xref: /freebsd/usr.bin/gcore/elfcore.c (revision b3b50e64d7e4c28bd0fd6323591ed811633826e4)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2017 Dell EMC
5  * Copyright (c) 2007 Sandvine Incorporated
6  * Copyright (c) 1998 John D. Polstra
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/endian.h>
35 #include <sys/param.h>
36 #include <sys/procfs.h>
37 #include <sys/ptrace.h>
38 #include <sys/queue.h>
39 #include <sys/linker_set.h>
40 #include <sys/sbuf.h>
41 #include <sys/sysctl.h>
42 #include <sys/user.h>
43 #include <sys/wait.h>
44 #include <machine/elf.h>
45 #include <vm/vm_param.h>
46 #include <vm/vm.h>
47 #include <assert.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <stdbool.h>
52 #include <stdint.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 #include <libutil.h>
58 
59 #include "extern.h"
60 
61 /*
62  * Code for generating ELF core dumps.
63  */
64 
65 struct map_entry {
66 	struct map_entry *next;
67 	vm_offset_t start;
68 	vm_offset_t end;
69 	vm_prot_t protection;
70 };
71 
72 typedef void (*segment_callback)(struct map_entry *, void *);
73 
74 /* Closure for cb_put_phdr(). */
75 struct phdr_closure {
76 	Elf_Phdr *phdr;		/* Program header to fill in */
77 	Elf_Off offset;		/* Offset of segment in core file */
78 };
79 
80 /* Closure for cb_size_segment(). */
81 struct sseg_closure {
82 	int count;		/* Count of writable segments. */
83 	size_t size;		/* Total size of all writable segments. */
84 };
85 
86 #ifdef ELFCORE_COMPAT_32
87 typedef struct fpreg32 elfcore_fpregset_t;
88 typedef struct reg32   elfcore_gregset_t;
89 typedef struct prpsinfo32 elfcore_prpsinfo_t;
90 typedef struct prstatus32 elfcore_prstatus_t;
91 typedef struct ptrace_lwpinfo32 elfcore_lwpinfo_t;
92 static void elf_convert_lwpinfo(struct ptrace_lwpinfo32 *pld,
93     struct ptrace_lwpinfo *pls);
94 #else
95 typedef fpregset_t elfcore_fpregset_t;
96 typedef gregset_t  elfcore_gregset_t;
97 typedef prpsinfo_t elfcore_prpsinfo_t;
98 typedef prstatus_t elfcore_prstatus_t;
99 typedef struct ptrace_lwpinfo elfcore_lwpinfo_t;
100 #define	elf_convert_lwpinfo(d,s)	*d = *s
101 #endif
102 
103 typedef void* (*notefunc_t)(void *, size_t *);
104 
105 static void cb_put_phdr(struct map_entry *, void *);
106 static void cb_size_segment(struct map_entry *, void *);
107 static void each_dumpable_segment(struct map_entry *, segment_callback,
108     void *closure);
109 static void elf_detach(void);	/* atexit() handler. */
110 static void *elf_note_prpsinfo(void *, size_t *);
111 static void *elf_note_thrmisc(void *, size_t *);
112 static void *elf_note_ptlwpinfo(void *, size_t *);
113 #if defined(__arm__)
114 static void *elf_note_arm_vfp(void *, size_t *);
115 #endif
116 #if defined(__i386__) || defined(__amd64__)
117 static void *elf_note_x86_xstate(void *, size_t *);
118 #endif
119 #if defined(__powerpc__)
120 static void *elf_note_powerpc_vmx(void *, size_t *);
121 static void *elf_note_powerpc_vsx(void *, size_t *);
122 #endif
123 static void *elf_note_procstat_auxv(void *, size_t *);
