (brand_info == NULL) {
845 		for (i = 0; i < MAX_BRANDS; i++) {
846 			Elf_Brandinfo *bi = elf_brand_list[i];
847 
848 			if (bi != NULL && fallback_elf_brand == bi->brand) {
849 				brand_info = bi;
850 				break;
851 			}
852 		}
853 	}
854 
855 	if (brand_info == NULL) {
856 		uprintf("ELF binary type \"%u\" not known.\n",
857 		    hdr->e_ident[EI_OSABI]);
858 		error = ENOEXEC;
859 		goto fail;
860 	}
861 
862 	imgp->proc->p_sysent = brand_info->sysvec;
863 	EVENTHANDLER_INVOKE(process_exec, imgp);
864 
865 	if (interp != NULL) {
866 		path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
867 	        ksnprintf(path, MAXPATHLEN, "%s%s",
868 			 brand_info->emul_path, interp);
869 		if ((error = elf_load_file(imgp->proc, path, &addr,
870 					   &imgp->entry_addr)) != 0) {
871 		        if ((error = elf_load_file(imgp->proc, interp, &addr,
872 						   &imgp->entry_addr)) != 0) {
873 			        uprintf("ELF interpreter %s not found\n", path);
874 				kfree(path, M_TEMP);
875 				goto fail;
876 			}
877                 }
878 		kfree(path, M_TEMP);
879 	} else {
880 		addr = 0;
881 	}
882 
883 	/*
884 	 * Construct auxargs table (used by the fixup routine)
885 	 */
886 	elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
887 	elf_auxargs->execfd = -1;
888 	elf_auxargs->phdr = proghdr;
889 	elf_auxargs->phent = hdr->e_phentsize;
890 	elf_auxargs->phnum = hdr->e_phnum;
891 	elf_auxargs->pagesz = PAGE_SIZE;
892 	elf_auxargs->base = addr;
893 	elf_auxargs->flags = 0;
894 	elf_auxargs->entry = entry;
895 	elf_auxargs->trace = elf_trace;
896 
897 	imgp->auxargs = elf_auxargs;
898 	imgp->interpreted = 0;
899 
900 fail:
901 	return error;
902 }
903 
904 static int
905 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp)
906 {
907 	Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
908 	register_t *pos;
909 
910 	pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
911 
912 	if (args->trace) {
913 		AUXARGS_ENTRY(pos, AT_DEBUG, 1);
914 	}
915 	if (args->execfd != -1) {
916 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
917 	}
918 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
919 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
920 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
921 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
922 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
923 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
924 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
925 	AUXARGS_ENTRY(pos, AT_NULL, 0);
926 
927 	kfree(imgp->auxargs, M_TEMP);
928 	imgp->auxargs = NULL;
929 
930 	(*stack_base)--;
931 	suword(*stack_base, (long) imgp->args->argc);
932 	return 0;
933 }
934 
935 /*
936  * Code for generating ELF core dumps.
937  */
938 
939 typedef int (*segment_callback) (vm_map_entry_t, void *);
940 
941 /* Closure for cb_put_phdr(). */
942 struct phdr_closure {
943 	Elf_Phdr *phdr;		/* Program header to fill in (incremented) */
944 	Elf_Phdr *phdr_max;	/* Pointer bound for error check */
945 	Elf_Off offset;		/* Offset of segment in core file */
946 };
947 
948 /* Closure for cb_size_segment(). */
949 struct sseg_closure {
950 	int count;		/* Count of writable segments. */
951 	size_t vsize;		/* Total size of all writable segments. */
952 };
953 
954 /* Closure for cb_put_fp(). */
955 struct fp_closure {
956 	struct vn_hdr *vnh;
957 	struct vn_hdr *vnh_max;
958 	int count;
959 	struct stat *sb;
960 };
961 
962 typedef struct elf_buf {
963 	char	*buf;
964 	size_t	off;
965 	size_t	off_max;
966 } *elf_buf_t;
967 
968 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
969 
970 static int cb_put_phdr (vm_map_entry_t, void *);
971 static int cb_size_segment (vm_map_entry_t, void *);
972 static int cb_fpcount_segment(vm_map_entry_t, void *);
973 static int cb_put_fp(vm_map_entry_t, void *);
974 
975 
976 static int each_segment (struct proc *, segment_callback, void *, int);
977 static int elf_corehdr (struct lwp *, int, struct file *, struct ucred *,
978 			int, elf_buf_t);
979 enum putmode { WRITE, DRYRUN };
980 static int elf_puthdr (struct lwp *, elf_buf_t, int sig, enum putmode,
981 			int, struct file *);
982 static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
983 static int elf_putnote (elf_buf_t, const char *, int, const void *, size_t);
984 
985 static int elf_putsigs(struct lwp *, elf_buf_t);
986 static int elf_puttextvp(struct proc *, elf_buf_t);
987 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
988 
989 extern int osreldate;
990 
991 int
992 elf_coredump(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
993 {
994 	struct file *fp;
995 	int error;
996 
997 	if ((error = falloc(NULL, &fp, NULL)) != 0)
998 		return (error);
999 	fsetcred(fp, lp->lwp_proc->p_ucred);
1000 
1001 	/*
1002 	 * XXX fixme.
