xref: /freebsd/usr.bin/gcore/elfcore.c (revision 5dd76dd0cc19450133aa379ce0ce4a68ae07fb39)
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/param.h>
32 #include <sys/procfs.h>
33 #include <sys/ptrace.h>
34 #include <sys/queue.h>
35 #include <sys/linker_set.h>
36 #include <sys/sbuf.h>
37 #include <sys/sysctl.h>
38 #include <sys/user.h>
39 #include <sys/wait.h>
40 #include <machine/elf.h>
41 #include <vm/vm_param.h>
42 #include <vm/vm.h>
43 #include <vm/pmap.h>
44 #include <vm/vm_map.h>
45 #include <assert.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <stdint.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <libutil.h>
55 
56 #include "extern.h"
57 
58 /*
59  * Code for generating ELF core dumps.
60  */
61 
62 typedef void (*segment_callback)(vm_map_entry_t, void *);
63 
64 /* Closure for cb_put_phdr(). */
65 struct phdr_closure {
66 	Elf_Phdr *phdr;		/* Program header to fill in */
67 	Elf_Off offset;		/* Offset of segment in core file */
68 };
69 
70 /* Closure for cb_size_segment(). */
71 struct sseg_closure {
72 	int count;		/* Count of writable segments. */
73 	size_t size;		/* Total size of all writable segments. */
74 };
75 
76 typedef void* (*notefunc_t)(void *, size_t *);
77 
78 static void cb_put_phdr(vm_map_entry_t, void *);
79 static void cb_size_segment(vm_map_entry_t, void *);
80 static void each_writable_segment(vm_map_entry_t, segment_callback,
81     void *closure);
82 static void elf_detach(void);	/* atexit() handler. */
83 static void *elf_note_fpregset(void *, size_t *);
84 static void *elf_note_prpsinfo(void *, size_t *);
85 static void *elf_note_prstatus(void *, size_t *);
86 static void *elf_note_thrmisc(void *, size_t *);
87 static void *elf_note_procstat_auxv(void *, size_t *);
88 static void *elf_note_procstat_files(void *, size_t *);
89 static void *elf_note_procstat_groups(void *, size_t *);
90 static void *elf_note_procstat_osrel(void *, size_t *);
91 static void *elf_note_procstat_proc(void *, size_t *);
92 static void *elf_note_procstat_psstrings(void *, size_t *);
93 static void *elf_note_procstat_rlimit(void *, size_t *);
94 static void *elf_note_procstat_umask(void *, size_t *);
95 static void *elf_note_procstat_vmmap(void *, size_t *);
96 static void elf_puthdr(pid_t, vm_map_entry_t, void *, size_t, size_t, size_t,
97     int);
98 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
99 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
100 static void freemap(vm_map_entry_t);
101 static vm_map_entry_t readmap(pid_t);
102 static void *procstat_sysctl(void *, int, size_t, size_t *sizep);
103 
104 static pid_t g_pid;		/* Pid being dumped, global for elf_detach */
105 
106 static int
107 elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
108 {
109 	Elf_Ehdr hdr;
110 	int cnt;
111 
112 	cnt = read(efd, &hdr, sizeof(hdr));
113 	if (cnt != sizeof(hdr))
114 		return (0);
115 	if (IS_ELF(hdr))
116 		return (1);
117 	return (0);
118 }
119 
120 static void
121 elf_detach(void)
122 {
123 
124 	if (g_pid != 0)
125 		ptrace(PT_DETACH, g_pid, (caddr_t)1, 0);
126 }
127 
128 /*
129  * Write an ELF coredump for the given pid to the given fd.
