xref: /freebsd/usr.bin/gcore/elfcore.c (revision ccb83afd8192c1b5070aa7b4e888223bfd08b00a)
1 /*-
2  * Copyright (c) 2007 Sandvine Incorporated
3  * Copyright (c) 1998 John D. Polstra
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/endian.h>
32 #include <sys/param.h>
33 #include <sys/procfs.h>
34 #include <sys/ptrace.h>
35 #include <sys/queue.h>
36 #include <sys/linker_set.h>
37 #include <sys/sbuf.h>
38 #include <sys/sysctl.h>
39 #include <sys/user.h>
40 #include <sys/wait.h>
41 #include <machine/elf.h>
42 #include <vm/vm_param.h>
43 #include <vm/vm.h>
44 #include <vm/pmap.h>
45 #include <vm/vm_map.h>
46 #include <assert.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <stdbool.h>
51 #include <stdint.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <libutil.h>
57 
58 #include "extern.h"
59 
60 /*
61  * Code for generating ELF core dumps.
62  */
63 
64 typedef void (*segment_callback)(vm_map_entry_t, void *);
65 
66 /* Closure for cb_put_phdr(). */
67 struct phdr_closure {
68 	Elf_Phdr *phdr;		/* Program header to fill in */
69 	Elf_Off offset;		/* Offset of segment in core file */
70 };
71 
72 /* Closure for cb_size_segment(). */
73 struct sseg_closure {
74 	int count;		/* Count of writable segments. */
75 	size_t size;		/* Total size of all writable segments. */
76 };
77 
78 #ifdef ELFCORE_COMPAT_32
79 typedef struct fpreg32 elfcore_fpregset_t;
80 typedef struct reg32   elfcore_gregset_t;
81 typedef struct prpsinfo32 elfcore_prpsinfo_t;
82 typedef struct prstatus32 elfcore_prstatus_t;
83 static void elf_convert_gregset(elfcore_gregset_t *rd, struct reg *rs);
84 static void elf_convert_fpregset(elfcore_fpregset_t *rd, struct fpreg *rs);
85 #else
86 typedef fpregset_t elfcore_fpregset_t;
87 typedef gregset_t  elfcore_gregset_t;
88 typedef prpsinfo_t elfcore_prpsinfo_t;
89 typedef prstatus_t elfcore_prstatus_t;
90 #define elf_convert_gregset(d,s)	*d = *s
91 #define elf_convert_fpregset(d,s)	*d = *s
92 #endif
93 
94 typedef void* (*notefunc_t)(void *, size_t *);
95 
96 static void cb_put_phdr(vm_map_entry_t, void *);
97 static void cb_size_segment(vm_map_entry_t, void *);
98 static void each_writable_segment(vm_map_entry_t, segment_callback,
99     void *closure);
100 static void elf_detach(void);	/* atexit() handler. */
101 static void *elf_note_fpregset(void *, size_t *);
102 static void *elf_note_prpsinfo(void *, size_t *);
103 static void *elf_note_prstatus(void *, size_t *);
104 static void *elf_note_thrmisc(void *, size_t *);
105 #if defined(__i386__) || defined(__amd64__)
106 static void *elf_note_x86_xstate(void *, size_t *);
107 #endif
108 #if defined(__powerpc__)
109 static void *elf_note_powerpc_vmx(void *, size_t *);
110 #endif
111 static void *elf_note_procstat_auxv(void *, size_t *);
112 static void *elf_note_procstat_files(void *, size_t *);
