xref: /freebsd/usr.bin/gcore/elfcore.c (revision 3e8eb5c7f4909209c042403ddee340b2ee7003a5)
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(__i386__) || defined(__amd64__)
114 static void *elf_note_x86_xstate(void *, size_t *);
115 #endif
116 #if defined(__powerpc__)
117 static void *elf_note_powerpc_vmx(void *, size_t *);
118 static void *elf_note_powerpc_vsx(void *, size_t *);
119 #endif
120 static void *elf_note_procstat_auxv(void *, size_t *);
121 static void *elf_note_procstat_files(void *, size_t *);
122 static void *elf_note_procstat_groups(void *, size_t *);
123 static void *elf_note_procstat_osrel(void *, size_t *);
124 static void *elf_note_procstat_proc(void *, size_t *);
125 static void *elf_note_procstat_psstrings(void *, size_t *);
126 static void *elf_note_procstat_rlimit(void *, size_t *);
127 static void *elf_note_procstat_umask(void *, size_t *);
128 static void *elf_note_procstat_vmmap(void *, size_t *);
129 static void elf_puthdr(int, pid_t, struct map_entry *, void *, size_t, size_t,
130     size_t, int);
131 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
132 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
133 static void elf_putregnote(int, lwpid_t, struct sbuf *);
134 static void freemap(struct map_entry *);
135 static struct map_entry *readmap(pid_t);
136 static void *procstat_sysctl(void *, int, size_t, size_t *sizep);
137 
138 static pid_t g_pid;		/* Pid being dumped, global for elf_detach */
139 static int g_status;		/* proc status after ptrace attach */
140 
141 static int
142 elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
143 {
144 	Elf_Ehdr hdr;
145 	int cnt;
146 	uint16_t machine;
147 
148 	cnt = read(efd, &hdr, sizeof(hdr));
149 	if (cnt != sizeof(hdr))
150 		return (0);
151 	if (!IS_ELF(hdr))
152 		return (0);
153 	switch (hdr.e_ident[EI_DATA]) {
154 	case ELFDATA2LSB:
155 		machine = le16toh(hdr.e_machine);
156 		break;
157 	case ELFDATA2MSB:
158 		machine = be16toh(hdr.e_machine);
159 		break;
160 	default:
161 		return (0);
162 	}
163 	if (!ELF_MACHINE_OK(machine))
164 		return (0);
165 
166 	/* Looks good. */
167 	return (1);
168 }
169 
170 static void
171 elf_detach(void)
172 {
173 	int sig;
174 
175 	if (g_pid != 0) {
176 		/*
177 		 * Forward any pending signals. SIGSTOP is generated by ptrace
178 		 * itself, so ignore it.
179 		 */
180 		sig = WIFSTOPPED(g_status) ? WSTOPSIG(g_status) : 0;
181 		if (sig == SIGSTOP)
182 			sig = 0;
183 		ptrace(PT_DETACH, g_pid, (caddr_t)1, sig);
184 	}
185 }
186 
187 /*
188  * Write an ELF coredump for the given pid to the given fd.
189  */
190 static void
191 elf_coredump(int efd, int fd, pid_t pid)
192 {
193 	struct map_entry *map;
194 	struct sseg_closure seginfo;
195 	struct sbuf *sb;
196 	void *hdr;
197 	size_t hdrsize, notesz, segoff;
198 	ssize_t n, old_len;
199 	Elf_Phdr *php;
200 	int i;
201 
202 	/* Attach to process to dump. */
203 	g_pid = pid;
204 	if (atexit(elf_detach) != 0)
205 		err(1, "atexit");
206 	errno = 0;
207 	ptrace(PT_ATTACH, pid, NULL, 0);
208 	if (errno)
209 		err(1, "PT_ATTACH");
210 	if (waitpid(pid, &g_status, 0) == -1)
211 		err(1, "waitpid");
212 
213 	/* Get the program's memory map. */
214 	map = readmap(pid);
215 
216 	/* Size the program segments. */
217 	seginfo.count = 0;
218 	seginfo.size = 0;
219 	each_dumpable_segment(map, cb_size_segment, &seginfo);
220 
221 	/*
222 	 * Build the header and the notes using sbuf and write to the file.