130  */
131 static void
132 elf_coredump(int efd __unused, int fd, pid_t pid)
133 {
134 	vm_map_entry_t map;
135 	struct sseg_closure seginfo;
136 	struct sbuf *sb;
137 	void *hdr;
138 	size_t hdrsize, notesz, segoff;
139 	ssize_t n, old_len;
140 	Elf_Phdr *php;
141 	int i;
142 
143 	/* Attach to process to dump. */
144 	g_pid = pid;
145 	if (atexit(elf_detach) != 0)
146 		err(1, "atexit");
147 	errno = 0;
148 	ptrace(PT_ATTACH, pid, NULL, 0);
149 	if (errno)
150 		err(1, "PT_ATTACH");
151 	if (waitpid(pid, NULL, 0) == -1)
152 		err(1, "waitpid");
153 
154 	/* Get the program's memory map. */
155 	map = readmap(pid);
156 
157 	/* Size the program segments. */
158 	seginfo.count = 0;
159 	seginfo.size = 0;
160 	each_writable_segment(map, cb_size_segment, &seginfo);
161 
162 	/*
163 	 * Build the header and the notes using sbuf and write to the file.
164 	 */
165 	sb = sbuf_new_auto();
166 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
167 	/* Start header + notes section. */
168 	sbuf_start_section(sb, NULL);
169 	/* Make empty header subsection. */
170 	sbuf_start_section(sb, &old_len);
171 	sbuf_putc(sb, 0);
172 	sbuf_end_section(sb, old_len, hdrsize, 0);
173 	/* Put notes. */
174 	elf_putnotes(pid, sb, &notesz);
175 	/* Align up to a page boundary for the program segments. */
176 	sbuf_end_section(sb, -1, PAGE_SIZE, 0);
177 	if (sbuf_finish(sb) != 0)
178 		err(1, "sbuf_finish");
179 	hdr = sbuf_data(sb);
180 	segoff = sbuf_len(sb);
181 	/* Fill in the header. */
182 	elf_puthdr(pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
183 
184 	n = write(fd, hdr, segoff);
185 	if (n == -1)
186 		err(1, "write");
187 	if (n < segoff)
188               errx(1, "short write");
189 
190 	/* Write the contents of all of the writable segments. */
191 	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
192 	for (i = 0;  i < seginfo.count;  i++) {
193 		struct ptrace_io_desc iorequest;
194 		uintmax_t nleft = php->p_filesz;
195 
196 		iorequest.piod_op = PIOD_READ_D;
197 		iorequest.piod_offs = (caddr_t)php->p_vaddr;
198 		while (nleft > 0) {
199 			char buf[8*1024];
200 			size_t nwant;
201 			ssize_t ngot;
202 
203 			if (nleft > sizeof(buf))
204 				nwant = sizeof buf;
205 			else
206 				nwant = nleft;
207 			iorequest.piod_addr = buf;
208 			iorequest.piod_len = nwant;
209 			ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
210 			ngot = iorequest.piod_len;
211 			if ((size_t)ngot < nwant)
212 				errx(1, "short read wanted %zu, got %zd",
213 				    nwant, ngot);
214 			ngot = write(fd, buf, nwant);
215 			if (ngot == -1)
216 				err(1, "write of segment %d failed", i);
217 			if ((size_t)ngot != nwant)
218 				errx(1, "short write");
219 			nleft -= nwant;
220 			iorequest.piod_offs += ngot;
221 		}
222 		php++;
223 	}
224 	sbuf_delete(sb);
225 	freemap(map);
226 }
227 
228 /*
229  * A callback for each_writable_segment() to write out the segment's
230  * program header entry.