113 static void *elf_note_procstat_groups(void *, size_t *);
114 static void *elf_note_procstat_osrel(void *, size_t *);
115 static void *elf_note_procstat_proc(void *, size_t *);
116 static void *elf_note_procstat_psstrings(void *, size_t *);
117 static void *elf_note_procstat_rlimit(void *, size_t *);
118 static void *elf_note_procstat_umask(void *, size_t *);
119 static void *elf_note_procstat_vmmap(void *, size_t *);
120 static void elf_puthdr(pid_t, vm_map_entry_t, void *, size_t, size_t, size_t,
121     int);
122 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
123 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
124 static void freemap(vm_map_entry_t);
125 static vm_map_entry_t readmap(pid_t);
126 static void *procstat_sysctl(void *, int, size_t, size_t *sizep);
127 
128 static pid_t g_pid;		/* Pid being dumped, global for elf_detach */
129 static int g_status;		/* proc status after ptrace attach */
130 
131 static int
132 elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
133 {
134 	Elf_Ehdr hdr;
135 	int cnt;
136 	uint16_t machine;
137 
138 	cnt = read(efd, &hdr, sizeof(hdr));
139 	if (cnt != sizeof(hdr))
140 		return (0);
141 	if (!IS_ELF(hdr))
142 		return (0);
143 	switch (hdr.e_ident[EI_DATA]) {
144 	case ELFDATA2LSB:
145 		machine = le16toh(hdr.e_machine);
146 		break;
147 	case ELFDATA2MSB:
148 		machine = be16toh(hdr.e_machine);
149 		break;
150 	default:
151 		return (0);
152 	}
153 	if (!ELF_MACHINE_OK(machine))
154 		return (0);
155 
156 	/* Looks good. */
157 	return (1);
158 }
159 
160 static void
161 elf_detach(void)
162 {
163 	int sig;
164 
165 	if (g_pid != 0) {
166 		/*
167 		 * Forward any pending signals. SIGSTOP is generated by ptrace
168 		 * itself, so ignore it.
169 		 */
170 		sig = WIFSTOPPED(g_status) ? WSTOPSIG(g_status) : 0;
171 		if (sig == SIGSTOP)
172 			sig = 0;
173 		ptrace(PT_DETACH, g_pid, (caddr_t)1, sig);
174 	}
175 }
176 
177 /*
178  * Write an ELF coredump for the given pid to the given fd.
179  */
180 static void
181 elf_coredump(int efd __unused, int fd, pid_t pid)
182 {
183 	vm_map_entry_t map;
184 	struct sseg_closure seginfo;
185 	struct sbuf *sb;
186 	void *hdr;
187 	size_t hdrsize, notesz, segoff;
188 	ssize_t n, old_len;
189 	Elf_Phdr *php;
190 	int i;
191 
192 	/* Attach to process to dump. */
193 	g_pid = pid;
194 	if (atexit(elf_detach) != 0)
195 		err(1, "atexit");
196 	errno = 0;
197 	ptrace(PT_ATTACH, pid, NULL, 0);
198 	if (errno)
199 		err(1, "PT_ATTACH");
200 	if (waitpid(pid, &g_status, 0) == -1)
201 		err(1, "waitpid");
202 
203 	/* Get the program's memory map. */
204 	map = readmap(pid);
205 
206 	/* Size the program segments. */
207 	seginfo.count = 0;
208 	seginfo.size = 0;
209 	each_writable_segment(map, cb_size_segment, &seginfo);
210 
211 	/*
212 	 * Build the header and the notes using sbuf and write to the file.
