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savecore.c revision 1.84.2.1
      1 /*	$NetBSD: savecore.c,v 1.84.2.1 2012/04/17 00:05:43 yamt 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\
     35  The Regents of the University of California.  All rights reserved.");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)savecore.c	8.5 (Berkeley) 4/28/95";
     41 #else
     42 __RCSID("$NetBSD: savecore.c,v 1.84.2.1 2012/04/17 00:05:43 yamt Exp $");
     43 #endif
     44 #endif /* not lint */
     45 
     46 #define _KSYMS_PRIVATE
     47 
     48 #include <stdbool.h>
     49 
     50 #include <sys/param.h>
     51 #include <sys/mount.h>
     52 #include <sys/msgbuf.h>
     53 #include <sys/syslog.h>
     54 #include <sys/time.h>
     55 #include <sys/ksyms.h>
     56 
     57 #include <dirent.h>
     58 #include <errno.h>
     59 #include <fcntl.h>
     60 #include <nlist.h>
     61 #include <paths.h>
     62 #include <stddef.h>
     63 #include <stdio.h>
     64 #include <stdlib.h>
     65 #include <string.h>
     66 #include <time.h>
     67 #include <tzfile.h>
     68 #include <unistd.h>
     69 #include <util.h>
     70 #include <limits.h>
     71 #include <stdarg.h>
     72 #include <kvm.h>
     73 
     74 extern FILE *zopen(const char *fname, const char *mode);
     75 
     76 #define	KREAD(kd, addr, p)\
     77 	(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
     78 
     79 static struct nlist current_nl[] = {	/* Namelist for currently running system. */
     80 #define	X_DUMPDEV	0
     81 	{ .n_name = "_dumpdev" },
     82 #define	X_DUMPLO	1
     83 	{ .n_name = "_dumplo" },
     84 #define	X_TIME_SECOND	2
     85 	{ .n_name = "_time_second" },
     86 #define X_TIME		3
     87 	{ .n_name = "_time" },
     88 #define	X_DUMPSIZE	4
     89 	{ .n_name = "_dumpsize" },
     90 #define	X_VERSION	5
     91 	{ .n_name = "_version" },
     92 #define	X_DUMPMAG	6
     93 	{ .n_name = "_dumpmag" },
     94 #define	X_PANICSTR	7
     95 	{ .n_name = "_panicstr" },
     96 #define	X_PANICSTART	8
     97 	{ .n_name = "_panicstart" },
     98 #define	X_PANICEND	9
     99 	{ .n_name = "_panicend" },
    100 #define	X_MSGBUF	10
    101 	{ .n_name = "_msgbufp" },
    102 #define	X_DUMPCDEV	11
    103 	{ .n_name = "_dumpcdev" },
    104 #define X_SYMSZ		12
    105 	{ .n_name = "_ksyms_symsz" },
    106 #define X_STRSZ		13
    107 	{ .n_name = "_ksyms_strsz" },
    108 #define X_KHDR		14
    109 	{ .n_name = "_ksyms_hdr" },
    110 #define X_SYMTABS	15
    111 	{ .n_name = "_ksyms_symtabs" },
    112 	{ .n_name = NULL },
    113 };
    114 static int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, X_DUMPCDEV, -1 };
    115 static int dumpsyms[] = { X_TIME_SECOND, X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR,
    116     X_DUMPMAG, X_SYMSZ, X_STRSZ, X_KHDR, X_SYMTABS, -1 };
    117 
    118 static struct nlist dump_nl[] = {	/* Name list for dumped system. */
    119 	{ .n_name = "_dumpdev" },	/* Entries MUST be the same as */
    120 	{ .n_name = "_dumplo" },	/*	those in current_nl[].  */
    121 	{ .n_name = "_time_second" },
    122 	{ .n_name = "_time" },
    123 	{ .n_name = "_dumpsize" },
    124 	{ .n_name = "_version" },
    125 	{ .n_name = "_dumpmag" },
    126 	{ .n_name = "_panicstr" },
    127 	{ .n_name = "_panicstart" },
    128 	{ .n_name = "_panicend" },
    129 	{ .n_name = "_msgbufp" },
    130 	{ .n_name = "_dumpcdev" },
    131 	{ .n_name = "_ksyms_symsz" },
    132 	{ .n_name = "_ksyms_strsz" },
