xref: /freebsd/usr.bin/gcore/elfcore.c (revision 10626f7384f9e39a8c02dfd475b1fd14fd7395dd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/endian.h>
33 #include <sys/param.h>
34 #include <sys/procfs.h>
35 #include <sys/ptrace.h>
36 #include <sys/queue.h>
37 #include <sys/linker_set.h>
38 #include <sys/sbuf.h>
39 #include <sys/sysctl.h>
40 #include <sys/user.h>
41 #include <sys/wait.h>
42 #include <machine/elf.h>
43 #include <vm/vm_param.h>
44 #include <vm/vm.h>
45 #include <assert.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <stdbool.h>
50 #include <stdint.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 #include <libutil.h>
56 
57 #include "extern.h"
58 
59 /*
60  * Code for generating ELF core dumps.
61  */
62 
63 struct map_entry {
64 	struct map_entry *next;
65 	vm_offset_t start;
66 	vm_offset_t end;
67 	vm_prot_t protection;
68 };
69 
70 typedef void (*segment_callback)(struct map_entry *, void *);
71 
72 /* Closure for cb_put_phdr(). */
73 struct phdr_closure {
74 	Elf_Phdr *phdr;		/* Program header to fill in */
75 	Elf_Off offset;		/* Offset of segment in core file */
76 };
77 
78 /* Closure for cb_size_segment(). */
79 struct sseg_closure {
80 	int count;		/* Count of writable segments. */
81 	size_t size;		/* Total size of all writable segments. */
82 };
83 
84 #ifdef ELFCORE_COMPAT_32
85 typedef struct prpsinfo32 elfcore_prpsinfo_t;
86 #else
87 typedef prpsinfo_t elfcore_prpsinfo_t;
88 #endif
89 
90 typedef void* (*notefunc_t)(void *, size_t *);
91 
92 static void cb_put_phdr(struct map_entry *, void *);
93 static void cb_size_segment(struct map_entry *, void *);
94 static void each_dumpable_segment(struct map_entry *, segment_callback,
95     void *closure);
96 static void elf_detach(void);	/* atexit() handler. */
97 static void *elf_note_prpsinfo(void *, size_t *);
98 #if defined(__i386__) || defined(__amd64__)
99 static void *elf_note_x86_xstate(void *, size_t *);
100 #endif
101 #if defined(__powerpc__)
102 static void *elf_note_powerpc_vmx(void *, size_t *);
103 static void *elf_note_powerpc_vsx(void *, size_t *);
104 #endif
105 static void *elf_note_procstat_auxv(void *, size_t *);
106 static void *elf_note_procstat_files(void *, size_t *);
107 static void *elf_note_procstat_groups(void *, size_t *);
108 static void *elf_note_procstat_kqueues(void *, size_t *);
109 static void *elf_note_procstat_osrel(void *, size_t *);
110 static void *elf_note_procstat_proc(void *, size_t *);
111 static void *elf_note_procstat_psstrings(void *, size_t *);
112 static void *elf_note_procstat_rlimit(void *, size_t *);
113 static void *elf_note_procstat_umask(void *, size_t *);
114 static void *elf_note_procstat_vmmap(void *, size_t *);
115 static void elf_puthdr(int, pid_t, struct map_entry *, void *, size_t, size_t,
116     size_t, int);
117 static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
118 static void elf_putnotes(pid_t, struct sbuf *, size_t *);
119 static void elf_putregnote(int, lwpid_t, struct sbuf *);
120 static void freemap(struct map_entry *);
121 static struct map_entry *readmap(pid_t);
122 static void *procstat_sysctl(void *, int, size_t, size_t *sizep);
123 
124 static pid_t g_pid;		/* Pid being dumped, global for elf_detach */
125 static int g_status;		/* proc status after ptrace attach */
126 
127 static int
elf_ident(int efd,pid_t pid __unused,char * binfile __unused)128 elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
129 {
130 	Elf_Ehdr hdr;
131 	int cnt;
132 	uint16_t machine;
133 
134 	cnt = read(efd, &hdr, sizeof(hdr));
135 	if (cnt != sizeof(hdr))
136 		return (0);
137 	if (!IS_ELF(hdr))
138 		return (0);
139 	switch (hdr.e_ident[EI_DATA]) {
140 	case ELFDATA2LSB:
141 		machine = le16toh(hdr.e_machine);
142 		break;
143 	case ELFDATA2MSB:
144 		machine = be16toh(hdr.e_machine);
145 		break;
146 	default:
147 		return (0);
148 	}
149 	if (!ELF_MACHINE_OK(machine))
150 		return (0);
151 
152 	/* Looks good. */
153 	return (1);
154 }
155 
156 static void
elf_detach(void)157 elf_detach(void)
158 {
159 	int sig;
160 
161 	if (g_pid != 0) {
162 		/*
163 		 * Forward any pending signals. SIGSTOP is generated by ptrace
164 		 * itself, so ignore it.