213 	 */
214 	sb = sbuf_new_auto();
215 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
216 	/* Start header + notes section. */
217 	sbuf_start_section(sb, NULL);
218 	/* Make empty header subsection. */
219 	sbuf_start_section(sb, &old_len);
220 	sbuf_putc(sb, 0);
221 	sbuf_end_section(sb, old_len, hdrsize, 0);
222 	/* Put notes. */
223 	elf_putnotes(pid, sb, &notesz);
224 	/* Align up to a page boundary for the program segments. */
225 	sbuf_end_section(sb, -1, PAGE_SIZE, 0);
226 	if (sbuf_finish(sb) != 0)
227 		err(1, "sbuf_finish");
228 	hdr = sbuf_data(sb);
229 	segoff = sbuf_len(sb);
230 	/* Fill in the header. */
231 	elf_puthdr(pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
232 
233 	n = write(fd, hdr, segoff);
234 	if (n == -1)
235 		err(1, "write");
236 	if (n < segoff)
237               errx(1, "short write");
238 
239 	/* Write the contents of all of the writable segments. */
240 	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
241 	for (i = 0;  i < seginfo.count;  i++) {
242 		struct ptrace_io_desc iorequest;
243 		uintmax_t nleft = php->p_filesz;
244 
245 		iorequest.piod_op = PIOD_READ_D;
246 		iorequest.piod_offs = (caddr_t)(uintptr_t)php->p_vaddr;
247 		while (nleft > 0) {
248 			char buf[8*1024];
249 			size_t nwant;
250 			ssize_t ngot;
251 
252 			if (nleft > sizeof(buf))
253 				nwant = sizeof buf;
254 			else
255 				nwant = nleft;
256 			iorequest.piod_addr = buf;
257 			iorequest.piod_len = nwant;
258 			ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
259 			ngot = iorequest.piod_len;
260 			if ((size_t)ngot < nwant)
261 				errx(1, "short read wanted %zu, got %zd",
262 				    nwant, ngot);
263 			ngot = write(fd, buf, nwant);
264 			if (ngot == -1)
265 				err(1, "write of segment %d failed", i);
266 			if ((size_t)ngot != nwant)
267 				errx(1, "short write");
268 			nleft -= nwant;
269 			iorequest.piod_offs += ngot;
270 		}
271 		php++;
272 	}
273 	sbuf_delete(sb);
274 	freemap(map);
275 }
276 
277 /*
278  * A callback for each_writable_segment() to write out the segment's
279  * program header entry.
280  */
281 static void
282 cb_put_phdr(vm_map_entry_t entry, void *closure)
283 {
284 	struct phdr_closure *phc = (struct phdr_closure *)closure;
285 	Elf_Phdr *phdr = phc->phdr;
286 
287 	phc->offset = round_page(phc->offset);
288 
289 	phdr->p_type = PT_LOAD;
290 	phdr->p_offset = phc->offset;
291 	phdr->p_vaddr = entry->start;
292 	phdr->p_paddr = 0;
293 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
294 	phdr->p_align = PAGE_SIZE;
295 	phdr->p_flags = 0;
296 	if (entry->protection & VM_PROT_READ)
297 		phdr->p_flags |= PF_R;
298 	if (entry->protection & VM_PROT_WRITE)
299 		phdr->p_flags |= PF_W;
300 	if (entry->protection & VM_PROT_EXECUTE)
301 		phdr->p_flags |= PF_X;
302 
303 	phc->offset += phdr->p_filesz;
304 	phc->phdr++;
305 }
306 
307 /*
308  * A callback for each_writable_segment() to gather information about
309  * the number of segments and their total size.
310  */
311 static void
312 cb_size_segment(vm_map_entry_t entry, void *closure)
313 {
314 	struct sseg_closure *ssc = (struct sseg_closure *)closure;
315 
316 	ssc->count++;
317 	ssc->size += entry->end - entry->start;
318 }
319 
320 /*
321  * For each segment in the given memory map, call the given function
322  * with a pointer to the map entry and some arbitrary caller-supplied
323  * data.
324  */
325 static void
326 each_writable_segment(vm_map_entry_t map, segment_callback func, void *closure)
327 {
328 	vm_map_entry_t entry;
329 
330 	for (entry = map;  entry != NULL;  entry = entry->next)
331 		(*func)(entry, closure);
332 }
333 
334 static void
335 elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
336 {
337 	lwpid_t *tids;
338 	size_t threads, old_len;
339 	ssize_t size;
340 	int i;
341 
342 	errno = 0;
343 	threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
344 	if (errno)
345 		err(1, "PT_GETNUMLWPS");
346 	tids = malloc(threads * sizeof(*tids));
347 	if (tids == NULL)
348 		errx(1, "out of memory");
349 	errno = 0;
350 	ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
351 	if (errno)
352 		err(1, "PT_GETLWPLIST");
353 
354 	sbuf_start_section(sb, &old_len);
355 	elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);
356 
357 	for (i = 0; i < threads; ++i) {
358 		elf_putnote(NT_PRSTATUS, elf_note_prstatus, tids + i, sb);
359 		elf_putnote(NT_FPREGSET, elf_note_fpregset, tids + i, sb);
360 		elf_putnote(NT_THRMISC, elf_note_thrmisc, tids + i, sb);
361 #if defined(__i386__) || defined(__amd64__)
362 		elf_putnote(NT_X86_XSTATE, elf_note_x86_xstate, tids + i, sb);
363 #endif
364 #if defined(__powerpc__)
365 		elf_putnote(NT_PPC_VMX, elf_note_powerpc_vmx, tids + i, sb);
366 #endif
367 	}
368 
369 #ifndef ELFCORE_COMPAT_32
370 	elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
371 	elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
372 	elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
373 	elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
374 	elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
375 	elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
376 	elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
377 	elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
378 	    sb);
379 	elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
380 #endif
381 
382 	size = sbuf_end_section(sb, old_len, 1, 0);
383 	if (size == -1)
384 		err(1, "sbuf_end_section");
385 	free(tids);
386 	*sizep = size;
387 }
388 
389 /*
390  * Emit one note section to sbuf.