    133 	{ .n_name = "_ksyms_hdr" },
    134 	{ .n_name = "_ksyms_symtabs" },
    135 	{ .n_name = NULL },
    136 };
    137 
    138 /* Types match kernel declarations. */
    139 static off_t	dumplo;				/* where dump starts on dumpdev */
    140 static u_int32_t dumpmag;			/* magic number in dump */
    141 static int	dumpsize;			/* amount of memory dumped */
    142 static off_t dumpbytes;			/* in bytes */
    143 
    144 static const char	*kernel;		/* name of used kernel */
    145 static const char	*dirname;		/* directory to save dumps in */
    146 static char	*ddname;			/* name of dump device */
    147 static dev_t	dumpdev;			/* dump device */
    148 static dev_t	dumpcdev = NODEV;		/* dump device (char equivalent) */
    149 static int	dumpfd;				/* read/write descriptor on dev */
    150 static kvm_t	*kd_dump;			/* kvm descriptor on dev	*/
    151 static time_t	now;				/* current date */
    152 static char	panic_mesg[1024];
    153 static long	panicstr;
    154 static char	vers[1024];
    155 static char	gzmode[3];
    156 
    157 static int	clear, compress, force, verbose;	/* flags */
    158 
    159 static void	check_kmem(void);
    160 static int	check_space(void);
    161 static void	clear_dump(void);
    162 static int	Create(char *, int);
    163 static int	dump_exists(void);
    164 static char	*find_dev(dev_t, mode_t);
    165 static int	get_crashtime(void);
    166 static void	kmem_setup(void);
    167 static void	Lseek(int, off_t, int);
    168 static int	Open(const char *, int rw);
    169 static void	save_core(void);
    170 __dead static void	usage(const char *fmt, ...) __printflike(1, 2);
    171 
    172 int
    173 main(int argc, char *argv[])
    174 {
    175 	int ch, level, testonly;
    176 	char *ep;
    177 
    178 	kernel = NULL;
    179 	level = 1;		/* default to fastest gzip compression */
    180 	testonly = 0;
    181 	gzmode[0] = 'w';
    182 
    183 	openlog("savecore", LOG_PERROR, LOG_DAEMON);
    184 
    185 	while ((ch = getopt(argc, argv, "cdfnN:vzZ:")) != -1)
    186 		switch(ch) {
    187 		case 'c':
    188 			clear = 1;
    189 			break;
    190 		case 'd':		/* Not documented. */
    191 		case 'v':
    192 			verbose = 1;
    193 			break;
    194 		case 'f':
    195 			force = 1;
    196 			break;
    197 		case 'n':
    198 			testonly = 1;
    199 			break;
    200 		case 'N':
    201 			kernel = optarg;
    202 			break;
    203 		case 'z':
    204 			compress = 1;
    205 			break;
    206 		case 'Z':
    207 			level = (int)strtol(optarg, &ep, 10);
    208 			if (level < 0 || level > 9)
    209 				usage("Invalid compression `%s'", optarg);
    210 			break;
    211 		case '?':
    212 			usage("Missing argument for flag `%c'", optopt);
    213 		default:
    214 			usage("Unknown flag `%c'", ch);
    215 		}
    216 	argc -= optind;
    217 	argv += optind;
    218 
    219 	if (argc != 0)
    220 		dirname = argv[0];
    221 	else
    222 		dirname = "/var/crash";
    223 
    224 	gzmode[1] = level + '0';
    225 
    226 	(void)time(&now);
    227 	kmem_setup();
    228 
    229 	if (clear && !testonly) {
    230 		clear_dump();
    231 		exit(0);
    232 	}
    233 
    234 	if (!dump_exists() && !force)
    235 		exit(1);
    236 
    237 	if (testonly)
    238 		/* If -n was passed and there was a dump, exit at level 0 */
    239 		exit(0);
    240 
    241 	check_kmem();
    242 
    243 	if (panicstr)
    244 		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
