savecore.c revision 1.43 1 /* $NetBSD: savecore.c,v 1.43 2000/10/08 07:04:28 darrenr Exp $ */
2
3 /*-
4 * Copyright (c) 1986, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\n\
39 The Regents of the University of California. All rights reserved.\n");
40 #endif /* not lint */
41
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)savecore.c 8.5 (Berkeley) 4/28/95";
45 #else
46 __RCSID("$NetBSD: savecore.c,v 1.43 2000/10/08 07:04:28 darrenr Exp $");
47 #endif
48 #endif /* not lint */
49
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 #include <sys/mount.h>
53 #include <sys/syslog.h>
54 #include <sys/time.h>
55
56 #include <dirent.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <nlist.h>
60 #include <paths.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <time.h>
65 #include <tzfile.h>
66 #include <unistd.h>
67 #include <limits.h>
68 #include <kvm.h>
69
70 extern FILE *zopen __P((const char *fname, const char *mode, int bits));
71
72 #define KREAD(kd, addr, p)\
73 (kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
74
75 struct nlist current_nl[] = { /* Namelist for currently running system. */
76 #define X_DUMPDEV 0
77 { "_dumpdev" },
78 #define X_DUMPLO 1
79 { "_dumplo" },
80 #define X_TIME 2
81 { "_time" },
82 #define X_DUMPSIZE 3
83 { "_dumpsize" },
84 #define X_VERSION 4
85 { "_version" },
86 #define X_PANICSTR 5
87 { "_panicstr" },
88 #define X_DUMPMAG 6
89 { "_dumpmag" },
90 { NULL },
91 };
92 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
93 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
94
95 struct nlist dump_nl[] = { /* Name list for dumped system. */
96 { "_dumpdev" }, /* Entries MUST be the same as */
97 { "_dumplo" }, /* those in current_nl[]. */
98 { "_time" },
99 { "_dumpsize" },
100 { "_version" },
101 { "_panicstr" },
102 { "_dumpmag" },
103 { NULL },
104 };
105
106 /* Types match kernel declarations. */
107 long dumplo; /* where dump starts on dumpdev */
108 int dumpmag; /* magic number in dump */
109 int dumpsize; /* amount of memory dumped */
110
111 char *kernel = _PATH_UNIX;
112 char *dirname; /* directory to save dumps in */
113 char *ddname; /* name of dump device */
114 dev_t dumpdev; /* dump device */
115 int dumpfd; /* read/write descriptor on block dev */
116 kvm_t *kd_dump; /* kvm descriptor on block dev */
117 time_t now; /* current date */
118 char panic_mesg[1024];
119 long panicstr;
120 char vers[1024];
121
122 int clear, compress, force, verbose; /* flags */
123
124 void check_kmem __P((void));
125 int check_space __P((void));
126 void clear_dump __P((void));
127 int Create __P((char *, int));
128 int dump_exists __P((void));
129 char *find_dev __P((dev_t, int));
130 int get_crashtime __P((void));
131 void kmem_setup __P((void));
132 void log __P((int, char *, ...));
133 void Lseek __P((int, off_t, int));
134 int main __P((int, char *[]));
135 int Open __P((char *, int rw));
136 char *rawname __P((char *s));
137 void save_core __P((void));
138 void usage __P((void));
139 void Write __P((int, void *, int));
140
141 int
142 main(argc, argv)
143 int argc;
144 char *argv[];
145 {
146 int ch;
147
148 openlog("savecore", LOG_PERROR, LOG_DAEMON);
149
150 while ((ch = getopt(argc, argv, "cdfN:vz")) != -1)
151 switch(ch) {
152 case 'c':
153 clear = 1;
154 break;
155 case 'd': /* Not documented. */
156 case 'v':
157 verbose = 1;
158 break;
159 case 'f':
160 force = 1;