391  */
392 static void
393 elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
394 {
395 	Elf_Note note;
396 	size_t descsz;
397 	ssize_t old_len;
398 	void *desc;
399 
400 	desc = notefunc(arg, &descsz);
401 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
402 	note.n_descsz = descsz;
403 	note.n_type = type;
404 
405 	sbuf_bcat(sb, &note, sizeof(note));
406 	sbuf_start_section(sb, &old_len);
407 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
408 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
409 	if (descsz == 0)
410 		return;
411 	sbuf_start_section(sb, &old_len);
412 	sbuf_bcat(sb, desc, descsz);
413 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
414 	free(desc);
415 }
416 
417 /*
418  * Generate the ELF coredump header.
419  */
420 static void
421 elf_puthdr(pid_t pid, vm_map_entry_t map, void *hdr, size_t hdrsize,
422     size_t notesz, size_t segoff, int numsegs)
423 {
424 	Elf_Ehdr *ehdr;
425 	Elf_Phdr *phdr;
426 	struct phdr_closure phc;
427 
428 	ehdr = (Elf_Ehdr *)hdr;
429 	phdr = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr));
430 
431 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
432 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
433 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
434 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
435 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
436 	ehdr->e_ident[EI_DATA] = ELF_DATA;
437 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
438 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
439 	ehdr->e_ident[EI_ABIVERSION] = 0;
440 	ehdr->e_ident[EI_PAD] = 0;
441 	ehdr->e_type = ET_CORE;
442 	ehdr->e_machine = ELF_ARCH;
443 	ehdr->e_version = EV_CURRENT;
444 	ehdr->e_entry = 0;
445 	ehdr->e_phoff = sizeof(Elf_Ehdr);
446 	ehdr->e_flags = 0;
447 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
448 	ehdr->e_phentsize = sizeof(Elf_Phdr);
449 	ehdr->e_phnum = numsegs + 1;
450 	ehdr->e_shentsize = sizeof(Elf_Shdr);
451 	ehdr->e_shnum = 0;
452 	ehdr->e_shstrndx = SHN_UNDEF;
453 
454 	/*
455 	 * Fill in the program header entries.
456 	 */
457 
458 	/* The note segement. */
459 	phdr->p_type = PT_NOTE;
460 	phdr->p_offset = hdrsize;
461 	phdr->p_vaddr = 0;
462 	phdr->p_paddr = 0;
463 	phdr->p_filesz = notesz;
464 	phdr->p_memsz = 0;
465 	phdr->p_flags = PF_R;
466 	phdr->p_align = sizeof(Elf32_Size);
467 	phdr++;
468 
469 	/* All the writable segments from the program. */
470 	phc.phdr = phdr;
471 	phc.offset = segoff;
472 	each_writable_segment(map, cb_put_phdr, &phc);
473 }
474 
475 /*
476  * Free the memory map.
477  */
478 static void
479 freemap(vm_map_entry_t map)
480 {
481 
482 	while (map != NULL) {
483 		vm_map_entry_t next = map->next;
484 		free(map);
485 		map = next;
486 	}
487 }
488 
489 /*
490  * Read the process's memory map using kinfo_getvmmap(), and return a list of
491  * VM map entries.  Only the non-device read/writable segments are
492  * returned.  The map entries in the list aren't fully filled in; only
493  * the items we need are present.
