1 /*- 2 * Copyright (c) 1986, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static const char copyright[] = 36 "@(#) Copyright (c) 1986, 1992, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)savecore.c 8.3 (Berkeley) 1/2/94"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD$"; 46 #endif /* not lint */ 47 48 #include <sys/param.h> 49 #include <sys/stat.h> 50 #include <sys/mount.h> 51 #include <sys/syslog.h> 52 #include <sys/sysctl.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/pmap.h> 57 58 #include <dirent.h> 59 #include <errno.h> 60 #include <fcntl.h> 61 #include <nlist.h> 62 #include <paths.h> 63 #include <stdio.h> 64 #include <stdlib.h> 65 #include <string.h> 66 #include <unistd.h> 67 #include "zopen.h" 68 69 #ifdef __alpha__ 70 #define ok(number) ALPHA_K0SEG_TO_PHYS(number) 71 #endif 72 73 #ifdef __i386__ 74 #define ok(number) ((number) - KERNBASE) 75 #endif 76 77 struct nlist current_nl[] = { /* Namelist for currently running system. */ 78 #define X_DUMPLO 0 79 { "_dumplo" }, 80 #define X_TIME 1 81 { "_time_second" }, 82 #define X_DUMPSIZE 2 83 { "_dumpsize" }, 84 #define X_VERSION 3 85 { "_version" }, 86 #define X_PANICSTR 4 87 { "_panicstr" }, 88 #define X_DUMPMAG 5 89 { "_dumpmag" }, 90 { "" }, 91 }; 92 int cursyms[] = { 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 { "_dumplo" }, /* Entries MUST be the same as */ 97 { "_time_second" }, /* those in current_nl[]. */ 98 { "_dumpsize" }, 99 { "_version" }, 100 { "_panicstr" }, 101 { "_dumpmag" }, 102 { "" }, 103 }; 104 105 /* Types match kernel declarations. */ 106 long dumplo; /* where dump starts on dumpdev */ 107 int dumpmag; /* magic number in dump */ 108 int dumpsize; /* amount of memory dumped */ 109 110 char *kernel; 111 char *dirname; /* directory to save dumps in */ 112 char *ddname; /* name of dump device */ 113 dev_t dumpdev; /* dump device */ 114 int dumpfd; /* read/write descriptor on char dev */ 115 time_t now; /* current date */ 116 char panic_mesg[1024]; 117 int panicstr; 118 char vers[1024]; 119 120 int clear, compress, force, verbose; /* flags */ 121 122 void check_kmem __P((void)); 123 int check_space __P((void)); 124 void clear_dump __P((void)); 125 int Create __P((char *, int)); 126 void DumpRead __P((int fd, void *bp, int size, off_t off, int flag)); 127 void DumpWrite __P((int fd, void *bp, int size, off_t off, int flag)); 128 int dump_exists __P((void)); 129 char *find_dev __P((dev_t)); 130 int get_crashtime __P((void)); 131 void get_dumpsize __P((void)); 132 void kmem_setup __P((void)); 133 void log __P((int, char *, ...)); 134 void Lseek __P((int, off_t, int)); 135 int Open __P((const char *, int rw)); 136 int Read __P((int, void *, int)); 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 get_dumpsize(); 202 203 if ((!get_crashtime() || !check_space()) && !force) 204 exit(1); 205 206 save_core(); 207 208 clear_dump(); 209 exit(0); 210 } 211 212 void 213 kmem_setup() 214 { 215 FILE *fp; 216 int kmem, i; 217 const char *dump_sys; 218 int mib[2]; 219 size_t len; 220 221 /* 222 * Some names we need for the currently running