    245 	else
    246 		syslog(LOG_ALERT, "reboot");
    247 
    248 	if ((!get_crashtime() || !check_space()) && !force)
    249 		exit(1);
    250 
    251 	save_core();
    252 
    253 	clear_dump();
    254 	exit(0);
    255 }
    256 
    257 static void
    258 kmem_setup(void)
    259 {
    260 	kvm_t *kd_kern;
    261 	char errbuf[_POSIX2_LINE_MAX];
    262 	int i, hdrsz;
    263 
    264 	/*
    265 	 * Some names we need for the currently running system, others for
    266 	 * the system that was running when the dump was made.  The values
    267 	 * obtained from the current system are used to look for things in
    268 	 * /dev/kmem that cannot be found in the kernel namelist, but are
    269 	 * presumed to be the same (since the disk partitions are probably
    270 	 * the same!)
    271 	 */
    272 	kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
    273 	if (kd_kern == NULL) {
    274 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
    275 		exit(1);
    276 	}
    277 	if (kvm_nlist(kd_kern, current_nl) == -1)
    278 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
    279 		    kvm_geterr(kd_kern));
    280 
    281 	for (i = 0; cursyms[i] != -1; i++) {
    282 		if (current_nl[cursyms[i]].n_value != 0)
    283 			continue;
    284 		switch (cursyms[i]) {
    285 		case X_TIME_SECOND:
    286 		case X_TIME:
    287 		case X_DUMPCDEV:
    288 			break;
    289 		default:
    290 			syslog(LOG_ERR, "%s: %s not in namelist",
    291 			    kernel, current_nl[cursyms[i]].n_name);
    292 			exit(1);
    293 		}
    294 	}
    295 
    296 	if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
    297 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    298 		exit(1);
    299 	}
    300 	if (dumpdev == NODEV) {
    301 		syslog(LOG_WARNING, "no core dump (no dumpdev)");
    302 		exit(1);
    303 	}
    304 	{
    305 	    long l_dumplo;
    306 
    307 	    if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
    308 		    syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    309 		    exit(1);
    310 	    }
    311 	    if (l_dumplo == -1) {
    312 		syslog(LOG_WARNING, "no core dump (invalid dumplo)");
    313 		exit(1);
    314 	    }
    315 	    dumplo = DEV_BSIZE * (off_t) l_dumplo;
    316 	}
    317 
    318 	if (verbose)
    319 		(void)printf("dumplo = %lld (%ld * %ld)\n",
    320 		    (long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
    321 	if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
    322 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
    323 		exit(1);
    324 	}
    325 
    326 	(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
    327 	    sizeof(vers));
    328 	vers[sizeof(vers) - 1] = '\0';
    329 
    330 	if (current_nl[X_DUMPCDEV].n_value != 0) {
    331 		if (KREAD(kd_kern, current_nl[X_DUMPCDEV].n_value,
    332 		    &dumpcdev) != 0) {
    333 			syslog(LOG_WARNING, "kvm_read: %s",
    334 			    kvm_geterr(kd_kern));
    335 			exit(1);
    336 		}
    337 		ddname = find_dev(dumpcdev, S_IFCHR);
    338 	} else
    339 		ddname = find_dev(dumpdev, S_IFBLK);
    340 	if (strncmp(ddname, "/dev/cons", 8) == 0 ||
    341 	    strncmp(ddname, "/dev/tty", 7) == 0 ||
    342 	    strncmp(ddname, "/dev/pty", 7) == 0 ||
    343 	    strncmp(ddname, "/dev/pts", 7) == 0) {
    344 		syslog(LOG_ERR, "dumpdev %s is tty; override kernel", ddname);
    345 		exit(1);
    346 	}
    347 	dumpfd = Open(ddname, O_RDWR);
    348 
