xref: /freebsd/sys/kern/imgact_elf.c (revision 3ff01b231dfa83d518854c63e7c9cd1debd1139e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2017 Dell EMC
5  * Copyright (c) 2000-2001, 2003 David O'Brien
6  * Copyright (c) 1995-1996 Søren Schmidt
7  * Copyright (c) 1996 Peter Wemm
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer
15  *    in this position and unchanged.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_capsicum.h"
38 
39 #include <sys/param.h>
40 #include <sys/capsicum.h>
41 #include <sys/compressor.h>
42 #include <sys/exec.h>
43 #include <sys/fcntl.h>
44 #include <sys/imgact.h>
45 #include <sys/imgact_elf.h>
46 #include <sys/jail.h>
47 #include <sys/kernel.h>
48 #include <sys/lock.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/mman.h>
52 #include <sys/namei.h>
53 #include <sys/proc.h>
54 #include <sys/procfs.h>
55 #include <sys/ptrace.h>
56 #include <sys/racct.h>
57 #include <sys/resourcevar.h>
58 #include <sys/rwlock.h>
59 #include <sys/sbuf.h>
60 #include <sys/sf_buf.h>
61 #include <sys/smp.h>
62 #include <sys/systm.h>
63 #include <sys/signalvar.h>
64 #include <sys/stat.h>
65 #include <sys/sx.h>
66 #include <sys/syscall.h>
67 #include <sys/sysctl.h>
68 #include <sys/sysent.h>
69 #include <sys/vnode.h>
70 #include <sys/syslog.h>
71 #include <sys/eventhandler.h>
72 #include <sys/user.h>
73 
74 #include <vm/vm.h>
75 #include <vm/vm_kern.h>
76 #include <vm/vm_param.h>
77 #include <vm/pmap.h>
78 #include <vm/vm_map.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_extern.h>
81 
82 #include <machine/elf.h>
83 #include <machine/md_var.h>
84 
85 #define ELF_NOTE_ROUNDSIZE	4
86 #define OLD_EI_BRAND	8
87 
88 static int __elfN(check_header)(const Elf_Ehdr *hdr);
89 static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
90     const char *interp, int32_t *osrel, uint32_t *fctl0);
91 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
92     u_long *entry);
93 static int __elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset,
94     caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot);
95 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
96 static bool __elfN(freebsd_trans_osrel)(const Elf_Note *note,
97     int32_t *osrel);
98 static bool kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel);
99 static boolean_t __elfN(check_note)(struct image_params *imgp,
100     Elf_Brandnote *checknote, int32_t *osrel, boolean_t *has_fctl0,
101     uint32_t *fctl0);
102 static vm_prot_t __elfN(trans_prot)(Elf_Word);
103 static Elf_Word __elfN(untrans_prot)(vm_prot_t);
104 
105 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE),
106     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
107     "");
108 
109 int __elfN(fallback_brand) = -1;
110 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
111     fallback_brand, CTLFLAG_RWTUN, &__elfN(fallback_brand), 0,
112     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
113 
114 static int elf_legacy_coredump = 0;
115 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW,
116     &elf_legacy_coredump, 0,
117     "include all and only RW pages in core dumps");
118 
119 int __elfN(nxstack) =
120 #if defined(__amd64__) || defined(__powerpc64__) /* both 64 and 32 bit */ || \
121     (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__) || \
122     defined(__riscv)
123 	1;
124 #else
125 	0;
126 #endif
127 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
128     nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
129     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
130 
131 #if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__))
132 int i386_read_exec = 0;
133 SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0,
134     "enable execution from readable segments");
135 #endif
136 
137 static u_long __elfN(pie_base) = ET_DYN_LOAD_ADDR;
138 static int
139 sysctl_pie_base(SYSCTL_HANDLER_ARGS)
140 {
141 	u_long val;
142 	int error;
143 
144 	val = __elfN(pie_base);
145 	error = sysctl_handle_long(oidp, &val, 0, req);
146 	if (error != 0 || req->newptr == NULL)
147 		return (error);
148 	if ((val & PAGE_MASK) != 0)
149 		return (EINVAL);
150 	__elfN(pie_base) = val;
151 	return (0);
152 }
153 SYSCTL_PROC(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, pie_base,
154     CTLTYPE_ULONG | CTLFLAG_MPSAFE | CTLFLAG_RW, NULL, 0,
155     sysctl_pie_base, "LU",
156     "PIE load base without randomization");
157 
158 SYSCTL_NODE(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, aslr,
159     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
160     "");
161 #define	ASLR_NODE_OID	__CONCAT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), _aslr)
162 
163 static int __elfN(aslr_enabled) = 0;
164 SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, enable, CTLFLAG_RWTUN,
165     &__elfN(aslr_enabled), 0,
166     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
167     ": enable address map randomization");
168 
169 static int __elfN(pie_aslr_enabled) = 0;
170 SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, pie_enable, CTLFLAG_RWTUN,
171     &__elfN(pie_aslr_enabled), 0,
172     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
173     ": enable address map randomization for PIE binaries");
174 
175 static int __elfN(aslr_honor_sbrk) = 1;
176 SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, honor_sbrk, CTLFLAG_RW,
177     &__elfN(aslr_honor_sbrk), 0,
178     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": assume sbrk is used");
179 
180 static int __elfN(aslr_stack_gap) = 3;
181 SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, stack_gap, CTLFLAG_RW,
182     &__elfN(aslr_stack_gap), 0,
183     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
184     ": maximum percentage of main stack to waste on a random gap");
185 
186 static int __elfN(sigfastblock) = 1;
187 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, sigfastblock,
188     CTLFLAG_RWTUN, &__elfN(sigfastblock), 0,
189     "enable sigfastblock for new processes");
190 
191 static bool __elfN(allow_wx) = true;
192 SYSCTL_BOOL(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, allow_wx,
193     CTLFLAG_RWTUN, &__elfN(allow_wx), 0,
194     "Allow pages to be mapped simultaneously writable and executable");
195 
196 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
197 
198 #define	aligned(a, t)	(rounddown2((u_long)(a), sizeof(t)) == (u_long)(a))
199 
200 static const char FREEBSD_ABI_VENDOR[] = "FreeBSD";
201 
202 Elf_Brandnote __elfN(freebsd_brandnote) = {
203 	.hdr.n_namesz	= sizeof(FREEBSD_ABI_VENDOR),
204 	.hdr.n_descsz	= sizeof(int32_t),
205 	.hdr.n_type	= NT_FREEBSD_ABI_TAG,
206 	.vendor		= FREEBSD_ABI_VENDOR,
207 	.flags		= BN_TRANSLATE_OSREL,
208 	.trans_osrel	= __elfN(freebsd_trans_osrel)
209 };
210 
211 static bool
212 __elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
213 {
214 	uintptr_t p;
215 
216 	p = (uintptr_t)(note + 1);
217 	p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
218 	*osrel = *(const int32_t *)(p);
219 
220 	return (true);
221 }
222 
223 static const char GNU_ABI_VENDOR[] = "GNU";
224 static int GNU_KFREEBSD_ABI_DESC = 3;
225 
226 Elf_Brandnote __elfN(kfreebsd_brandnote) = {
227 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
228 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
229 	.hdr.n_type	= 1,
230 	.vendor		= GNU_ABI_VENDOR,
231 	.flags		= BN_TRANSLATE_OSREL,
232 	.trans_osrel	= kfreebsd_trans_osrel
233 };
234 
235 static bool
236 kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel)
237 {
238 	const Elf32_Word *desc;
239 	uintptr_t p;
240 
241 	p = (uintptr_t)(note + 1);
242 	p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
243 
244 	desc = (const Elf32_Word *)p;
245 	if (desc[0] != GNU_KFREEBSD_ABI_DESC)
246 		return (false);
247 
248 	/*
249 	 * Debian GNU/kFreeBSD embed the earliest compatible kernel version
250 	 * (__FreeBSD_version: <major><two digit minor>Rxx) in the LSB way.
251 	 */
252 	*osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];
253 
254 	return (true);
255 }
256 
257 int
258 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
259 {
260 	int i;
261 
262 	for (i = 0; i < MAX_BRANDS; i++) {
263 		if (elf_brand_list[i] == NULL) {
264 			elf_brand_list[i] = entry;
265 			break;
266 		}
267 	}
268 	if (i == MAX_BRANDS) {
269 		printf("WARNING: %s: could not insert brandinfo entry: %p\n",
270 			__func__, entry);
271 		return (-1);
272 	}
273 	return (0);
274 }
275 
276 int
277 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
278 {
279 	int i;
280 
281 	for (i = 0; i < MAX_BRANDS; i++) {
282 		if (elf_brand_list[i] == entry) {
283 			elf_brand_list[i] = NULL;
284 			break;
285 		}
286 	}
287 	if (i == MAX_BRANDS)
288 		return (-1);
289 	return (0);
290 }
291 
292 int
293 __elfN(brand_inuse)(Elf_Brandinfo *entry)
294 {
295 	struct proc *p;
296 	int rval = FALSE;
297 
298 	sx_slock(&allproc_lock);
299 	FOREACH_PROC_IN_SYSTEM(p) {
300 		if (p->p_sysent == entry->sysvec) {
301 			rval = TRUE;
302 			break;
303 		}
304 	}
305 	sx_sunlock(&allproc_lock);
306 
307 	return (rval);
308 }
309 
310 static Elf_Brandinfo *
311 __elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
312     int32_t *osrel, uint32_t *fctl0)
313 {
314 	const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
315 	Elf_Brandinfo *bi, *bi_m;
316 	boolean_t ret, has_fctl0;
317 	int i, interp_name_len;
318 
319 	interp_name_len = interp != NULL ? strlen(interp) + 1 : 0;
320 
321 	/*
322 	 * We support four types of branding -- (1) the ELF EI_OSABI field
323 	 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
324 	 * branding w/in the ELF header, (3) path of the `interp_path'
325 	 * field, and (4) the ".note.ABI-tag" ELF section.
326 	 */
327 
328 	/* Look for an ".note.ABI-tag" ELF section */
329 	bi_m = NULL;
330 	for (i = 0; i < MAX_BRANDS; i++) {
331 		bi = elf_brand_list[i];
332 		if (bi == NULL)
333 			continue;
334 		if (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0)
335 			continue;
336 		if (hdr->e_machine == bi->machine && (bi->flags &
337 		    (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
338 			has_fctl0 = false;
339 			*fctl0 = 0;
340 			*osrel = 0;
341 			ret = __elfN(check_note)(imgp, bi->brand_note, osrel,
342 			    &has_fctl0, fctl0);
343 			/* Give brand a chance to veto check_note's guess */
344 			if (ret && bi->header_supported) {
345 				ret = bi->header_supported(imgp, osrel,
346 				    has_fctl0 ? fctl0 : NULL);
347 			}
348 			/*
349 			 * If note checker claimed the binary, but the
350 			 * interpreter path in the image does not
351 			 * match default one for the brand, try to
352 			 * search for other brands with the same
353 			 * interpreter.  Either there is better brand
354 			 * with the right interpreter, or, failing
355 			 * this, we return first brand which accepted
356 			 * our note and, optionally, header.
357 			 */
358 			if (ret && bi_m == NULL && interp != NULL &&
359 			    (bi->interp_path == NULL ||
360 			    (strlen(bi->interp_path) + 1 != interp_name_len ||
361 			    strncmp(interp, bi->interp_path, interp_name_len)
362 			    != 0))) {
363 				bi_m = bi;
364 				ret = 0;
365 			}
366 			if (ret)
367 				return (bi);
368 		}
369 	}
370 	if (bi_m != NULL)
371 		return (bi_m);
372 
373 	/* If the executable has a brand, search for it in the brand list. */
374 	for (i = 0; i < MAX_BRANDS; i++) {
375 		bi = elf_brand_list[i];
376 		if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 ||
377 		    (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0))
378 			continue;
379 		if (hdr->e_machine == bi->machine &&
380 		    (hdr->e_ident[EI_OSABI] == bi->brand ||
381 		    (bi->compat_3_brand != NULL &&
382 		    strcmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
383 		    bi->compat_3_brand) == 0))) {
384 			/* Looks good, but give brand a chance to veto */
385 			if (bi->header_supported == NULL ||
386 			    bi->header_supported(imgp, NULL, NULL)) {
387 				/*
388 				 * Again, prefer strictly matching
389 				 * interpreter path.