161 break;
162 case 'N':
163 kernel = optarg;
164 break;
165 case 'z':
166 compress = 1;
167 break;
168 case '?':
169 default:
170 usage();
171 }
172 argc -= optind;
173 argv += optind;
174
175 if (!clear) {
176 if (argc != 1 && argc != 2)
177 usage();
178 dirname = argv[0];
179 }
180 if (argc == 2)
181 kernel = argv[1];
182
183 (void)time(&now);
184 kmem_setup();
185
186 if (clear) {
187 clear_dump();
188 exit(0);
189 }
190
191 if (!dump_exists() && !force)
192 exit(1);
193
194 check_kmem();
195
196 if (panicstr)
197 syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
198 else
199 syslog(LOG_ALERT, "reboot");
200
201 if ((!get_crashtime() || !check_space()) && !force)
202 exit(1);
203
204 save_core();
205
206 clear_dump();
207 exit(0);
208 }
209
210 void
211 kmem_setup()
212 {
213 kvm_t *kd_kern;
214 char errbuf[_POSIX2_LINE_MAX];
215 int i, hdrsz;
216
217 /*
218 * Some names we need for the currently running system, others for
219 * the system that was running when the dump was made. The values
220 * obtained from the current system are used to look for things in
221 * /dev/kmem that cannot be found in the kernel namelist, but are
222 * presumed to be the same (since the disk partitions are probably
223 * the same!)
224 */
225 kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
226 if (kd_kern == NULL) {
227 syslog(LOG_ERR, "%s: kvm_openfiles: %s", _PATH_UNIX, errbuf);
228 exit(1);
229 }
230 if (kvm_nlist(kd_kern, current_nl) == -1)
231 syslog(LOG_ERR, "%s: kvm_nlist: %s", _PATH_UNIX,
232 kvm_geterr(kd_kern));
233
234 for (i = 0; cursyms[i] != -1; i++)
235 if (current_nl[cursyms[i]].n_value == 0) {
236 syslog(LOG_ERR, "%s: %s not in namelist",
237 _PATH_UNIX, current_nl[cursyms[i]].n_name);
238 exit(1);
239 }
240
241 if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
242 if (verbose)
243 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
244 exit(1);
245 }
246 if (dumpdev == NODEV) {
247 syslog(LOG_WARNING, "no core dump (no dumpdev)");
248 exit(1);
249 }
250 if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &dumplo) != 0) {
251 if (verbose)
252 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
253 exit(1);
254 }
255 dumplo *= DEV_BSIZE;
256 if (verbose)
257 (void)printf("dumplo = %ld (%ld * %ld)\n",
258 (long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
259 if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
260 if (verbose)
261 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
262 exit(1);
263 }
264
265 if (kernel == NULL) {
266 (void)kvm_read(kd_kern, current_nl[X_VERSION].n_value,
267 vers, sizeof(vers));
268 vers[sizeof(vers) - 1] = '\0';
269 }
270
271 ddname = find_dev(dumpdev, S_IFBLK);
272 dumpfd = Open(ddname, O_RDWR);
273
274 kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
275 if (kd_dump == NULL) {
276 syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
277 exit(1);
278 }
279
280 if (kvm_nlist(kd_dump, dump_nl) == -1)
281 syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
282 kvm_geterr(kd_dump));
283
284 for (i = 0; dumpsyms[i] != -1; i++)
285 if (dump_nl[dumpsyms[i]].n_value == 0) {
286 syslog(LOG_ERR, "%s: %s not in namelist",
287 kernel, dump_nl[dumpsyms[i]].n_name);
288 exit(1);
289 }
290 hdrsz = kvm_dump_mkheader(kd_dump, (off_t)dumplo);
291
292 /*
293 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
294 * checks, ergo no dump is present...