    349 	kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
    350 	if (kd_dump == NULL) {
    351 		syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
    352 		exit(1);
    353 	}
    354 
    355 	if (kvm_nlist(kd_dump, dump_nl) == -1)
    356 		syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
    357 		    kvm_geterr(kd_dump));
    358 
    359 	for (i = 0; dumpsyms[i] != -1; i++)
    360 		if (dump_nl[dumpsyms[i]].n_value == 0 &&
    361 			dumpsyms[i] != X_TIME_SECOND &&
    362 			dumpsyms[i] != X_TIME) {
    363 			syslog(LOG_ERR, "%s: %s not in namelist",
    364 			    kernel, dump_nl[dumpsyms[i]].n_name);
    365 			exit(1);
    366 		}
    367 	hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
    368 
    369 	/*
    370 	 * If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
    371 	 * checks, ergo no dump is present...
    372 	 */
    373 	if (hdrsz == 0) {
    374 		syslog(LOG_WARNING, "no core dump");
    375 		exit(1);
    376 	}
    377 	if (hdrsz == -1) {
    378 		syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
    379 		    kvm_geterr(kd_dump));
    380 		exit(1);
    381 	}
    382 	dumplo += hdrsz;
    383 	kvm_close(kd_kern);
    384 }
    385 
    386 static void
    387 check_kmem(void)
    388 {
    389 	char *cp, *bufdata;
    390 	struct kern_msgbuf msgbuf, *bufp;
    391 	long panicloc, panicstart, panicend;
    392 	char core_vers[1024];
    393 
    394 	(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
    395 	    sizeof(core_vers));
    396 	core_vers[sizeof(core_vers) - 1] = '\0';
    397 
    398 	if (strcmp(vers, core_vers) != 0)
    399 		syslog(LOG_WARNING,
    400 		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
    401 		    kvm_getkernelname(kd_dump), vers, core_vers);
    402 
    403 	panicstart = panicend = 0;
    404 	if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
    405 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    406 		goto nomsguf;
    407 	}
    408 	if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
    409 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    410 		goto nomsguf;
    411 	}
    412 	if (panicstart != 0 && panicend != 0) {
    413 		if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
    414 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    415 			goto nomsguf;
    416 		}
    417 		if (kvm_read(kd_dump, (long)bufp, &msgbuf,
    418 		    offsetof(struct kern_msgbuf, msg_bufc)) !=
    419 		    offsetof(struct kern_msgbuf, msg_bufc)) {
    420 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    421 			goto nomsguf;
    422 		}
    423 		if (msgbuf.msg_magic != MSG_MAGIC) {
    424 			syslog(LOG_WARNING, "msgbuf magic incorrect");
    425 			goto nomsguf;
    426 		}
    427 		bufdata = malloc(msgbuf.msg_bufs);
    428 		if (bufdata == NULL) {
    429 			syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
    430 			goto nomsguf;
    431 		}
    432 		if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
    433 		    msgbuf.msg_bufs) != msgbuf.msg_bufs) {
    434 			syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    435 			free(bufdata);
    436 			goto nomsguf;
    437 		}
    438 		cp = panic_mesg;
    439 		while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
    440 			*cp++ = bufdata[panicstart];
    441 			panicstart++;
    442 			if (panicstart >= msgbuf.msg_bufs)
    443 				panicstart = 0;
    444 		}
    445 		/* Don't end in a new-line */