390 				 */
391 				if (interp_name_len == 0 &&
392 				    bi->interp_path == NULL)
393 					return (bi);
394 				if (bi->interp_path != NULL &&
395 				    strlen(bi->interp_path) + 1 ==
396 				    interp_name_len && strncmp(interp,
397 				    bi->interp_path, interp_name_len) == 0)
398 					return (bi);
399 				if (bi_m == NULL)
400 					bi_m = bi;
401 			}
402 		}
403 	}
404 	if (bi_m != NULL)
405 		return (bi_m);
406 
407 	/* No known brand, see if the header is recognized by any brand */
408 	for (i = 0; i < MAX_BRANDS; i++) {
409 		bi = elf_brand_list[i];
410 		if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY ||
411 		    bi->header_supported == NULL)
412 			continue;
413 		if (hdr->e_machine == bi->machine) {
414 			ret = bi->header_supported(imgp, NULL, NULL);
415 			if (ret)
416 				return (bi);
417 		}
418 	}
419 
420 	/* Lacking a known brand, search for a recognized interpreter. */
421 	if (interp != NULL) {
422 		for (i = 0; i < MAX_BRANDS; i++) {
423 			bi = elf_brand_list[i];
424 			if (bi == NULL || (bi->flags &
425 			    (BI_BRAND_NOTE_MANDATORY | BI_BRAND_ONLY_STATIC))
426 			    != 0)
427 				continue;
428 			if (hdr->e_machine == bi->machine &&
429 			    bi->interp_path != NULL &&
430 			    /* ELF image p_filesz includes terminating zero */
431 			    strlen(bi->interp_path) + 1 == interp_name_len &&
432 			    strncmp(interp, bi->interp_path, interp_name_len)
433 			    == 0 && (bi->header_supported == NULL ||
434 			    bi->header_supported(imgp, NULL, NULL)))
435 				return (bi);
436 		}
437 	}
438 
439 	/* Lacking a recognized interpreter, try the default brand */
440 	for (i = 0; i < MAX_BRANDS; i++) {
441 		bi = elf_brand_list[i];
442 		if (bi == NULL || (bi->flags & BI_BRAND_NOTE_MANDATORY) != 0 ||
443 		    (interp != NULL && (bi->flags & BI_BRAND_ONLY_STATIC) != 0))
444 			continue;
445 		if (hdr->e_machine == bi->machine &&
446 		    __elfN(fallback_brand) == bi->brand &&
447 		    (bi->header_supported == NULL ||
448 		    bi->header_supported(imgp, NULL, NULL)))
449 			return (bi);
450 	}
451 	return (NULL);
452 }
453 
454 static bool
455 __elfN(phdr_in_zero_page)(const Elf_Ehdr *hdr)
456 {
457 	return (hdr->e_phoff <= PAGE_SIZE &&
458 	    (u_int)hdr->e_phentsize * hdr->e_phnum <= PAGE_SIZE - hdr->e_phoff);
459 }
460 
461 static int
462 __elfN(check_header)(const Elf_Ehdr *hdr)
463 {
464 	Elf_Brandinfo *bi;
465 	int i;
466 
467 	if (!IS_ELF(*hdr) ||
468 	    hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
469 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
470 	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||
471 	    hdr->e_phentsize != sizeof(Elf_Phdr) ||
472 	    hdr->e_version != ELF_TARG_VER)
473 		return (ENOEXEC);
474 
475 	/*
476 	 * Make sure we have at least one brand for this machine.
477 	 */
478 
479 	for (i = 0; i < MAX_BRANDS; i++) {
480 		bi = elf_brand_list[i];
481 		if (bi != NULL && bi->machine == hdr->e_machine)
482 			break;
483 	}
484 	if (i == MAX_BRANDS)
485 		return (ENOEXEC);
486 
487 	return (0);
488 }
489 
490 static int
491 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
492     vm_offset_t start, vm_offset_t end, vm_prot_t prot)
493 {
494 	struct sf_buf *sf;
495 	int error;
496 	vm_offset_t off;
497 
498 	/*
499 	 * Create the page if it doesn't exist yet. Ignore errors.
500 	 */
501 	vm_map_fixed(map, NULL, 0, trunc_page(start), round_page(end) -
502 	    trunc_page(start), VM_PROT_ALL, VM_PROT_ALL, MAP_CHECK_EXCL);
503 
504 	/*
505 	 * Find the page from the underlying object.
506 	 */
507 	if (object != NULL) {
508 		sf = vm_imgact_map_page(object, offset);
509 		if (sf == NULL)
510 			return (KERN_FAILURE);
511 		off = offset - trunc_page(offset);
512 		error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
513 		    end - start);
514 		vm_imgact_unmap_page(sf);
515 		if (error != 0)
516 			return (KERN_FAILURE);
517 	}
518 
519 	return (KERN_SUCCESS);
520 }
521 
522 static int
523 __elfN(map_insert)(struct image_params *imgp, vm_map_t map, vm_object_t object,
524     vm_ooffset_t offset, vm_offset_t start, vm_offset_t end, vm_prot_t prot,
525     int cow)
526 {
527 	struct sf_buf *sf;
528 	vm_offset_t off;
529 	vm_size_t sz;
530 	int error, locked, rv;
531 
532 	if (start != trunc_page(start)) {
533 		rv = __elfN(map_partial)(map, object, offset, start,
534 		    round_page(start), prot);
535 		if (rv != KERN_SUCCESS)
536 			return (rv);
537 		offset += round_page(start) - start;
538 		start = round_page(start);
539 	}
540 	if (end != round_page(end)) {
541 		rv = __elfN(map_partial)(map, object, offset +
542 		    trunc_page(end) - start, trunc_page(end), end, prot);
543 		if (rv != KERN_SUCCESS)
544 			return (rv);
545 		end = trunc_page(end);
546 	}
547 	if (start >= end)
548 		return (KERN_SUCCESS);
549 	if ((offset & PAGE_MASK) != 0) {
550 		/*
551 		 * The mapping is not page aligned.  This means that we have
552 		 * to copy the data.
553 		 */
554 		rv = vm_map_fixed(map, NULL, 0, start, end - start,
555 		    prot | VM_PROT_WRITE, VM_PROT_ALL, MAP_CHECK_EXCL);
556 		if (rv != KERN_SUCCESS)
557 			return (rv);
558 		if (object == NULL)
559 			return (KERN_SUCCESS);
560 		for (; start < end; start += sz) {
561 			sf = vm_imgact_map_page(object, offset);
562 			if (sf == NULL)
563 				return (KERN_FAILURE);
564 			off = offset - trunc_page(offset);
565 			sz = end - start;
566 			if (sz > PAGE_SIZE - off)
567 				sz = PAGE_SIZE - off;
568 			error = copyout((caddr_t)sf_buf_kva(sf) + off,
569 			    (caddr_t)start, sz);
570 			vm_imgact_unmap_page(sf);
571 			if (error != 0)
572 				return (KERN_FAILURE);
573 			offset += sz;
574 		}
575 	} else {
576 		vm_object_reference(object);
577 		rv = vm_map_fixed(map, object, offset, start, end - start,
578 		    prot, VM_PROT_ALL, cow | MAP_CHECK_EXCL |
579 		    (object != NULL ? MAP_VN_EXEC : 0));
580 		if (rv != KERN_SUCCESS) {
581 			locked = VOP_ISLOCKED(imgp->vp);
582 			VOP_UNLOCK(imgp->vp);
583 			vm_object_deallocate(object);
584 			vn_lock(imgp->vp, locked | LK_RETRY);
585 			return (rv);
586 		} else if (object != NULL) {
587 			MPASS(imgp->vp->v_object == object);
588 			VOP_SET_TEXT_CHECKED(imgp->vp);
589 		}
590 	}
591 	return (KERN_SUCCESS);
592 }
593 
594 static int
595 __elfN(load_section)(struct image_params *imgp, vm_ooffset_t offset,
596     caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot)
597 {
598 	struct sf_buf *sf;
599 	size_t map_len;
600 	vm_map_t map;
601 	vm_object_t object;
602 	vm_offset_t map_addr;
603 	int error, rv, cow;
604 	size_t copy_len;
605 	vm_ooffset_t file_addr;
606 
607 	/*
608 	 * It's necessary to fail if the filsz + offset taken from the
609 	 * header is greater than the actual file pager object's size.
610 	 * If we were to allow this, then the vm_map_find() below would
611 	 * walk right off the end of the file object and into the ether.
612 	 *
613 	 * While I'm here, might as well check for something else that
614 	 * is invalid: filsz cannot be greater than memsz.
615 	 */
616 	if ((filsz != 0 && (off_t)filsz + offset > imgp->attr->va_size) ||
617 	    filsz > memsz) {
618 		uprintf("elf_load_section: truncated ELF file\n");
619 		return (ENOEXEC);
620 	}
621 
622 	object = imgp->object;
623 	map = &imgp->proc->p_vmspace->vm_map;
624 	map_addr = trunc_page((vm_offset_t)vmaddr);
625 	file_addr = trunc_page(offset);
626 
627 	/*
628 	 * We have two choices.  We can either clear the data in the last page
629 	 * of an oversized mapping, or we can start the anon mapping a page
630 	 * early and copy the initialized data into that first page.  We
631 	 * choose the second.
632 	 */
633 	if (filsz == 0)
634 		map_len = 0;
635 	else if (memsz > filsz)
636 		map_len = trunc_page(offset + filsz) - file_addr;
637 	else
638 		map_len = round_page(offset + filsz) - file_addr;
639 
640 	if (map_len != 0) {
641 		/* cow flags: don't dump readonly sections in core */
642 		cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
643 		    (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
644 
645 		rv = __elfN(map_insert)(imgp, map, object, file_addr,
646 		    map_addr, map_addr + map_len, prot, cow);
647 		if (rv != KERN_SUCCESS)
648 			return (EINVAL);
649 
650 		/* we can stop now if we've covered it all */
651 		if (memsz == filsz)
652 			return (0);
653 	}
654 
655 	/*
656 	 * We have to get the remaining bit of the file into the first part
657 	 * of the oversized map segment.  This is normally because the .data
658 	 * segment in the file is extended to provide bss.  It's a neat idea
659 	 * to try and save a page, but it's a pain in the behind to implement.
660 	 */
661 	copy_len = filsz == 0 ? 0 : (offset + filsz) - trunc_page(offset +
662 	    filsz);
663 	map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
664 	map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
665 
666 	/* This had damn well better be true! */
667 	if (map_len != 0) {
668 		rv = __elfN(map_insert)(imgp, map, NULL, 0, map_addr,
669 		    map_addr + map_len, prot, 0);
670 		if (rv != KERN_SUCCESS)
671 			return (EINVAL);
672 	}
673 
674 	if (copy_len != 0) {
675 		sf = vm_imgact_map_page(object, offset + filsz);
676 		if (sf == NULL)
677 			return (EIO);
678 
679 		/* send the page fragment to user space */
680 		error = copyout((caddr_t)sf_buf_kva(sf), (caddr_t)map_addr,
681 		    copy_len);
682 		vm_imgact_unmap_page(sf);
683 		if (error != 0)
684 			return (error);
685 	}
686 
687 	/*
688 	 * Remove write access to the page if it was only granted by map_insert
689 	 * to allow copyout.
690 	 */
691 	if ((prot & VM_PROT_WRITE) == 0)
692 		vm_map_protect(map, trunc_page(map_addr), round_page(map_addr +
693 		    map_len), prot, 0, VM_MAP_PROTECT_SET_PROT);
694 
695 	return (0);
696 }
697 
698 static int
699 __elfN(load_sections)(struct image_params *imgp, const Elf_Ehdr *hdr,
700     const Elf_Phdr *phdr, u_long rbase, u_long *base_addrp)
701 {
702 	vm_prot_t prot;
703 	u_long base_addr;
704 	bool first;
705 	int error, i;
706 
707 	ASSERT_VOP_LOCKED(imgp->vp, __func__);
708 
709 	base_addr = 0;
710 	first = true;
711 
712 	for (i = 0; i < hdr->e_phnum; i++) {
713 		if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
714 			continue;
715 
716 		/* Loadable segment */
717 		prot = __elfN(trans_prot)(phdr[i].p_flags);
718 		error = __elfN(load_section)(imgp, phdr[i].p_offset,
719 		    (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
720 		    phdr[i].p_memsz, phdr[i].p_filesz, prot);
721 		if (error != 0)
722 			return (error);
723 
724 		/*
725 		 * Establish the base address if this is the first segment.
726 		 */
727 		if (first) {
728   			base_addr = trunc_page(phdr[i].p_vaddr + rbase);
729 			first = false;
730 		}
731 	}
732 
733 	if (base_addrp != NULL)
734 		*base_addrp = base_addr;
735 
736 	return (0);
737 }
738 
739 /*
740  * Load the file "file" into memory.  It may be either a shared object
741  * or an executable.
742  *
743  * The "addr" reference parameter is in/out.  On entry, it specifies
744  * the address where a shared object should be loaded.  If the file is
745  * an executable, this value is ignored.  On exit, "addr" specifies
746  * where the file was actually loaded.
747  *
748  * The "entry" reference parameter is out only.  On exit, it specifies
749  * the entry point for the loaded file.
750  */
751 static int
752 __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
753 	u_long *entry)
754 {
755 	struct {
756 		struct nameidata nd;
757 		struct vattr attr;
758 		struct image_params image_params;
759 	} *tempdata;
760 	const Elf_Ehdr *hdr = NULL;
761 	const Elf_Phdr *phdr = NULL;
762 	struct nameidata *nd;
763 	struct vattr *attr;
764 	struct image_params *imgp;
765 	u_long rbase;
766 	u_long base_addr = 0;
767 	int error;
768 
769 #ifdef CAPABILITY_MODE
770 	/*
771 	 * XXXJA: This check can go away once we are sufficiently confident
772 	 * that the checks in namei() are correct.