124 static void *elf_note_procstat_files(void *, size_t *);
125 static void *elf_note_procstat_groups(void *, size_t *);
126 static void *elf_note_procstat_osrel(void *, size_t *);
127 static void *elf_note_procstat_proc(void *, size_t *);
128 static void *elf_note_procstat_psstrings(void *, size_t *);
129 static void *elf_note_procstat_rlimit(void *, size_t *);
130 static void *elf_note_procstat_umask(void *, size_t *);
131 static void *elf_note_procstat_vmmap(void *, size_t *);
132 static void elf_puthdr(int, pid_t, struct map_entry *, void *, size_t, size_t,
133     size_t, int);
134 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
135 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
136 static void elf_putregnote(int, lwpid_t, struct sbuf *);
137 static void freemap(struct map_entry *);
138 static struct map_entry *readmap(pid_t);
139 static void *procstat_sysctl(void *, int, size_t, size_t *sizep);
140 
141 static pid_t g_pid;		/* Pid being dumped, global for elf_detach */
142 static int g_status;		/* proc status after ptrace attach */
143 
144 static int
145 elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
146 {
147 	Elf_Ehdr hdr;
148 	int cnt;
149 	uint16_t machine;
150 
151 	cnt = read(efd, &hdr, sizeof(hdr));
152 	if (cnt != sizeof(hdr))
153 		return (0);
154 	if (!IS_ELF(hdr))
155 		return (0);
156 	switch (hdr.e_ident[EI_DATA]) {
157 	case ELFDATA2LSB:
158 		machine = le16toh(hdr.e_machine);
159 		break;
160 	case ELFDATA2MSB:
161 		machine = be16toh(hdr.e_machine);
162 		break;
163 	default:
164 		return (0);
165 	}
166 	if (!ELF_MACHINE_OK(machine))
167 		return (0);
168 
169 	/* Looks good. */
170 	return (1);
171 }
172 
173 static void
174 elf_detach(void)
175 {
176 	int sig;
177 
178 	if (g_pid != 0) {
179 		/*
180 		 * Forward any pending signals. SIGSTOP is generated by ptrace
181 		 * itself, so ignore it.
182 		 */
183 		sig = WIFSTOPPED(g_status) ? WSTOPSIG(g_status) : 0;
184 		if (sig == SIGSTOP)
185 			sig = 0;
186 		ptrace(PT_DETACH, g_pid, (caddr_t)1, sig);
187 	}
188 }
189 
190 /*
191  * Write an ELF coredump for the given pid to the given fd.
192  */
193 static void
194 elf_coredump(int efd, int fd, pid_t pid)
195 {
196 	struct map_entry *map;
197 	struct sseg_closure seginfo;
198 	struct sbuf *sb;
199 	void *hdr;
200 	size_t hdrsize, notesz, segoff;
201 	ssize_t n, old_len;
202 	Elf_Phdr *php;
203 	int i;
204 
205 	/* Attach to process to dump. */
206 	g_pid = pid;
207 	if (atexit(elf_detach) != 0)
208 		err(1, "atexit");
209 	errno = 0;
210 	ptrace(PT_ATTACH, pid, NULL, 0);
211 	if (errno)
212 		err(1, "PT_ATTACH");
213 	if (waitpid(pid, &g_status, 0) == -1)
214 		err(1, "waitpid");
215 
216 	/* Get the program's memory map. */
217 	map = readmap(pid);
218 
219 	/* Size the program segments. */
220 	seginfo.count = 0;
221 	seginfo.size = 0;
222 	each_dumpable_segment(map, cb_size_segment, &seginfo);
223 
224 	/*
225 	 * Build the header and the notes using sbuf and write to the file.