165 		 */
166 		sig = WIFSTOPPED(g_status) ? WSTOPSIG(g_status) : 0;
167 		if (sig == SIGSTOP)
168 			sig = 0;
169 		ptrace(PT_DETACH, g_pid, (caddr_t)1, sig);
170 	}
171 }
172 
173 /*
174  * Write an ELF coredump for the given pid to the given fd.
175  */
176 static void
elf_coredump(int efd,int fd,pid_t pid)177 elf_coredump(int efd, int fd, pid_t pid)
178 {
179 	struct map_entry *map;
180 	struct sseg_closure seginfo;
181 	struct sbuf *sb;
182 	void *hdr;
183 	size_t hdrsize, notesz, segoff;
184 	ssize_t n, old_len;
185 	Elf_Phdr *php;
186 	int i;
187 
188 	/* Attach to process to dump. */
189 	g_pid = pid;
190 	if (atexit(elf_detach) != 0)
191 		err(1, "atexit");
192 	errno = 0;
193 	ptrace(PT_ATTACH, pid, NULL, 0);
194 	if (errno)
195 		err(1, "PT_ATTACH");
196 	if (waitpid(pid, &g_status, 0) == -1)
197 		err(1, "waitpid");
198 
199 	/* Get the program's memory map. */
200 	map = readmap(pid);
201 
202 	/* Size the program segments. */
203 	seginfo.count = 0;
204 	seginfo.size = 0;
205 	each_dumpable_segment(map, cb_size_segment, &seginfo);
206 
207 	/*
208 	 * Build the header and the notes using sbuf and write to the file.
209 	 */
210 	sb = sbuf_new_auto();
211 	hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
212 	if (seginfo.count + 1 >= PN_XNUM)
213 		hdrsize += sizeof(Elf_Shdr);
214 	/* Start header + notes section. */
215 	sbuf_start_section(sb, NULL);
216 	/* Make empty header subsection. */
217 	sbuf_start_section(sb, &old_len);
218 	sbuf_putc(sb, 0);
219 	sbuf_end_section(sb, old_len, hdrsize, 0);
220 	/* Put notes. */
221 	elf_putnotes(pid, sb, &notesz);
222 	/* Align up to a page boundary for the program segments. */
223 	sbuf_end_section(sb, -1, getpagesize(), 0);
224 	if (sbuf_finish(sb) != 0)
225 		err(1, "sbuf_finish");
226 	hdr = sbuf_data(sb);
227 	segoff = sbuf_len(sb);
228 	/* Fill in the header. */
229 	elf_puthdr(efd, pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);
230 
231 	n = write(fd, hdr, segoff);
232 	if (n == -1)
233 		err(1, "write");
234 	if (n < segoff)
235               errx(1, "short write");
236 
237 	/* Write the contents of all of the writable segments. */
238 	php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
239 	for (i = 0;  i < seginfo.count;  i++) {
240 		struct ptrace_io_desc iorequest;
241 		uintmax_t nleft = php->p_filesz;
242 
243 		iorequest.piod_op = PIOD_READ_D;
244 		iorequest.piod_offs = (caddr_t)(uintptr_t)php->p_vaddr;
245 		while (nleft > 0) {
246 			char buf[8*1024];
247 			size_t nwant;
248 			ssize_t ngot;
249 
250 			if (nleft > sizeof(buf))
251 				nwant = sizeof buf;
252 			else
253 				nwant = nleft;
254 			iorequest.piod_addr = buf;
255 			iorequest.piod_len = nwant;
256 			ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
257 			ngot = iorequest.piod_len;
258 			if ((size_t)ngot < nwant)
259 				errx(1, "short read wanted %zu, got %zd",
260 				    nwant, ngot);
261 			ngot = write(fd, buf, nwant);
262 			if (ngot == -1)
263 				err(1, "write of segment %d failed", i);
264 			if ((size_t)ngot != nwant)
265 				errx(1, "short write");
266 			nleft -= nwant;
267 			iorequest.piod_offs += ngot;
268 		}
269 		php++;
270 	}
271 	sbuf_delete(sb);
272 	freemap(map);
273 }
274 
275 /*
276  * A callback for each_dumpable_segment() to write out the segment's
277  * program header entry.
278  */
279 static void