773 	 */
774 	if (IN_CAPABILITY_MODE(curthread))
775 		return (ECAPMODE);
776 #endif
777 
778 	tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK | M_ZERO);
779 	nd = &tempdata->nd;
780 	attr = &tempdata->attr;
781 	imgp = &tempdata->image_params;
782 
783 	/*
784 	 * Initialize part of the common data
785 	 */
786 	imgp->proc = p;
787 	imgp->attr = attr;
788 
789 	NDINIT(nd, LOOKUP, ISOPEN | FOLLOW | LOCKSHARED | LOCKLEAF,
790 	    UIO_SYSSPACE, file, curthread);
791 	if ((error = namei(nd)) != 0) {
792 		nd->ni_vp = NULL;
793 		goto fail;
794 	}
795 	NDFREE(nd, NDF_ONLY_PNBUF);
796 	imgp->vp = nd->ni_vp;
797 
798 	/*
799 	 * Check permissions, modes, uid, etc on the file, and "open" it.
800 	 */
801 	error = exec_check_permissions(imgp);
802 	if (error)
803 		goto fail;
804 
805 	error = exec_map_first_page(imgp);
806 	if (error)
807 		goto fail;
808 
809 	imgp->object = nd->ni_vp->v_object;
810 
811 	hdr = (const Elf_Ehdr *)imgp->image_header;
812 	if ((error = __elfN(check_header)(hdr)) != 0)
813 		goto fail;
814 	if (hdr->e_type == ET_DYN)
815 		rbase = *addr;
816 	else if (hdr->e_type == ET_EXEC)
817 		rbase = 0;
818 	else {
819 		error = ENOEXEC;
820 		goto fail;
821 	}
822 
823 	/* Only support headers that fit within first page for now      */
824 	if (!__elfN(phdr_in_zero_page)(hdr)) {
825 		error = ENOEXEC;
826 		goto fail;
827 	}
828 
829 	phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
830 	if (!aligned(phdr, Elf_Addr)) {
831 		error = ENOEXEC;
832 		goto fail;
833 	}
834 
835 	error = __elfN(load_sections)(imgp, hdr, phdr, rbase, &base_addr);
836 	if (error != 0)
837 		goto fail;
838 
839 	*addr = base_addr;
840 	*entry = (unsigned long)hdr->e_entry + rbase;
841 
842 fail:
843 	if (imgp->firstpage)
844 		exec_unmap_first_page(imgp);
845 
846 	if (nd->ni_vp) {
847 		if (imgp->textset)
848 			VOP_UNSET_TEXT_CHECKED(nd->ni_vp);
849 		vput(nd->ni_vp);
850 	}
851 	free(tempdata, M_TEMP);
852 
853 	return (error);
854 }
855 
856 static u_long
857 __CONCAT(rnd_, __elfN(base))(vm_map_t map __unused, u_long minv, u_long maxv,
858     u_int align)
859 {
860 	u_long rbase, res;
861 
862 	MPASS(vm_map_min(map) <= minv);
863 	MPASS(maxv <= vm_map_max(map));
864 	MPASS(minv < maxv);
865 	MPASS(minv + align < maxv);
866 	arc4rand(&rbase, sizeof(rbase), 0);
867 	res = roundup(minv, (u_long)align) + rbase % (maxv - minv);
868 	res &= ~((u_long)align - 1);
869 	if (res >= maxv)
870 		res -= align;
871 	KASSERT(res >= minv,
872 	    ("res %#lx < minv %#lx, maxv %#lx rbase %#lx",
873 	    res, minv, maxv, rbase));
874 	KASSERT(res < maxv,
875 	    ("res %#lx > maxv %#lx, minv %#lx rbase %#lx",
876 	    res, maxv, minv, rbase));
877 	return (res);
878 }
879 
880 static int
881 __elfN(enforce_limits)(struct image_params *imgp, const Elf_Ehdr *hdr,
882     const Elf_Phdr *phdr, u_long et_dyn_addr)
883 {
884 	struct vmspace *vmspace;
885 	const char *err_str;
886 	u_long text_size, data_size, total_size, text_addr, data_addr;
887 	u_long seg_size, seg_addr;
888 	int i;
889 
890 	err_str = NULL;
891 	text_size = data_size = total_size = text_addr = data_addr = 0;
892 
893 	for (i = 0; i < hdr->e_phnum; i++) {
894 		if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
895 			continue;
896 
897 		seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
898 		seg_size = round_page(phdr[i].p_memsz +
899 		    phdr[i].p_vaddr + et_dyn_addr - seg_addr);
900 
901 		/*
902 		 * Make the largest executable segment the official
903 		 * text segment and all others data.
904 		 *
905 		 * Note that obreak() assumes that data_addr + data_size == end
906 		 * of data load area, and the ELF file format expects segments
907 		 * to be sorted by address.  If multiple data segments exist,
908 		 * the last one will be used.
909 		 */
910 
911 		if ((phdr[i].p_flags & PF_X) != 0 && text_size < seg_size) {
912 			text_size = seg_size;
913 			text_addr = seg_addr;
914 		} else {
915 			data_size = seg_size;
916 			data_addr = seg_addr;
917 		}
918 		total_size += seg_size;
919 	}
920 
921 	if (data_addr == 0 && data_size == 0) {
922 		data_addr = text_addr;
923 		data_size = text_size;
924 	}
925 
926 	/*
927 	 * Check limits.  It should be safe to check the
928 	 * limits after loading the segments since we do
929 	 * not actually fault in all the segments pages.
930 	 */
931 	PROC_LOCK(imgp->proc);
932 	if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA))
933 		err_str = "Data segment size exceeds process limit";
934 	else if (text_size > maxtsiz)
935 		err_str = "Text segment size exceeds system limit";
936 	else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM))
937 		err_str = "Total segment size exceeds process limit";
938 	else if (racct_set(imgp->proc, RACCT_DATA, data_size) != 0)
939 		err_str = "Data segment size exceeds resource limit";
940 	else if (racct_set(imgp->proc, RACCT_VMEM, total_size) != 0)
941 		err_str = "Total segment size exceeds resource limit";
942 	PROC_UNLOCK(imgp->proc);
943 	if (err_str != NULL) {
944 		uprintf("%s\n", err_str);
945 		return (ENOMEM);
946 	}
947 
948 	vmspace = imgp->proc->p_vmspace;
949 	vmspace->vm_tsize = text_size >> PAGE_SHIFT;
950 	vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
951 	vmspace->vm_dsize = data_size >> PAGE_SHIFT;
952 	vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
953 
954 	return (0);
955 }
956 
957 static int
958 __elfN(get_interp)(struct image_params *imgp, const Elf_Phdr *phdr,
959     char **interpp, bool *free_interpp)
960 {
961 	struct thread *td;
962 	char *interp;
963 	int error, interp_name_len;
964 
965 	KASSERT(phdr->p_type == PT_INTERP,
966 	    ("%s: p_type %u != PT_INTERP", __func__, phdr->p_type));
967 	ASSERT_VOP_LOCKED(imgp->vp, __func__);
968 
969 	td = curthread;
970 
971 	/* Path to interpreter */
972 	if (phdr->p_filesz < 2 || phdr->p_filesz > MAXPATHLEN) {
973 		uprintf("Invalid PT_INTERP\n");
974 		return (ENOEXEC);
975 	}
976 
977 	interp_name_len = phdr->p_filesz;
978 	if (phdr->p_offset > PAGE_SIZE ||
979 	    interp_name_len > PAGE_SIZE - phdr->p_offset) {
980 		/*
981 		 * The vnode lock might be needed by the pagedaemon to
982 		 * clean pages owned by the vnode.  Do not allow sleep
983 		 * waiting for memory with the vnode locked, instead
984 		 * try non-sleepable allocation first, and if it
985 		 * fails, go to the slow path were we drop the lock
986 		 * and do M_WAITOK.  A text reference prevents
987 		 * modifications to the vnode content.
988 		 */
989 		interp = malloc(interp_name_len + 1, M_TEMP, M_NOWAIT);
990 		if (interp == NULL) {
991 			VOP_UNLOCK(imgp->vp);
992 			interp = malloc(interp_name_len + 1, M_TEMP, M_WAITOK);
993 			vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
994 		}
995 
996 		error = vn_rdwr(UIO_READ, imgp->vp, interp,
997 		    interp_name_len, phdr->p_offset,
998 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
999 		    NOCRED, NULL, td);
1000 		if (error != 0) {
1001 			free(interp, M_TEMP);
1002 			uprintf("i/o error PT_INTERP %d\n", error);
1003 			return (error);
1004 		}
1005 		interp[interp_name_len] = '\0';
1006 
1007 		*interpp = interp;
1008 		*free_interpp = true;
1009 		return (0);
1010 	}
1011 
1012 	interp = __DECONST(char *, imgp->image_header) + phdr->p_offset;
1013 	if (interp[interp_name_len - 1] != '\0') {
1014 		uprintf("Invalid PT_INTERP\n");
1015 		return (ENOEXEC);
1016 	}
1017 
1018 	*interpp = interp;
1019 	*free_interpp = false;
1020 	return (0);
1021 }
1022 
1023 static int
1024 __elfN(load_interp)(struct image_params *imgp, const Elf_Brandinfo *brand_info,
1025     const char *interp, u_long *addr, u_long *entry)
1026 {
1027 	char *path;
1028 	int error;
1029 
1030 	if (brand_info->emul_path != NULL &&
1031 	    brand_info->emul_path[0] != '\0') {
1032 		path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1033 		snprintf(path, MAXPATHLEN, "%s%s",
1034 		    brand_info->emul_path, interp);
1035 		error = __elfN(load_file)(imgp->proc, path, addr, entry);
1036 		free(path, M_TEMP);
1037 		if (error == 0)
1038 			return (0);
1039 	}
1040 
1041 	if (brand_info->interp_newpath != NULL &&
1042 	    (brand_info->interp_path == NULL ||
1043 	    strcmp(interp, brand_info->interp_path) == 0)) {
1044 		error = __elfN(load_file)(imgp->proc,
1045 		    brand_info->interp_newpath, addr, entry);
1046 		if (error == 0)
1047 			return (0);
1048 	}
1049 
1050 	error = __elfN(load_file)(imgp->proc, interp, addr, entry);
1051 	if (error == 0)
1052 		return (0);
1053 
1054 	uprintf("ELF interpreter %s not found, error %d\n", interp, error);
1055 	return (error);
1056 }
1057 
1058 /*
1059  * Impossible et_dyn_addr initial value indicating that the real base
1060  * must be calculated later with some randomization applied.
1061  */
1062 #define	ET_DYN_ADDR_RAND	1
1063 
1064 static int
1065 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
1066 {
1067 	struct thread *td;
1068 	const Elf_Ehdr *hdr;
1069 	const Elf_Phdr *phdr;
1070 	Elf_Auxargs *elf_auxargs;
1071 	struct vmspace *vmspace;
1072 	vm_map_t map;
1073 	char *interp;
1074 	Elf_Brandinfo *brand_info;
1075 	struct sysentvec *sv;
1076 	u_long addr, baddr, et_dyn_addr, entry, proghdr;
1077 	u_long maxalign, mapsz, maxv, maxv1;
1078 	uint32_t fctl0;
1079 	int32_t osrel;
1080 	bool free_interp;
1081 	int error, i, n;
1082 
1083 	hdr = (const Elf_Ehdr *)imgp->image_header;
1084 
1085 	/*
1086 	 * Do we have a valid ELF header ?
1087 	 *
1088 	 * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
1089 	 * if particular brand doesn't support it.
1090 	 */
1091 	if (__elfN(check_header)(hdr) != 0 ||
1092 	    (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
1093 		return (-1);
1094 
1095 	/*
1096 	 * From here on down, we return an errno, not -1, as we've
1097 	 * detected an ELF file.
1098 	 */
1099 
1100 	if (!__elfN(phdr_in_zero_page)(hdr)) {
1101 		uprintf("Program headers not in the first page\n");
1102 		return (ENOEXEC);
1103 	}
1104 	phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
1105 	if (!aligned(phdr, Elf_Addr)) {
1106 		uprintf("Unaligned program headers\n");
1107 		return (ENOEXEC);
1108 	}
1109 
1110 	n = error = 0;
1111 	baddr = 0;
1112 	osrel = 0;
1113 	fctl0 = 0;
1114 	entry = proghdr = 0;
1115 	interp = NULL;
1116 	free_interp = false;
1117 	td = curthread;
1118 	maxalign = PAGE_SIZE;
1119 	mapsz = 0;
1120 
1121 	for (i = 0; i < hdr->e_phnum; i++) {
1122 		switch (phdr[i].p_type) {
1123 		case PT_LOAD:
1124 			if (n == 0)
1125 				baddr = phdr[i].p_vaddr;
1126 			if (phdr[i].p_align > maxalign)
1127 				maxalign = phdr[i].p_align;
1128 			mapsz += phdr[i].p_memsz;
1129 			n++;
1130 
1131 			/*
1132 			 * If this segment contains the program headers,
1133 			 * remember their virtual address for the AT_PHDR
1134 			 * aux entry. Static binaries don't usually include
1135 			 * a PT_PHDR entry.