system, others for 223 * the system that was running when the dump was made. The values 224 * obtained from the current system are used to look for things in 225 * /dev/kmem that cannot be found in the dump_sys namelist, but are 226 * presumed to be the same (since the disk partitions are probably 227 * the same!) 228 */ 229 if ((nlist(getbootfile(), current_nl)) == -1) 230 syslog(LOG_ERR, "%s: nlist: %s", getbootfile(), 231 strerror(errno)); 232 for (i = 0; cursyms[i] != -1; i++) 233 if (current_nl[cursyms[i]].n_value == 0) { 234 syslog(LOG_ERR, "%s: %s not in namelist", 235 getbootfile(), current_nl[cursyms[i]].n_name); 236 exit(1); 237 } 238 239 dump_sys = kernel ? kernel : getbootfile(); 240 if ((nlist(dump_sys, dump_nl)) == -1) 241 syslog(LOG_ERR, "%s: nlist: %s", dump_sys, strerror(errno)); 242 for (i = 0; dumpsyms[i] != -1; i++) 243 if (dump_nl[dumpsyms[i]].n_value == 0) { 244 syslog(LOG_ERR, "%s: %s not in namelist", 245 dump_sys, dump_nl[dumpsyms[i]].n_name); 246 exit(1); 247 } 248 249 mib[0] = CTL_KERN; 250 mib[1] = KERN_DUMPDEV; 251 len = sizeof dumpdev; 252 if (sysctl(mib, 2, &dumpdev, &len, NULL, 0) == -1) { 253 syslog(LOG_ERR, "sysctl: kern.dumpdev: %m"); 254 exit(1); 255 } 256 if (dumpdev == NODEV) { 257 syslog(LOG_WARNING, "no core dump (no dumpdev)"); 258 exit(1); 259 } 260 261 kmem = Open(_PATH_KMEM, O_RDONLY); 262 Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET); 263 (void)Read(kmem, &dumplo, sizeof(dumplo)); 264 if (verbose) 265 (void)printf("dumplo = %ld (%ld * %d)\n", 266 dumplo, dumplo/DEV_BSIZE, DEV_BSIZE); 267 Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET); 268 (void)Read(kmem, &dumpmag, sizeof(dumpmag)); 269 dumplo *= DEV_BSIZE; 270 ddname = find_dev(dumpdev); 271 dumpfd = Open(ddname, O_RDWR); 272 fp = fdopen(kmem, "r"); 273 if (fp == NULL) { 274 syslog(LOG_ERR, "%s: fdopen: %m", _PATH_KMEM); 275 exit(1); 276 } 277 if (kernel) 278 return; 279 (void)fseek(fp, (off_t)current_nl[X_VERSION].n_value, L_SET); 280 (void)fgets(vers, sizeof(vers), fp); 281 282 /* Don't fclose(fp), we use dumpfd later. */ 283 } 284 285 void 286 check_kmem() 287 { 288 char core_vers[1024], *p; 289 290 DumpRead(dumpfd, core_vers, sizeof(core_vers), 291 (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET); 292 core_vers[sizeof(core_vers) - 1] = '\0'; 293 p = strchr(core_vers, '\n'); 294 if (p) 295 p[1] = '\0'; 296 if (strcmp(vers, core_vers) && kernel == 0) 297 syslog(LOG_WARNING, 298 "warning: %s version mismatch:\n\t\"%s\"\nand\t\"%s\"\n", 299 getbootfile(), vers, core_vers); 300 DumpRead(dumpfd, &panicstr, sizeof(panicstr), 301 (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET); 302 if (panicstr) { 303 DumpRead(dumpfd, panic_mesg, sizeof(panic_mesg), 304 (off_t)(dumplo + ok(panicstr)), L_SET); 305 } 306 } 307 308 void 309 clear_dump() 310 { 311 long newdumplo; 312 313 newdumplo = 0; 314 DumpWrite(dumpfd, &newdumplo, sizeof(newdumplo), 315 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 316 close(dumpfd); 317 } 318 319 int 320 dump_exists() 321 { 322 int newdumpmag; 323 324 DumpRead(dumpfd, &newdumpmag, sizeof(newdumpmag), 