    446 		cp = &panic_mesg[strlen(panic_mesg)] - 1;
    447 		if (*cp == '\n')
    448 			*cp = '\0';
    449 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
    450 		free(bufdata);
    451 
    452 		panicstr = 1;	/* anything not zero */
    453 		return;
    454 	}
    455 nomsguf:
    456 	if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
    457 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    458 		return;
    459 	}
    460 	if (panicstr) {
    461 		cp = panic_mesg;
    462 		panicloc = panicstr;
    463 		do {
    464 			if (KREAD(kd_dump, panicloc, cp) != 0) {
    465 				syslog(LOG_WARNING, "kvm_read: %s",
    466 				    kvm_geterr(kd_dump));
    467 				break;
    468 			}
    469 			panicloc++;
    470 		} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
    471 		panic_mesg[sizeof(panic_mesg) - 1] = '\0';
    472 	}
    473 }
    474 
    475 static int
    476 dump_exists(void)
    477 {
    478 	u_int32_t newdumpmag;
    479 
    480 	if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
    481 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    482 		return (0);
    483 	}
    484 
    485 	/* Read the dump size. */
    486 	if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
    487 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    488 		return (0);
    489 	}
    490 	dumpbytes = (off_t)dumpsize * getpagesize();
    491 
    492 	/*
    493 	 * Return zero if core dump doesn't seem to be there, and note
    494 	 * it for syslog.  This check and return happens after the dump size
    495 	 * is read, so dumpsize is whether or not the core is valid (for -f).
    496 	 */
    497 	if (newdumpmag != dumpmag) {
    498 		if (verbose)
    499 			syslog(LOG_WARNING, "magic number mismatch "
    500 			    "(0x%x != 0x%x)", newdumpmag, dumpmag);
    501 		syslog(LOG_WARNING, "no core dump");
    502 		return (0);
    503 	}
    504 	return (1);
    505 }
    506 
    507 static void
    508 clear_dump(void)
    509 {
    510 	if (kvm_dump_inval(kd_dump) == -1)
    511 		syslog(LOG_ERR, "%s: kvm_dump_inval: %s", ddname,
    512 		    kvm_geterr(kd_dump));
    513 
    514 }
    515 
    516 static char buf[1024 * 1024];
    517 
    518 static void
    519 save_kernel(int ofd, FILE *fp, char *path)
    520 {
    521 	int nw, nr, ifd;
    522 
    523 	ifd = Open(kernel, O_RDONLY);
    524 	while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
    525 		if (compress)
    526 			nw = fwrite(buf, 1, nr, fp);
    527 		else
    528 			nw = write(ofd, buf, nr);
    529 		if (nw != nr) {
    530 			syslog(LOG_ERR, "%s: %s",
    531 			    path, strerror(nw == 0 ? EIO : errno));
    532 			syslog(LOG_WARNING,
    533 			    "WARNING: kernel may be incomplete");
    534 			exit(1);
    535 		}
    536 	}
    537 	if (nr < 0) {
    538 		syslog(LOG_ERR, "%s: %m", kernel);
    539 		syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
    540 		exit(1);
    541 	}
    542 }
    543 
    544 static int
    545 ksymsget(u_long addr, void *ptr, size_t size)
    546 {
    547 
    548 	if ((size_t)kvm_read(kd_dump, addr, ptr, size) != size) {
    549 		syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
    550 		return 1;
    551 	}
    552 	return 0;
    553 }
    554 
    555 static int
    556 save_ksyms(int ofd, FILE *fp, char *path)
    557 {
    558 	struct ksyms_hdr khdr;
    559 	int nw, symsz, strsz;
    560 	TAILQ_HEAD(, ksyms_symtab) symtabs;
    561 	struct ksyms_symtab st, *stptr;