226 	 */
227 	sb = sbuf_new_auto();
228 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
229 	if (seginfo.count + 1 >= PN_XNUM)
230 		hdrsize += sizeof(Elf_Shdr);
231 	/* Start header + notes section. */
232 	sbuf_start_section(sb, NULL);
233 	/* Make empty header subsection. */
234 	sbuf_start_section(sb, &old_len);
235 	sbuf_putc(sb, 0);
236 	sbuf_end_section(sb, old_len, hdrsize, 0);
237 	/* Put notes. */
238 	elf_putnotes(pid, sb, &notesz);
239 	/* Align up to a page boundary for the program segments. */
240 	sbuf_end_section(sb, -1, PAGE_SIZE, 0);
241 	if (sbuf_finish(sb) != 0)
242 		err(1, "sbuf_finish");
243 	hdr = sbuf_data(sb);
244 	segoff = sbuf_len(sb);
245 	/* Fill in the header. */
246 	elf_puthdr(efd, pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
247 
248 	n = write(fd, hdr, segoff);
249 	if (n == -1)
250 		err(1, "write");
251 	if (n < segoff)
252               errx(1, "short write");
253 
254 	/* Write the contents of all of the writable segments. */
255 	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
256 	for (i = 0;  i < seginfo.count;  i++) {
257 		struct ptrace_io_desc iorequest;
258 		uintmax_t nleft = php->p_filesz;
259 
260 		iorequest.piod_op = PIOD_READ_D;
261 		iorequest.piod_offs = (caddr_t)(uintptr_t)php->p_vaddr;
262 		while (nleft > 0) {
263 			char buf[8*1024];
264 			size_t nwant;
265 			ssize_t ngot;
266 
267 			if (nleft > sizeof(buf))
268 				nwant = sizeof buf;
269 			else
270 				nwant = nleft;
271 			iorequest.piod_addr = buf;
272 			iorequest.piod_len = nwant;
273 			ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
274 			ngot = iorequest.piod_len;
275 			if ((size_t)ngot < nwant)
276 				errx(1, "short read wanted %zu, got %zd",
277 				    nwant, ngot);
278 			ngot = write(fd, buf, nwant);
279 			if (ngot == -1)
280 				err(1, "write of segment %d failed", i);
281 			if ((size_t)ngot != nwant)
282 				errx(1, "short write");
283 			nleft -= nwant;
284 			iorequest.piod_offs += ngot;
285 		}
286 		php++;
287 	}
288 	sbuf_delete(sb);
289 	freemap(map);
290 }
291 
292 /*
293  * A callback for each_dumpable_segment() to write out the segment's
294  * program header entry.
295  */
296 static void
297 cb_put_phdr(struct map_entry *entry, void *closure)
298 {
299 	struct phdr_closure *phc = (struct phdr_closure *)closure;
300 	Elf_Phdr *phdr = phc->phdr;
301 
302 	phc->offset = round_page(phc->offset);
303 
304 	phdr->p_type = PT_LOAD;
305 	phdr->p_offset = phc->offset;
306 	phdr->p_vaddr = entry->start;
307 	phdr->p_paddr = 0;
308 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
309 	phdr->p_align = PAGE_SIZE;
310 	phdr->p_flags = 0;
311 	if (entry->protection & VM_PROT_READ)
312 		phdr->p_flags |= PF_R;
313 	if (entry->protection & VM_PROT_WRITE)
314 		phdr->p_flags |= PF_W;
315 	if (entry->protection & VM_PROT_EXECUTE)
316 		phdr->p_flags |= PF_X;
317 
318 	phc->offset += phdr->p_filesz;
319 	phc->phdr++;
320 }
321 
322 /*
323  * A callback for each_dumpable_segment() to gather information about
324  * the number of segments and their total size.
325  */
326 static void
327 cb_size_segment(struct map_entry *entry, void *closure)
328 {
329 	struct sseg_closure *ssc = (struct sseg_closure *)closure;
330 
331 	ssc->count++;
332 	ssc->size += entry->end - entry->start;
333 }
334 
335 /*
336  * For each segment in the given memory map, call the given function
337  * with a pointer to the map entry and some arbitrary caller-supplied
338  * data.