1003 	 */
1004 	fp->f_type = DTYPE_VNODE;
1005 	fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
1006 	fp->f_ops = &vnode_fileops;
1007 	fp->f_data = vp;
1008 	vn_unlock(vp);
1009 
1010 	error = generic_elf_coredump(lp, sig, fp, limit);
1011 
1012 	fp->f_type = 0;
1013 	fp->f_flag = 0;
1014 	fp->f_ops = &badfileops;
1015 	fp->f_data = NULL;
1016 	fdrop(fp);
1017 	return (error);
1018 }
1019 
1020 int
1021 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
1022 {
1023 	struct proc *p = lp->lwp_proc;
1024 	struct ucred *cred = p->p_ucred;
1025 	int error = 0;
1026 	struct sseg_closure seginfo;
1027 	struct elf_buf target;
1028 
1029 	if (!fp)
1030 		kprintf("can't dump core - null fp\n");
1031 
1032 	/*
1033 	 * Size the program segments
1034 	 */
1035 	seginfo.count = 0;
1036 	seginfo.vsize = 0;
1037 	each_segment(p, cb_size_segment, &seginfo, 1);
1038 
1039 	/*
1040 	 * Calculate the size of the core file header area by making
1041 	 * a dry run of generating it.  Nothing is written, but the
1042 	 * size is calculated.
1043 	 */
1044 	bzero(&target, sizeof(target));
1045 	elf_puthdr(lp, &target, sig, DRYRUN, seginfo.count, fp);
1046 
1047 	if (target.off + seginfo.vsize >= limit)
1048 		return (EFAULT);
1049 
1050 	/*
1051 	 * Allocate memory for building the header, fill it up,
1052 	 * and write it out.
1053 	 */
1054 	target.off_max = target.off;
1055 	target.off = 0;
1056 	target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
1057 
1058 	error = elf_corehdr(lp, sig, fp, cred, seginfo.count, &target);
1059 
1060 	/* Write the contents of all of the writable segments. */
1061 	if (error == 0) {
1062 		Elf_Phdr *php;
1063 		int i;
1064 		ssize_t nbytes;
1065 
1066 		php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
1067 		for (i = 0; i < seginfo.count; i++) {
1068 			error = fp_write(fp, (caddr_t)php->p_vaddr,
1069 					php->p_filesz, &nbytes, UIO_USERSPACE);
1070 			if (error != 0)
1071 				break;
1072 			php++;
1073 		}
1074 	}
1075 	kfree(target.buf, M_TEMP);
1076 
1077 	return error;
1078 }
1079 
1080 /*
1081  * A callback for each_segment() to write out the segment's
1082  * program header entry.