223 	 */
224 	sb = sbuf_new_auto();
225 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
226 	if (seginfo.count + 1 >= PN_XNUM)
227 		hdrsize += sizeof(Elf_Shdr);
228 	/* Start header + notes section. */
229 	sbuf_start_section(sb, NULL);
230 	/* Make empty header subsection. */
231 	sbuf_start_section(sb, &old_len);
232 	sbuf_putc(sb, 0);
233 	sbuf_end_section(sb, old_len, hdrsize, 0);
234 	/* Put notes. */
235 	elf_putnotes(pid, sb, &notesz);
236 	/* Align up to a page boundary for the program segments. */
237 	sbuf_end_section(sb, -1, getpagesize(), 0);
238 	if (sbuf_finish(sb) != 0)
239 		err(1, "sbuf_finish");
240 	hdr = sbuf_data(sb);
241 	segoff = sbuf_len(sb);
242 	/* Fill in the header. */
243 	elf_puthdr(efd, pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
244 
245 	n = write(fd, hdr, segoff);
246 	if (n == -1)
247 		err(1, "write");
248 	if (n < segoff)
249               errx(1, "short write");
250 
251 	/* Write the contents of all of the writable segments. */
252 	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
253 	for (i = 0;  i < seginfo.count;  i++) {
254 		struct ptrace_io_desc iorequest;
255 		uintmax_t nleft = php->p_filesz;
256 
257 		iorequest.piod_op = PIOD_READ_D;
258 		iorequest.piod_offs = (caddr_t)(uintptr_t)php->p_vaddr;
259 		while (nleft > 0) {
260 			char buf[8*1024];
261 			size_t nwant;
262 			ssize_t ngot;
263 
264 			if (nleft > sizeof(buf))
265 				nwant = sizeof buf;
266 			else
267 				nwant = nleft;
268 			iorequest.piod_addr = buf;
269 			iorequest.piod_len = nwant;
270 			ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
271 			ngot = iorequest.piod_len;
272 			if ((size_t)ngot < nwant)
273 				errx(1, "short read wanted %zu, got %zd",
274 				    nwant, ngot);
275 			ngot = write(fd, buf, nwant);
276 			if (ngot == -1)
277 				err(1, "write of segment %d failed", i);
278 			if ((size_t)ngot != nwant)
279 				errx(1, "short write");
280 			nleft -= nwant;
281 			iorequest.piod_offs += ngot;
282 		}
283 		php++;
284 	}
285 	sbuf_delete(sb);
286 	freemap(map);
287 }
288 
289 /*
290  * A callback for each_dumpable_segment() to write out the segment's
291  * program header entry.
292  */
293 static void
294 cb_put_phdr(struct map_entry *entry, void *closure)
295 {
296 	struct phdr_closure *phc = (struct phdr_closure *)closure;
297 	Elf_Phdr *phdr = phc->phdr;
298 	size_t page_size;
299 
300 	page_size = getpagesize();
301 	phc->offset = roundup2(phc->offset, page_size);
302 
303 	phdr->p_type = PT_LOAD;
304 	phdr->p_offset = phc->offset;
305 	phdr->p_vaddr = entry->start;
306 	phdr->p_paddr = 0;
307 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
308 	phdr->p_align = page_size;
309 	phdr->p_flags = 0;
310 	if (entry->protection & VM_PROT_READ)
311 		phdr->p_flags |= PF_R;
312 	if (entry->protection & VM_PROT_WRITE)
313 		phdr->p_flags |= PF_W;
314 	if (entry->protection & VM_PROT_EXECUTE)
315 		phdr->p_flags |= PF_X;
316 
317 	phc->offset += phdr->p_filesz;
318 	phc->phdr++;
319 }
320 
321 /*
322  * A callback for each_dumpable_segment() to gather information about
323  * the number of segments and their total size.
324  */
325 static void
326 cb_size_segment(struct map_entry *entry, void *closure)
327 {
328 	struct sseg_closure *ssc = (struct sseg_closure *)closure;
329 
330 	ssc->count++;
331 	ssc->size += entry->end - entry->start;
332 }
333 
334 /*
335  * For each segment in the given memory map, call the given function
336  * with a pointer to the map entry and some arbitrary caller-supplied
337  * data.