231  */
232 static void
233 cb_put_phdr(vm_map_entry_t entry, void *closure)
234 {
235 	struct phdr_closure *phc = (struct phdr_closure *)closure;
236 	Elf_Phdr *phdr = phc->phdr;
237 
238 	phc->offset = round_page(phc->offset);
239 
240 	phdr->p_type = PT_LOAD;
241 	phdr->p_offset = phc->offset;
242 	phdr->p_vaddr = entry->start;
243 	phdr->p_paddr = 0;
244 	phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
245 	phdr->p_align = PAGE_SIZE;
246 	phdr->p_flags = 0;
247 	if (entry->protection & VM_PROT_READ)
248 		phdr->p_flags |= PF_R;
249 	if (entry->protection & VM_PROT_WRITE)
250 		phdr->p_flags |= PF_W;
251 	if (entry->protection & VM_PROT_EXECUTE)
252 		phdr->p_flags |= PF_X;
253 
254 	phc->offset += phdr->p_filesz;
255 	phc->phdr++;
256 }
257 
258 /*
259  * A callback for each_writable_segment() to gather information about
260  * the number of segments and their total size.
261  */
262 static void
263 cb_size_segment(vm_map_entry_t entry, void *closure)
264 {
265 	struct sseg_closure *ssc = (struct sseg_closure *)closure;
266 
267 	ssc->count++;
268 	ssc->size += entry->end - entry->start;
269 }
270 
271 /*
272  * For each segment in the given memory map, call the given function
273  * with a pointer to the map entry and some arbitrary caller-supplied
274  * data.
275  */
276 static void
277 each_writable_segment(vm_map_entry_t map, segment_callback func, void *closure)
278 {
279 	vm_map_entry_t entry;
280 
281 	for (entry = map;  entry != NULL;  entry = entry->next)
282 		(*func)(entry, closure);
283 }
284 
285 static void
286 elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
287 {
288 	lwpid_t *tids;
289 	size_t threads, old_len;
290 	ssize_t size;
291 	int i;
292 
293 	errno = 0;
294 	threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
295 	if (errno)
296 		err(1, "PT_GETNUMLWPS");
297 	tids = malloc(threads * sizeof(*tids));
298 	if (tids == NULL)
299 		errx(1, "out of memory");
300 	errno = 0;
301 	ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
302 	if (errno)
303 		err(1, "PT_GETLWPLIST");
304 
305 	sbuf_start_section(sb, &old_len);
306 	elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);
307 
308 	for (i = 0; i < threads; ++i) {
309 		elf_putnote(NT_PRSTATUS, elf_note_prstatus, tids + i, sb);
310 		elf_putnote(NT_FPREGSET, elf_note_fpregset, tids + i, sb);
311 		elf_putnote(NT_THRMISC, elf_note_thrmisc, tids + i, sb);
312 	}
313 
314 	elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
315 	elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
316 	elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
317 	elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
318 	elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
319 	elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
320 	elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
321 	elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
322 	    sb);
323 	elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
324 
325 	size = sbuf_end_section(sb, old_len, 1, 0);
326 	if (size == -1)
327 		err(1, "sbuf_end_section");
328 	free(tids);
329 	*sizep = size;
330 }
331 
332 /*
333  * Emit one note section to sbuf.
334  */
335 static void
336 elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
337 {
338 	Elf_Note note;
339 	size_t descsz;
340 	ssize_t old_len;
341 	void *desc;
342 
343 	desc = notefunc(arg, &descsz);
344 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
345 	note.n_descsz = descsz;
346 	note.n_type = type;
347 
348 	sbuf_bcat(sb, &note, sizeof(note));
349 	sbuf_start_section(sb, &old_len);
350 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
351 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
352 	if (descsz == 0)
353 		return;
354 	sbuf_start_section(sb, &old_len);
355 	sbuf_bcat(sb, desc, descsz);
356 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
357 	free(desc);
358 }
359 
360 /*
361  * Generate the ELF coredump header.