1083  */
1084 static int
1085 cb_put_phdr(vm_map_entry_t entry, void *closure)
1086 {
1087 	struct phdr_closure *phc = closure;
1088 	Elf_Phdr *phdr = phc->phdr;
1089 
1090 	if (phc->phdr == phc->phdr_max)
1091 		return EINVAL;
1092 
1093 	phc->offset = round_page(phc->offset);
1094 
1095 	phdr->p_type = PT_LOAD;
1096 	phdr->p_offset = phc->offset;
1097 	phdr->p_vaddr = entry->start;
1098 	phdr->p_paddr = 0;
1099 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1100 	phdr->p_align = PAGE_SIZE;
1101 	phdr->p_flags = 0;
1102 	if (entry->protection & VM_PROT_READ)
1103 		phdr->p_flags |= PF_R;
1104 	if (entry->protection & VM_PROT_WRITE)
1105 		phdr->p_flags |= PF_W;
1106 	if (entry->protection & VM_PROT_EXECUTE)
1107 		phdr->p_flags |= PF_X;
1108 
1109 	phc->offset += phdr->p_filesz;
1110 	++phc->phdr;
1111 	return 0;
1112 }
1113 
1114 /*
1115  * A callback for each_writable_segment() to gather information about
1116  * the number of segments and their total size.
1117  */
1118 static int
1119 cb_size_segment(vm_map_entry_t entry, void *closure)
1120 {
1121 	struct sseg_closure *ssc = closure;
1122 
1123 	++ssc->count;
1124 	ssc->vsize += entry->end - entry->start;
1125 	return 0;
1126 }
1127 
1128 /*
1129  * A callback for each_segment() to gather information about
1130  * the number of text segments.
1131  */
1132 static int
1133 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
1134 {
1135 	int *count = closure;
1136 	struct vnode *vp;
1137 
1138 	if (entry->object.vm_object->type == OBJT_VNODE) {
1139 		vp = (struct vnode *)entry->object.vm_object->handle;
1140 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1141 			return 0;
1142 		++*count;
1143 	}
1144 	return 0;
1145 }
1146 
1147 static int
1148 cb_put_fp(vm_map_entry_t entry, void *closure)
1149 {
1150 	struct fp_closure *fpc = closure;
1151 	struct vn_hdr *vnh = fpc->vnh;
1152 	Elf_Phdr *phdr = &vnh->vnh_phdr;
1153 	struct vnode *vp;
1154 	int error;
1155 
1156 	/*
1157 	 * If an entry represents a vnode then write out a file handle.
1158 	 *
1159 	 * If we are checkpointing a checkpoint-restored program we do
1160 	 * NOT record the filehandle for the old checkpoint vnode (which
1161 	 * is mapped all over the place).  Instead we rely on the fact
1162 	 * that a checkpoint-restored program does not mmap() the checkpt
1163 	 * vnode NOCORE, so its contents will be written out to the
1164 	 * new checkpoint file.  This is necessary because the 'old'
1165 	 * checkpoint file is typically destroyed when a new one is created
1166 	 * and thus cannot be used to restore the new checkpoint.
1167 	 *
1168 	 * Theoretically we could create a chain of checkpoint files and
1169 	 * operate the checkpointing operation kinda like an incremental
1170 	 * checkpoint, but a checkpoint restore would then likely wind up
1171 	 * referencing many prior checkpoint files and that is a bit over
1172 	 * the top for the purpose of the checkpoint API.
1173 	 */
1174 	if (entry->object.vm_object->type == OBJT_VNODE) {
1175 		vp = (struct vnode *)entry->object.vm_object->handle;
1176 		if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
1177 			return 0;
1178 		if (vnh == fpc->vnh_max)
1179 			return EINVAL;
1180 
1181 		if (vp->v_mount)
1182 			vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1183 		error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
1184 		if (error) {
1185 			char *freepath, *fullpath;
1186 
1187 			if (vn_fullpath(curproc, vp, &fullpath, &freepath, 0)) {
1188 				kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
1189 			} else {
1190 				kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
1191 				kfree(freepath, M_TEMP);
1192 			}
1193 			error = 0;
1194 		}
1195 
1196 		phdr->p_type = PT_LOAD;
1197 		phdr->p_offset = 0;        /* not written to core */
1198 		phdr->p_vaddr = entry->start;
1199 		phdr->p_paddr = 0;
1200 		phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1201 		phdr->p_align = PAGE_SIZE;
1202 		phdr->p_flags = 0;
1203 		if (entry->protection & VM_PROT_READ)
1204 			phdr->p_flags |= PF_R;
1205 		if (entry->protection & VM_PROT_WRITE)
1206 			phdr->p_flags |= PF_W;
1207 		if (entry->protection & VM_PROT_EXECUTE)
1208 			phdr->p_flags |= PF_X;
1209 		++fpc->vnh;
1210 		++fpc->count;
1211 	}
1212 	return 0;
1213 }
1214 
1215 /*
1216  * For each writable segment in the process's memory map, call the given
1217  * function with a pointer to the map entry and some arbitrary
1218  * caller-supplied data.