339  */
340 static void
341 each_dumpable_segment(struct map_entry *map, segment_callback func,
342     void *closure)
343 {
344 	struct map_entry *entry;
345 
346 	for (entry = map; entry != NULL; entry = entry->next)
347 		(*func)(entry, closure);
348 }
349 
350 static void
351 elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
352 {
353 	lwpid_t *tids;
354 	size_t threads, old_len;
355 	ssize_t size;
356 	int i;
357 
358 	errno = 0;
359 	threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
360 	if (errno)
361 		err(1, "PT_GETNUMLWPS");
362 	tids = malloc(threads * sizeof(*tids));
363 	if (tids == NULL)
364 		errx(1, "out of memory");
365 	errno = 0;
366 	ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
367 	if (errno)
368 		err(1, "PT_GETLWPLIST");
369 
370 	sbuf_start_section(sb, &old_len);
371 	elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);
372 
373 	for (i = 0; i < threads; ++i) {
374 		elf_putregnote(NT_PRSTATUS, tids[i], sb);
375 		elf_putregnote(NT_FPREGSET, tids[i], sb);
376 		elf_putnote(NT_THRMISC, elf_note_thrmisc, tids + i, sb);
377 		elf_putnote(NT_PTLWPINFO, elf_note_ptlwpinfo, tids + i, sb);
378 #if defined(__arm__)
379 		elf_putnote(NT_ARM_VFP, elf_note_arm_vfp, tids + i, sb);
380 #endif
381 #if defined(__i386__) || defined(__amd64__)
382 		elf_putnote(NT_X86_XSTATE, elf_note_x86_xstate, tids + i, sb);
383 #endif
384 #if defined(__powerpc__)
385 		elf_putnote(NT_PPC_VMX, elf_note_powerpc_vmx, tids + i, sb);
386 #ifndef __SPE__
387 		elf_putnote(NT_PPC_VSX, elf_note_powerpc_vsx, tids + i, sb);
388 #endif
389 #endif
390 	}
391 
392 #ifndef ELFCORE_COMPAT_32
393 	elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
394 	elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
395 	elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
396 	elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
397 	elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
398 	elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
399 	elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
400 	elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
401 	    sb);
402 	elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
403 #endif
404 
405 	size = sbuf_end_section(sb, old_len, 1, 0);
406 	if (size == -1)
407 		err(1, "sbuf_end_section");
408 	free(tids);
409 	*sizep = size;
410 }
411 
412 /*
413  * Emit one register set note section to sbuf.
414  */
415 static void
416 elf_putregnote(int type, lwpid_t tid, struct sbuf *sb)
417 {
418 	Elf_Note note;
419 	struct iovec iov;
420 	ssize_t old_len;
421 
422 	iov.iov_base = NULL;
423 	iov.iov_len = 0;
424 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
425 		return;
426 	iov.iov_base = calloc(1, iov.iov_len);
427 	if (iov.iov_base == NULL)
428 		errx(1, "out of memory");
429 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
430 		errx(1, "failed to fetch register set %d", type);
431 
432 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
433 	note.n_descsz = iov.iov_len;
434 	note.n_type = type;
435 
436 	sbuf_bcat(sb, &note, sizeof(note));
437 	sbuf_start_section(sb, &old_len);
438 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
439 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
440 	sbuf_start_section(sb, &old_len);
441 	sbuf_bcat(sb, iov.iov_base, iov.iov_len);
442 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
443 	free(iov.iov_base);
444 }
445 
446 /*
447  * Emit one note section to sbuf.
448  */
449 static void
450 elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
451 {
452 	Elf_Note note;
453 	size_t descsz;
454 	ssize_t old_len;
455 	void *desc;
456 
457 	desc = notefunc(arg, &descsz);
458 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
459 	note.n_descsz = descsz;
460 	note.n_type = type;
461 
462 	sbuf_bcat(sb, &note, sizeof(note));
463 	sbuf_start_section(sb, &old_len);
464 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
465 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
466 	if (descsz == 0)
467 		return;
468 	sbuf_start_section(sb, &old_len);
469 	sbuf_bcat(sb, desc, descsz);
470 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
471 	free(desc);
472 }
473 
474 /*
475  * Generate the ELF coredump header.