295 */
296 if (hdrsz == 0) {
297 syslog(LOG_WARNING, "no core dump");
298 exit(1);
299 }
300 if (hdrsz == -1) {
301 syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
302 kvm_geterr(kd_dump));
303 exit(1);
304 }
305 dumplo += hdrsz;
306 kvm_close(kd_kern);
307 }
308
309 void
310 check_kmem()
311 {
312 char *cp;
313 long panicloc;
314 char core_vers[1024];
315
316 (void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
317 sizeof(core_vers));
318 core_vers[sizeof(core_vers) - 1] = '\0';
319
320 if (strcmp(vers, core_vers) && kernel == 0)
321 syslog(LOG_WARNING,
322 "warning: %s version mismatch:\n\t%s\nand\t%s\n",
323 _PATH_UNIX, vers, core_vers);
324
325 if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
326 if (verbose)
327 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
328 return;
329 }
330 if (panicstr) {
331 cp = panic_mesg;
332 panicloc = panicstr;
333 do {
334 if (KREAD(kd_dump, panicloc, cp) != 0) {
335 if (verbose)
336 syslog(LOG_WARNING, "kvm_read: %s",
337 kvm_geterr(kd_dump));
338 break;
339 }
340 panicloc++;
341 } while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
342 panic_mesg[sizeof(panic_mesg) - 1] = '\0';
343 }
344 }
345
346 int
347 dump_exists()
348 {
349 int newdumpmag;
350
351 if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
352 if (verbose)
353 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
354 return (0);
355 }
356
357 /* Read the dump size. */
358 if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
359 if (verbose)
360 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
361 return (0);
362 }
363 dumpsize *= getpagesize();
364
365 /*
366 * Return zero if core dump doesn't seem to be there, and note
367 * it for syslog. This check and return happens after the dump size
368 * is read, so dumpsize is whether or not the core is valid (for -f).
369 */
370 if (newdumpmag != dumpmag) {
371 if (verbose)
372 syslog(LOG_WARNING,
373 "magic number mismatch (0x%x != 0x%x)",
374 newdumpmag, dumpmag);
375 syslog(LOG_WARNING, "no core dump");
376 return (0);
377 }
378 return (1);
379 }
380
381 void
382 clear_dump()
383 {
384 if (kvm_dump_inval(kd_dump) == -1)
385 syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
386 kvm_geterr(kd_dump));
387
388 }
389
390 char buf[1024 * 1024];
391
392 void
393 save_core()
394 {
395 FILE *fp;
396 int bounds, ifd, nr, nw, ofd;
397 char *rawp, path[MAXPATHLEN];
398
399 ofd = -1;
400 /*
401 * Get the current number and update the bounds file. Do the update
402 * now, because may fail later and don't want to overwrite anything.
403 */
404 umask(066);
405 (void)snprintf(path, sizeof(path), "%s/bounds", dirname);
406 if ((fp = fopen(path, "r")) == NULL)
407 goto err1;
408 if (fgets(buf, sizeof(buf), fp) == NULL) {
409 if (ferror(fp))
410 err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
411 bounds = 0;
412 } else
413 bounds = atoi(buf);
414 if (fp != NULL)
415 (void)fclose(fp);
416 if ((fp = fopen(path, "w")) == NULL)
417 syslog(LOG_ERR, "%s: %m", path);
418 else {
419 (void)fprintf(fp, "%d\n", bounds + 1);
420 (void)fclose(fp);
421 }
422
423 /* Create the core file. */
424 (void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
425 dirname, bounds, compress ? ".Z" : "");
426 if (compress) {
427 if ((fp = zopen(path, "w", 0)) == NULL) {
428 syslog(LOG_ERR, "%s: %s", path, strerror(errno));