338  */
339 static void
340 each_dumpable_segment(struct map_entry *map, segment_callback func,
341     void *closure)
342 {
343 	struct map_entry *entry;
344 
345 	for (entry = map; entry != NULL; entry = entry->next)
346 		(*func)(entry, closure);
347 }
348 
349 static void
350 elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
351 {
352 	lwpid_t *tids;
353 	size_t threads, old_len;
354 	ssize_t size;
355 	int i;
356 
357 	errno = 0;
358 	threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
359 	if (errno)
360 		err(1, "PT_GETNUMLWPS");
361 	tids = malloc(threads * sizeof(*tids));
362 	if (tids == NULL)
363 		errx(1, "out of memory");
364 	errno = 0;
365 	ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
366 	if (errno)
367 		err(1, "PT_GETLWPLIST");
368 
369 	sbuf_start_section(sb, &old_len);
370 	elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);
371 
372 	for (i = 0; i < threads; ++i) {
373 		elf_putregnote(NT_PRSTATUS, tids[i], sb);
374 		elf_putregnote(NT_FPREGSET, tids[i], sb);
375 		elf_putnote(NT_THRMISC, elf_note_thrmisc, tids + i, sb);
376 		elf_putnote(NT_PTLWPINFO, elf_note_ptlwpinfo, tids + i, sb);
377 #if defined(__aarch64__) || defined(__arm__)
378 		elf_putregnote(NT_ARM_TLS, tids[i], sb);
379 #endif
380 #if (defined(ELFCORE_COMPAT_32) && defined(__aarch64__)) || defined(__arm__)
381 		elf_putregnote(NT_ARM_VFP, tids[i], sb);
382 #endif
383 #if defined(__i386__) || defined(__amd64__)
384 		elf_putregnote(NT_X86_SEGBASES, tids[i], sb);
385 		elf_putnote(NT_X86_XSTATE, elf_note_x86_xstate, tids + i, sb);
386 #endif
387 #if defined(__powerpc__)
388 		elf_putnote(NT_PPC_VMX, elf_note_powerpc_vmx, tids + i, sb);
389 #ifndef __SPE__
390 		elf_putnote(NT_PPC_VSX, elf_note_powerpc_vsx, tids + i, sb);
391 #endif
392 #endif
393 	}
394 
395 #ifndef ELFCORE_COMPAT_32
396 	elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
397 	elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
398 	elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
399 	elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
400 	elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
401 	elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
402 	elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
403 	elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
404 	    sb);
405 	elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
406 #endif
407 
408 	size = sbuf_end_section(sb, old_len, 1, 0);
409 	if (size == -1)
410 		err(1, "sbuf_end_section");
411 	free(tids);
412 	*sizep = size;
413 }
414 
415 /*
416  * Emit one register set note section to sbuf.
417  */
418 static void
419 elf_putregnote(int type, lwpid_t tid, struct sbuf *sb)
420 {
421 	Elf_Note note;
422 	struct iovec iov;
423 	ssize_t old_len;
424 
425 	iov.iov_base = NULL;
426 	iov.iov_len = 0;
427 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
428 		return;
429 	iov.iov_base = calloc(1, iov.iov_len);
430 	if (iov.iov_base == NULL)
431 		errx(1, "out of memory");
432 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
433 		errx(1, "failed to fetch register set %d", type);
434 
435 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
436 	note.n_descsz = iov.iov_len;
437 	note.n_type = type;
438 
439 	sbuf_bcat(sb, &note, sizeof(note));
440 	sbuf_start_section(sb, &old_len);
441 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
442 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
443 	sbuf_start_section(sb, &old_len);
444 	sbuf_bcat(sb, iov.iov_base, iov.iov_len);
445 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
446 	free(iov.iov_base);
447 }
448 
449 /*
450  * Emit one note section to sbuf.
451  */
452 static void
453 elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
454 {
455 	Elf_Note note;
456 	size_t descsz;
457 	ssize_t old_len;
458 	void *desc;
459 
460 	desc = notefunc(arg, &descsz);
461 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
462 	note.n_descsz = descsz;
463 	note.n_type = type;
464 
465 	sbuf_bcat(sb, &note, sizeof(note));
466 	sbuf_start_section(sb, &old_len);
467 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
468 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
469 	if (descsz == 0)
470 		return;
471 	sbuf_start_section(sb, &old_len);
472 	sbuf_bcat(sb, desc, descsz);
473 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
474 	free(desc);
475 }
476 
477 /*
478  * Generate the ELF coredump header.