476  */
477 static void
478 elf_puthdr(int efd, pid_t pid, struct map_entry *map, void *hdr, size_t hdrsize,
479     size_t notesz, size_t segoff, int numsegs)
480 {
481 	Elf_Ehdr *ehdr, binhdr;
482 	Elf_Phdr *phdr;
483 	Elf_Shdr *shdr;
484 	struct phdr_closure phc;
485 	ssize_t cnt;
486 
487 	cnt = read(efd, &binhdr, sizeof(binhdr));
488 	if (cnt < 0)
489 		err(1, "Failed to re-read ELF header");
490 	else if (cnt != sizeof(binhdr))
491 		errx(1, "Failed to re-read ELF header");
492 
493 	ehdr = (Elf_Ehdr *)hdr;
494 
495 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
496 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
497 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
498 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
499 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
500 	ehdr->e_ident[EI_DATA] = ELF_DATA;
501 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
502 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
503 	ehdr->e_ident[EI_ABIVERSION] = 0;
504 	ehdr->e_ident[EI_PAD] = 0;
505 	ehdr->e_type = ET_CORE;
506 	ehdr->e_machine = binhdr.e_machine;
507 	ehdr->e_version = EV_CURRENT;
508 	ehdr->e_entry = 0;
509 	ehdr->e_phoff = sizeof(Elf_Ehdr);
510 	ehdr->e_flags = binhdr.e_flags;
511 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
512 	ehdr->e_phentsize = sizeof(Elf_Phdr);
513 	ehdr->e_shentsize = sizeof(Elf_Shdr);
514 	ehdr->e_shstrndx = SHN_UNDEF;
515 	if (numsegs + 1 < PN_XNUM) {
516 		ehdr->e_phnum = numsegs + 1;
517 		ehdr->e_shnum = 0;
518 	} else {
519 		ehdr->e_phnum = PN_XNUM;
520 		ehdr->e_shnum = 1;
521 
522 		ehdr->e_shoff = ehdr->e_phoff +
523 		    (numsegs + 1) * ehdr->e_phentsize;
524 
525 		shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
526 		memset(shdr, 0, sizeof(*shdr));
527 		/*
528 		 * A special first section is used to hold large segment and
529 		 * section counts.  This was proposed by Sun Microsystems in
530 		 * Solaris and has been adopted by Linux; the standard ELF
531 		 * tools are already familiar with the technique.
532 		 *
533 		 * See table 7-7 of the Solaris "Linker and Libraries Guide"
534 		 * (or 12-7 depending on the version of the document) for more
535 		 * details.
536 		 */
537 		shdr->sh_type = SHT_NULL;
538 		shdr->sh_size = ehdr->e_shnum;
539 		shdr->sh_link = ehdr->e_shstrndx;
540 		shdr->sh_info = numsegs + 1;
541 	}
542 
543 	/*
544 	 * Fill in the program header entries.
545 	 */
546 	phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);
547 
548 	/* The note segment. */
549 	phdr->p_type = PT_NOTE;
550 	phdr->p_offset = hdrsize;
551 	phdr->p_vaddr = 0;
552 	phdr->p_paddr = 0;
553 	phdr->p_filesz = notesz;
554 	phdr->p_memsz = 0;
555 	phdr->p_flags = PF_R;
556 	phdr->p_align = sizeof(Elf32_Size);
557 	phdr++;
558 
559 	/* All the writable segments from the program. */
560 	phc.phdr = phdr;
561 	phc.offset = segoff;
562 	each_dumpable_segment(map, cb_put_phdr, &phc);
563 }
564 
565 /*
566  * Free the memory map.
567  */
568 static void
569 freemap(struct map_entry *map)
570 {
571 	struct map_entry *next;
572 
573 	while (map != NULL) {
574 		next = map->next;
575 		free(map);
576 		map = next;
577 	}
578 }
579 
580 /*
581  * Read the process's memory map using kinfo_getvmmap(), and return a list of
582  * VM map entries.  Only the non-device read/writable segments are
583  * returned.  The map entries in the list aren't fully filled in; only
584  * the items we need are present.
585  */
586 static struct map_entry *
587 readmap(pid_t pid)
588 {
589 	struct map_entry *ent, **linkp, *map;
590 	struct kinfo_vmentry *vmentl, *kve;
591 	int i, nitems;
592 
593 	vmentl = kinfo_getvmmap(pid, &nitems);
594 	if (vmentl == NULL)
595 		err(1, "cannot retrieve mappings for %u process", pid);
596 
597 	map = NULL;
598 	linkp = &map;
599 	for (i = 0; i < nitems; i++) {
600 		kve = &vmentl[i];
601 
602 		/*
603 		 * Ignore 'malformed' segments or ones representing memory
604 		 * mapping with MAP_NOCORE on.
605 		 * If the 'full' support is disabled, just dump the most
606 		 * meaningful data segments.