1136 			 */
1137 			if (phdr[i].p_offset == 0 &&
1138 			    hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
1139 				<= phdr[i].p_filesz)
1140 				proghdr = phdr[i].p_vaddr + hdr->e_phoff;
1141 			break;
1142 		case PT_INTERP:
1143 			/* Path to interpreter */
1144 			if (interp != NULL) {
1145 				uprintf("Multiple PT_INTERP headers\n");
1146 				error = ENOEXEC;
1147 				goto ret;
1148 			}
1149 			error = __elfN(get_interp)(imgp, &phdr[i], &interp,
1150 			    &free_interp);
1151 			if (error != 0)
1152 				goto ret;
1153 			break;
1154 		case PT_GNU_STACK:
1155 			if (__elfN(nxstack))
1156 				imgp->stack_prot =
1157 				    __elfN(trans_prot)(phdr[i].p_flags);
1158 			imgp->stack_sz = phdr[i].p_memsz;
1159 			break;
1160 		case PT_PHDR: 	/* Program header table info */
1161 			proghdr = phdr[i].p_vaddr;
1162 			break;
1163 		}
1164 	}
1165 
1166 	brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel, &fctl0);
1167 	if (brand_info == NULL) {
1168 		uprintf("ELF binary type \"%u\" not known.\n",
1169 		    hdr->e_ident[EI_OSABI]);
1170 		error = ENOEXEC;
1171 		goto ret;
1172 	}
1173 	sv = brand_info->sysvec;
1174 	et_dyn_addr = 0;
1175 	if (hdr->e_type == ET_DYN) {
1176 		if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0) {
1177 			uprintf("Cannot execute shared object\n");
1178 			error = ENOEXEC;
1179 			goto ret;
1180 		}
1181 		/*
1182 		 * Honour the base load address from the dso if it is
1183 		 * non-zero for some reason.
1184 		 */
1185 		if (baddr == 0) {
1186 			if ((sv->sv_flags & SV_ASLR) == 0 ||
1187 			    (fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0)
1188 				et_dyn_addr = __elfN(pie_base);
1189 			else if ((__elfN(pie_aslr_enabled) &&
1190 			    (imgp->proc->p_flag2 & P2_ASLR_DISABLE) == 0) ||
1191 			    (imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0)
1192 				et_dyn_addr = ET_DYN_ADDR_RAND;
1193 			else
1194 				et_dyn_addr = __elfN(pie_base);
1195 		}
1196 	}
1197 
1198 	/*
1199 	 * Avoid a possible deadlock if the current address space is destroyed
1200 	 * and that address space maps the locked vnode.  In the common case,
1201 	 * the locked vnode's v_usecount is decremented but remains greater
1202 	 * than zero.  Consequently, the vnode lock is not needed by vrele().
1203 	 * However, in cases where the vnode lock is external, such as nullfs,
1204 	 * v_usecount may become zero.
1205 	 *
1206 	 * The VV_TEXT flag prevents modifications to the executable while
1207 	 * the vnode is unlocked.
1208 	 */
1209 	VOP_UNLOCK(imgp->vp);
1210 
1211 	/*
1212 	 * Decide whether to enable randomization of user mappings.
1213 	 * First, reset user preferences for the setid binaries.
1214 	 * Then, account for the support of the randomization by the
1215 	 * ABI, by user preferences, and make special treatment for
1216 	 * PIE binaries.
1217 	 */
1218 	if (imgp->credential_setid) {
1219 		PROC_LOCK(imgp->proc);
1220 		imgp->proc->p_flag2 &= ~(P2_ASLR_ENABLE | P2_ASLR_DISABLE);
1221 		PROC_UNLOCK(imgp->proc);
1222 	}
1223 	if ((sv->sv_flags & SV_ASLR) == 0 ||
1224 	    (imgp->proc->p_flag2 & P2_ASLR_DISABLE) != 0 ||
1225 	    (fctl0 & NT_FREEBSD_FCTL_ASLR_DISABLE) != 0) {
1226 		KASSERT(et_dyn_addr != ET_DYN_ADDR_RAND,
1227 		    ("et_dyn_addr == RAND and !ASLR"));
1228 	} else if ((imgp->proc->p_flag2 & P2_ASLR_ENABLE) != 0 ||
1229 	    (__elfN(aslr_enabled) && hdr->e_type == ET_EXEC) ||
1230 	    et_dyn_addr == ET_DYN_ADDR_RAND) {
1231 		imgp->map_flags |= MAP_ASLR;
1232 		/*
1233 		 * If user does not care about sbrk, utilize the bss
1234 		 * grow region for mappings as well.  We can select
1235 		 * the base for the image anywere and still not suffer
1236 		 * from the fragmentation.
1237 		 */
1238 		if (!__elfN(aslr_honor_sbrk) ||
1239 		    (imgp->proc->p_flag2 & P2_ASLR_IGNSTART) != 0)
1240 			imgp->map_flags |= MAP_ASLR_IGNSTART;
1241 	}
1242 
1243 	if (!__elfN(allow_wx) && (fctl0 & NT_FREEBSD_FCTL_WXNEEDED) == 0)
1244 		imgp->map_flags |= MAP_WXORX;
1245 
1246 	error = exec_new_vmspace(imgp, sv);
1247 	vmspace = imgp->proc->p_vmspace;
1248 	map = &vmspace->vm_map;
1249 
1250 	imgp->proc->p_sysent = sv;
1251 
1252 	maxv = vm_map_max(map) - lim_max(td, RLIMIT_STACK);
1253 	if (et_dyn_addr == ET_DYN_ADDR_RAND) {
1254 		KASSERT((map->flags & MAP_ASLR) != 0,
1255 		    ("ET_DYN_ADDR_RAND but !MAP_ASLR"));
1256 		et_dyn_addr = __CONCAT(rnd_, __elfN(base))(map,
1257 		    vm_map_min(map) + mapsz + lim_max(td, RLIMIT_DATA),
1258 		    /* reserve half of the address space to interpreter */
1259 		    maxv / 2, 1UL << flsl(maxalign));
1260 	}
1261 
1262 	vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
1263 	if (error != 0)
1264 		goto ret;
1265 
1266 	error = __elfN(load_sections)(imgp, hdr, phdr, et_dyn_addr, NULL);
1267 	if (error != 0)
1268 		goto ret;
1269 
1270 	error = __elfN(enforce_limits)(imgp, hdr, phdr, et_dyn_addr);
1271 	if (error != 0)
1272 		goto ret;
1273 
1274 	entry = (u_long)hdr->e_entry + et_dyn_addr;
1275 
1276 	/*
1277 	 * We load the dynamic linker where a userland call
1278 	 * to mmap(0, ...) would put it.  The rationale behind this
1279 	 * calculation is that it leaves room for the heap to grow to
1280 	 * its maximum allowed size.
1281 	 */
1282 	addr = round_page((vm_offset_t)vmspace->vm_daddr + lim_max(td,
1283 	    RLIMIT_DATA));
1284 	if ((map->flags & MAP_ASLR) != 0) {
1285 		maxv1 = maxv / 2 + addr / 2;
1286 		MPASS(maxv1 >= addr);	/* No overflow */
1287 		map->anon_loc = __CONCAT(rnd_, __elfN(base))(map, addr, maxv1,
1288 		    (MAXPAGESIZES > 1 && pagesizes[1] != 0) ?
1289 		    pagesizes[1] : pagesizes[0]);
1290 	} else {
1291 		map->anon_loc = addr;
1292 	}
1293 
1294 	imgp->entry_addr = entry;
1295 
1296 	if (interp != NULL) {
1297 		VOP_UNLOCK(imgp->vp);
1298 		if ((map->flags & MAP_ASLR) != 0) {
1299 			/* Assume that interpreter fits into 1/4 of AS */
1300 			maxv1 = maxv / 2 + addr / 2;
1301 			MPASS(maxv1 >= addr);	/* No overflow */
1302 			addr = __CONCAT(rnd_, __elfN(base))(map, addr,
1303 			    maxv1, PAGE_SIZE);
1304 		}
1305 		error = __elfN(load_interp)(imgp, brand_info, interp, &addr,
1306 		    &imgp->entry_addr);
1307 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
1308 		if (error != 0)
1309 			goto ret;
1310 	} else
1311 		addr = et_dyn_addr;
1312 
1313 	/*
1314 	 * Construct auxargs table (used by the copyout_auxargs routine)
1315 	 */
1316 	elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_NOWAIT);
1317 	if (elf_auxargs == NULL) {
1318 		VOP_UNLOCK(imgp->vp);
1319 		elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
1320 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
1321 	}
1322 	elf_auxargs->execfd = -1;
1323 	elf_auxargs->phdr = proghdr + et_dyn_addr;
1324 	elf_auxargs->phent = hdr->e_phentsize;
1325 	elf_auxargs->phnum = hdr->e_phnum;
1326 	elf_auxargs->pagesz = PAGE_SIZE;
1327 	elf_auxargs->base = addr;
1328 	elf_auxargs->flags = 0;
1329 	elf_auxargs->entry = entry;
1330 	elf_auxargs->hdr_eflags = hdr->e_flags;
1331 
1332 	imgp->auxargs = elf_auxargs;
1333 	imgp->interpreted = 0;
1334 	imgp->reloc_base = addr;
1335 	imgp->proc->p_osrel = osrel;
1336 	imgp->proc->p_fctl0 = fctl0;
1337 	imgp->proc->p_elf_machine = hdr->e_machine;
1338 	imgp->proc->p_elf_flags = hdr->e_flags;
1339 
1340 ret:
1341 	if (free_interp)
1342 		free(interp, M_TEMP);
1343 	return (error);
1344 }
1345 
1346 #define	suword __CONCAT(suword, __ELF_WORD_SIZE)
1347 
1348 int
1349 __elfN(freebsd_copyout_auxargs)(struct image_params *imgp, uintptr_t base)
1350 {
1351 	Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
1352 	Elf_Auxinfo *argarray, *pos;
1353 	int error;
1354 
1355 	argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP,
1356 	    M_WAITOK | M_ZERO);
1357 
1358 	if (args->execfd != -1)
1359 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
1360 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
1361 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
1362 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
1363 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
1364 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
1365 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
1366 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
1367 	AUXARGS_ENTRY(pos, AT_EHDRFLAGS, args->hdr_eflags);
1368 	if (imgp->execpathp != 0)
1369 		AUXARGS_ENTRY_PTR(pos, AT_EXECPATH, imgp->execpathp);
1370 	AUXARGS_ENTRY(pos, AT_OSRELDATE,
1371 	    imgp->proc->p_ucred->cr_prison->pr_osreldate);
1372 	if (imgp->canary != 0) {
1373 		AUXARGS_ENTRY_PTR(pos, AT_CANARY, imgp->canary);
1374 		AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen);
1375 	}
1376 	AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus);
1377 	if (imgp->pagesizes != 0) {
1378 		AUXARGS_ENTRY_PTR(pos, AT_PAGESIZES, imgp->pagesizes);
1379 		AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen);
1380 	}
1381 	if (imgp->sysent->sv_timekeep_base != 0) {
1382 		AUXARGS_ENTRY(pos, AT_TIMEKEEP,
1383 		    imgp->sysent->sv_timekeep_base);
1384 	}
1385 	AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
1386 	    != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1387 	    imgp->sysent->sv_stackprot);
1388 	if (imgp->sysent->sv_hwcap != NULL)
1389 		AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap);
1390 	if (imgp->sysent->sv_hwcap2 != NULL)
1391 		AUXARGS_ENTRY(pos, AT_HWCAP2, *imgp->sysent->sv_hwcap2);
1392 	AUXARGS_ENTRY(pos, AT_BSDFLAGS, __elfN(sigfastblock) ?
1393 	    ELF_BSDF_SIGFASTBLK : 0);
1394 	AUXARGS_ENTRY(pos, AT_ARGC, imgp->args->argc);
1395 	AUXARGS_ENTRY_PTR(pos, AT_ARGV, imgp->argv);
1396 	AUXARGS_ENTRY(pos, AT_ENVC, imgp->args->envc);
1397 	AUXARGS_ENTRY_PTR(pos, AT_ENVV, imgp->envv);
1398 	AUXARGS_ENTRY_PTR(pos, AT_PS_STRINGS, imgp->ps_strings);
1399 	if (imgp->sysent->sv_fxrng_gen_base != 0)
1400 		AUXARGS_ENTRY(pos, AT_FXRNG, imgp->sysent->sv_fxrng_gen_base);
1401 	AUXARGS_ENTRY(pos, AT_NULL, 0);
1402 
1403 	free(imgp->auxargs, M_TEMP);
1404 	imgp->auxargs = NULL;
1405 	KASSERT(pos - argarray <= AT_COUNT, ("Too many auxargs"));
1406 
1407 	error = copyout(argarray, (void *)base, sizeof(*argarray) * AT_COUNT);
1408 	free(argarray, M_TEMP);
1409 	return (error);
1410 }
1411 
1412 int
1413 __elfN(freebsd_fixup)(uintptr_t *stack_base, struct image_params *imgp)
1414 {
1415 	Elf_Addr *base;
1416 
1417 	base = (Elf_Addr *)*stack_base;
1418 	base--;
1419 	if (suword(base, imgp->args->argc) == -1)
1420 		return (EFAULT);
1421 	*stack_base = (uintptr_t)base;
1422 	return (0);
1423 }
1424 
1425 /*
1426  * Code for generating ELF core dumps.