cb_put_phdr(struct map_entry * entry,void * closure)280 cb_put_phdr(struct map_entry *entry, void *closure)
281 {
282 	struct phdr_closure *phc = (struct phdr_closure *)closure;
283 	Elf_Phdr *phdr = phc->phdr;
284 	size_t page_size;
285 
286 	page_size = getpagesize();
287 	phc->offset = roundup2(phc->offset, page_size);
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_dumpable_segment() to gather information about
309  * the number of segments and their total size.
310  */
311 static void
cb_size_segment(struct map_entry * entry,void * closure)312 cb_size_segment(struct map_entry *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
each_dumpable_segment(struct map_entry * map,segment_callback func,void * closure)326 each_dumpable_segment(struct map_entry *map, segment_callback func,
327     void *closure)
328 {
329 	struct map_entry *entry;
330 
331 	for (entry = map; entry != NULL; entry = entry->next)
332 		(*func)(entry, closure);
333 }
334 
335 static void
elf_putnotes(pid_t pid,struct sbuf * sb,size_t * sizep)336 elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
337 {
338 	lwpid_t *tids;
339 	size_t threads, old_len;
340 	ssize_t size;
341 	int i;
342 
343 	errno = 0;
344 	threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
345 	if (errno)
346 		err(1, "PT_GETNUMLWPS");
347 	tids = malloc(threads * sizeof(*tids));
348 	if (tids == NULL)
349 		errx(1, "out of memory");
350 	errno = 0;
351 	ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
352 	if (errno)
353 		err(1, "PT_GETLWPLIST");
354 
355 	sbuf_start_section(sb, &old_len);
356 	elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);
357 
358 	for (i = 0; i < threads; ++i) {
359 		elf_putregnote(NT_PRSTATUS, tids[i], sb);
360 		elf_putregnote(NT_FPREGSET, tids[i], sb);
361 		elf_putregnote(NT_THRMISC, tids[i], sb);
362 		elf_putregnote(NT_PTLWPINFO, tids[i], sb);
363 #if defined(__aarch64__) || defined(__arm__)
364 		elf_putregnote(NT_ARM_TLS, tids[i], sb);
365 #endif
366 #if (defined(ELFCORE_COMPAT_32) && defined(__aarch64__)) || defined(__arm__)
367 		elf_putregnote(NT_ARM_VFP, tids[i], sb);
368 #endif
369 #if defined(__i386__) || defined(__amd64__)
370 		elf_putregnote(NT_X86_SEGBASES, tids[i], sb);
371 		elf_putnote(NT_X86_XSTATE, elf_note_x86_xstate, tids + i, sb);
372 #endif
373 #if defined(__powerpc__)
374 		elf_putnote(NT_PPC_VMX, elf_note_powerpc_vmx, tids + i, sb);
375 #ifndef __SPE__
376 		elf_putnote(NT_PPC_VSX, elf_note_powerpc_vsx, tids + i, sb);
377 #endif
378 #endif
379 	}
380 
381 #ifndef ELFCORE_COMPAT_32
382 	elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
383 	elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
384 	elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
385 	elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
386 	elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
387 	elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
388 	elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
389 	elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
390 	    sb);
391 	elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
392 	elf_putnote(NT_PROCSTAT_KQUEUES, elf_note_procstat_kqueues, &pid, sb);
393 #endif
394 
395 	size = sbuf_end_section(sb, old_len, 1, 0);
396 	if (size == -1)
397 		err(1, "sbuf_end_section");
398 	free(tids);
399 	*sizep = size;
400 }
401 
402 /*
403  * Emit one register set note section to sbuf.