362  */
363 static void
364 elf_puthdr(pid_t pid, vm_map_entry_t map, void *hdr, size_t hdrsize,
365     size_t notesz, size_t segoff, int numsegs)
366 {
367 	Elf_Ehdr *ehdr;
368 	Elf_Phdr *phdr;
369 	struct phdr_closure phc;
370 
371 	ehdr = (Elf_Ehdr *)hdr;
372 	phdr = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr));
373 
374 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
375 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
376 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
377 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
378 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
379 	ehdr->e_ident[EI_DATA] = ELF_DATA;
380 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
381 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
382 	ehdr->e_ident[EI_ABIVERSION] = 0;
383 	ehdr->e_ident[EI_PAD] = 0;
384 	ehdr->e_type = ET_CORE;
385 	ehdr->e_machine = ELF_ARCH;
386 	ehdr->e_version = EV_CURRENT;
387 	ehdr->e_entry = 0;
388 	ehdr->e_phoff = sizeof(Elf_Ehdr);
389 	ehdr->e_flags = 0;
390 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
391 	ehdr->e_phentsize = sizeof(Elf_Phdr);
392 	ehdr->e_phnum = numsegs + 1;
393 	ehdr->e_shentsize = sizeof(Elf_Shdr);
394 	ehdr->e_shnum = 0;
395 	ehdr->e_shstrndx = SHN_UNDEF;
396 
397 	/*
398 	 * Fill in the program header entries.
399 	 */
400 
401 	/* The note segement. */
402 	phdr->p_type = PT_NOTE;
403 	phdr->p_offset = hdrsize;
404 	phdr->p_vaddr = 0;
405 	phdr->p_paddr = 0;
406 	phdr->p_filesz = notesz;
407 	phdr->p_memsz = 0;
408 	phdr->p_flags = PF_R;
409 	phdr->p_align = sizeof(Elf32_Size);
410 	phdr++;
411 
412 	/* All the writable segments from the program. */
413 	phc.phdr = phdr;
414 	phc.offset = segoff;
415 	each_writable_segment(map, cb_put_phdr, &phc);
416 }
417 
418 /*
419  * Free the memory map.
420  */
421 static void
422 freemap(vm_map_entry_t map)
423 {
424 
425 	while (map != NULL) {
426 		vm_map_entry_t next = map->next;
427 		free(map);
428 		map = next;
429 	}
430 }
431 
432 /*
433  * Read the process's memory map using kinfo_getvmmap(), and return a list of
434  * VM map entries.  Only the non-device read/writable segments are
435  * returned.  The map entries in the list aren't fully filled in; only
436  * the items we need are present.
437  */
438 static vm_map_entry_t
439 readmap(pid_t pid)
440 {
441 	vm_map_entry_t ent, *linkp, map;
442 	struct kinfo_vmentry *vmentl, *kve;
443 	int i, nitems;
444 
445 	vmentl = kinfo_getvmmap(pid, &nitems);
446 	if (vmentl == NULL)
447 		err(1, "cannot retrieve mappings for %u process", pid);
448 
449 	map = NULL;
450 	linkp = &map;
451 	for (i = 0; i < nitems; i++) {
452 		kve = &vmentl[i];
453 
454 		/*
455 		 * Ignore 'malformed' segments or ones representing memory
456 		 * mapping with MAP_NOCORE on.
457 		 * If the 'full' support is disabled, just dump the most
458 		 * meaningful data segments.
459 		 */
460 		if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
461 		    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
462 		    kve->kve_type == KVME_TYPE_DEAD ||
463 		    kve->kve_type == KVME_TYPE_UNKNOWN ||
464 		    ((pflags & PFLAGS_FULL) == 0 &&
465 		    kve->kve_type != KVME_TYPE_DEFAULT &&
466 		    kve->kve_type != KVME_TYPE_VNODE &&
467 		    kve->kve_type != KVME_TYPE_SWAP))
468 			continue;
469 
470 		ent = calloc(1, sizeof(*ent));
471 		if (ent == NULL)
472 			errx(1, "out of memory");
473 		ent->start = (vm_offset_t)kve->kve_start;
474 		ent->end = (vm_offset_t)kve->kve_end;
475 		ent->protection = VM_PROT_READ | VM_PROT_WRITE;
476 		if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
477 			ent->protection |= VM_PROT_EXECUTE;
478 
479 		*linkp = ent;
480 		linkp = &ent->next;
481 	}
482 	free(vmentl);
483 	return (map);
484 }
485 
486 /*
487  * Miscellaneous note out functions.