494  */
495 static vm_map_entry_t
496 readmap(pid_t pid)
497 {
498 	vm_map_entry_t ent, *linkp, map;
499 	struct kinfo_vmentry *vmentl, *kve;
500 	int i, nitems;
501 
502 	vmentl = kinfo_getvmmap(pid, &nitems);
503 	if (vmentl == NULL)
504 		err(1, "cannot retrieve mappings for %u process", pid);
505 
506 	map = NULL;
507 	linkp = &map;
508 	for (i = 0; i < nitems; i++) {
509 		kve = &vmentl[i];
510 
511 		/*
512 		 * Ignore 'malformed' segments or ones representing memory
513 		 * mapping with MAP_NOCORE on.
514 		 * If the 'full' support is disabled, just dump the most
515 		 * meaningful data segments.
516 		 */
517 		if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
518 		    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
519 		    kve->kve_type == KVME_TYPE_DEAD ||
520 		    kve->kve_type == KVME_TYPE_UNKNOWN ||
521 		    ((pflags & PFLAGS_FULL) == 0 &&
522 		    kve->kve_type != KVME_TYPE_DEFAULT &&
523 		    kve->kve_type != KVME_TYPE_VNODE &&
524 		    kve->kve_type != KVME_TYPE_SWAP &&
525 		    kve->kve_type != KVME_TYPE_PHYS))
526 			continue;
527 
528 		ent = calloc(1, sizeof(*ent));
529 		if (ent == NULL)
530 			errx(1, "out of memory");
531 		ent->start = (vm_offset_t)kve->kve_start;
532 		ent->end = (vm_offset_t)kve->kve_end;
533 		ent->protection = VM_PROT_READ | VM_PROT_WRITE;
534 		if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
535 			ent->protection |= VM_PROT_EXECUTE;
536 
537 		*linkp = ent;
538 		linkp = &ent->next;
539 	}
540 	free(vmentl);
541 	return (map);
542 }
543 
544 /*
545  * Miscellaneous note out functions.
546  */
547 
548 static void *
549 elf_note_prpsinfo(void *arg, size_t *sizep)
550 {
551 	char *cp, *end;
552 	pid_t pid;
553 	elfcore_prpsinfo_t *psinfo;
554 	struct kinfo_proc kip;
555 	size_t len;
556 	int name[4];
557 
558 	pid = *(pid_t *)arg;
559 	psinfo = calloc(1, sizeof(*psinfo));
560 	if (psinfo == NULL)
561 		errx(1, "out of memory");
562 	psinfo->pr_version = PRPSINFO_VERSION;
563 	psinfo->pr_psinfosz = sizeof(*psinfo);
564 
565 	name[0] = CTL_KERN;
566 	name[1] = KERN_PROC;
567 	name[2] = KERN_PROC_PID;
568 	name[3] = pid;
569 	len = sizeof(kip);
570 	if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
571 		err(1, "kern.proc.pid.%u", pid);
572 	if (kip.ki_pid != pid)
573 		err(1, "kern.proc.pid.%u", pid);
574 	strlcpy(psinfo->pr_fname, kip.ki_comm, sizeof(psinfo->pr_fname));
575 	name[2] = KERN_PROC_ARGS;
576 	len = sizeof(psinfo->pr_psargs) - 1;
577 	if (sysctl(name, 4, psinfo->pr_psargs, &len, NULL, 0) == 0 && len > 0) {
578 		cp = psinfo->pr_psargs;
579 		end = cp + len - 1;
580 		for (;;) {
581 			cp = memchr(cp, '\0', end - cp);
582 			if (cp == NULL)
583 				break;
584 			*cp = ' ';
585 		}
586 	} else
587 		strlcpy(psinfo->pr_psargs, kip.ki_comm,
588 		    sizeof(psinfo->pr_psargs));
589 	psinfo->pr_pid = pid;
590 
591 	*sizep = sizeof(*psinfo);
592 	return (psinfo);
593 }
594 
595 static void *
596 elf_note_prstatus(void *arg, size_t *sizep)
597 {
598 	lwpid_t tid;
599 	elfcore_prstatus_t *status;
600 	struct reg greg;
601 
602 	tid = *(lwpid_t *)arg;