1219  */
1220 static int
1221 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
1222 {
1223 	int error = 0;
1224 	vm_map_t map = &p->p_vmspace->vm_map;
1225 	vm_map_entry_t entry;
1226 
1227 	for (entry = map->header.next; error == 0 && entry != &map->header;
1228 	    entry = entry->next) {
1229 		vm_object_t obj;
1230 
1231 		/*
1232 		 * Don't dump inaccessible mappings, deal with legacy
1233 		 * coredump mode.
1234 		 *
1235 		 * Note that read-only segments related to the elf binary
1236 		 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1237 		 * need to arbitrarily ignore such segments.
1238 		 */
1239 		if (elf_legacy_coredump) {
1240 			if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
1241 				continue;
1242 		} else {
1243 			if (writable && (entry->protection & VM_PROT_ALL) == 0)
1244 				continue;
1245 		}
1246 
1247 		/*
1248 		 * Dont include memory segment in the coredump if
1249 		 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1250 		 * madvise(2).
1251 		 *
1252 		 * Currently we only dump normal VM object maps.  We do
1253 		 * not dump submaps or virtual page tables.
1254 		 */
1255 		if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
1256 			continue;
1257 		if (entry->maptype != VM_MAPTYPE_NORMAL)
1258 			continue;
1259 		if ((obj = entry->object.vm_object) == NULL)
1260 			continue;
1261 
1262 		/* Find the deepest backing object. */
1263 		while (obj->backing_object != NULL)
1264 			obj = obj->backing_object;
1265 
1266 		/* Ignore memory-mapped devices and such things. */
1267 		if (obj->type != OBJT_DEFAULT &&
1268 		    obj->type != OBJT_SWAP &&
1269 		    obj->type != OBJT_VNODE)
1270 			continue;
1271 
1272 		error = (*func)(entry, closure);
1273 	}
1274 	return error;
1275 }
1276 
1277 static
1278 void *
1279 target_reserve(elf_buf_t target, size_t bytes, int *error)
1280 {
1281     void *res = NULL;
1282 
1283     if (target->buf) {
1284 	    if (target->off + bytes > target->off_max)
1285 		    *error = EINVAL;
1286 	    else
1287 		    res = target->buf + target->off;
1288     }
1289     target->off += bytes;
1290     return (res);
1291 }
1292 
1293 /*
1294  * Write the core file header to the file, including padding up to
1295  * the page boundary.
1296  */
1297 static int
1298 elf_corehdr(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
1299 	    int numsegs, elf_buf_t target)
1300 {
1301 	int error;
1302 	ssize_t nbytes;
1303 
1304 	/*
1305 	 * Fill in the header.  The fp is passed so we can detect and flag
1306 	 * a checkpoint file pointer within the core file itself, because
1307 	 * it may not be restored from the same file handle.
1308 	 */
1309 	error = elf_puthdr(lp, target, sig, WRITE, numsegs, fp);
1310 
1311 	/* Write it to the core file. */
1312 	if (error == 0) {
1313 		error = fp_write(fp, target->buf, target->off, &nbytes,
1314 				 UIO_SYSSPACE);
1315 	}
1316 	return error;
1317 }
1318 
1319 static int
1320 elf_puthdr(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
1321     int numsegs, struct file *fp)
1322 {
1323 	struct proc *p = lp->lwp_proc;
1324 	int error = 0;
1325 	size_t phoff;
1326 	size_t noteoff;
1327 	size_t notesz;
1328 	Elf_Ehdr *ehdr;
1329 	Elf_Phdr *phdr;
1330 
1331 	ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
1332 
1333 	phoff = target->off;
1334 	phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
1335 
1336 	noteoff = target->off;
1337 	if (error == 0)
1338 		elf_putallnotes(lp, target, sig, mode);
1339 	notesz = target->off - noteoff;
1340 
1341 	/*
1342 	 * put extra cruft for dumping process state here
1343 	 *  - we really want it be before all the program
1344 	 *    mappings
1345 	 *  - we just need to update the offset accordingly
1346 	 *    and GDB will be none the wiser.