1427  */
1428 
1429 typedef void (*segment_callback)(vm_map_entry_t, void *);
1430 
1431 /* Closure for cb_put_phdr(). */
1432 struct phdr_closure {
1433 	Elf_Phdr *phdr;		/* Program header to fill in */
1434 	Elf_Off offset;		/* Offset of segment in core file */
1435 };
1436 
1437 typedef void (*outfunc_t)(void *, struct sbuf *, size_t *);
1438 
1439 struct note_info {
1440 	int		type;		/* Note type. */
1441 	outfunc_t 	outfunc; 	/* Output function. */
1442 	void		*outarg;	/* Argument for the output function. */
1443 	size_t		outsize;	/* Output size. */
1444 	TAILQ_ENTRY(note_info) link;	/* Link to the next note info. */
1445 };
1446 
1447 TAILQ_HEAD(note_info_list, note_info);
1448 
1449 extern int compress_user_cores;
1450 extern int compress_user_cores_level;
1451 
1452 static void cb_put_phdr(vm_map_entry_t, void *);
1453 static void cb_size_segment(vm_map_entry_t, void *);
1454 static void each_dumpable_segment(struct thread *, segment_callback, void *,
1455     int);
1456 static int __elfN(corehdr)(struct coredump_params *, int, void *, size_t,
1457     struct note_info_list *, size_t, int);
1458 static void __elfN(prepare_notes)(struct thread *, struct note_info_list *,
1459     size_t *);
1460 static void __elfN(putnote)(struct note_info *, struct sbuf *);
1461 static size_t register_note(struct note_info_list *, int, outfunc_t, void *);
1462 
1463 static void __elfN(note_fpregset)(void *, struct sbuf *, size_t *);
1464 static void __elfN(note_prpsinfo)(void *, struct sbuf *, size_t *);
1465 static void __elfN(note_prstatus)(void *, struct sbuf *, size_t *);
1466 static void __elfN(note_threadmd)(void *, struct sbuf *, size_t *);
1467 static void __elfN(note_thrmisc)(void *, struct sbuf *, size_t *);
1468 static void __elfN(note_ptlwpinfo)(void *, struct sbuf *, size_t *);
1469 static void __elfN(note_procstat_auxv)(void *, struct sbuf *, size_t *);
1470 static void __elfN(note_procstat_proc)(void *, struct sbuf *, size_t *);
1471 static void __elfN(note_procstat_psstrings)(void *, struct sbuf *, size_t *);
1472 static void note_procstat_files(void *, struct sbuf *, size_t *);
1473 static void note_procstat_groups(void *, struct sbuf *, size_t *);
1474 static void note_procstat_osrel(void *, struct sbuf *, size_t *);
1475 static void note_procstat_rlimit(void *, struct sbuf *, size_t *);
1476 static void note_procstat_umask(void *, struct sbuf *, size_t *);
1477 static void note_procstat_vmmap(void *, struct sbuf *, size_t *);
1478 
1479 static int
1480 core_compressed_write(void *base, size_t len, off_t offset, void *arg)
1481 {
1482 
1483 	return (core_write((struct coredump_params *)arg, base, len, offset,
1484 	    UIO_SYSSPACE, NULL));
1485 }
1486 
1487 int
1488 __elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags)
1489 {
1490 	struct ucred *cred = td->td_ucred;
1491 	int compm, error = 0;
1492 	struct sseg_closure seginfo;
1493 	struct note_info_list notelst;
1494 	struct coredump_params params;
1495 	struct note_info *ninfo;
1496 	void *hdr, *tmpbuf;
1497 	size_t hdrsize, notesz, coresize;
1498 
1499 	hdr = NULL;
1500 	tmpbuf = NULL;
1501 	TAILQ_INIT(&notelst);
1502 
1503 	/* Size the program segments. */
1504 	__elfN(size_segments)(td, &seginfo, flags);
1505 
1506 	/*
1507 	 * Collect info about the core file header area.
1508 	 */
1509 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
1510 	if (seginfo.count + 1 >= PN_XNUM)
1511 		hdrsize += sizeof(Elf_Shdr);
1512 	__elfN(prepare_notes)(td, &notelst, &notesz);
1513 	coresize = round_page(hdrsize + notesz) + seginfo.size;
1514 
1515 	/* Set up core dump parameters. */
1516 	params.offset = 0;
1517 	params.active_cred = cred;
1518 	params.file_cred = NOCRED;
1519 	params.td = td;
1520 	params.vp = vp;
1521 	params.comp = NULL;
1522 
1523 #ifdef RACCT
1524 	if (racct_enable) {
1525 		PROC_LOCK(td->td_proc);
1526 		error = racct_add(td->td_proc, RACCT_CORE, coresize);
1527 		PROC_UNLOCK(td->td_proc);
1528 		if (error != 0) {
1529 			error = EFAULT;
1530 			goto done;
1531 		}
1532 	}
1533 #endif
1534 	if (coresize >= limit) {
1535 		error = EFAULT;
1536 		goto done;
1537 	}
1538 
1539 	/* Create a compression stream if necessary. */
1540 	compm = compress_user_cores;
1541 	if ((flags & (SVC_PT_COREDUMP | SVC_NOCOMPRESS)) == SVC_PT_COREDUMP &&
1542 	    compm == 0)
1543 		compm = COMPRESS_GZIP;
1544 	if (compm != 0) {
1545 		params.comp = compressor_init(core_compressed_write,
1546 		    compm, CORE_BUF_SIZE,
1547 		    compress_user_cores_level, &params);
1548 		if (params.comp == NULL) {
1549 			error = EFAULT;
1550 			goto done;
1551 		}
1552 		tmpbuf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO);
1553         }
1554 
1555 	/*
1556 	 * Allocate memory for building the header, fill it up,
1557 	 * and write it out following the notes.
1558 	 */
1559 	hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
1560 	error = __elfN(corehdr)(&params, seginfo.count, hdr, hdrsize, &notelst,
1561 	    notesz, flags);
1562 
1563 	/* Write the contents of all of the writable segments. */
1564 	if (error == 0) {
1565 		Elf_Phdr *php;
1566 		off_t offset;
1567 		int i;
1568 
1569 		php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
1570 		offset = round_page(hdrsize + notesz);
1571 		for (i = 0; i < seginfo.count; i++) {
1572 			error = core_output((char *)(uintptr_t)php->p_vaddr,
1573 			    php->p_filesz, offset, &params, tmpbuf);
1574 			if (error != 0)
1575 				break;
1576 			offset += php->p_filesz;
1577 			php++;
1578 		}
1579 		if (error == 0 && params.comp != NULL)
1580 			error = compressor_flush(params.comp);
1581 	}
1582 	if (error) {
1583 		log(LOG_WARNING,
1584 		    "Failed to write core file for process %s (error %d)\n",
1585 		    curproc->p_comm, error);
1586 	}
1587 
1588 done:
1589 	free(tmpbuf, M_TEMP);
1590 	if (params.comp != NULL)
1591 		compressor_fini(params.comp);
1592 	while ((ninfo = TAILQ_FIRST(&notelst)) != NULL) {
1593 		TAILQ_REMOVE(&notelst, ninfo, link);
1594 		free(ninfo, M_TEMP);
1595 	}
1596 	if (hdr != NULL)
1597 		free(hdr, M_TEMP);
1598 
1599 	return (error);
1600 }
1601 
1602 /*
1603  * A callback for each_dumpable_segment() to write out the segment's
1604  * program header entry.
1605  */
1606 static void
1607 cb_put_phdr(vm_map_entry_t entry, void *closure)
1608 {
1609 	struct phdr_closure *phc = (struct phdr_closure *)closure;
1610 	Elf_Phdr *phdr = phc->phdr;
1611 
1612 	phc->offset = round_page(phc->offset);
1613 
1614 	phdr->p_type = PT_LOAD;
1615 	phdr->p_offset = phc->offset;
1616 	phdr->p_vaddr = entry->start;
1617 	phdr->p_paddr = 0;
1618 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
1619 	phdr->p_align = PAGE_SIZE;
1620 	phdr->p_flags = __elfN(untrans_prot)(entry->protection);
1621 
1622 	phc->offset += phdr->p_filesz;
1623 	phc->phdr++;
1624 }
1625 
1626 /*
1627  * A callback for each_dumpable_segment() to gather information about
1628  * the number of segments and their total size.
1629  */
1630 static void
1631 cb_size_segment(vm_map_entry_t entry, void *closure)
1632 {
1633 	struct sseg_closure *ssc = (struct sseg_closure *)closure;
1634 
1635 	ssc->count++;
1636 	ssc->size += entry->end - entry->start;
1637 }
1638 
1639 void
1640 __elfN(size_segments)(struct thread *td, struct sseg_closure *seginfo,
1641     int flags)
1642 {
1643 	seginfo->count = 0;
1644 	seginfo->size = 0;
1645 
1646 	each_dumpable_segment(td, cb_size_segment, seginfo, flags);
1647 }
1648 
1649 /*
1650  * For each writable segment in the process's memory map, call the given
1651  * function with a pointer to the map entry and some arbitrary
1652  * caller-supplied data.
1653  */
1654 static void
1655 each_dumpable_segment(struct thread *td, segment_callback func, void *closure,
1656     int flags)
1657 {
1658 	struct proc *p = td->td_proc;
1659 	vm_map_t map = &p->p_vmspace->vm_map;
1660 	vm_map_entry_t entry;
1661 	vm_object_t backing_object, object;
1662 	bool ignore_entry;
1663 
1664 	vm_map_lock_read(map);
1665 	VM_MAP_ENTRY_FOREACH(entry, map) {
1666 		/*
1667 		 * Don't dump inaccessible mappings, deal with legacy
1668 		 * coredump mode.
1669 		 *
1670 		 * Note that read-only segments related to the elf binary
1671 		 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
1672 		 * need to arbitrarily ignore such segments.
1673 		 */
1674 		if ((flags & SVC_ALL) == 0) {
1675 			if (elf_legacy_coredump) {
1676 				if ((entry->protection & VM_PROT_RW) !=
1677 				    VM_PROT_RW)
1678 					continue;
1679 			} else {
1680 				if ((entry->protection & VM_PROT_ALL) == 0)
1681 					continue;
1682 			}
1683 		}
1684 
1685 		/*
1686 		 * Dont include memory segment in the coredump if
1687 		 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
1688 		 * madvise(2).  Do not dump submaps (i.e. parts of the
1689 		 * kernel map).
1690 		 */
1691 		if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
1692 			continue;
1693 		if ((entry->eflags & MAP_ENTRY_NOCOREDUMP) != 0 &&
1694 		    (flags & SVC_ALL) == 0)
1695 			continue;
1696 		if ((object = entry->object.vm_object) == NULL)
1697 			continue;
1698 
1699 		/* Ignore memory-mapped devices and such things. */
1700 		VM_OBJECT_RLOCK(object);
1701 		while ((backing_object = object->backing_object) != NULL) {
1702 			VM_OBJECT_RLOCK(backing_object);
1703 			VM_OBJECT_RUNLOCK(object);
1704 			object = backing_object;
1705 		}
1706 		ignore_entry = (object->flags & OBJ_FICTITIOUS) != 0;
1707 		VM_OBJECT_RUNLOCK(object);
1708 		if (ignore_entry)
1709 			continue;
1710 
1711 		(*func)(entry, closure);
1712 	}
1713 	vm_map_unlock_read(map);
1714 }
1715 
1716 /*
1717  * Write the core file header to the file, including padding up to
1718  * the page boundary.