607 		 */
608 		if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
609 		    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
610 		    kve->kve_type == KVME_TYPE_DEAD ||
611 		    kve->kve_type == KVME_TYPE_UNKNOWN ||
612 		    ((pflags & PFLAGS_FULL) == 0 &&
613 		    kve->kve_type != KVME_TYPE_DEFAULT &&
614 		    kve->kve_type != KVME_TYPE_VNODE &&
615 		    kve->kve_type != KVME_TYPE_SWAP &&
616 		    kve->kve_type != KVME_TYPE_PHYS))
617 			continue;
618 
619 		ent = calloc(1, sizeof(*ent));
620 		if (ent == NULL)
621 			errx(1, "out of memory");
622 		ent->start = (vm_offset_t)kve->kve_start;
623 		ent->end = (vm_offset_t)kve->kve_end;
624 		ent->protection = VM_PROT_READ | VM_PROT_WRITE;
625 		if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
626 			ent->protection |= VM_PROT_EXECUTE;
627 
628 		*linkp = ent;
629 		linkp = &ent->next;
630 	}
631 	free(vmentl);
632 	return (map);
633 }
634 
635 /*
636  * Miscellaneous note out functions.
637  */
638 
639 static void *
640 elf_note_prpsinfo(void *arg, size_t *sizep)
641 {
642 	char *cp, *end;
643 	pid_t pid;
644 	elfcore_prpsinfo_t *psinfo;
645 	struct kinfo_proc kip;
646 	size_t len;
647 	int name[4];
648 
649 	pid = *(pid_t *)arg;
650 	psinfo = calloc(1, sizeof(*psinfo));
651 	if (psinfo == NULL)
652 		errx(1, "out of memory");
653 	psinfo->pr_version = PRPSINFO_VERSION;
654 	psinfo->pr_psinfosz = sizeof(*psinfo);
655 
656 	name[0] = CTL_KERN;
657 	name[1] = KERN_PROC;
658 	name[2] = KERN_PROC_PID;
659 	name[3] = pid;
660 	len = sizeof(kip);
661 	if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
662 		err(1, "kern.proc.pid.%u", pid);
663 	if (kip.ki_pid != pid)
664 		err(1, "kern.proc.pid.%u", pid);
665 	strlcpy(psinfo->pr_fname, kip.ki_comm, sizeof(psinfo->pr_fname));
666 	name[2] = KERN_PROC_ARGS;
667 	len = sizeof(psinfo->pr_psargs) - 1;
668 	if (sysctl(name, 4, psinfo->pr_psargs, &len, NULL, 0) == 0 && len > 0) {
669 		cp = psinfo->pr_psargs;
670 		end = cp + len - 1;
671 		for (;;) {
672 			cp = memchr(cp, '\0', end - cp);
673 			if (cp == NULL)
674 				break;
675 			*cp = ' ';
676 		}
677 	} else
678 		strlcpy(psinfo->pr_psargs, kip.ki_comm,
679 		    sizeof(psinfo->pr_psargs));
680 	psinfo->pr_pid = pid;
681 
682 	*sizep = sizeof(*psinfo);
683 	return (psinfo);
684 }
685 
686 static void *
687 elf_note_thrmisc(void *arg, size_t *sizep)
688 {
689 	lwpid_t tid;
690 	struct ptrace_lwpinfo lwpinfo;
691 	thrmisc_t *thrmisc;
692 
693 	tid = *(lwpid_t *)arg;
694 	thrmisc = calloc(1, sizeof(*thrmisc));
695 	if (thrmisc == NULL)
696 		errx(1, "out of memory");
697 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo,
698 	    sizeof(lwpinfo));
699 	memset(&thrmisc->_pad, 0, sizeof(thrmisc->_pad));
700 	strcpy(thrmisc->pr_tname, lwpinfo.pl_tdname);
701 
702 	*sizep = sizeof(*thrmisc);
703 	return (thrmisc);
704 }
705 
706 static void *
707 elf_note_ptlwpinfo(void *arg, size_t *sizep)
708 {
709 	lwpid_t tid;
710 	elfcore_lwpinfo_t *elf_info;
711 	struct ptrace_lwpinfo lwpinfo;
712 	void *p;
713 
714 	tid = *(lwpid_t *)arg;