603 	status = calloc(1, sizeof(*status));
604 	if (status == NULL)
605 		errx(1, "out of memory");
606 	status->pr_version = PRSTATUS_VERSION;
607 	status->pr_statussz = sizeof(*status);
608 	status->pr_gregsetsz = sizeof(elfcore_gregset_t);
609 	status->pr_fpregsetsz = sizeof(elfcore_fpregset_t);
610 	status->pr_osreldate = __FreeBSD_version;
611 	status->pr_pid = tid;
612 	ptrace(PT_GETREGS, tid, (void *)&greg, 0);
613 	elf_convert_gregset(&status->pr_reg, &greg);
614 
615 	*sizep = sizeof(*status);
616 	return (status);
617 }
618 
619 static void *
620 elf_note_fpregset(void *arg, size_t *sizep)
621 {
622 	lwpid_t tid;
623 	elfcore_fpregset_t *fpregset;
624 	fpregset_t fpreg;
625 
626 	tid = *(lwpid_t *)arg;
627 	fpregset = calloc(1, sizeof(*fpregset));
628 	if (fpregset == NULL)
629 		errx(1, "out of memory");
630 	ptrace(PT_GETFPREGS, tid, (void *)&fpreg, 0);
631 	elf_convert_fpregset(fpregset, &fpreg);
632 
633 	*sizep = sizeof(*fpregset);
634 	return (fpregset);
635 }
636 
637 static void *
638 elf_note_thrmisc(void *arg, size_t *sizep)
639 {
640 	lwpid_t tid;
641 	struct ptrace_lwpinfo lwpinfo;
642 	thrmisc_t *thrmisc;
643 
644 	tid = *(lwpid_t *)arg;
645 	thrmisc = calloc(1, sizeof(*thrmisc));
646 	if (thrmisc == NULL)
647 		errx(1, "out of memory");
648 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo,
649 	    sizeof(lwpinfo));
650 	memset(&thrmisc->_pad, 0, sizeof(thrmisc->_pad));
651 	strcpy(thrmisc->pr_tname, lwpinfo.pl_tdname);
652 
653 	*sizep = sizeof(*thrmisc);
654 	return (thrmisc);
655 }
656 
657 #if defined(__i386__) || defined(__amd64__)
658 static void *
659 elf_note_x86_xstate(void *arg, size_t *sizep)
660 {
661 	lwpid_t tid;
662 	char *xstate;
663 	static bool xsave_checked = false;
664 	static struct ptrace_xstate_info info;
665 
666 	tid = *(lwpid_t *)arg;
667 	if (!xsave_checked) {
668 		if (ptrace(PT_GETXSTATE_INFO, tid, (void *)&info,
669 		    sizeof(info)) != 0)
670 			info.xsave_len = 0;
671 		xsave_checked = true;
672 	}
673 	if (info.xsave_len == 0) {
674 		*sizep = 0;
675 		return (NULL);
676 	}
677 	xstate = calloc(1, info.xsave_len);
678 	ptrace(PT_GETXSTATE, tid, xstate, 0);
679 	*(uint64_t *)(xstate + X86_XSTATE_XCR0_OFFSET) = info.xsave_mask;
680 	*sizep = info.xsave_len;
681 	return (xstate);
682 }
683 #endif
684 
685 #if defined(__powerpc__)
686 static void *
687 elf_note_powerpc_vmx(void *arg, size_t *sizep)
688 {
689 	lwpid_t tid;
690 	struct vmxreg *vmx;
691 	static bool has_vmx = true;
692 	struct vmxreg info;
693 
694 	tid = *(lwpid_t *)arg;
695 	if (has_vmx) {
696 		if (ptrace(PT_GETVRREGS, tid, (void *)&info,
697 		    sizeof(info)) != 0)
698 			has_vmx = false;
699 	}
700 	if (!has_vmx) {
701 		*sizep = 0;
702 		return (NULL);
703 	}
704 	vmx = calloc(1, sizeof(*vmx));
705 	memcpy(vmx, &info, sizeof(*vmx));
706 	*sizep = sizeof(*vmx);
707 	return (vmx);
708 }
709 #endif
710 
711 static void *
712 procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
713 {
714 	size_t len;
715 	pid_t pid;
716 	int name[4], structsize;
717 	void *buf, *p;
718 
719 	pid = *(pid_t *)arg;
720 	structsize = structsz;