429 exit(1);
430 }
431 } else {
432 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
433 fp = fdopen(ofd, "w");
434 if (fp == NULL) {
435 syslog(LOG_ERR, "%s: fdopen: %s", path,
436 strerror(errno));
437 exit(1);
438 }
439 }
440
441 /* Open the raw device. */
442 rawp = rawname(ddname);
443 if ((ifd = open(rawp, O_RDONLY)) == -1) {
444 syslog(LOG_WARNING, "%s: %m; using block device", rawp);
445 ifd = dumpfd;
446 }
447
448 /* Seek to the start of the core. */
449 Lseek(ifd, (off_t)dumplo, SEEK_SET);
450
451 if (kvm_dump_wrtheader(kd_dump, fp, dumpsize) == -1) {
452 syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
453 kvm_geterr(kd_dump));
454 exit(1);
455 }
456
457 /* Copy the core file. */
458 syslog(LOG_NOTICE, "writing %score to %s",
459 compress ? "compressed " : "", path);
460 for (; dumpsize > 0; dumpsize -= nr) {
461 (void)printf("%6dK\r", dumpsize / 1024);
462 (void)fflush(stdout);
463 nr = read(ifd, buf, MIN(dumpsize, sizeof(buf)));
464 if (nr <= 0) {
465 if (nr == 0)
466 syslog(LOG_WARNING,
467 "WARNING: EOF on dump device");
468 else
469 syslog(LOG_ERR, "%s: %m", rawp);
470 goto err2;
471 }
472 nw = fwrite(buf, 1, nr, fp);
473 if (nw != nr) {
474 syslog(LOG_ERR, "%s: %s",
475 path, strerror(nw == 0 ? EIO : errno));
476 err2: syslog(LOG_WARNING,
477 "WARNING: core may be incomplete");
478 (void)printf("\n");
479 exit(1);
480 }
481 }
482 (void)close(ifd);
483 (void)fclose(fp);
484
485 /* Copy the kernel. */
486 ifd = Open(kernel ? kernel : _PATH_UNIX, O_RDONLY);
487 (void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
488 dirname, bounds, compress ? ".Z" : "");
489 if (compress) {
490 if ((fp = zopen(path, "w", 0)) == NULL) {
491 syslog(LOG_ERR, "%s: %s", path, strerror(errno));
492 exit(1);
493 }
494 } else
495 ofd = Create(path, S_IRUSR | S_IWUSR);
496 syslog(LOG_NOTICE, "writing %skernel to %s",
497 compress ? "compressed " : "", path);
498 while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
499 if (compress)
500 nw = fwrite(buf, 1, nr, fp);
501 else
502 nw = write(ofd, buf, nr);
503 if (nw != nr) {
504 syslog(LOG_ERR, "%s: %s",
505 path, strerror(nw == 0 ? EIO : errno));
506 syslog(LOG_WARNING,
507 "WARNING: kernel may be incomplete");
508 exit(1);
509 }
510 }
511 if (nr < 0) {
512 syslog(LOG_ERR, "%s: %s",
513 kernel ? kernel : _PATH_UNIX, strerror(errno));
514 syslog(LOG_WARNING,
515 "WARNING: kernel may be incomplete");
516 exit(1);
517 }
518 if (compress)
519 (void)fclose(fp);
520 else
521 (void)close(ofd);
522 }
523
524 char *
525 find_dev(dev, type)
526 dev_t dev;
527 int type;
528 {
529 DIR *dfd;
530 struct dirent *dir;
531 struct stat sb;
532 char *dp, devname[MAXPATHLEN + 1];
533
534 if ((dfd = opendir(_PATH_DEV)) == NULL) {
535 syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno));
536 exit(1);
537 }
538 (void)strcpy(devname, _PATH_DEV);
539 while ((dir = readdir(dfd))) {
540 (void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name);
541 if (lstat(devname, &sb)) {
542 syslog(LOG_ERR, "%s: %s", devname, strerror(errno));
543 continue;
544 }
545 if ((sb.st_mode & S_IFMT) != type)
546 continue;
547 if (dev == sb.st_rdev) {
548 closedir(dfd);
549 if ((dp = strdup(devname)) == NULL) {
550 syslog(LOG_ERR, "%s", strerror(errno));
551 exit(1);
552 }
553 return (dp);
554 }
555 }
556 closedir(dfd);