715 	p = calloc(1, sizeof(int) + sizeof(elfcore_lwpinfo_t));
716 	if (p == NULL)
717 		errx(1, "out of memory");
718 	*(int *)p = sizeof(elfcore_lwpinfo_t);
719 	elf_info = (void *)((int *)p + 1);
720 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo, sizeof(lwpinfo));
721 	elf_convert_lwpinfo(elf_info, &lwpinfo);
722 
723 	*sizep = sizeof(int) + sizeof(struct ptrace_lwpinfo);
724 	return (p);
725 }
726 
727 #if defined(__arm__)
728 static void *
729 elf_note_arm_vfp(void *arg, size_t *sizep)
730 {
731 	lwpid_t tid;
732 	struct vfpreg *vfp;
733 	static bool has_vfp = true;
734 	struct vfpreg info;
735 
736 	tid = *(lwpid_t *)arg;
737 	if (has_vfp) {
738 		if (ptrace(PT_GETVFPREGS, tid, (void *)&info, 0) != 0)
739 			has_vfp = false;
740 	}
741 	if (!has_vfp) {
742 		*sizep = 0;
743 		return (NULL);
744 	}
745 	vfp = calloc(1, sizeof(*vfp));
746 	memcpy(vfp, &info, sizeof(*vfp));
747 	*sizep = sizeof(*vfp);
748 	return (vfp);
749 }
750 #endif
751 
752 #if defined(__i386__) || defined(__amd64__)
753 static void *
754 elf_note_x86_xstate(void *arg, size_t *sizep)
755 {
756 	lwpid_t tid;
757 	char *xstate;
758 	static bool xsave_checked = false;
759 	static struct ptrace_xstate_info info;
760 
761 	tid = *(lwpid_t *)arg;
762 	if (!xsave_checked) {
763 		if (ptrace(PT_GETXSTATE_INFO, tid, (void *)&info,
764 		    sizeof(info)) != 0)
765 			info.xsave_len = 0;
766 		xsave_checked = true;
767 	}
768 	if (info.xsave_len == 0) {
769 		*sizep = 0;
770 		return (NULL);
771 	}
772 	xstate = calloc(1, info.xsave_len);
773 	ptrace(PT_GETXSTATE, tid, xstate, 0);
774 	*(uint64_t *)(xstate + X86_XSTATE_XCR0_OFFSET) = info.xsave_mask;
775 	*sizep = info.xsave_len;
776 	return (xstate);
777 }
778 #endif
779 
780 #if defined(__powerpc__)
781 static void *
782 elf_note_powerpc_vmx(void *arg, size_t *sizep)
783 {
784 	lwpid_t tid;
785 	struct vmxreg *vmx;
786 	static bool has_vmx = true;
787 	struct vmxreg info;
788 
789 	tid = *(lwpid_t *)arg;
790 	if (has_vmx) {
791 		if (ptrace(PT_GETVRREGS, tid, (void *)&info,
792 		    sizeof(info)) != 0)
793 			has_vmx = false;
794 	}
795 	if (!has_vmx) {
796 		*sizep = 0;
797 		return (NULL);
798 	}
799 	vmx = calloc(1, sizeof(*vmx));
800 	memcpy(vmx, &info, sizeof(*vmx));
801 	*sizep = sizeof(*vmx);
802 	return (vmx);
803 }
804 
805 static void *
806 elf_note_powerpc_vsx(void *arg, size_t *sizep)
807 {
808 	lwpid_t tid;
809 	char *vshr_data;
810 	static bool has_vsx = true;
811 	uint64_t vshr[32];
812 
813 	tid = *(lwpid_t *)arg;
814 	if (has_vsx) {
815 		if (ptrace(PT_GETVSRREGS, tid, (void *)vshr,
816 		    sizeof(vshr)) != 0)
817 			has_vsx = false;
818 	}
819 	if (!has_vsx) {
820 		*sizep = 0;
821 		return (NULL);
822 	}
823 	vshr_data = calloc(1, sizeof(vshr));
824 	memcpy(vshr_data, vshr, sizeof(vshr));
825 	*sizep = sizeof(vshr);
826 	return (vshr_data);
827 }
828 #endif
829 
830 static void *
831 procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
832 {
833 	size_t len;
834 	pid_t pid;
835 	int name[4], structsize;
836 	void *buf, *p;
837 
838 	pid = *(pid_t *)arg;
839 	structsize = structsz;
840 	name[0] = CTL_KERN;