721 	name[0] = CTL_KERN;
722 	name[1] = KERN_PROC;
723 	name[2] = what;
724 	name[3] = pid;
725 	len = 0;
726 	if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
727 		err(1, "kern.proc.%d.%u", what, pid);
728 	buf = calloc(1, sizeof(structsize) + len * 4 / 3);
729 	if (buf == NULL)
730 		errx(1, "out of memory");
731 	bcopy(&structsize, buf, sizeof(structsize));
732 	p = (char *)buf + sizeof(structsize);
733 	if (sysctl(name, 4, p, &len, NULL, 0) == -1)
734 		err(1, "kern.proc.%d.%u", what, pid);
735 
736 	*sizep = sizeof(structsize) + len;
737 	return (buf);
738 }
739 
740 static void *
741 elf_note_procstat_proc(void *arg, size_t *sizep)
742 {
743 
744 	return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
745 	    sizeof(struct kinfo_proc), sizep));
746 }
747 
748 static void *
749 elf_note_procstat_files(void *arg, size_t *sizep)
750 {
751 
752 	return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
753 	    sizeof(struct kinfo_file), sizep));
754 }
755 
756 static void *
757 elf_note_procstat_vmmap(void *arg, size_t *sizep)
758 {
759 
760 	return (procstat_sysctl(arg, KERN_PROC_VMMAP,
761 	    sizeof(struct kinfo_vmentry), sizep));
762 }
763 
764 static void *
765 elf_note_procstat_groups(void *arg, size_t *sizep)
766 {
767 
768 	return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
769 }
770 
771 static void *
772 elf_note_procstat_umask(void *arg, size_t *sizep)
773 {
774 
775 	return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
776 }
777 
778 static void *
779 elf_note_procstat_osrel(void *arg, size_t *sizep)
780 {
781 
782 	return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
783 }
784 
785 static void *
786 elf_note_procstat_psstrings(void *arg, size_t *sizep)
787 {
788 
789 	return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
790 	    sizeof(vm_offset_t), sizep));
791 }
792 
793 static void *
794 elf_note_procstat_auxv(void *arg, size_t *sizep)
795 {
796 
797 	return (procstat_sysctl(arg, KERN_PROC_AUXV,
798 	    sizeof(Elf_Auxinfo), sizep));
799 }
800 
801 static void *
802 elf_note_procstat_rlimit(void *arg, size_t *sizep)
803 {
804 	pid_t pid;
805 	size_t len;
806 	int i, name[5], structsize;
807 	void *buf, *p;
808 
809 	pid = *(pid_t *)arg;
810 	structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
811 	buf = calloc(1, sizeof(structsize) + structsize);
812 	if (buf == NULL)
813 		errx(1, "out of memory");
814 	bcopy(&structsize, buf, sizeof(structsize));
815 	p = (char *)buf + sizeof(structsize);
816 	name[0] = CTL_KERN;
817 	name[1] = KERN_PROC;
818 	name[2] = KERN_PROC_RLIMIT;
819 	name[3] = pid;
820 	len = sizeof(struct rlimit);
821 	for (i = 0; i < RLIM_NLIMITS; i++) {
822 		name[4] = i;
823 		if (sysctl(name, 5, p, &len, NULL, 0) == -1)
824 			err(1, "kern.proc.rlimit.%u", pid);
825 		if (len != sizeof(struct rlimit))
826 			errx(1, "kern.proc.rlimit.%u: short read", pid);
827 		p += len;
828 	}
829 
830 	*sizep = sizeof(structsize) + structsize;
831 	return (buf);
832 }
833 
834 struct dumpers __elfN(dump) = { elf_ident, elf_coredump };
835 TEXT_SET(dumpset, __elfN(dump));
836