    562 	void *p;
    563 
    564 	/* Get basic info and ELF headers, check if ksyms was on. */
    565 	if (ksymsget(dump_nl[X_KHDR].n_value, &khdr, sizeof(khdr)))
    566 		return 1;
    567 	if (ksymsget(dump_nl[X_SYMSZ].n_value, &symsz, sizeof(symsz)))
    568 		return 1;
    569 	if (ksymsget(dump_nl[X_STRSZ].n_value, &strsz, sizeof(strsz)))
    570 		return 1;
    571 	if (symsz == 0 || strsz == 0)
    572 		return 1;
    573 
    574 	/* Update the ELF section headers for symbols/strings. */
    575 	khdr.kh_shdr[SYMTAB].sh_size = symsz;
    576 	khdr.kh_shdr[SYMTAB].sh_info = symsz / sizeof(Elf_Sym);
    577 	khdr.kh_shdr[STRTAB].sh_offset = symsz +
    578 	    khdr.kh_shdr[SYMTAB].sh_offset;
    579 	khdr.kh_shdr[STRTAB].sh_size = strsz;
    580 
    581 	/* Write out the ELF headers. */
    582 	if (compress)
    583 		nw = fwrite(&khdr, 1, sizeof(khdr), fp);
    584 	else
    585 		nw = write(ofd, &khdr, sizeof(khdr));
    586 	if (nw != sizeof(khdr)) {
    587 		syslog(LOG_ERR, "%s: %s",
    588 		    path, strerror(nw == 0 ? EIO : errno));
    589 		syslog(LOG_WARNING,
    590 		    "WARNING: kernel may be incomplete");
    591 		exit(1);
    592         }
    593 
    594         /* Dump symbol table. */
    595 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
    596 		return 1;
    597 	stptr = TAILQ_FIRST(&symtabs);
    598 	while (stptr != NULL) {
    599 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
    600 			return 1;
    601 		stptr = TAILQ_NEXT(&st, sd_queue);
    602 		if ((p = malloc(st.sd_symsize)) == NULL)
    603 			return 1;
    604 		if (ksymsget((u_long)st.sd_symstart, p, st.sd_symsize)) {
    605 			free(p);
    606 			return 1;
    607 		}
    608 		if (compress)
    609 			nw = fwrite(p, 1, st.sd_symsize, fp);
    610 		else
    611 			nw = write(ofd, p, st.sd_symsize);
    612 		free(p);
    613 		if (nw != st.sd_symsize) {
    614 			syslog(LOG_ERR, "%s: %s",
    615 			    path, strerror(nw == 0 ? EIO : errno));
    616 			syslog(LOG_WARNING,
    617 			    "WARNING: kernel may be incomplete");
    618 			exit(1);
    619 		}
    620 	}
    621 
    622 	/* Dump string table. */
    623 	if (ksymsget(dump_nl[X_SYMTABS].n_value, &symtabs, sizeof(symtabs)))
    624 		return 1;
    625 	stptr = TAILQ_FIRST(&symtabs);
    626 	while (stptr != NULL) {
    627 		if (ksymsget((u_long)stptr, &st, sizeof(st)))
    628 			return 1;
    629 		stptr = TAILQ_NEXT(&st, sd_queue);
    630 		if ((p = malloc(st.sd_symsize)) == NULL)
    631 			return 1;
    632 		if (ksymsget((u_long)st.sd_strstart, p, st.sd_strsize)) {
    633 			free(p);
    634 			return 1;
    635 		}
    636 		if (compress)
    637 			nw = fwrite(p, 1, st.sd_strsize, fp);
    638 		else
    639 			nw = write(ofd, p, st.sd_strsize);
    640 		free(p);
    641 		if (nw != st.sd_strsize) {
    642 			syslog(LOG_ERR, "%s: %s",
    643 			    path, strerror(nw == 0 ? EIO : errno));
    644 			syslog(LOG_WARNING,
    645 			    "WARNING: kernel may be incomplete");
    646 			exit(1);
    647 		}
    648 	}
    649 
    650 	return 0;
    651 }
    652 
    653 static void
    654 save_core(void)
    655 {
    656 	FILE *fp;
    657 	int bounds, ifd, nr, nw, ofd, tryksyms;
    658 	char path[MAXPATHLEN], rbuf[MAXPATHLEN];
    659 	const char *rawp;
    660 
    661 	ofd = -1;
    662 	/*
    663 	 * Get the current number and update the bounds file.  Do the update
    664 	 * now, because may fail later and don't want to overwrite anything.