488  */
489 
490 static void *
491 elf_note_prpsinfo(void *arg, size_t *sizep)
492 {
493 	pid_t pid;
494 	prpsinfo_t *psinfo;
495 	struct kinfo_proc kip;
496 	size_t len;
497 	int name[4];
498 
499 	pid = *(pid_t *)arg;
500 	psinfo = calloc(1, sizeof(*psinfo));
501 	if (psinfo == NULL)
502 		errx(1, "out of memory");
503 	psinfo->pr_version = PRPSINFO_VERSION;
504 	psinfo->pr_psinfosz = sizeof(prpsinfo_t);
505 
506 	name[0] = CTL_KERN;
507 	name[1] = KERN_PROC;
508 	name[2] = KERN_PROC_PID;
509 	name[3] = pid;
510 	len = sizeof(kip);
511 	if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
512 		err(1, "kern.proc.pid.%u", pid);
513 	if (kip.ki_pid != pid)
514 		err(1, "kern.proc.pid.%u", pid);
515 	strncpy(psinfo->pr_fname, kip.ki_comm, MAXCOMLEN);
516 	strncpy(psinfo->pr_psargs, psinfo->pr_fname, PRARGSZ);
517 
518 	*sizep = sizeof(*psinfo);
519 	return (psinfo);
520 }
521 
522 static void *
523 elf_note_prstatus(void *arg, size_t *sizep)
524 {
525 	lwpid_t tid;
526 	prstatus_t *status;
527 
528 	tid = *(lwpid_t *)arg;
529 	status = calloc(1, sizeof(*status));
530 	if (status == NULL)
531 		errx(1, "out of memory");
532 	status->pr_version = PRSTATUS_VERSION;
533 	status->pr_statussz = sizeof(prstatus_t);
534 	status->pr_gregsetsz = sizeof(gregset_t);
535 	status->pr_fpregsetsz = sizeof(fpregset_t);
536 	status->pr_osreldate = __FreeBSD_version;
537 	status->pr_pid = tid;
538 	ptrace(PT_GETREGS, tid, (void *)&status->pr_reg, 0);
539 
540 	*sizep = sizeof(*status);
541 	return (status);
542 }
543 
544 static void *
545 elf_note_fpregset(void *arg, size_t *sizep)
546 {
547 	lwpid_t tid;
548 	prfpregset_t *fpregset;
549 
550 	tid = *(lwpid_t *)arg;
551 	fpregset = calloc(1, sizeof(*fpregset));
552 	if (fpregset == NULL)
553 		errx(1, "out of memory");
554 	ptrace(PT_GETFPREGS, tid, (void *)fpregset, 0);
555 
556 	*sizep = sizeof(*fpregset);
557 	return (fpregset);
558 }
559 
560 static void *
561 elf_note_thrmisc(void *arg, size_t *sizep)
562 {
563 	lwpid_t tid;
564 	struct ptrace_lwpinfo lwpinfo;
565 	thrmisc_t *thrmisc;
566 
567 	tid = *(lwpid_t *)arg;
568 	thrmisc = calloc(1, sizeof(*thrmisc));
569 	if (thrmisc == NULL)
570 		errx(1, "out of memory");
571 	ptrace(PT_LWPINFO, tid, (void *)&lwpinfo,
572 	    sizeof(lwpinfo));
573 	memset(&thrmisc->_pad, 0, sizeof(thrmisc->_pad));
574 	strcpy(thrmisc->pr_tname, lwpinfo.pl_tdname);
575 
576 	*sizep = sizeof(*thrmisc);
577 	return (thrmisc);
578 }
579 
580 static void *
581 procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
582 {
583 	size_t len, oldlen;
584 	pid_t pid;
585 	int name[4], structsize;
586 	void *buf, *p;
587 
588 	pid = *(pid_t *)arg;
589 	structsize = structsz;
590 	name[0] = CTL_KERN;
591 	name[1] = KERN_PROC;
592 	name[2] = what;
593 	name[3] = pid;
594 	len = 0;
595 	if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
596 		err(1, "kern.proc.%d.%u", what, pid);
