savecore.c revision 1.26
1 /* $NetBSD: savecore.c,v 1.26 1996/03/18 21:16:05 leo 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 #ifndef lint 37 static char copyright[] = 38 "@(#) 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 8.3 (Berkeley) 1/2/94"; 45 #else 46 static char rcsid[] = "$NetBSD: savecore.c,v 1.26 1996/03/18 21:16:05 leo 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 <tzfile.h> 65 #include <unistd.h> 66 #include <limits.h> 67 #include <kvm.h> 68 69 extern FILE *zopen __P((const char *fname, const char *mode, int bits)); 70 71 #define KREAD(kd, addr, p)\ 72 (kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p))) 73 74 struct nlist current_nl[] = { /* Namelist for currently running system. */ 75 #define X_DUMPDEV 0 76 { "_dumpdev" }, 77 #define X_DUMPLO 1 78 { "_dumplo" }, 79 #define X_TIME 2 80 { "_time" }, 81 #define X_DUMPSIZE 3 82 { "_dumpsize" }, 83 #define X_VERSION 4 84 { "_version" }, 85 #define X_PANICSTR 5 86 { "_panicstr" }, 87 #define X_DUMPMAG 6 88 { "_dumpmag" }, 89 { NULL }, 90 }; 91 int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 }; 92 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 }; 93 94 struct nlist dump_nl[] = { /* Name list for dumped system. */ 95 { "_dumpdev" }, /* Entries MUST be the same as */ 96 { "_dumplo" }, /* those in current_nl[]. */ 97 { "_time" }, 98 { "_dumpsize" }, 99 { "_version" }, 100 { "_panicstr" }, 101 { "_dumpmag" }, 102 { NULL }, 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 block dev */ 115 kvm_t *kd_dump; /* kvm descriptor on block dev */ 116 time_t now; /* current date */ 117 char panic_mesg[1024]; 118 int panicstr; 119 char vers[1024]; 120 121 int clear, compress, force, verbose; /* flags */ 122 123 void check_kmem __P((void)); 124 int check_space __P((void)); 125 void clear_dump __P((void)); 126 int Create __P((char *, int)); 127 int dump_exists __P((void)); 128 char *find_dev __P((dev_t, int)); 129 int get_crashtime __P((void)); 130 void kmem_setup __P((void)); 131 void log __P((int, char *, ...)); 132 void Lseek __P((int, off_t, int)); 133 int Open __P((char *, int rw)); 134 char *rawname __P((char *s)); 135 void save_core __P((void)); 136 void usage __P((void)); 137 void Write __P((int, void *, int)); 138 139 int 140 main(argc, argv) 141 int argc; 142 char *argv[]; 143 { 144 int ch; 145 146 openlog("savecore", LOG_PERROR, LOG_DAEMON); 147 148 while ((ch = getopt(argc, argv, "cdfN:vz")) != -1) 149 switch(ch) { 150 case 'c': 151 clear = 1; 152 break; 153 case 'd': /* Not documented. */ 154 case 'v': 155 verbose = 1; 156 break; 157 case 'f': 158 force = 1; 159 break; 160 case 'N': 161 kernel = optarg; 162 break; 163 case 'z': 164 compress = 1; 165 break; 166 case '?': 167 default: 168 usage(); 169 } 170 argc -= optind; 171 argv += optind; 172 173 if (!clear) { 174 if (argc != 1 && argc != 2) 175 usage(); 176 dirname = argv[0]; 177 } 178 if (argc == 2) 179 kernel = argv[1]; 180 181 (void)time(&now); 182 kmem_setup(); 183 184 if (clear) { 185 clear_dump(); 186 exit(0); 187 } 188 189 if (!dump_exists() && !force) 190 exit(1); 191 192 check_kmem(); 193 194 if (panicstr) 195 syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg); 196 else 197 syslog(LOG_ALERT, "reboot"); 198 199 if ((!get_crashtime() || !check_space()) && !force) 200 exit(1); 201 202 save_core(); 203 204 clear_dump(); 205 exit(0); 206 } 207 208 void 209 kmem_setup() 210 { 211 kvm_t *kd_kern; 212 char errbuf[_POSIX2_LINE_MAX]; 213 int i, hdrsz; 214 char *dump_sys; 215 216 /* 217 * Some names we need for the currently running system, others for 218 * the system that was running when the dump was made. The values 219 * obtained from the current system are used to look for things in 220 * /dev/kmem that cannot be found in the dump_sys