479  */
480 static void
481 elf_puthdr(int efd, pid_t pid, struct map_entry *map, void *hdr, size_t hdrsize,
482     size_t notesz, size_t segoff, int numsegs)
483 {
484 	Elf_Ehdr *ehdr, binhdr;
485 	Elf_Phdr *phdr;
486 	Elf_Shdr *shdr;
487 	struct phdr_closure phc;
488 	ssize_t cnt;
489 
490 	cnt = read(efd, &binhdr, sizeof(binhdr));
491 	if (cnt < 0)
492 		err(1, "Failed to re-read ELF header");
493 	else if (cnt != sizeof(binhdr))
494 		errx(1, "Failed to re-read ELF header");
495 
496 	ehdr = (Elf_Ehdr *)hdr;
497 
498 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
499 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
500 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
501 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
502 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
503 	ehdr->e_ident[EI_DATA] = ELF_DATA;
504 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
505 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
506 	ehdr->e_ident[EI_ABIVERSION] = 0;
507 	ehdr->e_ident[EI_PAD] = 0;
508 	ehdr->e_type = ET_CORE;
509 	ehdr->e_machine = binhdr.e_machine;
510 	ehdr->e_version = EV_CURRENT;
511 	ehdr->e_entry = 0;
512 	ehdr->e_phoff = sizeof(Elf_Ehdr);
513 	ehdr->e_flags = binhdr.e_flags;
514 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
515 	ehdr->e_phentsize = sizeof(Elf_Phdr);
516 	ehdr->e_shentsize = sizeof(Elf_Shdr);
517 	ehdr->e_shstrndx = SHN_UNDEF;
518 	if (numsegs + 1 < PN_XNUM) {
519 		ehdr->e_phnum = numsegs + 1;
520 		ehdr->e_shnum = 0;
521 	} else {
522 		ehdr->e_phnum = PN_XNUM;
523 		ehdr->e_shnum = 1;
524 
525 		ehdr->e_shoff = ehdr->e_phoff +
526 		    (numsegs + 1) * ehdr->e_phentsize;
527 
528 		shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
529 		memset(shdr, 0, sizeof(*shdr));
530 		/*
531 		 * A special first section is used to hold large segment and
532 		 * section counts.  This was proposed by Sun Microsystems in
533 		 * Solaris and has been adopted by Linux; the standard ELF
534 		 * tools are already familiar with the technique.
535 		 *
536 		 * See table 7-7 of the Solaris "Linker and Libraries Guide"
537 		 * (or 12-7 depending on the version of the document) for more
538 		 * details.
539 		 */
540 		shdr->sh_type = SHT_NULL;
541 		shdr->sh_size = ehdr->e_shnum;
542 		shdr->sh_link = ehdr->e_shstrndx;
543 		shdr->sh_info = numsegs + 1;
544 	}
545 
546 	/*
547 	 * Fill in the program header entries.
548 	 */
549 	phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);
550 
551 	/* The note segment. */
552 	phdr->p_type = PT_NOTE;
553 	phdr->p_offset = hdrsize;
554 	phdr->p_vaddr = 0;
555 	phdr->p_paddr = 0;
556 	phdr->p_filesz = notesz;
557 	phdr->p_memsz = 0;
558 	phdr->p_flags = PF_R;
559 	phdr->p_align = sizeof(Elf32_Size);
560 	phdr++;
561 
562 	/* All the writable segments from the program. */
563 	phc.phdr = phdr;
564 	phc.offset = segoff;
565 	each_dumpable_segment(map, cb_put_phdr, &phc);
566 }
567 
568 /*
569  * Free the memory map.
570  */
571 static void
572 freemap(struct map_entry *map)
573 {
574 	struct map_entry *next;
575 
576 	while (map != NULL) {
577 		next = map->next;
578 		free(map);
579 		map = next;
580 	}
581 }
582 
583 /*
584  * Read the process's memory map using kinfo_getvmmap(), and return a list of
585  * VM map entries.  Only the non-device read/writable segments are
586  * returned.  The map entries in the list aren't fully filled in; only
587  * the items we need are present.