597 	buf = calloc(1, sizeof(structsize) + len * 4 / 3);
598 	if (buf == NULL)
599 		errx(1, "out of memory");
600 	bcopy(&structsize, buf, sizeof(structsize));
601 	p = (char *)buf + sizeof(structsize);
602 	if (sysctl(name, 4, p, &len, NULL, 0) == -1)
603 		err(1, "kern.proc.%d.%u", what, pid);
604 
605 	*sizep = sizeof(structsize) + len;
606 	return (buf);
607 }
608 
609 static void *
610 elf_note_procstat_proc(void *arg, size_t *sizep)
611 {
612 
613 	return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
614 	    sizeof(struct kinfo_proc), sizep));
615 }
616 
617 static void *
618 elf_note_procstat_files(void *arg, size_t *sizep)
619 {
620 
621 	return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
622 	    sizeof(struct kinfo_file), sizep));
623 }
624 
625 static void *
626 elf_note_procstat_vmmap(void *arg, size_t *sizep)
627 {
628 
629 	return (procstat_sysctl(arg, KERN_PROC_VMMAP,
630 	    sizeof(struct kinfo_vmentry), sizep));
631 }
632 
633 static void *
634 elf_note_procstat_groups(void *arg, size_t *sizep)
635 {
636 
637 	return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
638 }
639 
640 static void *
641 elf_note_procstat_umask(void *arg, size_t *sizep)
642 {
643 
644 	return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
645 }
646 
647 static void *
648 elf_note_procstat_osrel(void *arg, size_t *sizep)
649 {
650 
651 	return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
652 }
653 
654 static void *
655 elf_note_procstat_psstrings(void *arg, size_t *sizep)
656 {
657 
658 	return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
659 	    sizeof(vm_offset_t), sizep));
660 }
661 
662 static void *
663 elf_note_procstat_auxv(void *arg, size_t *sizep)
664 {
665 
666 	return (procstat_sysctl(arg, KERN_PROC_AUXV,
667 	    sizeof(Elf_Auxinfo), sizep));
668 }
669 
670 static void *
671 elf_note_procstat_rlimit(void *arg, size_t *sizep)
672 {
673 	pid_t pid;
674 	size_t len;
675 	int i, name[5], structsize;
676 	void *buf, *p;
677 
678 	pid = *(pid_t *)arg;
679 	structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
680 	buf = calloc(1, sizeof(structsize) + structsize);
681 	if (buf == NULL)
682 		errx(1, "out of memory");
683 	bcopy(&structsize, buf, sizeof(structsize));
684 	p = (char *)buf + sizeof(structsize);
685 	name[0] = CTL_KERN;
686 	name[1] = KERN_PROC;
687 	name[2] = KERN_PROC_RLIMIT;
688 	name[3] = pid;
689 	len = sizeof(struct rlimit);
690 	for (i = 0; i < RLIM_NLIMITS; i++) {
691 		name[4] = i;
692 		if (sysctl(name, 5, p, &len, NULL, 0) == -1)
693 			err(1, "kern.proc.rlimit.%u", pid);
694 		if (len != sizeof(struct rlimit))
695 			errx(1, "kern.proc.rlimit.%u: short read", pid);
696 		p += len;
697 	}
698 
699 	*sizep = sizeof(structsize) + structsize;
700 	return (buf);
701 }
702 
703 struct dumpers elfdump = { elf_ident, elf_coredump };
704 TEXT_SET(dumpset, elfdump);
705