namelist, but are 221 * presumed to be the same (since the disk partitions are probably 222 * the same!) 223 */ 224 kd_kern = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf); 225 if (kd_kern == NULL) { 226 syslog(LOG_ERR, "%s: kvm_openfiles: %s", _PATH_UNIX, errbuf); 227 exit(1); 228 } 229 if (kvm_nlist(kd_kern, current_nl) == -1) 230 syslog(LOG_ERR, "%s: kvm_nlist: %s", _PATH_UNIX, 231 kvm_geterr(kd_kern)); 232 233 for (i = 0; cursyms[i] != -1; i++) 234 if (current_nl[cursyms[i]].n_value == 0) { 235 syslog(LOG_ERR, "%s: %s not in namelist", 236 _PATH_UNIX, current_nl[cursyms[i]].n_name); 237 exit(1); 238 } 239 240 KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev); 241 if (dumpdev == NODEV) { 242 syslog(LOG_WARNING, "no core dump (no dumpdev)"); 243 exit(1); 244 } 245 KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &dumplo); 246 dumplo *= DEV_BSIZE; 247 if (verbose) 248 (void)printf("dumplo = %d (%d * %d)\n", 249 dumplo, dumplo / DEV_BSIZE, DEV_BSIZE); 250 KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag); 251 252 if (kernel == NULL) { 253 (void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, 254 vers, sizeof(vers)); 255 vers[sizeof(vers) - 1] = '\0'; 256 } 257 258 ddname = find_dev(dumpdev, S_IFBLK); 259 dumpfd = Open(ddname, O_RDWR); 260 261 dump_sys = kernel ? kernel : _PATH_UNIX; 262 263 kd_dump = kvm_openfiles(dump_sys, ddname, NULL, O_RDWR, errbuf); 264 if (kd_dump == NULL) { 265 syslog(LOG_ERR, "%s: kvm_openfiles: %s", dump_sys, errbuf); 266 exit(1); 267 } 268 269 if (kvm_nlist(kd_dump, dump_nl) == -1) 270 syslog(LOG_ERR, "%s: kvm_nlist: %s", dump_sys, 271 kvm_geterr(kd_dump)); 272 273 for (i = 0; dumpsyms[i] != -1; i++) 274 if (dump_nl[dumpsyms[i]].n_value == 0) { 275 syslog(LOG_ERR, "%s: %s not in namelist", 276 dump_sys, dump_nl[dumpsyms[i]].n_name); 277 exit(1); 278 } 279 hdrsz = kvm_dump_mkheader(kd_dump, (off_t)dumplo); 280 if (hdrsz == -1) { 281 syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", dump_sys, 282 kvm_geterr(kd_dump)); 283 exit(1); 284 } 285 dumplo += hdrsz; 286 kvm_close(kd_kern); 287 } 288 289 void 290 check_kmem() 291 { 292 register char *cp; 293 register int panicloc; 294 char core_vers[1024]; 295 296 (void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers, 297 sizeof(core_vers)); 298 core_vers[sizeof(core_vers) - 1] = '\0'; 299 300 if (strcmp(vers, core_vers) && kernel == 0) 301 syslog(LOG_WARNING, 302 "warning: %s version mismatch:\n\t%s\nand\t%s\n", 303 _PATH_UNIX, vers, core_vers); 304 305 KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr); 306 if (panicstr) { 307 cp = panic_mesg; 308 panicloc = panicstr; 309 do { 310 KREAD(kd_dump, panicloc, cp); 311 panicloc++; 312 } while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)]); 313 } 314 } 315 316 int 317 dump_exists() 318 { 319 int newdumpmag; 320 321 KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag); 322 323 /* Read the dump size. */ 324 KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize); 325 dumpsize *= getpagesize(); 326 327 /* 328 * Return zero if core dump doesn't seem to be there, and note 329 * it for syslog. This check and return happens after the dump size 330 * is read, so dumpsize is whether or not the core is valid (for -f). 331 */ 332 if (newdumpmag != dumpmag) { 333 if (verbose) 334 syslog(LOG_WARNING, "magic number mismatch (%x != %x)", 335 newdumpmag, dumpmag); 336 syslog(LOG_WARNING, "no core dump"); 337 return (0); 338 } 339 return (1); 340 } 341 342 void 343 clear_dump() 344 { 345 if (kvm_dump_inval(kd_dump) == -1) 346 syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname, 347 kvm_geterr(kd_dump)); 348 349 } 350 351 char buf[1024 * 1024]; 352 353 void 354 save_core() 355 { 356 register FILE *fp; 357 register int bounds, ifd, nr, nw, ofd; 358 char *rawp, path[MAXPATHLEN]; 359 360 /* 361 * Get the current number and update the bounds file. Do the update 362 * now, because may fail later and don't want to overwrite anything. 