588  */
589 static struct map_entry *
590 readmap(pid_t pid)
591 {
592 	struct map_entry *ent, **linkp, *map;
593 	struct kinfo_vmentry *vmentl, *kve;
594 	int i, nitems;
595 
596 	vmentl = kinfo_getvmmap(pid, &nitems);
597 	if (vmentl == NULL)
598 		err(1, "cannot retrieve mappings for %u process", pid);
599 
600 	map = NULL;
601 	linkp = &map;
602 	for (i = 0; i < nitems; i++) {
603 		kve = &vmentl[i];
604 
605 		/*
606 		 * Ignore 'malformed' segments or ones representing memory
607 		 * mapping with MAP_NOCORE on.
608 		 * If the 'full' support is disabled, just dump the most
609 		 * meaningful data segments.
610 		 */
611 		if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
612 		    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
613 		    kve->kve_type == KVME_TYPE_DEAD ||
614 		    kve->kve_type == KVME_TYPE_UNKNOWN ||
615 		    ((pflags & PFLAGS_FULL) == 0 &&
616 		    kve->kve_type != KVME_TYPE_DEFAULT &&
617 		    kve->kve_type != KVME_TYPE_VNODE &&
618 		    kve->kve_type != KVME_TYPE_SWAP &&
619 		    kve->kve_type != KVME_TYPE_PHYS))
620 			continue;
621 
622 		ent = calloc(1, sizeof(*ent));
623 		if (ent == NULL)
624 			errx(1, "out of memory");
625 		ent->start = (vm_offset_t)kve->kve_start;
626 		ent->end = (vm_offset_t)kve->kve_end;
627 		ent->protection = VM_PROT_READ;
628 		if ((kve->kve_protection & KVME_PROT_WRITE) != 0)
629 			ent->protection |= VM_PROT_WRITE;
630 		if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
631 			ent->protection |= VM_PROT_EXECUTE;
632 
633 		*linkp = ent;
634 		linkp = &ent->next;
635 	}
636 	free(vmentl);
637 	return (map);
638 }
639 
640 /*
641  * Miscellaneous note out functions.
642  */
643 
644 static void *
645 elf_note_prpsinfo(void *arg, size_t *sizep)
646 {
647 	char *cp, *end;
648 	pid_t pid;
649 	elfcore_prpsinfo_t *psinfo;
650 	struct kinfo_proc kip;
651 	size_t len;
652 	int name[4];
653 
654 	pid = *(pid_t *)arg;
655 	psinfo = calloc(1, sizeof(*psinfo));
656 	if (psinfo == NULL)
657 		errx(1, "out of memory");
658 	psinfo->pr_version = PRPSINFO_VERSION;
659 	psinfo->pr_psinfosz = sizeof(*psinfo);
660 
661 	name[0] = CTL_KERN;
662 	name[1] = KERN_PROC;
663 	name[2] = KERN_PROC_PID;
664 	name[3] = pid;
665 	len = sizeof(kip);
666 	if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
667 		err(1, "kern.proc.pid.%u", pid);
668 	if (kip.ki_pid != pid)
669 		err(1, "kern.proc.pid.%u", pid);
670 	strlcpy(psinfo->pr_fname, kip.ki_comm, sizeof(psinfo->pr_fname));
671 	name[2] = KERN_PROC_ARGS;
672 	len = sizeof(psinfo->pr_psargs) - 1;
673 	if (sysctl(name, 4, psinfo->pr_psargs, &len, NULL, 0) == 0 && len > 0) {
674 		cp = psinfo->pr_psargs;
675 		end = cp + len - 1;
676 		for (;;) {
677 			cp = memchr(cp, '\0', end - cp);
678 			if (cp == NULL)
679 				break;
680 			*cp = ' ';
681 		}
682 	} else
683 		strlcpy(psinfo->pr_psargs, kip.ki_comm,
684 		    sizeof(psinfo->pr_psargs));
685 	psinfo->pr_pid = pid;
686 
687 	*sizep = sizeof(*psinfo);
688 	return (psinfo);
689 }
690 
691 static void *
692 elf_note_thrmisc(void *arg, size_t *sizep)
693 {
694 	lwpid_t tid;
695 	struct ptrace_lwpinfo lwpinfo;