    665 	 */
    666 	umask(066);
    667 	(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
    668 	if ((fp = fopen(path, "r")) == NULL)
    669 		goto err1;
    670 	if (fgets(buf, sizeof(buf), fp) == NULL) {
    671 		if (ferror(fp))
    672 err1:			syslog(LOG_WARNING, "%s: %m", path);
    673 		bounds = 0;
    674 	} else
    675 		bounds = atoi(buf);
    676 	if (fp != NULL)
    677 		(void)fclose(fp);
    678 	if ((fp = fopen(path, "w")) == NULL)
    679 		syslog(LOG_ERR, "%s: %m", path);
    680 	else {
    681 		(void)fprintf(fp, "%d\n", bounds + 1);
    682 		(void)fclose(fp);
    683 	}
    684 
    685 	/* Create the core file. */
    686 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
    687 	    dirname, bounds, compress ? ".gz" : "");
    688 	if (compress) {
    689 		if ((fp = zopen(path, gzmode)) == NULL) {
    690 			syslog(LOG_ERR, "%s: %m", path);
    691 			exit(1);
    692 		}
    693 	} else {
    694 		ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
    695 		fp  = fdopen(ofd, "w");
    696 		if (fp == NULL) {
    697 			syslog(LOG_ERR, "%s: fdopen: %m", path);
    698 			exit(1);
    699 		}
    700 	}
    701 
    702 	if (dumpcdev == NODEV) {
    703 		/* Open the raw device. */
    704 		rawp = getdiskrawname(rbuf, sizeof(rbuf), ddname);
    705 		if (rawp == NULL) {
    706 			syslog(LOG_WARNING, "%s: %m; can't convert to raw",
    707 			    ddname);
    708 			rawp = ddname;
    709 		}
    710 		if ((ifd = open(rawp, O_RDONLY)) == -1) {
    711 			syslog(LOG_WARNING, "%s: %m; using block device",
    712 			    rawp);
    713 			ifd = dumpfd;
    714 		}
    715 	} else {
    716 		rawp = ddname;
    717 		ifd = dumpfd;
    718 	}
    719 
    720 	/* Seek to the start of the core. */
    721 	Lseek(ifd, dumplo, SEEK_SET);
    722 
    723 	if (kvm_dump_wrtheader(kd_dump, fp, (int32_t)dumpbytes) == -1) {
    724 		syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
    725 		    kvm_geterr(kd_dump));
    726 		exit(1);
    727 	}
    728 
    729 	/* Copy the core file. */
    730 	syslog(LOG_NOTICE, "writing %score to %s",
    731 	    compress ? "compressed " : "", path);
    732 	for (; dumpbytes > (off_t)0; dumpbytes -= (off_t)nr) {
    733 		char nbuf[7];
    734 		humanize_number(nbuf, 7, dumpbytes, "", HN_AUTOSCALE, 0);
    735 		(void)printf("%7s\r", nbuf);
    736 		(void)fflush(stdout);
    737 		nr = read(ifd, buf, MIN(dumpbytes, (off_t)sizeof(buf)));
    738 		if (nr <= 0) {
    739 			if (nr == 0)
    740 				syslog(LOG_WARNING,
    741 				    "WARNING: EOF on dump device");
    742 			else
    743 				syslog(LOG_ERR, "%s: %m", rawp);
    744 			goto err2;
    745 		}
    746 		nw = fwrite(buf, 1, nr, fp);
    747 		if (nw != nr) {
    748 			syslog(LOG_ERR, "%s: %s",
    749 			    path, strerror(nw == 0 ? EIO : errno));
    750 err2:			syslog(LOG_WARNING,
    751 			    "WARNING: core may be incomplete");