841 	name[1] = KERN_PROC;
842 	name[2] = what;
843 	name[3] = pid;
844 	len = 0;
845 	if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
846 		err(1, "kern.proc.%d.%u", what, pid);
847 	buf = calloc(1, sizeof(structsize) + len * 4 / 3);
848 	if (buf == NULL)
849 		errx(1, "out of memory");
850 	bcopy(&structsize, buf, sizeof(structsize));
851 	p = (char *)buf + sizeof(structsize);
852 	if (sysctl(name, 4, p, &len, NULL, 0) == -1)
853 		err(1, "kern.proc.%d.%u", what, pid);
854 
855 	*sizep = sizeof(structsize) + len;
856 	return (buf);
857 }
858 
859 static void *
860 elf_note_procstat_proc(void *arg, size_t *sizep)
861 {
862 
863 	return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
864 	    sizeof(struct kinfo_proc), sizep));
865 }
866 
867 static void *
868 elf_note_procstat_files(void *arg, size_t *sizep)
869 {
870 
871 	return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
872 	    sizeof(struct kinfo_file), sizep));
873 }
874 
875 static void *
876 elf_note_procstat_vmmap(void *arg, size_t *sizep)
877 {
878 
879 	return (procstat_sysctl(arg, KERN_PROC_VMMAP,
880 	    sizeof(struct kinfo_vmentry), sizep));
881 }
882 
883 static void *
884 elf_note_procstat_groups(void *arg, size_t *sizep)
885 {
886 
887 	return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
888 }
889 
890 static void *
891 elf_note_procstat_umask(void *arg, size_t *sizep)
892 {
893 
894 	return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
895 }
896 
897 static void *
898 elf_note_procstat_osrel(void *arg, size_t *sizep)
899 {
900 
901 	return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
902 }
903 
904 static void *
905 elf_note_procstat_psstrings(void *arg, size_t *sizep)
906 {
907 
908 	return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
909 	    sizeof(vm_offset_t), sizep));
910 }
911 
912 static void *
913 elf_note_procstat_auxv(void *arg, size_t *sizep)
914 {
915 
916 	return (procstat_sysctl(arg, KERN_PROC_AUXV,
917 	    sizeof(Elf_Auxinfo), sizep));
918 }
919 
920 static void *
921 elf_note_procstat_rlimit(void *arg, size_t *sizep)
922 {
923 	pid_t pid;
924 	size_t len;
925 	int i, name[5], structsize;
926 	void *buf, *p;
927 
928 	pid = *(pid_t *)arg;
929 	structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
930 	buf = calloc(1, sizeof(structsize) + structsize);
931 	if (buf == NULL)
932 		errx(1, "out of memory");
933 	bcopy(&structsize, buf, sizeof(structsize));
934 	p = (char *)buf + sizeof(structsize);
935 	name[0] = CTL_KERN;
936 	name[1] = KERN_PROC;
937 	name[2] = KERN_PROC_RLIMIT;
938 	name[3] = pid;
939 	len = sizeof(struct rlimit);
940 	for (i = 0; i < RLIM_NLIMITS; i++) {
941 		name[4] = i;
942 		if (sysctl(name, 5, p, &len, NULL, 0) == -1)
943 			err(1, "kern.proc.rlimit.%u", pid);
944 		if (len != sizeof(struct rlimit))
945 			errx(1, "kern.proc.rlimit.%u: short read", pid);
946 		p += len;
947 	}
948 
949 	*sizep = sizeof(structsize) + structsize;
950 	return (buf);
951 }
952 
953 struct dumpers __elfN(dump) = { elf_ident, elf_coredump };
954 TEXT_SET(dumpset, __elfN(dump));
955