363 */ 364 (void)snprintf(path, sizeof(path), "%s/bounds", dirname); 365 if ((fp = fopen(path, "r")) == NULL) 366 goto err1; 367 if (fgets(buf, sizeof(buf), fp) == NULL) { 368 if (ferror(fp)) 369 err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno)); 370 bounds = 0; 371 } else 372 bounds = atoi(buf); 373 if (fp != NULL) 374 (void)fclose(fp); 375 if ((fp = fopen(path, "w")) == NULL) 376 syslog(LOG_ERR, "%s: %m", path); 377 else { 378 (void)fprintf(fp, "%d\n", bounds + 1); 379 (void)fclose(fp); 380 } 381 (void)fclose(fp); 382 383 /* Create the core file. */ 384 (void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s", 385 dirname, bounds, compress ? ".Z" : ""); 386 if (compress) { 387 if ((fp = zopen(path, "w", 0)) == NULL) { 388 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 389 exit(1); 390 } 391 } else { 392 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 393 fp = fdopen(ofd, "w"); 394 if (fp == NULL) { 395 syslog(LOG_ERR, "%s: fdopen: %s", path); 396 exit(1); 397 } 398 } 399 400 /* Open the raw device. */ 401 rawp = rawname(ddname); 402 if ((ifd = open(rawp, O_RDONLY)) == -1) { 403 syslog(LOG_WARNING, "%s: %m; using block device", rawp); 404 ifd = dumpfd; 405 } 406 407 /* Seek to the start of the core. */ 408 Lseek(ifd, (off_t)dumplo, L_SET); 409 410 if (kvm_dump_wrtheader(kd_dump, fp, dumpsize) == -1) { 411 syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path, 412 kvm_geterr(kd_dump)); 413 exit(1); 414 } 415 416 /* Copy the core file. */ 417 syslog(LOG_NOTICE, "writing %score to %s", 418 compress ? "compressed " : "", path); 419 for (; dumpsize > 0; dumpsize -= nr) { 420 (void)printf("%6dK\r", dumpsize / 1024); 421 (void)fflush(stdout); 422 nr = read(ifd, buf, MIN(dumpsize, sizeof(buf))); 423 if (nr <= 0) { 424 if (nr == 0) 425 syslog(LOG_WARNING, 426 "WARNING: EOF on dump device"); 427 else 428 syslog(LOG_ERR, "%s: %m", rawp); 429 goto err2; 430 } 431 nw = fwrite(buf, 1, nr, fp); 432 if (nw != nr) { 433 syslog(LOG_ERR, "%s: %s", 434 path, strerror(nw == 0 ? EIO : errno)); 435 err2: syslog(LOG_WARNING, 436 "WARNING: core may be incomplete"); 437 (void)printf("\n"); 438 exit(1); 439 } 440 } 441 (void)close(ifd); 442 (void)fclose(fp); 443 444 /* Copy the kernel. */ 445 ifd = Open(kernel ? kernel : _PATH_UNIX, O_RDONLY); 446 (void)snprintf(path, sizeof(path), "%s/netbsd.%d%s", 447 dirname, bounds, compress ? ".Z" : ""); 448 if (compress) { 449 if ((fp = zopen(path, "w", 0)) == NULL) { 450 syslog(LOG_ERR, "%s: %s", path, strerror(errno)); 451 exit(1); 452 } 453 } else 454 ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); 455 syslog(LOG_NOTICE, "writing %skernel to %s", 456 compress ? "compressed " : "", path); 457 while ((nr = read(ifd, buf, sizeof(buf))) > 0) { 458 if (compress) 459 nw = fwrite(buf, 1, nr, fp); 460 else 461 nw = write(ofd, buf, nr); 462 if (nw != nr) { 463 syslog(LOG_ERR, "%s: %s", 464 path, strerror(nw == 0 ? EIO : errno)); 465 syslog(LOG_WARNING, 466 "WARNING: kernel may be incomplete"); 467 exit(1); 468 } 469 } 470 if (nr < 0) { 471 syslog(LOG_ERR, "%s: %s", 472 kernel ? kernel : _PATH_UNIX, strerror(errno)); 473 syslog(LOG_WARNING, 474 "WARNING: kernel may be incomplete"); 475 exit(1); 476 } 477 if (compress) 478 (void)fclose(fp); 479 else 480 (void)close(ofd); 481 } 482 483 char * 484 find_dev(dev, type) 485 register dev_t dev; 486 register int type; 487 { 488 register DIR *dfd; 489 struct dirent *dir; 490 struct stat sb; 491 char *dp, devname[MAXPATHLEN + 1]; 492 493 if ((dfd = opendir(_PATH_DEV)) == NULL) { 494 syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno)); 