696 	thrmisc_t *thrmisc;
697 
698 	tid = *(lwpid_t *)arg;
699 	thrmisc = calloc(1, sizeof(*thrmisc));
700 	if (thrmisc == NULL)
701 		errx(1, "out of memory");
702 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo,
703 	    sizeof(lwpinfo));
704 	memset(&thrmisc->_pad, 0, sizeof(thrmisc->_pad));
705 	strcpy(thrmisc->pr_tname, lwpinfo.pl_tdname);
706 
707 	*sizep = sizeof(*thrmisc);
708 	return (thrmisc);
709 }
710 
711 static void *
712 elf_note_ptlwpinfo(void *arg, size_t *sizep)
713 {
714 	lwpid_t tid;
715 	elfcore_lwpinfo_t *elf_info;
716 	struct ptrace_lwpinfo lwpinfo;
717 	void *p;
718 
719 	tid = *(lwpid_t *)arg;
720 	p = calloc(1, sizeof(int) + sizeof(elfcore_lwpinfo_t));
721 	if (p == NULL)
722 		errx(1, "out of memory");
723 	*(int *)p = sizeof(elfcore_lwpinfo_t);
724 	elf_info = (void *)((int *)p + 1);
725 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo, sizeof(lwpinfo));
726 	elf_convert_lwpinfo(elf_info, &lwpinfo);
727 
728 	*sizep = sizeof(int) + sizeof(struct ptrace_lwpinfo);
729 	return (p);
730 }
731 
732 #if defined(__i386__) || defined(__amd64__)
733 static void *
734 elf_note_x86_xstate(void *arg, size_t *sizep)
735 {
736 	lwpid_t tid;
737 	char *xstate;
738 	static bool xsave_checked = false;
739 	static struct ptrace_xstate_info info;
740 
741 	tid = *(lwpid_t *)arg;
742 	if (!xsave_checked) {
743 		if (ptrace(PT_GETXSTATE_INFO, tid, (void *)&info,
744 		    sizeof(info)) != 0)
745 			info.xsave_len = 0;
746 		xsave_checked = true;
747 	}
748 	if (info.xsave_len == 0) {
749 		*sizep = 0;
750 		return (NULL);
751 	}
752 	xstate = calloc(1, info.xsave_len);
753 	ptrace(PT_GETXSTATE, tid, xstate, 0);
754 	*(uint64_t *)(xstate + X86_XSTATE_XCR0_OFFSET) = info.xsave_mask;
755 	*sizep = info.xsave_len;
756 	return (xstate);
757 }
758 #endif
759 
760 #if defined(__powerpc__)
761 static void *
762 elf_note_powerpc_vmx(void *arg, size_t *sizep)
763 {
764 	lwpid_t tid;
765 	struct vmxreg *vmx;
766 	static bool has_vmx = true;
767 	struct vmxreg info;
768 
769 	tid = *(lwpid_t *)arg;
770 	if (has_vmx) {
771 		if (ptrace(PT_GETVRREGS, tid, (void *)&info,
772 		    sizeof(info)) != 0)
773 			has_vmx = false;
774 	}
775 	if (!has_vmx) {
776 		*sizep = 0;
777 		return (NULL);
778 	}
779 	vmx = calloc(1, sizeof(*vmx));
780 	memcpy(vmx, &info, sizeof(*vmx));
781 	*sizep = sizeof(*vmx);
782 	return (vmx);
783 }
784 
785 static void *
786 elf_note_powerpc_vsx(void *arg, size_t *sizep)
787 {
788 	lwpid_t tid;
789 	char *vshr_data;
790 	static bool has_vsx = true;
791 	uint64_t vshr[32];
792 
793 	tid = *(lwpid_t *)arg;
794 	if (has_vsx) {
795 		if (ptrace(PT_GETVSRREGS, tid, (void *)vshr,
796 		    sizeof(vshr)) != 0)
797 			has_vsx = false;
798 	}
799 	if (!has_vsx) {
800 		*sizep = 0;
801 		return (NULL);
802 	}
803 	vshr_data = calloc(1, sizeof(vshr));
804 	memcpy(vshr_data, vshr, sizeof(vshr));
805 	*sizep = sizeof(vshr);
806 	return (vshr_data);
807 }
808 #endif
809 
810 static void *
811 procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
812 {
813 	size_t len;
814 	pid_t pid;
815 	int name[4], structsize;
816 	void *buf, *p;
817 
818 	pid = *(pid_t *)arg;