404  */
405 static void
elf_putregnote(int type,lwpid_t tid,struct sbuf * sb)406 elf_putregnote(int type, lwpid_t tid, struct sbuf *sb)
407 {
408 	Elf_Note note;
409 	struct iovec iov;
410 	ssize_t old_len;
411 
412 	iov.iov_base = NULL;
413 	iov.iov_len = 0;
414 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
415 		return;
416 	iov.iov_base = calloc(1, iov.iov_len);
417 	if (iov.iov_base == NULL)
418 		errx(1, "out of memory");
419 	if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
420 		errx(1, "failed to fetch register set %d", type);
421 
422 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
423 	note.n_descsz = iov.iov_len;
424 	note.n_type = type;
425 
426 	sbuf_bcat(sb, &note, sizeof(note));
427 	sbuf_start_section(sb, &old_len);
428 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
429 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
430 	sbuf_start_section(sb, &old_len);
431 	sbuf_bcat(sb, iov.iov_base, iov.iov_len);
432 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
433 	free(iov.iov_base);
434 }
435 
436 /*
437  * Emit one note section to sbuf.
438  */
439 static void
elf_putnote(int type,notefunc_t notefunc,void * arg,struct sbuf * sb)440 elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
441 {
442 	Elf_Note note;
443 	size_t descsz;
444 	ssize_t old_len;
445 	void *desc;
446 
447 	desc = notefunc(arg, &descsz);
448 	note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
449 	note.n_descsz = descsz;
450 	note.n_type = type;
451 
452 	sbuf_bcat(sb, &note, sizeof(note));
453 	sbuf_start_section(sb, &old_len);
454 	sbuf_bcat(sb, "FreeBSD", note.n_namesz);
455 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
456 	if (descsz == 0)
457 		return;
458 	sbuf_start_section(sb, &old_len);
459 	sbuf_bcat(sb, desc, descsz);
460 	sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
461 	free(desc);
462 }
463 
464 /*
465  * Generate the ELF coredump header.
