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 44static 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 70extern 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 75struct 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}; 92int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 }; 93int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 }; 94 95struct 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. */ 107long dumplo; /* where dump starts on dumpdev */ 108int dumpmag; /* magic number in dump */ 109int dumpsize; /* amount of memory dumped */ 110 111char *kernel = _PATH_UNIX; 112char *dirname; /* directory to save dumps in */ 113char *ddname; /* name of dump device */ 114dev_t dumpdev; /* dump device */ 115int dumpfd; /* read/write descriptor on block dev */ 116kvm_t *kd_dump; /* kvm descriptor on block dev */ 117time_t now; /* current date */ 118char panic_mesg[1024]; 119long panicstr; 120char vers[1024]; 121 122int clear, compress, force, verbose; /* flags */ 123 124void check_kmem __P((void)); 125int check_space __P((void)); 126void clear_dump __P((void)); 127int Create __P((char *, int)); 128int dump_exists __P((void)); 129char *find_dev __P((dev_t, int)); 130int get_crashtime __P((void)); 131void kmem_setup __P((void)); 132void log __P((int, char *, ...)); 133void Lseek __P((int, off_t, int)); 134int main __P((int, char *[])); 135int Open __P((char *, int rw)); 136char *rawname __P((char *s)); 137void save_core __P((void)); 138void usage __P((void)); 139void Write __P((int, void *, int)); 140 141int 142main(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 210void 211kmem_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 309void 310check_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 346int 347dump_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 381void 382clear_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 390char buf[1024 * 1024]; 391 392void 393save_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)) 410err1: 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)); 476err2: 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 524char * 525find_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 561char * 562rawname(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 581int 582get_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 607int 608check_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 656int 657Open(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 670void 671Lseek(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 684int 685Create(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 699void 700Write(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 712void 713usage() 714{ 715 (void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory"); 716 exit(1); 717} 718