1347 	 */
1348 	if (error == 0)
1349 		error = elf_puttextvp(p, target);
1350 	if (error == 0)
1351 		error = elf_putsigs(lp, target);
1352 	if (error == 0)
1353 		error = elf_putfiles(p, target, fp);
1354 
1355 	/*
1356 	 * Align up to a page boundary for the program segments.  The
1357 	 * actual data will be written to the outptu file, not to elf_buf_t,
1358 	 * so we do not have to do any further bounds checking.
1359 	 */
1360 	target->off = round_page(target->off);
1361 	if (error == 0 && ehdr != NULL) {
1362 		/*
1363 		 * Fill in the ELF header.
1364 		 */
1365 		ehdr->e_ident[EI_MAG0] = ELFMAG0;
1366 		ehdr->e_ident[EI_MAG1] = ELFMAG1;
1367 		ehdr->e_ident[EI_MAG2] = ELFMAG2;
1368 		ehdr->e_ident[EI_MAG3] = ELFMAG3;
1369 		ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1370 		ehdr->e_ident[EI_DATA] = ELF_DATA;
1371 		ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1372 		ehdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
1373 		ehdr->e_ident[EI_ABIVERSION] = 0;
1374 		ehdr->e_ident[EI_PAD] = 0;
1375 		ehdr->e_type = ET_CORE;
1376 		ehdr->e_machine = ELF_ARCH;
1377 		ehdr->e_version = EV_CURRENT;
1378 		ehdr->e_entry = 0;
1379 		ehdr->e_phoff = phoff;
1380 		ehdr->e_flags = 0;
1381 		ehdr->e_ehsize = sizeof(Elf_Ehdr);
1382 		ehdr->e_phentsize = sizeof(Elf_Phdr);
1383 		ehdr->e_phnum = numsegs + 1;
1384 		ehdr->e_shentsize = sizeof(Elf_Shdr);
1385 		ehdr->e_shnum = 0;
1386 		ehdr->e_shstrndx = SHN_UNDEF;
1387 	}
1388 	if (error == 0 && phdr != NULL) {
1389 		/*
1390 		 * Fill in the program header entries.
1391 		 */
1392 		struct phdr_closure phc;
1393 
1394 		/* The note segement. */
1395 		phdr->p_type = PT_NOTE;
1396 		phdr->p_offset = noteoff;
1397 		phdr->p_vaddr = 0;
1398 		phdr->p_paddr = 0;
1399 		phdr->p_filesz = notesz;
1400 		phdr->p_memsz = 0;
1401 		phdr->p_flags = 0;
1402 		phdr->p_align = 0;
1403 		++phdr;
1404 
1405 		/* All the writable segments from the program. */
1406 		phc.phdr = phdr;
1407 		phc.phdr_max = phdr + numsegs;
1408 		phc.offset = target->off;
1409 		each_segment(p, cb_put_phdr, &phc, 1);
1410 	}
1411 	return (error);
1412 }
1413 
1414 /*
1415  * Append core dump notes to target ELF buffer or simply update target size
1416  * if dryrun selected.
1417  */
1418 static int
1419 elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
1420     enum putmode mode)
1421 {
1422 	struct proc *p = corelp->lwp_proc;
1423 	int error;
1424 	struct {
1425 		prstatus_t status;
1426 		prfpregset_t fpregs;
1427 		prpsinfo_t psinfo;
1428 	} *tmpdata;
1429 	prstatus_t *status;
1430 	prfpregset_t *fpregs;
1431 	prpsinfo_t *psinfo;
1432 	struct lwp *lp;
1433 
1434 	/*
1435 	 * Allocate temporary storage for notes on heap to avoid stack overflow.
1436 	 */
1437 	if (mode != DRYRUN) {
1438 		tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
1439 		status = &tmpdata->status;
1440 		fpregs = &tmpdata->fpregs;
1441 		psinfo = &tmpdata->psinfo;
1442 	} else {
1443 		tmpdata = NULL;
1444 		status = NULL;
1445 		fpregs = NULL;
1446 		psinfo = NULL;
1447 	}
1448 
1449 	/*
1450 	 * Append LWP-agnostic note.