466  */
467 static void
elf_puthdr(int efd,pid_t pid,struct map_entry * map,void * hdr,size_t hdrsize,size_t notesz,size_t segoff,int numsegs)468 elf_puthdr(int efd, pid_t pid, struct map_entry *map, void *hdr, size_t hdrsize,
469     size_t notesz, size_t segoff, int numsegs)
470 {
471 	Elf_Ehdr *ehdr, binhdr;
472 	Elf_Phdr *phdr;
473 	Elf_Shdr *shdr;
474 	struct phdr_closure phc;
475 	ssize_t cnt;
476 
477 	cnt = read(efd, &binhdr, sizeof(binhdr));
478 	if (cnt < 0)
479 		err(1, "Failed to re-read ELF header");
480 	else if (cnt != sizeof(binhdr))
481 		errx(1, "Failed to re-read ELF header");
482 
483 	ehdr = (Elf_Ehdr *)hdr;
484 
485 	ehdr->e_ident[EI_MAG0] = ELFMAG0;
486 	ehdr->e_ident[EI_MAG1] = ELFMAG1;
487 	ehdr->e_ident[EI_MAG2] = ELFMAG2;
488 	ehdr->e_ident[EI_MAG3] = ELFMAG3;
489 	ehdr->e_ident[EI_CLASS] = ELF_CLASS;
490 	ehdr->e_ident[EI_DATA] = ELF_DATA;
491 	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
492 	ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
493 	ehdr->e_ident[EI_ABIVERSION] = 0;
494 	ehdr->e_ident[EI_PAD] = 0;
495 	ehdr->e_type = ET_CORE;
496 	ehdr->e_machine = binhdr.e_machine;
497 	ehdr->e_version = EV_CURRENT;
498 	ehdr->e_entry = 0;
499 	ehdr->e_phoff = sizeof(Elf_Ehdr);
500 	ehdr->e_flags = binhdr.e_flags;
501 	ehdr->e_ehsize = sizeof(Elf_Ehdr);
502 	ehdr->e_phentsize = sizeof(Elf_Phdr);
503 	ehdr->e_shentsize = sizeof(Elf_Shdr);
504 	ehdr->e_shstrndx = SHN_UNDEF;
505 	if (numsegs + 1 < PN_XNUM) {
506 		ehdr->e_phnum = numsegs + 1;
507 		ehdr->e_shnum = 0;
508 	} else {
509 		ehdr->e_phnum = PN_XNUM;
510 		ehdr->e_shnum = 1;
511 
512 		ehdr->e_shoff = ehdr->e_phoff +
513 		    (numsegs + 1) * ehdr->e_phentsize;
514 
515 		shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
516 		memset(shdr, 0, sizeof(*shdr));
517 		/*
518 		 * A special first section is used to hold large segment and
519 		 * section counts.  This was proposed by Sun Microsystems in
520 		 * Solaris and has been adopted by Linux; the standard ELF
521 		 * tools are already familiar with the technique.
522 		 *
523 		 * See table 7-7 of the Solaris "Linker and Libraries Guide"
524 		 * (or 12-7 depending on the version of the document) for more
525 		 * details.
526 		 */
527 		shdr->sh_type = SHT_NULL;
528 		shdr->sh_size = ehdr->e_shnum;
529 		shdr->sh_link = ehdr->e_shstrndx;
530 		shdr->sh_info = numsegs + 1;
531 	}
532 
533 	/*
534 	 * Fill in the program header entries.
535 	 */
536 	phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);
537 
538 	/* The note segment. */
539 	phdr->p_type = PT_NOTE;
540 	phdr->p_offset = hdrsize;
541 	phdr->p_vaddr = 0;
542 	phdr->p_paddr = 0;
543 	phdr->p_filesz = notesz;
544 	phdr->p_memsz = 0;
545 	phdr->p_flags = PF_R;
546 	phdr->p_align = sizeof(Elf32_Size);
547 	phdr++;
548 
549 	/* All the writable segments from the program. */
550 	phc.phdr = phdr;
551 	phc.offset = segoff;
552 	each_dumpable_segment(map, cb_put_phdr, &phc);
553 }
554 
555 /*
556  * Free the memory map.
557  */
558 static void
freemap(struct map_entry * map)559 freemap(struct map_entry *map)
560 {
561 	struct map_entry *next;
562 
563 	while (map != NULL) {
564 		next = map->next;
565 		free(map);
566 		map = next;
567 	}
568 }
569 
570 /*
571  * Read the process's memory map using kinfo_getvmmap(), and return a list of
572  * VM map entries.  Only the non-device read/writable segments are
573  * returned.  The map entries in the list aren't fully filled in; only
574  * the items we need are present.