819 	structsize = structsz;
820 	name[0] = CTL_KERN;
821 	name[1] = KERN_PROC;
822 	name[2] = what;
823 	name[3] = pid;
824 	len = 0;
825 	if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
826 		err(1, "kern.proc.%d.%u", what, pid);
827 	buf = calloc(1, sizeof(structsize) + len * 4 / 3);
828 	if (buf == NULL)
829 		errx(1, "out of memory");
830 	bcopy(&structsize, buf, sizeof(structsize));
831 	p = (char *)buf + sizeof(structsize);
832 	if (sysctl(name, 4, p, &len, NULL, 0) == -1)
833 		err(1, "kern.proc.%d.%u", what, pid);
834 
835 	*sizep = sizeof(structsize) + len;
836 	return (buf);
837 }
838 
839 static void *
840 elf_note_procstat_proc(void *arg, size_t *sizep)
841 {
842 
843 	return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
844 	    sizeof(struct kinfo_proc), sizep));
845 }
846 
847 static void *
848 elf_note_procstat_files(void *arg, size_t *sizep)
849 {
850 
851 	return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
852 	    sizeof(struct kinfo_file), sizep));
853 }
854 
855 static void *
856 elf_note_procstat_vmmap(void *arg, size_t *sizep)
857 {
858 
859 	return (procstat_sysctl(arg, KERN_PROC_VMMAP,
860 	    sizeof(struct kinfo_vmentry), sizep));
861 }
862 
863 static void *
864 elf_note_procstat_groups(void *arg, size_t *sizep)
865 {
866 
867 	return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
868 }
869 
870 static void *
871 elf_note_procstat_umask(void *arg, size_t *sizep)
872 {
873 
874 	return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
875 }
876 
877 static void *
878 elf_note_procstat_osrel(void *arg, size_t *sizep)
879 {
880 
881 	return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
882 }
883 
884 static void *
885 elf_note_procstat_psstrings(void *arg, size_t *sizep)
886 {
887 
888 	return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
889 	    sizeof(vm_offset_t), sizep));
890 }
891 
892 static void *
893 elf_note_procstat_auxv(void *arg, size_t *sizep)
894 {
895 
896 	return (procstat_sysctl(arg, KERN_PROC_AUXV,
897 	    sizeof(Elf_Auxinfo), sizep));
898 }
899 
900 static void *
901 elf_note_procstat_rlimit(void *arg, size_t *sizep)
902 {
903 	pid_t pid;
904 	size_t len;
905 	int i, name[5], structsize;
906 	void *buf, *p;
907 
908 	pid = *(pid_t *)arg;
909 	structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
910 	buf = calloc(1, sizeof(structsize) + structsize);
911 	if (buf == NULL)
912 		errx(1, "out of memory");
913 	bcopy(&structsize, buf, sizeof(structsize));
914 	p = (char *)buf + sizeof(structsize);
915 	name[0] = CTL_KERN;
916 	name[1] = KERN_PROC;
917 	name[2] = KERN_PROC_RLIMIT;
918 	name[3] = pid;
919 	len = sizeof(struct rlimit);
920 	for (i = 0; i < RLIM_NLIMITS; i++) {
921 		name[4] = i;
922 		if (sysctl(name, 5, p, &len, NULL, 0) == -1)
923 			err(1, "kern.proc.rlimit.%u", pid);
924 		if (len != sizeof(struct rlimit))
925 			errx(1, "kern.proc.rlimit.%u: short read", pid);
926 		p += len;
927 	}
928 
929 	*sizep = sizeof(structsize) + structsize;
930 	return (buf);
931 }
932 
933 struct dumpers __elfN(dump) = { elf_ident, elf_coredump };
934 TEXT_SET(dumpset, __elfN(dump));
935