1451 	 */
1452 	if (mode != DRYRUN) {
1453 		psinfo->pr_version = PRPSINFO_VERSION;
1454 		psinfo->pr_psinfosz = sizeof(prpsinfo_t);
1455 		strncpy(psinfo->pr_fname, p->p_comm,
1456 			sizeof(psinfo->pr_fname) - 1);
1457 		/*
1458 		 * XXX - We don't fill in the command line arguments
1459 		 * properly yet.
1460 		 */
1461 		strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ);
1462 	}
1463 	error =
1464 	    elf_putnote(target, "CORE", NT_PRPSINFO, psinfo, sizeof *psinfo);
1465 	if (error)
1466 		goto exit;
1467 
1468 	/*
1469 	 * Append first note for LWP that triggered core so that it is
1470 	 * the selected one when the debugger starts.
1471 	 */
1472 	if (mode != DRYRUN) {
1473 		status->pr_version = PRSTATUS_VERSION;
1474 		status->pr_statussz = sizeof(prstatus_t);
1475 		status->pr_gregsetsz = sizeof(gregset_t);
1476 		status->pr_fpregsetsz = sizeof(fpregset_t);
1477 		status->pr_osreldate = osreldate;
1478 		status->pr_cursig = sig;
1479 		/*
1480 		 * XXX GDB needs unique pr_pid for each LWP and does not
1481 		 * not support pr_pid==0 but lwp_tid can be 0, so hack unique
1482 		 * value.
1483 		 */
1484 		status->pr_pid = corelp->lwp_tid;
1485 		fill_regs(corelp, &status->pr_reg);
1486 		fill_fpregs(corelp, fpregs);
1487 	}
1488 	error =
1489 	    elf_putnote(target, "CORE", NT_PRSTATUS, status, sizeof *status);
1490 	if (error)
1491 		goto exit;
1492 	error =
1493 	    elf_putnote(target, "CORE", NT_FPREGSET, fpregs, sizeof *fpregs);
1494 	if (error)
1495 		goto exit;
1496 
1497 	/*
1498 	 * Then append notes for other LWPs.
1499 	 */
1500 	FOREACH_LWP_IN_PROC(lp, p) {
1501 		if (lp == corelp)
1502 			continue;
1503 		/* skip lwps being created */
1504 		if (lp->lwp_thread == NULL)
1505 			continue;
1506 		if (mode != DRYRUN) {
1507 			status->pr_pid = lp->lwp_tid;
1508 			fill_regs(lp, &status->pr_reg);
1509 			fill_fpregs(lp, fpregs);
1510 		}
1511 		error = elf_putnote(target, "CORE", NT_PRSTATUS,
1512 					status, sizeof *status);
1513 		if (error)
1514 			goto exit;
1515 		error = elf_putnote(target, "CORE", NT_FPREGSET,
1516 					fpregs, sizeof *fpregs);
1517 		if (error)
1518 			goto exit;
1519 	}
1520 
1521 exit:
1522 	if (tmpdata != NULL)
1523 		kfree(tmpdata, M_TEMP);
1524 	return (error);
1525 }
1526 
1527 /*
1528  * Generate a note sub-structure.
1529  *
1530  * NOTE: 4-byte alignment.
1531  */
1532 static int
1533 elf_putnote(elf_buf_t target, const char *name, int type,
1534 	    const void *desc, size_t descsz)
1535 {
1536 	int error = 0;
1537 	char *dst;
1538 	Elf_Note note;
1539 
1540 	note.n_namesz = strlen(name) + 1;
1541 	note.n_descsz = descsz;
1542 	note.n_type = type;
1543 	dst = target_reserve(target, sizeof(note), &error);
1544 	if (dst != NULL)
1545 		bcopy(&note, dst, sizeof note);
1546 	dst = target_reserve(target, note.n_namesz, &error);
1547 	if (dst != NULL)
1548 		bcopy(name, dst, note.n_namesz);
1549 	target->off = roundup2(target->off, sizeof(Elf_Word));
1550 	dst = target_reserve(target, note.n_descsz, &error);
1551 	if (dst != NULL)
1552 		bcopy(desc, dst, note.n_descsz);
1553 	target->off = roundup2(target->off, sizeof(Elf_Word));
1554 	return(error);
1555 }
1556 
1557 
1558 static int
1559 elf_putsigs(struct lwp *lp, elf_buf_t target)
1560 {
1561 	/* XXX lwp handle more than one lwp */
1562 	struct proc *p = lp->lwp_proc;
1563 	int error = 0;
1564 	struct ckpt_siginfo *csi;
1565 
1566 	csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
1567 	if (csi) {
1568 		csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
1569 		bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
1570 		bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
1571 		bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
1572 			sizeof(sigset_t));
1573 		csi->csi_sigparent = p->p_sigparent;
1574 	}
1575 	return(error);
1576 }
1577 
1578 static int
1579 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
1580 {
1581 	int error = 0;
1582 	int i;
1583 	struct ckpt_filehdr *cfh = NULL;
1584 	struct ckpt_fileinfo *cfi;
1585 	struct file *fp;
1586 	struct vnode *vp;
1587 	/*
1588 	 * the duplicated loop is gross, but it was the only way
1589 	 * to eliminate uninitialized variable warnings
1590 	 */
1591 	cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
1592 	if (cfh) {
1593 		cfh->cfh_nfiles = 0;
1594 	}
1595 
1596 	/*
1597 	 * ignore STDIN/STDERR/STDOUT.