575  */
576 static struct map_entry *
readmap(pid_t pid)577 readmap(pid_t pid)
578 {
579 	struct map_entry *ent, **linkp, *map;
580 	struct kinfo_vmentry *vmentl, *kve;
581 	int i, nitems;
582 
583 	vmentl = kinfo_getvmmap(pid, &nitems);
584 	if (vmentl == NULL)
585 		err(1, "cannot retrieve mappings for %u process", pid);
586 
587 	map = NULL;
588 	linkp = &map;
589 	for (i = 0; i < nitems; i++) {
590 		kve = &vmentl[i];
591 
592 		/*
593 		 * Ignore 'malformed' segments or ones representing memory
594 		 * mapping with MAP_NOCORE on.
595 		 * If the 'full' support is disabled, just dump the most
596 		 * meaningful data segments.
597 		 */
598 		if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
599 		    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
600 		    kve->kve_type == KVME_TYPE_DEAD ||
601 		    kve->kve_type == KVME_TYPE_UNKNOWN ||
602 		    ((pflags & PFLAGS_FULL) == 0 &&
603 		    kve->kve_type != KVME_TYPE_DEFAULT &&
604 		    kve->kve_type != KVME_TYPE_VNODE &&
605 		    kve->kve_type != KVME_TYPE_SWAP &&
606 		    kve->kve_type != KVME_TYPE_PHYS))
607 			continue;
608 
609 		ent = calloc(1, sizeof(*ent));
610 		if (ent == NULL)
611 			errx(1, "out of memory");
612 		ent->start = (vm_offset_t)kve->kve_start;
613 		ent->end = (vm_offset_t)kve->kve_end;
614 		ent->protection = VM_PROT_READ;
615 		if ((kve->kve_protection & KVME_PROT_WRITE) != 0)
616 			ent->protection |= VM_PROT_WRITE;
617 		if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
618 			ent->protection |= VM_PROT_EXECUTE;
619 
620 		*linkp = ent;
621 		linkp = &ent->next;
622 	}
623 	free(vmentl);
624 	return (map);
625 }
626 
627 /*
628  * Miscellaneous note out functions.
629  */
630 
631 static void *
elf_note_prpsinfo(void * arg,size_t * sizep)632 elf_note_prpsinfo(void *arg, size_t *sizep)
633 {
634 	char *cp, *end;
635 	pid_t pid;
636 	elfcore_prpsinfo_t *psinfo;
637 	struct kinfo_proc kip;
638 	size_t len;
639 	int name[4];
640 
641 	pid = *(pid_t *)arg;
642 	psinfo = calloc(1, sizeof(*psinfo));
643 	if (psinfo == NULL)
644 		errx(1, "out of memory");
645 	psinfo->pr_version = PRPSINFO_VERSION;
646 	psinfo->pr_psinfosz = sizeof(*psinfo);
647 
648 	name[0] = CTL_KERN;
649 	name[1] = KERN_PROC;
650 	name[2] = KERN_PROC_PID;
651 	name[3] = pid;
652 	len = sizeof(kip);
653 	if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
654 		err(1, "kern.proc.pid.%u", pid);
655 	if (kip.ki_pid != pid)
656 		err(1, "kern.proc.pid.%u", pid);
657 	strlcpy(psinfo->pr_fname, kip.ki_comm, sizeof(psinfo->pr_fname));
658 	name[2] = KERN_PROC_ARGS;
659 	len = sizeof(psinfo->pr_psargs) - 1;
660 	if (sysctl(name, 4, psinfo->pr_psargs, &len, NULL, 0) == 0 && len > 0) {
661 		cp = psinfo->pr_psargs;
662 		end = cp + len - 1;
663 		for (;;) {
664 			cp = memchr(cp, '\0', end - cp);
665 			if (cp == NULL)
666 				break;
667 			*cp = ' ';
668 		}
669 	} else
670 		strlcpy(psinfo->pr_psargs, kip.ki_comm,
671 		    sizeof(psinfo->pr_psargs));
672 	psinfo->pr_pid = pid;
673 
674 	*sizep = sizeof(*psinfo);
675 	return (psinfo);
676 }
677 