1719  */
1720 static int
1721 __elfN(corehdr)(struct coredump_params *p, int numsegs, void *hdr,
1722     size_t hdrsize, struct note_info_list *notelst, size_t notesz,
1723     int flags)
1724 {
1725 	struct note_info *ninfo;
1726 	struct sbuf *sb;
1727 	int error;
1728 
1729 	/* Fill in the header. */
1730 	bzero(hdr, hdrsize);
1731 	__elfN(puthdr)(p->td, hdr, hdrsize, numsegs, notesz, flags);
1732 
1733 	sb = sbuf_new(NULL, NULL, CORE_BUF_SIZE, SBUF_FIXEDLEN);
1734 	sbuf_set_drain(sb, sbuf_drain_core_output, p);
1735 	sbuf_start_section(sb, NULL);
1736 	sbuf_bcat(sb, hdr, hdrsize);
1737 	TAILQ_FOREACH(ninfo, notelst, link)
1738 	    __elfN(putnote)(ninfo, sb);
1739 	/* Align up to a page boundary for the program segments. */
1740 	sbuf_end_section(sb, -1, PAGE_SIZE, 0);
1741 	error = sbuf_finish(sb);
1742 	sbuf_delete(sb);
1743 
1744 	return (error);
1745 }
1746 
1747 static void
1748 __elfN(prepare_notes)(struct thread *td, struct note_info_list *list,
1749     size_t *sizep)
1750 {
1751 	struct proc *p;
1752 	struct thread *thr;
1753 	size_t size;
1754 
1755 	p = td->td_proc;
1756 	size = 0;
1757 
1758 	size += register_note(list, NT_PRPSINFO, __elfN(note_prpsinfo), p);
1759 
1760 	/*
1761 	 * To have the debugger select the right thread (LWP) as the initial
1762 	 * thread, we dump the state of the thread passed to us in td first.
1763 	 * This is the thread that causes the core dump and thus likely to
1764 	 * be the right thread one wants to have selected in the debugger.
1765 	 */
1766 	thr = td;
1767 	while (thr != NULL) {
1768 		size += register_note(list, NT_PRSTATUS,
1769 		    __elfN(note_prstatus), thr);
1770 		size += register_note(list, NT_FPREGSET,
1771 		    __elfN(note_fpregset), thr);
1772 		size += register_note(list, NT_THRMISC,
1773 		    __elfN(note_thrmisc), thr);
1774 		size += register_note(list, NT_PTLWPINFO,
1775 		    __elfN(note_ptlwpinfo), thr);
1776 		size += register_note(list, -1,
1777 		    __elfN(note_threadmd), thr);
1778 
1779 		thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
1780 		    TAILQ_NEXT(thr, td_plist);
1781 		if (thr == td)
1782 			thr = TAILQ_NEXT(thr, td_plist);
1783 	}
1784 
1785 	size += register_note(list, NT_PROCSTAT_PROC,
1786 	    __elfN(note_procstat_proc), p);
1787 	size += register_note(list, NT_PROCSTAT_FILES,
1788 	    note_procstat_files, p);
1789 	size += register_note(list, NT_PROCSTAT_VMMAP,
1790 	    note_procstat_vmmap, p);
1791 	size += register_note(list, NT_PROCSTAT_GROUPS,
1792 	    note_procstat_groups, p);
1793 	size += register_note(list, NT_PROCSTAT_UMASK,
1794 	    note_procstat_umask, p);
1795 	size += register_note(list, NT_PROCSTAT_RLIMIT,
1796 	    note_procstat_rlimit, p);
1797 	size += register_note(list, NT_PROCSTAT_OSREL,
1798 	    note_procstat_osrel, p);
1799 	size += register_note(list, NT_PROCSTAT_PSSTRINGS,
1800 	    __elfN(note_procstat_psstrings), p);
1801 	size += register_note(list, NT_PROCSTAT_AUXV,
1802 	    __elfN(note_procstat_auxv), p);
1803 
1804 	*sizep = size;
1805 }
1806 
1807 void
1808 __elfN(puthdr)(struct thread *td, void *hdr, size_t hdrsize, int numsegs,
1809     size_t notesz, int flags)
1810 {
1811 	Elf_Ehdr *ehdr;
1812 	Elf_Phdr *phdr;
1813 	Elf_Shdr *shdr;
1814 	struct phdr_closure phc;
1815 
1816 	ehdr = (Elf_Ehdr *)hdr;
1817 
1818 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
1819 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
1820 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
1821 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
1822 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
1823 	ehdr->e_ident[EI_DATA] = ELF_DATA;
1824 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
1825 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
1826 	ehdr->e_ident[EI_ABIVERSION] = 0;
1827 	ehdr->e_ident[EI_PAD] = 0;
1828 	ehdr->e_type = ET_CORE;
1829 	ehdr->e_machine = td->td_proc->p_elf_machine;
1830 	ehdr->e_version = EV_CURRENT;
1831 	ehdr->e_entry = 0;
1832 	ehdr->e_phoff = sizeof(Elf_Ehdr);
1833 	ehdr->e_flags = td->td_proc->p_elf_flags;
1834 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
1835 	ehdr->e_phentsize = sizeof(Elf_Phdr);
1836 	ehdr->e_shentsize = sizeof(Elf_Shdr);
1837 	ehdr->e_shstrndx = SHN_UNDEF;
1838 	if (numsegs + 1 < PN_XNUM) {
1839 		ehdr->e_phnum = numsegs + 1;
1840 		ehdr->e_shnum = 0;
1841 	} else {
1842 		ehdr->e_phnum = PN_XNUM;
1843 		ehdr->e_shnum = 1;
1844 
1845 		ehdr->e_shoff = ehdr->e_phoff +
1846 		    (numsegs + 1) * ehdr->e_phentsize;
1847 		KASSERT(ehdr->e_shoff == hdrsize - sizeof(Elf_Shdr),
1848 		    ("e_shoff: %zu, hdrsize - shdr: %zu",
1849 		     (size_t)ehdr->e_shoff, hdrsize - sizeof(Elf_Shdr)));
1850 
1851 		shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
1852 		memset(shdr, 0, sizeof(*shdr));
1853 		/*
1854 		 * A special first section is used to hold large segment and
1855 		 * section counts.  This was proposed by Sun Microsystems in
1856 		 * Solaris and has been adopted by Linux; the standard ELF
1857 		 * tools are already familiar with the technique.
1858 		 *
1859 		 * See table 7-7 of the Solaris "Linker and Libraries Guide"
1860 		 * (or 12-7 depending on the version of the document) for more
1861 		 * details.
1862 		 */
1863 		shdr->sh_type = SHT_NULL;
1864 		shdr->sh_size = ehdr->e_shnum;
1865 		shdr->sh_link = ehdr->e_shstrndx;
1866 		shdr->sh_info = numsegs + 1;
1867 	}
1868 
1869 	/*
1870 	 * Fill in the program header entries.
1871 	 */
1872 	phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);
1873 
1874 	/* The note segement. */
1875 	phdr->p_type = PT_NOTE;
1876 	phdr->p_offset = hdrsize;
1877 	phdr->p_vaddr = 0;
1878 	phdr->p_paddr = 0;
1879 	phdr->p_filesz = notesz;
1880 	phdr->p_memsz = 0;
1881 	phdr->p_flags = PF_R;
1882 	phdr->p_align = ELF_NOTE_ROUNDSIZE;
1883 	phdr++;
1884 
1885 	/* All the writable segments from the program. */
1886 	phc.phdr = phdr;
1887 	phc.offset = round_page(hdrsize + notesz);
1888 	each_dumpable_segment(td, cb_put_phdr, &phc, flags);
1889 }
1890 
1891 static size_t
1892 register_note(struct note_info_list *list, int type, outfunc_t out, void *arg)
1893 {
1894 	struct note_info *ninfo;
1895 	size_t size, notesize;
1896 
1897 	size = 0;
1898 	out(arg, NULL, &size);
1899 	ninfo = malloc(sizeof(*ninfo), M_TEMP, M_ZERO | M_WAITOK);
1900 	ninfo->type = type;
1901 	ninfo->outfunc = out;
1902 	ninfo->outarg = arg;
1903 	ninfo->outsize = size;
1904 	TAILQ_INSERT_TAIL(list, ninfo, link);
1905 
1906 	if (type == -1)
1907 		return (size);
1908 
1909 	notesize = sizeof(Elf_Note) +		/* note header */
1910 	    roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) +
1911 						/* note name */
1912 	    roundup2(size, ELF_NOTE_ROUNDSIZE);	/* note description */
1913 
1914 	return (notesize);
1915 }
1916 
1917 static size_t
1918 append_note_data(const void *src, void *dst, size_t len)
1919 {
1920 	size_t padded_len;
1921 
1922 	padded_len = roundup2(len, ELF_NOTE_ROUNDSIZE);
1923 	if (dst != NULL) {
1924 		bcopy(src, dst, len);
1925 		bzero((char *)dst + len, padded_len - len);
1926 	}
1927 	return (padded_len);
1928 }
1929 
1930 size_t
1931 __elfN(populate_note)(int type, void *src, void *dst, size_t size, void **descp)
1932 {
1933 	Elf_Note *note;
1934 	char *buf;
1935 	size_t notesize;
1936 
1937 	buf = dst;
1938 	if (buf != NULL) {
1939 		note = (Elf_Note *)buf;
1940 		note->n_namesz = sizeof(FREEBSD_ABI_VENDOR);
1941 		note->n_descsz = size;
1942 		note->n_type = type;
1943 		buf += sizeof(*note);
1944 		buf += append_note_data(FREEBSD_ABI_VENDOR, buf,
1945 		    sizeof(FREEBSD_ABI_VENDOR));
1946 		append_note_data(src, buf, size);
1947 		if (descp != NULL)
1948 			*descp = buf;
1949 	}
1950 
1951 	notesize = sizeof(Elf_Note) +		/* note header */
1952 	    roundup2(sizeof(FREEBSD_ABI_VENDOR), ELF_NOTE_ROUNDSIZE) +
1953 						/* note name */
1954 	    roundup2(size, ELF_NOTE_ROUNDSIZE);	/* note description */
1955 
1956 	return (notesize);
1957 }
1958 
1959 static void
1960 __elfN(putnote)(struct note_info *ninfo, struct sbuf *sb)
1961 {
1962 	Elf_Note note;
1963 	ssize_t old_len, sect_len;
1964 	size_t new_len, descsz, i;
1965 
1966 	if (ninfo->type == -1) {
1967 		ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
1968 		return;
1969 	}
1970 
1971 	note.n_namesz = sizeof(FREEBSD_ABI_VENDOR);
1972 	note.n_descsz = ninfo->outsize;
1973 	note.n_type = ninfo->type;
1974 
1975 	sbuf_bcat(sb, &note, sizeof(note));
1976 	sbuf_start_section(sb, &old_len);
1977 	sbuf_bcat(sb, FREEBSD_ABI_VENDOR, sizeof(FREEBSD_ABI_VENDOR));
1978 	sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
1979 	if (note.n_descsz == 0)
1980 		return;
1981 	sbuf_start_section(sb, &old_len);
1982 	ninfo->outfunc(ninfo->outarg, sb, &ninfo->outsize);
1983 	sect_len = sbuf_end_section(sb, old_len, ELF_NOTE_ROUNDSIZE, 0);
1984 	if (sect_len < 0)
1985 		return;
1986 
1987 	new_len = (size_t)sect_len;
1988 	descsz = roundup(note.n_descsz, ELF_NOTE_ROUNDSIZE);
1989 	if (new_len < descsz) {
1990 		/*
1991 		 * It is expected that individual note emitters will correctly
1992 		 * predict their expected output size and fill up to that size
1993 		 * themselves, padding in a format-specific way if needed.
1994 		 * However, in case they don't, just do it here with zeros.
1995 		 */
1996 		for (i = 0; i < descsz - new_len; i++)
1997 			sbuf_putc(sb, 0);
1998 	} else if (new_len > descsz) {
1999 		/*
2000 		 * We can't always truncate sb -- we may have drained some
2001 		 * of it already.
2002 		 */
2003 		KASSERT(new_len == descsz, ("%s: Note type %u changed as we "
2004 		    "read it (%zu > %zu).  Since it is longer than "
2005 		    "expected, this coredump's notes are corrupt.  THIS "
2006 		    "IS A BUG in the note_procstat routine for type %u.\n",
2007 		    __func__, (unsigned)note.n_type, new_len, descsz,
2008 		    (unsigned)note.n_type));
2009 	}
2010 }
2011 
2012 /*
2013  * Miscellaneous note out functions.