495 exit(1); 496 } 497 (void)strcpy(devname, _PATH_DEV); 498 while ((dir = readdir(dfd))) { 499 (void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name); 500 if (lstat(devname, &sb)) { 501 syslog(LOG_ERR, "%s: %s", devname, strerror(errno)); 502 continue; 503 } 504 if ((sb.st_mode & S_IFMT) != type) 505 continue; 506 if (dev == sb.st_rdev) { 507 closedir(dfd); 508 if ((dp = strdup(devname)) == NULL) { 509 syslog(LOG_ERR, "%s", strerror(errno)); 510 exit(1); 511 } 512 return (dp); 513 } 514 } 515 closedir(dfd); 516 syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev)); 517 exit(1); 518 } 519 520 char * 521 rawname(s) 522 char *s; 523 { 524 char *sl, name[MAXPATHLEN]; 525 526 if ((sl = strrchr(s, '/')) == NULL || sl[1] == '0') { 527 syslog(LOG_ERR, 528 "can't make raw dump device name from %s", s); 529 return (s); 530 } 531 (void)snprintf(name, sizeof(name), "%.*s/r%s", sl - s, s, sl + 1); 532 if ((sl = strdup(name)) == NULL) { 533 syslog(LOG_ERR, "%s", strerror(errno)); 534 exit(1); 535 } 536 return (sl); 537 } 538 539 int 540 get_crashtime() 541 { 542 time_t dumptime; /* Time the dump was taken. */ 543 544 KREAD(kd_dump, dump_nl[X_TIME].n_value, &dumptime); 545 if (dumptime == 0) { 546 if (verbose) 547 syslog(LOG_ERR, "dump time is zero"); 548 return (0); 549 } 550 (void)printf("savecore: system went down at %s", ctime(&dumptime)); 551 #define LEEWAY (7 * SECSPERDAY) 552 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) { 553 (void)printf("dump time is unreasonable\n"); 554 return (0); 555 } 556 return (1); 557 } 558 559 int 560 check_space() 561 { 562 register FILE *fp; 563 char *tkernel; 564 off_t minfree, spacefree, kernelsize, needed; 565 struct stat st; 566 struct statfs fsbuf; 567 char buf[100], path[MAXPATHLEN]; 568 569 tkernel = kernel ? kernel : _PATH_UNIX; 570 if (stat(tkernel, &st) < 0) { 571 syslog(LOG_ERR, "%s: %m", tkernel); 572 exit(1); 573 } 574 kernelsize = st.st_blocks * S_BLKSIZE; 575 if (statfs(dirname, &fsbuf) < 0) { 576 syslog(LOG_ERR, "%s: %m", dirname); 577 exit(1); 578 } 579 spacefree = (fsbuf.f_bavail * fsbuf.f_bsize) / 1024; 580 581 (void)snprintf(path, sizeof(path), "%s/minfree", dirname); 582 if ((fp = fopen(path, "r")) == NULL) 583 minfree = 0; 584 else { 585 if (fgets(buf, sizeof(buf), fp) == NULL) 586 minfree = 0; 587 else 588 minfree = atoi(buf); 589 (void)fclose(fp); 590 } 591 592 needed = (dumpsize + kernelsize) / 1024; 593 if (minfree > 0 && spacefree - needed < minfree) { 594 syslog(LOG_WARNING, 595 "no dump, not enough free space on device"); 596 return (0); 597 } 598 if (spacefree - needed < minfree) 599 syslog(LOG_WARNING, 600 "dump performed, but free space threshold crossed"); 601 return (1); 602 } 603 604 int 605 Open(name, rw) 606 char *name; 607 int rw; 608 { 609 int fd; 610 611 if ((fd = open(name, rw, 0)) < 0) { 612 syslog(LOG_ERR, "%s: %m", name); 613 exit(1); 614 } 615 return (fd); 616 } 617 618 void 619 Lseek(fd, off, flag) 620 int fd, flag; 621 off_t off; 622 { 623 off_t ret; 624 625 ret = lseek(fd, off, flag); 626 if (ret == -1) { 627 syslog(LOG_ERR, "lseek: %m"); 628 exit(1); 629 } 630 } 631 632 int 633 Create(file, mode) 634 char *file; 635 int mode; 636 { 637 register int fd; 638 639 fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode); 640 if (fd < 0) { 641 syslog(LOG_ERR, "%s: %m", file); 642 exit(1); 643 } 644 return (fd); 645 } 646 647 void 648 Write(fd, bp, size) 649 int fd, size; 650 void *bp; 651 { 652 int n; 653 654 if ((n = write(fd, bp, size)) < size) { 655 syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO)); 656 exit(1); 657 } 658 } 659 660 void 661 usage() 662 { 663 (void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory"); 664 exit(1); 665 } 666
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