678 #if defined(__i386__) || defined(__amd64__)
679 static void *
elf_note_x86_xstate(void * arg,size_t * sizep)680 elf_note_x86_xstate(void *arg, size_t *sizep)
681 {
682 	lwpid_t tid;
683 	char *xstate;
684 	static bool xsave_checked = false;
685 	static struct ptrace_xstate_info info;
686 
687 	tid = *(lwpid_t *)arg;
688 	if (!xsave_checked) {
689 		if (ptrace(PT_GETXSTATE_INFO, tid, (void *)&info,
690 		    sizeof(info)) != 0)
691 			info.xsave_len = 0;
692 		xsave_checked = true;
693 	}
694 	if (info.xsave_len == 0) {
695 		*sizep = 0;
696 		return (NULL);
697 	}
698 	xstate = calloc(1, info.xsave_len);
699 	ptrace(PT_GETXSTATE, tid, xstate, 0);
700 	*(uint64_t *)(xstate + X86_XSTATE_XCR0_OFFSET) = info.xsave_mask;
701 	*sizep = info.xsave_len;
702 	return (xstate);
703 }
704 #endif
705 
706 #if defined(__powerpc__)
707 static void *
elf_note_powerpc_vmx(void * arg,size_t * sizep)708 elf_note_powerpc_vmx(void *arg, size_t *sizep)
709 {
710 	lwpid_t tid;
711 	struct vmxreg *vmx;
712 	static bool has_vmx = true;
713 	struct vmxreg info;
714 
715 	tid = *(lwpid_t *)arg;
716 	if (has_vmx) {
717 		if (ptrace(PT_GETVRREGS, tid, (void *)&info,
718 		    sizeof(info)) != 0)
719 			has_vmx = false;
720 	}
721 	if (!has_vmx) {
722 		*sizep = 0;
723 		return (NULL);
724 	}
725 	vmx = calloc(1, sizeof(*vmx));
726 	memcpy(vmx, &info, sizeof(*vmx));
727 	*sizep = sizeof(*vmx);
728 	return (vmx);
729 }
730 
731 static void *
elf_note_powerpc_vsx(void * arg,size_t * sizep)732 elf_note_powerpc_vsx(void *arg, size_t *sizep)
733 {
734 	lwpid_t tid;
735 	char *vshr_data;
736 	static bool has_vsx = true;
737 	uint64_t vshr[32];
738 
739 	tid = *(lwpid_t *)arg;
740 	if (has_vsx) {
741 		if (ptrace(PT_GETVSRREGS, tid, (void *)vshr,
742 		    sizeof(vshr)) != 0)
743 			has_vsx = false;
744 	}
745 	if (!has_vsx) {
746 		*sizep = 0;
747 		return (NULL);
748 	}
749 	vshr_data = calloc(1, sizeof(vshr));
750 	memcpy(vshr_data, vshr, sizeof(vshr));
751 	*sizep = sizeof(vshr);
752 	return (vshr_data);
753 }
754 #endif
755 
756 static void *
procstat_sysctl(void * arg,int what,size_t structsz,size_t * sizep)757 procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
758 {
759 	size_t len;
760 	pid_t pid;
761 	int name[5], structsize;
762 	void *buf, *p;
763 
764 	pid = *(pid_t *)arg;
765 	structsize = structsz;
766 	name[0] = CTL_KERN;
767 	name[1] = KERN_PROC;
768 	name[2] = what;
769 	name[3] = pid;
770 	len = 0;
771 	if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
772 		err(1, "kern.proc.%d.%u", what, pid);
773 	buf = calloc(1, sizeof(structsize) + len * 4 / 3);
774 	if (buf == NULL)
775 		errx(1, "out of memory");
776 	bcopy(&structsize, buf, sizeof(structsize));
777 	p = (char *)buf + sizeof(structsize);
778 	if (sysctl(name, 4, p, &len, NULL, 0) == -1)
779 		err(1, "kern.proc.%d.%u", what, pid);
780 
781 	*sizep = sizeof(structsize) + len;
782 	return (buf);
783 }
784 
785 static void *
elf_note_procstat_proc(void * arg,size_t * sizep)786 elf_note_procstat_proc(void *arg, size_t *sizep)
787 {
788 