325 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); 326 if (newdumpmag != dumpmag) { 327 if (verbose) 328 syslog(LOG_WARNING, "magic number mismatch (%x != %x)", 329 newdumpmag, dumpmag); 330 syslog(LOG_WARNING, "no core dump"); 331 return (0); 332 } 333 return (1); 334 } 335 336 char buf[1024 * 1024]; 337 338 void 339 save_core() 340 { 341 register FILE *fp; 342 register int bounds, ifd, nr, nw, ofd; 343 char path[MAXPATHLEN]; 344 mode_t oumask; 345 346 /* 347 * Get the current number and update the bounds file. Do the update 348 * now, because may fail later and don't want to overwrite anything. 349 */ 350 (void)snprintf(path, sizeof(path), "%s/bounds", dirname); 351 if ((fp = fopen(path, "r")) == NULL) 352 goto err1; 353 if (fgets(buf, sizeof(buf), fp) == NULL) { 354 if (ferror(fp)) 355 err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno)); 356 bounds = 0; 357 } else 358 bounds = atoi(buf); 359 if (fp != NULL) 360 (void)fclose(fp); 361 if ((fp = fopen(path, "w")) == NULL) 362 syslog(LOG_ERR, "%s: %m", path); 363 else { 364 (void)fprintf(fp, "%d\n", bounds + 1); 365 (void)fclose(fp); 366 } 367 368 /* Create the core file. */ 369 oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/ 370 (void)snprintf(path, sizeof(path), "%s/vmcore.%d%s", 371 dirname, bounds, compress ? ".Z" : ""); 372 if (compress) { 373 if ((fp = zopen(path, "w", 0)) == NULL) { 374 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 375 exit(1); 376 } 377 ofd = -1; /* Not actually used. */ 378 } else 379 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 380 (void)umask(oumask); 381 382 /* Seek to the start of the core. */ 383 Lseek(dumpfd, (off_t)dumplo, L_SET); 384 385 /* Copy the core file. */ 386 syslog(LOG_NOTICE, "writing %score to %s", 387 compress ? "compressed " : "", path); 388 for (; dumpsize > 0; dumpsize -= nr) { 389 (void)printf("%6dK\r", dumpsize / 1024); 390 (void)fflush(stdout); 391 nr = read(dumpfd, buf, MIN(dumpsize, sizeof(buf))); 392 if (nr <= 0) { 393 if (nr == 0) 394 syslog(LOG_WARNING, 395 "WARNING: EOF on dump device"); 396 else 397 syslog(LOG_ERR, "%s: %m", ddname); 398 goto err2; 399 } 400 if (compress) 401 nw = fwrite(buf, 1, nr, fp); 402 else 403 nw = write(ofd, buf, nr); 404 if (nw != nr) { 405 syslog(LOG_ERR, "%s: %s", 406 path, strerror(nw == 0 ? EIO : errno)); 407 err2: syslog(LOG_WARNING, 408 "WARNING: vmcore may be incomplete"); 409 (void)printf("\n"); 410 exit(1); 411 } 412 } 413 414 if (compress) 415 (void)fclose(fp); 416 else 417 (void)close(ofd); 418 419 /* Copy the kernel. */ 420 ifd = Open(kernel ? kernel : getbootfile(), O_RDONLY); 421 (void)snprintf(path, sizeof(path), "%s/kernel.