2014  */
2015 
2016 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2017 #include <compat/freebsd32/freebsd32.h>
2018 #include <compat/freebsd32/freebsd32_signal.h>
2019 
2020 typedef struct prstatus32 elf_prstatus_t;
2021 typedef struct prpsinfo32 elf_prpsinfo_t;
2022 typedef struct fpreg32 elf_prfpregset_t;
2023 typedef struct fpreg32 elf_fpregset_t;
2024 typedef struct reg32 elf_gregset_t;
2025 typedef struct thrmisc32 elf_thrmisc_t;
2026 #define ELF_KERN_PROC_MASK	KERN_PROC_MASK32
2027 typedef struct kinfo_proc32 elf_kinfo_proc_t;
2028 typedef uint32_t elf_ps_strings_t;
2029 #else
2030 typedef prstatus_t elf_prstatus_t;
2031 typedef prpsinfo_t elf_prpsinfo_t;
2032 typedef prfpregset_t elf_prfpregset_t;
2033 typedef prfpregset_t elf_fpregset_t;
2034 typedef gregset_t elf_gregset_t;
2035 typedef thrmisc_t elf_thrmisc_t;
2036 #define ELF_KERN_PROC_MASK	0
2037 typedef struct kinfo_proc elf_kinfo_proc_t;
2038 typedef vm_offset_t elf_ps_strings_t;
2039 #endif
2040 
2041 static void
2042 __elfN(note_prpsinfo)(void *arg, struct sbuf *sb, size_t *sizep)
2043 {
2044 	struct sbuf sbarg;
2045 	size_t len;
2046 	char *cp, *end;
2047 	struct proc *p;
2048 	elf_prpsinfo_t *psinfo;
2049 	int error;
2050 
2051 	p = (struct proc *)arg;
2052 	if (sb != NULL) {
2053 		KASSERT(*sizep == sizeof(*psinfo), ("invalid size"));
2054 		psinfo = malloc(sizeof(*psinfo), M_TEMP, M_ZERO | M_WAITOK);
2055 		psinfo->pr_version = PRPSINFO_VERSION;
2056 		psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
2057 		strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
2058 		PROC_LOCK(p);
2059 		if (p->p_args != NULL) {
2060 			len = sizeof(psinfo->pr_psargs) - 1;
2061 			if (len > p->p_args->ar_length)
2062 				len = p->p_args->ar_length;
2063 			memcpy(psinfo->pr_psargs, p->p_args->ar_args, len);
2064 			PROC_UNLOCK(p);
2065 			error = 0;
2066 		} else {
2067 			_PHOLD(p);
2068 			PROC_UNLOCK(p);
2069 			sbuf_new(&sbarg, psinfo->pr_psargs,
2070 			    sizeof(psinfo->pr_psargs), SBUF_FIXEDLEN);
2071 			error = proc_getargv(curthread, p, &sbarg);
2072 			PRELE(p);
2073 			if (sbuf_finish(&sbarg) == 0)
2074 				len = sbuf_len(&sbarg) - 1;
2075 			else
2076 				len = sizeof(psinfo->pr_psargs) - 1;
2077 			sbuf_delete(&sbarg);
2078 		}
2079 		if (error || len == 0)
2080 			strlcpy(psinfo->pr_psargs, p->p_comm,
2081 			    sizeof(psinfo->pr_psargs));
2082 		else {
2083 			KASSERT(len < sizeof(psinfo->pr_psargs),
2084 			    ("len is too long: %zu vs %zu", len,
2085 			    sizeof(psinfo->pr_psargs)));
2086 			cp = psinfo->pr_psargs;
2087 			end = cp + len - 1;
2088 			for (;;) {
2089 				cp = memchr(cp, '\0', end - cp);
2090 				if (cp == NULL)
2091 					break;
2092 				*cp = ' ';
2093 			}
2094 		}
2095 		psinfo->pr_pid = p->p_pid;
2096 		sbuf_bcat(sb, psinfo, sizeof(*psinfo));
2097 		free(psinfo, M_TEMP);
2098 	}
2099 	*sizep = sizeof(*psinfo);
2100 }
2101 
2102 static void
2103 __elfN(note_prstatus)(void *arg, struct sbuf *sb, size_t *sizep)
2104 {
2105 	struct thread *td;
2106 	elf_prstatus_t *status;
2107 
2108 	td = (struct thread *)arg;
2109 	if (sb != NULL) {
2110 		KASSERT(*sizep == sizeof(*status), ("invalid size"));
2111 		status = malloc(sizeof(*status), M_TEMP, M_ZERO | M_WAITOK);
2112 		status->pr_version = PRSTATUS_VERSION;
2113 		status->pr_statussz = sizeof(elf_prstatus_t);
2114 		status->pr_gregsetsz = sizeof(elf_gregset_t);
2115 		status->pr_fpregsetsz = sizeof(elf_fpregset_t);
2116 		status->pr_osreldate = osreldate;
2117 		status->pr_cursig = td->td_proc->p_sig;
2118 		status->pr_pid = td->td_tid;
2119 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2120 		fill_regs32(td, &status->pr_reg);
2121 #else
2122 		fill_regs(td, &status->pr_reg);
2123 #endif
2124 		sbuf_bcat(sb, status, sizeof(*status));
2125 		free(status, M_TEMP);
2126 	}
2127 	*sizep = sizeof(*status);
2128 }
2129 
2130 static void
2131 __elfN(note_fpregset)(void *arg, struct sbuf *sb, size_t *sizep)
2132 {
2133 	struct thread *td;
2134 	elf_prfpregset_t *fpregset;
2135 
2136 	td = (struct thread *)arg;
2137 	if (sb != NULL) {
2138 		KASSERT(*sizep == sizeof(*fpregset), ("invalid size"));
2139 		fpregset = malloc(sizeof(*fpregset), M_TEMP, M_ZERO | M_WAITOK);
2140 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2141 		fill_fpregs32(td, fpregset);
2142 #else
2143 		fill_fpregs(td, fpregset);
2144 #endif
2145 		sbuf_bcat(sb, fpregset, sizeof(*fpregset));
2146 		free(fpregset, M_TEMP);
2147 	}
2148 	*sizep = sizeof(*fpregset);
2149 }
2150 
2151 static void
2152 __elfN(note_thrmisc)(void *arg, struct sbuf *sb, size_t *sizep)
2153 {
2154 	struct thread *td;
2155 	elf_thrmisc_t thrmisc;
2156 
2157 	td = (struct thread *)arg;
2158 	if (sb != NULL) {
2159 		KASSERT(*sizep == sizeof(thrmisc), ("invalid size"));
2160 		bzero(&thrmisc, sizeof(thrmisc));
2161 		strcpy(thrmisc.pr_tname, td->td_name);
2162 		sbuf_bcat(sb, &thrmisc, sizeof(thrmisc));
2163 	}
2164 	*sizep = sizeof(thrmisc);
2165 }
2166 
2167 static void
2168 __elfN(note_ptlwpinfo)(void *arg, struct sbuf *sb, size_t *sizep)
2169 {
2170 	struct thread *td;
2171 	size_t size;
2172 	int structsize;
2173 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2174 	struct ptrace_lwpinfo32 pl;
2175 #else
2176 	struct ptrace_lwpinfo pl;
2177 #endif
2178 
2179 	td = (struct thread *)arg;
2180 	size = sizeof(structsize) + sizeof(pl);
2181 	if (sb != NULL) {
2182 		KASSERT(*sizep == size, ("invalid size"));
2183 		structsize = sizeof(pl);
2184 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2185 		bzero(&pl, sizeof(pl));
2186 		pl.pl_lwpid = td->td_tid;
2187 		pl.pl_event = PL_EVENT_NONE;
2188 		pl.pl_sigmask = td->td_sigmask;
2189 		pl.pl_siglist = td->td_siglist;
2190 		if (td->td_si.si_signo != 0) {
2191 			pl.pl_event = PL_EVENT_SIGNAL;
2192 			pl.pl_flags |= PL_FLAG_SI;
2193 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2194 			siginfo_to_siginfo32(&td->td_si, &pl.pl_siginfo);
2195 #else
2196 			pl.pl_siginfo = td->td_si;
2197 #endif
2198 		}
2199 		strcpy(pl.pl_tdname, td->td_name);
2200 		/* XXX TODO: supply more information in struct ptrace_lwpinfo*/
2201 		sbuf_bcat(sb, &pl, sizeof(pl));
2202 	}
2203 	*sizep = size;
2204 }
2205 
2206 /*
2207  * Allow for MD specific notes, as well as any MD
2208  * specific preparations for writing MI notes.
2209  */
2210 static void
2211 __elfN(note_threadmd)(void *arg, struct sbuf *sb, size_t *sizep)
2212 {
2213 	struct thread *td;
2214 	void *buf;
2215 	size_t size;
2216 
2217 	td = (struct thread *)arg;
2218 	size = *sizep;
2219 	if (size != 0 && sb != NULL)
2220 		buf = malloc(size, M_TEMP, M_ZERO | M_WAITOK);
2221 	else
2222 		buf = NULL;
2223 	size = 0;
2224 	__elfN(dump_thread)(td, buf, &size);
2225 	KASSERT(sb == NULL || *sizep == size, ("invalid size"));
2226 	if (size != 0 && sb != NULL)
2227 		sbuf_bcat(sb, buf, size);
2228 	free(buf, M_TEMP);
2229 	*sizep = size;
2230 }
2231 
2232 #ifdef KINFO_PROC_SIZE
2233 CTASSERT(sizeof(struct kinfo_proc) == KINFO_PROC_SIZE);
2234 #endif
2235 
2236 static void
2237 __elfN(note_procstat_proc)(void *arg, struct sbuf *sb, size_t *sizep)
2238 {
2239 	struct proc *p;
2240 	size_t size;
2241 	int structsize;
2242 
2243 	p = (struct proc *)arg;
2244 	size = sizeof(structsize) + p->p_numthreads *
2245 	    sizeof(elf_kinfo_proc_t);
2246 
2247 	if (sb != NULL) {
2248 		KASSERT(*sizep == size, ("invalid size"));
2249 		structsize = sizeof(elf_kinfo_proc_t);
2250 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2251 		sx_slock(&proctree_lock);
2252 		PROC_LOCK(p);
2253 		kern_proc_out(p, sb, ELF_KERN_PROC_MASK);
2254 		sx_sunlock(&proctree_lock);
2255 	}
2256 	*sizep = size;
2257 }
2258 
2259 #ifdef KINFO_FILE_SIZE
2260 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
2261 #endif
2262 
2263 static void
2264 note_procstat_files(void *arg, struct sbuf *sb, size_t *sizep)
2265 {
2266 	struct proc *p;
2267 	size_t size, sect_sz, i;
2268 	ssize_t start_len, sect_len;
2269 	int structsize, filedesc_flags;
2270 
2271 	if (coredump_pack_fileinfo)
2272 		filedesc_flags = KERN_FILEDESC_PACK_KINFO;
2273 	else
2274 		filedesc_flags = 0;
2275 
2276 	p = (struct proc *)arg;
2277 	structsize = sizeof(struct kinfo_file);
2278 	if (sb == NULL) {
2279 		size = 0;
2280 		sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
2281 		sbuf_set_drain(sb, sbuf_count_drain, &size);
2282 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2283 		PROC_LOCK(p);
2284 		kern_proc_filedesc_out(p, sb, -1, filedesc_flags);
2285 		sbuf_finish(sb);
2286 		sbuf_delete(sb);
2287 		*sizep = size;
2288 	} else {
2289 		sbuf_start_section(sb, &start_len);
2290 
2291 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2292 		PROC_LOCK(p);
2293 		kern_proc_filedesc_out(p, sb, *sizep - sizeof(structsize),
2294 		    filedesc_flags);
2295 
2296 		sect_len = sbuf_end_section(sb, start_len, 0, 0);
2297 		if (sect_len < 0)
2298 			return;
2299 		sect_sz = sect_len;
2300 
2301 		KASSERT(sect_sz <= *sizep,
2302 		    ("kern_proc_filedesc_out did not respect maxlen; "
2303 		     "requested %zu, got %zu", *sizep - sizeof(structsize),
2304 		     sect_sz - sizeof(structsize)));
2305 
2306 		for (i = 0; i < *sizep - sect_sz && sb->s_error == 0; i++)
2307 			sbuf_putc(sb, 0);
2308 	}
2309 }
2310 
2311 #ifdef KINFO_VMENTRY_SIZE
2312 CTASSERT(sizeof(struct kinfo_vmentry) == KINFO_VMENTRY_SIZE);
2313 #endif
2314 
2315 static void
2316 note_procstat_vmmap(void *arg, struct sbuf *sb, size_t *sizep)
2317 {
2318 	struct proc *p;
2319 	size_t size;
2320 	int structsize, vmmap_flags;
2321 
2322 	if (coredump_pack_vmmapinfo)
2323 		vmmap_flags = KERN_VMMAP_PACK_KINFO;
2324 	else
2325 		vmmap_flags = 0;
2326 
2327 	p = (struct proc *)arg;
2328 	structsize = sizeof(struct kinfo_vmentry);
2329 	if (sb == NULL) {
2330 		size = 0;
2331 		sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
2332 		sbuf_set_drain(sb, sbuf_count_drain, &size);
2333 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2334 		PROC_LOCK(p);
2335 		kern_proc_vmmap_out(p, sb, -1, vmmap_flags);
2336 		sbuf_finish(sb);
2337 		sbuf_delete(sb);
2338 		*sizep = size;
2339 	} else {
2340 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2341 		PROC_LOCK(p);
2342 		kern_proc_vmmap_out(p, sb, *sizep - sizeof(structsize),
2343 		    vmmap_flags);
2344 	}
2345 }
2346 
2347 static void
2348 note_procstat_groups(void *arg, struct sbuf *sb, size_t *sizep)
2349 {
2350 	struct proc *p;