789 	return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
790 	    sizeof(struct kinfo_proc), sizep));
791 }
792 
793 static void *
elf_note_procstat_files(void * arg,size_t * sizep)794 elf_note_procstat_files(void *arg, size_t *sizep)
795 {
796 
797 	return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
798 	    sizeof(struct kinfo_file), sizep));
799 }
800 
801 static void *
elf_note_procstat_vmmap(void * arg,size_t * sizep)802 elf_note_procstat_vmmap(void *arg, size_t *sizep)
803 {
804 
805 	return (procstat_sysctl(arg, KERN_PROC_VMMAP,
806 	    sizeof(struct kinfo_vmentry), sizep));
807 }
808 
809 static void *
elf_note_procstat_groups(void * arg,size_t * sizep)810 elf_note_procstat_groups(void *arg, size_t *sizep)
811 {
812 
813 	return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
814 }
815 
816 static void *
elf_note_procstat_umask(void * arg,size_t * sizep)817 elf_note_procstat_umask(void *arg, size_t *sizep)
818 {
819 
820 	return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
821 }
822 
823 static void *
elf_note_procstat_osrel(void * arg,size_t * sizep)824 elf_note_procstat_osrel(void *arg, size_t *sizep)
825 {
826 
827 	return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
828 }
829 
830 static void *
elf_note_procstat_psstrings(void * arg,size_t * sizep)831 elf_note_procstat_psstrings(void *arg, size_t *sizep)
832 {
833 
834 	return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
835 	    sizeof(vm_offset_t), sizep));
836 }
837 
838 static void *
elf_note_procstat_auxv(void * arg,size_t * sizep)839 elf_note_procstat_auxv(void *arg, size_t *sizep)
840 {
841 
842 	return (procstat_sysctl(arg, KERN_PROC_AUXV,
843 	    sizeof(Elf_Auxinfo), sizep));
844 }
845 
846 static void *
elf_note_procstat_kqueues(void * arg,size_t * sizep)847 elf_note_procstat_kqueues(void *arg, size_t *sizep)
848 {
849 
850 	return (procstat_sysctl(arg, KERN_PROC_KQUEUE,
851 	    sizeof(struct kinfo_knote), sizep));
852 }
853 
854 static void *
elf_note_procstat_rlimit(void * arg,size_t * sizep)855 elf_note_procstat_rlimit(void *arg, size_t *sizep)
856 {
857 	pid_t pid;
858 	size_t len;
859 	int i, name[5], structsize;
860 	void *buf, *p;
861 
862 	pid = *(pid_t *)arg;
863 	structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
864 	buf = calloc(1, sizeof(structsize) + structsize);
865 	if (buf == NULL)
866 		errx(1, "out of memory");
867 	bcopy(&structsize, buf, sizeof(structsize));
868 	p = (char *)buf + sizeof(structsize);
869 	name[0] = CTL_KERN;
870 	name[1] = KERN_PROC;
871 	name[2] = KERN_PROC_RLIMIT;
872 	name[3] = pid;
873 	len = sizeof(struct rlimit);
874 	for (i = 0; i < RLIM_NLIMITS; i++) {
875 		name[4] = i;
876 		if (sysctl(name, 5, p, &len, NULL, 0) == -1)
877 			err(1, "kern.proc.rlimit.%u", pid);
878 		if (len != sizeof(struct rlimit))
879 			errx(1, "kern.proc.rlimit.%u: short read", pid);
880 		p += len;
881 	}
882 
883 	*sizep = sizeof(structsize) + structsize;
884 	return (buf);
885 }
886 
887 struct dumpers __elfN(dump) = { elf_ident, elf_coredump };
888 TEXT_SET(dumpset, __elfN(dump));
889