%d%s", 422 dirname, bounds, compress ? ".Z" : ""); 423 if (compress) { 424 if ((fp = zopen(path, "w", 0)) == NULL) { 425 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 426 exit(1); 427 } 428 } else 429 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 430 syslog(LOG_NOTICE, "writing %skernel to %s", 431 compress ? "compressed " : "", path); 432 while ((nr = read(ifd, buf, sizeof(buf))) > 0) { 433 if (compress) 434 nw = fwrite(buf, 1, nr, fp); 435 else 436 nw = write(ofd, buf, nr); 437 if (nw != nr) { 438 syslog(LOG_ERR, "%s: %s", 439 path, strerror(nw == 0 ? EIO : errno)); 440 syslog(LOG_WARNING, 441 "WARNING: kernel may be incomplete"); 442 exit(1); 443 } 444 } 445 if (nr < 0) { 446 syslog(LOG_ERR, "%s: %s", 447 kernel ? kernel : getbootfile(), strerror(errno)); 448 syslog(LOG_WARNING, 449 "WARNING: kernel may be incomplete"); 450 exit(1); 451 } 452 if (compress) 453 (void)fclose(fp); 454 else 455 (void)close(ofd); 456 close(ifd); 457 } 458 459 char * 460 find_dev(dev) 461 register dev_t dev; 462 { 463 register DIR *dfd; 464 struct dirent *dir; 465 struct stat sb; 466 char *dp, devname[MAXPATHLEN + 1]; 467 468 if ((dfd = opendir(_PATH_DEV)) == NULL) { 469 syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno)); 470 exit(1); 471 } 472 (void)strcpy(devname, _PATH_DEV); 473 while ((dir = readdir(dfd))) { 474 (void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name); 475 if (lstat(devname, &sb)) { 476 syslog(LOG_ERR, "%s: %s", devname, strerror(errno)); 477 continue; 478 } 479 if ((sb.st_mode & S_IFMT) != S_IFCHR && 480 (sb.st_mode & S_IFMT) != S_IFBLK) 481 continue; 482 if (dev == sb.st_rdev) { 483 closedir(dfd); 484 if ((dp = strdup(devname)) == NULL) { 485 syslog(LOG_ERR, "%s", strerror(errno)); 486 exit(1); 487 } 488 return (dp); 489 } 490 } 491 closedir(dfd); 492 syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev)); 493 exit(1); 494 } 495 496 int 497 get_crashtime() 498 { 499 time_t dumptime; /* Time the dump was taken. */ 500 501 DumpRead(dumpfd, &dumptime, sizeof(dumptime), 502 (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET); 503 if (dumptime == 0) { 504 if (verbose) 505 syslog(LOG_ERR, "dump time is zero"); 506 return (0); 507 } 508 (void)printf("savecore: system went down at %s", ctime(&dumptime)); 509 #define LEEWAY (7 * 86400) 510 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) { 511 (void)printf("dump time is unreasonable\n"); 512 return (0); 513 } 514 return (1); 515 } 516 517 void 518 get_dumpsize() 519 { 520 /* Read the dump size. */ 521 DumpRead(dumpfd, &dumpsize, sizeof(dumpsize), 522 (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET); 523 dumpsize *= getpagesize(); 524 } 525 526 int 527 check_space() 528 { 529 register FILE *fp; 530 const char *tkernel; 531 off_t minfree, spacefree, totfree, kernelsize, needed; 532 struct stat st; 533 struct statfs fsbuf; 534 char buf[100], path[MAXPATHLEN]; 535 536 tkernel = kernel ? kernel : getbootfile(); 537 if (stat(tkernel, &st) < 0) { 538 syslog(LOG_ERR, "%s: %m", tkernel); 539 exit(1); 540 } 541 kernelsize = st.st_blocks * S_BLKSIZE; 542 543 if (statfs(dirname, &fsbuf) < 0) { 544 syslog(LOG_ERR, "%s: %m", dirname); 545 exit(1); 546 } 547 spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024; 548 totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024; 549 550 (void)snprintf(path, sizeof(path), "%s/minfree", dirname); 551 if ((fp = fopen(path, "r")) == NULL) 552 minfree = 0; 553 else { 554 if (fgets(buf, sizeof(buf), fp) == NULL) 