557 syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
558 exit(1);
559 }
560
561 char *
562 rawname(s)
563 char *s;
564 {
565 char *sl, name[MAXPATHLEN];
566
567 if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') {
568 syslog(LOG_ERR,
569 "can't make raw dump device name from %s", s);
570 return (s);
571 }
572 (void)snprintf(name, sizeof(name), "%.*s/r%s", (int)(sl - s), s,
573 sl + 1);
574 if ((sl = strdup(name)) == NULL) {
575 syslog(LOG_ERR, "%s", strerror(errno));
576 exit(1);
577 }
578 return (sl);
579 }
580
581 int
582 get_crashtime()
583 {
584 struct timeval time;
585 time_t dumptime; /* Time the dump was taken. */
586
587 if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &time) != 0) {
588 if (verbose)
589 syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
590 return (0);
591 }
592 dumptime = time.tv_sec;
593 if (dumptime == 0) {
594 if (verbose)
595 syslog(LOG_ERR, "dump time is zero");
596 return (0);
597 }
598 (void)printf("savecore: system went down at %s", ctime(&dumptime));
599 #define LEEWAY (7 * SECSPERDAY)
600 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
601 (void)printf("dump time is unreasonable\n");
602 return (0);
603 }
604 return (1);
605 }
606
607 int
608 check_space()
609 {
610 FILE *fp;
611 off_t minfree, spacefree, kernelsize, needed;
612 struct stat st;
613 struct statfs fsbuf;
614 char buf[100], path[MAXPATHLEN];
615
616 #ifdef __GNUC__
617 (void) &minfree;
618 #endif
619
620 if (stat(kernel, &st) < 0) {
621 syslog(LOG_ERR, "%s: %m", kernel);
622 exit(1);
623 }
624 kernelsize = st.st_blocks * S_BLKSIZE;
625 if (statfs(dirname, &fsbuf) < 0) {
626 syslog(LOG_ERR, "%s: %m", dirname);
627 exit(1);
628 }
629 spacefree = fsbuf.f_bavail;
630 spacefree *= fsbuf.f_bsize;
631 spacefree /= 1024;
632
633 (void)snprintf(path, sizeof(path), "%s/minfree", dirname);
634 if ((fp = fopen(path, "r")) == NULL)
635 minfree = 0;
636 else {
637 if (fgets(buf, sizeof(buf), fp) == NULL)
638 minfree = 0;
639 else
640 minfree = atoi(buf);
641 (void)fclose(fp);
642 }
643
644 needed = (dumpsize + kernelsize) / 1024;
645 if (minfree > 0 && spacefree - needed < minfree) {
646 syslog(LOG_WARNING,
647 "no dump, not enough free space in %s", dirname);
648 return (0);
649 }
650 if (spacefree - needed < minfree)
651 syslog(LOG_WARNING,
652 "dump performed, but free space threshold crossed");
653 return (1);
654 }
655
656 int
657 Open(name, rw)
658 char *name;
659 int rw;
660 {
661 int fd;
662
663 if ((fd = open(name, rw, 0)) < 0) {
664 syslog(LOG_ERR, "%s: %m", name);
665 exit(1);
666 }
667 return (fd);
668 }
669
670 void
671 Lseek(fd, off, flag)
672 int fd, flag;
673 off_t off;
674 {
675 off_t ret;
676
677 ret = lseek(fd, off, flag);
678 if (ret == -1) {
679 syslog(LOG_ERR, "lseek: %m");
680 exit(1);
681 }
682 }
683
684 int
685 Create(file, mode)
686 char *file;
687 int mode;
688 {
689 int fd;
690
691 fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
692 if (fd < 0) {
693 syslog(LOG_ERR, "%s: %m", file);
694 exit(1);
695 }
696 return (fd);
697 }
698
699 void
700 Write(fd, bp, size)
701 int fd, size;
702 void *bp;
703 {
704 int n;
705
706 if ((n = write(fd, bp, size)) < size) {
707 syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
708 exit(1);
709 }
710 }
711
712 void
713 usage()
714 {
715 (void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory");
716 exit(1);
717 }
718