1598 	 */
1599 	for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
1600 		fp = holdfp(p->p_fd, i, -1);
1601 		if (fp == NULL)
1602 			continue;
1603 		/*
1604 		 * XXX Only checkpoint vnodes for now.
1605 		 */
1606 		if (fp->f_type != DTYPE_VNODE) {
1607 			fdrop(fp);
1608 			continue;
1609 		}
1610 		cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
1611 					&error);
1612 		if (cfi == NULL) {
1613 			fdrop(fp);
1614 			continue;
1615 		}
1616 		cfi->cfi_index = -1;
1617 		cfi->cfi_type = fp->f_type;
1618 		cfi->cfi_flags = fp->f_flag;
1619 		cfi->cfi_offset = fp->f_offset;
1620 		cfi->cfi_ckflags = 0;
1621 
1622 		if (fp == ckfp)
1623 			cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
1624 		/* f_count and f_msgcount should not be saved/restored */
1625 		/* XXX save cred info */
1626 
1627 		switch(fp->f_type) {
1628 		case DTYPE_VNODE:
1629 			vp = (struct vnode *)fp->f_data;
1630 			/*
1631 			 * it looks like a bug in ptrace is marking
1632 			 * a non-vnode as a vnode - until we find the
1633 			 * root cause this will at least prevent
1634 			 * further panics from truss
1635 			 */
1636 			if (vp == NULL || vp->v_mount == NULL)
1637 				break;
1638 			cfh->cfh_nfiles++;
1639 			cfi->cfi_index = i;
1640 			cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
1641 			error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
1642 			break;
1643 		default:
1644 			break;
1645 		}
1646 		fdrop(fp);
1647 	}
1648 	return(error);
1649 }
1650 
1651 static int
1652 elf_puttextvp(struct proc *p, elf_buf_t target)
1653 {
1654 	int error = 0;
1655 	int *vn_count;
1656 	struct fp_closure fpc;
1657 	struct ckpt_vminfo *vminfo;
1658 
1659 	vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
1660 	if (vminfo != NULL) {
1661 		vminfo->cvm_dsize = p->p_vmspace->vm_dsize;
1662 		vminfo->cvm_tsize = p->p_vmspace->vm_tsize;
1663 		vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
1664 		vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
1665 	}
1666 
1667 	fpc.count = 0;
1668 	vn_count = target_reserve(target, sizeof(int), &error);
1669 	if (target->buf != NULL) {
1670 		fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
1671 		fpc.vnh_max = fpc.vnh +
1672 			(target->off_max - target->off) / sizeof(struct vn_hdr);
1673 		error = each_segment(p, cb_put_fp, &fpc, 0);
1674 		if (vn_count)
1675 			*vn_count = fpc.count;
1676 	} else {
1677 		error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
1678 	}
1679 	target->off += fpc.count * sizeof(struct vn_hdr);
1680 	return(error);
1681 }
1682 
1683 
1684 /*
1685  * Tell kern_execve.c about it, with a little help from the linker.
1686  */
1687 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"};
1688 EXEC_SET_ORDERED(elf, elf_execsw, SI_ORDER_FIRST);
1689