2351 	size_t size;
2352 	int structsize;
2353 
2354 	p = (struct proc *)arg;
2355 	size = sizeof(structsize) + p->p_ucred->cr_ngroups * sizeof(gid_t);
2356 	if (sb != NULL) {
2357 		KASSERT(*sizep == size, ("invalid size"));
2358 		structsize = sizeof(gid_t);
2359 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2360 		sbuf_bcat(sb, p->p_ucred->cr_groups, p->p_ucred->cr_ngroups *
2361 		    sizeof(gid_t));
2362 	}
2363 	*sizep = size;
2364 }
2365 
2366 static void
2367 note_procstat_umask(void *arg, struct sbuf *sb, size_t *sizep)
2368 {
2369 	struct proc *p;
2370 	size_t size;
2371 	int structsize;
2372 
2373 	p = (struct proc *)arg;
2374 	size = sizeof(structsize) + sizeof(p->p_pd->pd_cmask);
2375 	if (sb != NULL) {
2376 		KASSERT(*sizep == size, ("invalid size"));
2377 		structsize = sizeof(p->p_pd->pd_cmask);
2378 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2379 		sbuf_bcat(sb, &p->p_pd->pd_cmask, sizeof(p->p_pd->pd_cmask));
2380 	}
2381 	*sizep = size;
2382 }
2383 
2384 static void
2385 note_procstat_rlimit(void *arg, struct sbuf *sb, size_t *sizep)
2386 {
2387 	struct proc *p;
2388 	struct rlimit rlim[RLIM_NLIMITS];
2389 	size_t size;
2390 	int structsize, i;
2391 
2392 	p = (struct proc *)arg;
2393 	size = sizeof(structsize) + sizeof(rlim);
2394 	if (sb != NULL) {
2395 		KASSERT(*sizep == size, ("invalid size"));
2396 		structsize = sizeof(rlim);
2397 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2398 		PROC_LOCK(p);
2399 		for (i = 0; i < RLIM_NLIMITS; i++)
2400 			lim_rlimit_proc(p, i, &rlim[i]);
2401 		PROC_UNLOCK(p);
2402 		sbuf_bcat(sb, rlim, sizeof(rlim));
2403 	}
2404 	*sizep = size;
2405 }
2406 
2407 static void
2408 note_procstat_osrel(void *arg, struct sbuf *sb, size_t *sizep)
2409 {
2410 	struct proc *p;
2411 	size_t size;
2412 	int structsize;
2413 
2414 	p = (struct proc *)arg;
2415 	size = sizeof(structsize) + sizeof(p->p_osrel);
2416 	if (sb != NULL) {
2417 		KASSERT(*sizep == size, ("invalid size"));
2418 		structsize = sizeof(p->p_osrel);
2419 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2420 		sbuf_bcat(sb, &p->p_osrel, sizeof(p->p_osrel));
2421 	}
2422 	*sizep = size;
2423 }
2424 
2425 static void
2426 __elfN(note_procstat_psstrings)(void *arg, struct sbuf *sb, size_t *sizep)
2427 {
2428 	struct proc *p;
2429 	elf_ps_strings_t ps_strings;
2430 	size_t size;
2431 	int structsize;
2432 
2433 	p = (struct proc *)arg;
2434 	size = sizeof(structsize) + sizeof(ps_strings);
2435 	if (sb != NULL) {
2436 		KASSERT(*sizep == size, ("invalid size"));
2437 		structsize = sizeof(ps_strings);
2438 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
2439 		ps_strings = PTROUT(p->p_sysent->sv_psstrings);
2440 #else
2441 		ps_strings = p->p_sysent->sv_psstrings;
2442 #endif
2443 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2444 		sbuf_bcat(sb, &ps_strings, sizeof(ps_strings));
2445 	}
2446 	*sizep = size;
2447 }
2448 
2449 static void
2450 __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
2451 {
2452 	struct proc *p;
2453 	size_t size;
2454 	int structsize;
2455 
2456 	p = (struct proc *)arg;
2457 	if (sb == NULL) {
2458 		size = 0;
2459 		sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
2460 		sbuf_set_drain(sb, sbuf_count_drain, &size);
2461 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2462 		PHOLD(p);
2463 		proc_getauxv(curthread, p, sb);
2464 		PRELE(p);
2465 		sbuf_finish(sb);
2466 		sbuf_delete(sb);
2467 		*sizep = size;
2468 	} else {
2469 		structsize = sizeof(Elf_Auxinfo);
2470 		sbuf_bcat(sb, &structsize, sizeof(structsize));
2471 		PHOLD(p);
2472 		proc_getauxv(curthread, p, sb);
2473 		PRELE(p);
2474 	}
2475 }
2476 
2477 static boolean_t
2478 __elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote,
2479     const char *note_vendor, const Elf_Phdr *pnote,
2480     boolean_t (*cb)(const Elf_Note *, void *, boolean_t *), void *cb_arg)
2481 {
2482 	const Elf_Note *note, *note0, *note_end;
2483 	const char *note_name;
2484 	char *buf;
2485 	int i, error;
2486 	boolean_t res;
2487 
2488 	/* We need some limit, might as well use PAGE_SIZE. */
2489 	if (pnote == NULL || pnote->p_filesz > PAGE_SIZE)
2490 		return (FALSE);
2491 	ASSERT_VOP_LOCKED(imgp->vp, "parse_notes");
2492 	if (pnote->p_offset > PAGE_SIZE ||
2493 	    pnote->p_filesz > PAGE_SIZE - pnote->p_offset) {
2494 		buf = malloc(pnote->p_filesz, M_TEMP, M_NOWAIT);
2495 		if (buf == NULL) {
2496 			VOP_UNLOCK(imgp->vp);
2497 			buf = malloc(pnote->p_filesz, M_TEMP, M_WAITOK);
2498 			vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
2499 		}
2500 		error = vn_rdwr(UIO_READ, imgp->vp, buf, pnote->p_filesz,
2501 		    pnote->p_offset, UIO_SYSSPACE, IO_NODELOCKED,
2502 		    curthread->td_ucred, NOCRED, NULL, curthread);
2503 		if (error != 0) {
2504 			uprintf("i/o error PT_NOTE\n");
2505 			goto retf;
2506 		}
2507 		note = note0 = (const Elf_Note *)buf;
2508 		note_end = (const Elf_Note *)(buf + pnote->p_filesz);
2509 	} else {
2510 		note = note0 = (const Elf_Note *)(imgp->image_header +
2511 		    pnote->p_offset);
2512 		note_end = (const Elf_Note *)(imgp->image_header +
2513 		    pnote->p_offset + pnote->p_filesz);
2514 		buf = NULL;
2515 	}
2516 	for (i = 0; i < 100 && note >= note0 && note < note_end; i++) {
2517 		if (!aligned(note, Elf32_Addr) || (const char *)note_end -
2518 		    (const char *)note < sizeof(Elf_Note)) {
2519 			goto retf;
2520 		}
2521 		if (note->n_namesz != checknote->n_namesz ||
2522 		    note->n_descsz != checknote->n_descsz ||
2523 		    note->n_type != checknote->n_type)
2524 			goto nextnote;
2525 		note_name = (const char *)(note + 1);
2526 		if (note_name + checknote->n_namesz >=
2527 		    (const char *)note_end || strncmp(note_vendor,
2528 		    note_name, checknote->n_namesz) != 0)
2529 			goto nextnote;
2530 
2531 		if (cb(note, cb_arg, &res))
2532 			goto ret;
2533 nextnote:
2534 		note = (const Elf_Note *)((const char *)(note + 1) +
2535 		    roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) +
2536 		    roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE));
2537 	}
2538 retf:
2539 	res = FALSE;
2540 ret:
2541 	free(buf, M_TEMP);
2542 	return (res);
2543 }
2544 
2545 struct brandnote_cb_arg {
2546 	Elf_Brandnote *brandnote;
2547 	int32_t *osrel;
2548 };
2549 
2550 static boolean_t
2551 brandnote_cb(const Elf_Note *note, void *arg0, boolean_t *res)
2552 {
2553 	struct brandnote_cb_arg *arg;
2554 
2555 	arg = arg0;
2556 
2557 	/*
2558 	 * Fetch the osreldate for binary from the ELF OSABI-note if
2559 	 * necessary.
2560 	 */
2561 	*res = (arg->brandnote->flags & BN_TRANSLATE_OSREL) != 0 &&
2562 	    arg->brandnote->trans_osrel != NULL ?
2563 	    arg->brandnote->trans_osrel(note, arg->osrel) : TRUE;
2564 
2565 	return (TRUE);
2566 }
2567 
2568 static Elf_Note fctl_note = {
2569 	.n_namesz = sizeof(FREEBSD_ABI_VENDOR),
2570 	.n_descsz = sizeof(uint32_t),
2571 	.n_type = NT_FREEBSD_FEATURE_CTL,
2572 };
2573 
2574 struct fctl_cb_arg {
2575 	boolean_t *has_fctl0;
2576 	uint32_t *fctl0;
2577 };
2578 
2579 static boolean_t
2580 note_fctl_cb(const Elf_Note *note, void *arg0, boolean_t *res)
2581 {
2582 	struct fctl_cb_arg *arg;
2583 	const Elf32_Word *desc;
2584 	uintptr_t p;
2585 
2586 	arg = arg0;
2587 	p = (uintptr_t)(note + 1);
2588 	p += roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE);
2589 	desc = (const Elf32_Word *)p;
2590 	*arg->has_fctl0 = TRUE;
2591 	*arg->fctl0 = desc[0];
2592 	*res = TRUE;
2593 	return (TRUE);
2594 }
2595 
2596 /*
2597  * Try to find the appropriate ABI-note section for checknote, fetch
2598  * the osreldate and feature control flags for binary from the ELF
2599  * OSABI-note.  Only the first page of the image is searched, the same
2600  * as for headers.
2601  */
2602 static boolean_t
2603 __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *brandnote,
2604     int32_t *osrel, boolean_t *has_fctl0, uint32_t *fctl0)
2605 {
2606 	const Elf_Phdr *phdr;
2607 	const Elf_Ehdr *hdr;
2608 	struct brandnote_cb_arg b_arg;
2609 	struct fctl_cb_arg f_arg;
2610 	int i, j;
2611 
2612 	hdr = (const Elf_Ehdr *)imgp->image_header;
2613 	phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
2614 	b_arg.brandnote = brandnote;
2615 	b_arg.osrel = osrel;
2616 	f_arg.has_fctl0 = has_fctl0;
2617 	f_arg.fctl0 = fctl0;
2618 
2619 	for (i = 0; i < hdr->e_phnum; i++) {
2620 		if (phdr[i].p_type == PT_NOTE && __elfN(parse_notes)(imgp,
2621 		    &brandnote->hdr, brandnote->vendor, &phdr[i], brandnote_cb,
2622 		    &b_arg)) {
2623 			for (j = 0; j < hdr->e_phnum; j++) {
2624 				if (phdr[j].p_type == PT_NOTE &&
2625 				    __elfN(parse_notes)(imgp, &fctl_note,
2626 				    FREEBSD_ABI_VENDOR, &phdr[j],
2627 				    note_fctl_cb, &f_arg))
2628 					break;
2629 			}
2630 			return (TRUE);
2631 		}
2632 	}
2633 	return (FALSE);
2634 
2635 }
2636 
2637 /*
2638  * Tell kern_execve.c about it, with a little help from the linker.
2639  */
2640 static struct execsw __elfN(execsw) = {
2641 	.ex_imgact = __CONCAT(exec_, __elfN(imgact)),
2642 	.ex_name = __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
2643 };
2644 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));
2645 
2646 static vm_prot_t
2647 __elfN(trans_prot)(Elf_Word flags)
2648 {
2649 	vm_prot_t prot;
2650 
2651 	prot = 0;
2652 	if (flags & PF_X)
2653 		prot |= VM_PROT_EXECUTE;
2654 	if (flags & PF_W)
2655 		prot |= VM_PROT_WRITE;
2656 	if (flags & PF_R)
2657 		prot |= VM_PROT_READ;
2658 #if __ELF_WORD_SIZE == 32 && (defined(__amd64__) || defined(__i386__))
2659 	if (i386_read_exec && (flags & PF_R))
2660 		prot |= VM_PROT_EXECUTE;
2661 #endif
2662 	return (prot);
2663 }
2664 
2665 static Elf_Word
2666 __elfN(untrans_prot)(vm_prot_t prot)
2667 {
2668 	Elf_Word flags;
2669 
2670 	flags = 0;
2671 	if (prot & VM_PROT_EXECUTE)
2672 		flags |= PF_X;
2673 	if (prot & VM_PROT_READ)
2674 		flags |= PF_R;
2675 	if (prot & VM_PROT_WRITE)
2676 		flags |= PF_W;
2677 	return (flags);
2678 }
2679 
2680 void
2681 __elfN(stackgap)(struct image_params *imgp, uintptr_t *stack_base)
2682 {
2683 	uintptr_t range, rbase, gap;
2684 	int pct;
2685 
2686 	pct = __elfN(aslr_stack_gap);
2687 	if (pct == 0)
2688 		return;
2689 	if (pct > 50)
2690 		pct = 50;
2691 	range = imgp->eff_stack_sz * pct / 100;
2692 	arc4rand(&rbase, sizeof(rbase), 0);
2693 	gap = rbase % range;
2694 	gap &= ~(sizeof(u_long) - 1);
2695 	*stack_base -= gap;
2696 }
2697