555 minfree = 0; 556 else 557 minfree = atoi(buf); 558 (void)fclose(fp); 559 } 560 561 needed = (dumpsize + kernelsize) / 1024; 562 if (((minfree > 0) ? spacefree : totfree) - needed < minfree) { 563 syslog(LOG_WARNING, 564 "no dump, not enough free space on device (%lld available, need %lld)", 565 (long long)(minfree > 0 ? spacefree : totfree), 566 (long long)needed); 567 return (0); 568 } 569 if (spacefree - needed < 0) 570 syslog(LOG_WARNING, 571 "dump performed, but free space threshold crossed"); 572 return (1); 573 } 574 575 int 576 Open(name, rw) 577 const char *name; 578 int rw; 579 { 580 int fd; 581 582 if ((fd = open(name, rw, 0)) < 0) { 583 syslog(LOG_ERR, "%s: %m", name); 584 exit(1); 585 } 586 return (fd); 587 } 588 589 int 590 Read(fd, bp, size) 591 int fd, size; 592 void *bp; 593 { 594 int nr; 595 596 nr = read(fd, bp, size); 597 if (nr != size) { 598 syslog(LOG_ERR, "read: %m"); 599 exit(1); 600 } 601 return (nr); 602 } 603 604 void 605 Lseek(fd, off, flag) 606 int fd, flag; 607 off_t off; 608 { 609 off_t ret; 610 611 ret = lseek(fd, off, flag); 612 if (ret == -1) { 613 syslog(LOG_ERR, "lseek: %m"); 614 exit(1); 615 } 616 } 617 618 /* 619 * DumpWrite and DumpRead block io requests to the * dump device. 620 */ 621 #define DUMPBUFSIZE 8192 622 void 623 DumpWrite(fd, bp, size, off, flag) 624 int fd, size, flag; 625 void *bp; 626 off_t off; 627 { 628 unsigned char buf[DUMPBUFSIZE], *p, *q; 629 off_t pos; 630 int i, j; 631 632 if (flag != L_SET) { 633 syslog(LOG_ERR, "lseek: not LSET"); 634 exit(2); 635 } 636 q = bp; 637 while (size) { 638 pos = off & ~(DUMPBUFSIZE - 1); 639 Lseek(fd, pos, flag); 640 (void)Read(fd, buf, sizeof(buf)); 641 j = off & (DUMPBUFSIZE - 1); 642 p = buf + j; 643 i = size; 644 if (i > DUMPBUFSIZE - j) 645 i = DUMPBUFSIZE - j; 646 memcpy(p, q, i); 647 Lseek(fd, pos, flag); 648 (void)Write(fd, buf, sizeof(buf)); 649 size -= i; 650 q += i; 651 off += i; 652 } 653 } 654 655 void 656 DumpRead(fd, bp, size, off, flag) 657 int fd, size, flag; 658 void *bp; 659 off_t off; 660 { 661 unsigned char buf[DUMPBUFSIZE], *p, *q; 662 off_t pos; 663 int i, j; 664 665 if (flag != L_SET) { 666 syslog(LOG_ERR, "lseek: not LSET"); 667 exit(2); 668 } 669 q = bp; 670 while (size) { 671 pos = off & ~(DUMPBUFSIZE - 1); 672 Lseek(fd, pos, flag); 673 (void)Read(fd, buf, sizeof(buf)); 674 j = off & (DUMPBUFSIZE - 1); 675 p = buf + j; 676 i = size; 677 if (i > DUMPBUFSIZE - j) 678 i = DUMPBUFSIZE - j; 679 memcpy(q, p, i); 680 size -= i; 681 q += i; 682 off += i; 683 } 684 } 685 686 int 687 Create(file, mode) 688 char *file; 689 int mode; 690 { 691 register int fd; 692 693 fd = creat(file, mode); 694 if (fd < 0) { 695 syslog(LOG_ERR, "%s: %m", file); 696 exit(1); 697 } 698 return (fd); 699 } 700 701 void 702 Write(fd, bp, size) 703 int fd, size; 704 void *bp; 705 { 706 int n; 707 708 if ((n = write(fd, bp, size)) < size) { 709 syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO)); 710 exit(1); 711 } 712 } 713 714 void 715 usage() 716 { 717 (void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory"); 718 exit(1); 719 } 720