    752 			(void)printf("\n");
    753 			exit(1);
    754 		}
    755 	}
    756 	if (dumpcdev == NODEV)
    757 		(void)close(ifd);
    758 	(void)fclose(fp);
    759 
    760 	/* Create a kernel. */
    761 	(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
    762 	    dirname, bounds, compress ? ".gz" : "");
    763 	syslog(LOG_NOTICE, "writing %skernel to %s",
    764 	    compress ? "compressed " : "", path);
    765 	for (tryksyms = 1;; tryksyms = 0) {
    766 		if (compress) {
    767 			if ((fp = zopen(path, gzmode)) == NULL) {
    768 				syslog(LOG_ERR, "%s: %m", path);
    769 				exit(1);
    770 			}
    771 		} else
    772 			ofd = Create(path, S_IRUSR | S_IWUSR);
    773 		if (tryksyms) {
    774 			if (!save_ksyms(ofd, fp, path))
    775 				break;
    776 			if (compress)
    777 				(void)fclose(fp);
    778 			else
    779 				(void)close(ofd);
    780 			unlink(path);
    781 		} else {
    782 			save_kernel(ofd, fp, path);
    783 			break;
    784 		}
    785 	}
    786 	if (compress)
    787 		(void)fclose(fp);
    788 	else
    789 		(void)close(ofd);
    790 
    791 	/*
    792 	 * For development systems where the crash occurs during boot
    793 	 * to multiuser.
    794 	 */
    795 	sync();
    796 	sleep(1);
    797 	sync();
    798 	sleep(1);
    799 }
    800 
    801 static char *
    802 find_dev(dev_t dev, mode_t type)
    803 {
    804 	DIR *dfd;
    805 	struct dirent *dir;
    806 	struct stat sb;
    807 	char *dp, device[MAXPATHLEN + 1], *p;
    808 	size_t l;
    809 
    810 	if ((dfd = opendir(_PATH_DEV)) == NULL) {
    811 		syslog(LOG_ERR, "%s: %m", _PATH_DEV);
    812 		exit(1);
    813 	}
    814 	strlcpy(device, _PATH_DEV, sizeof(device));
    815 	p = &device[strlen(device)];
    816 	l = sizeof(device) - strlen(device);
    817 	while ((dir = readdir(dfd))) {
    818 		strlcpy(p, dir->d_name, l);
    819 		if (lstat(device, &sb)) {
    820 			syslog(LOG_ERR, "%s: %m", device);
    821 			continue;
    822 		}
    823 		if ((sb.st_mode & S_IFMT) != type)
    824 			continue;
    825 		if (dev == sb.st_rdev) {
    826 			closedir(dfd);
    827 			if ((dp = strdup(device)) == NULL) {
    828 				syslog(LOG_ERR, "%m");
    829 				exit(1);
    830 			}
    831 			return (dp);
    832 		}
    833 	}
    834 	closedir(dfd);
    835 	syslog(LOG_ERR, "can't find device %lld/%lld",
    836 	    (long long)major(dev), (long long)minor(dev));
    837 	exit(1);
    838 }
    839 
    840 static int
    841 get_crashtime(void)
    842 {
    843 	time_t dumptime;			/* Time the dump was taken. */
    844 	struct timeval dtime;
    845 
    846 	if (KREAD(kd_dump, dump_nl[X_TIME_SECOND].n_value, &dumptime) != 0) {
    847 		if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
    848 			syslog(LOG_WARNING, "kvm_read: %s (and _time_second "
    849 			    "is not defined also)", kvm_geterr(kd_dump));
    850 			return (0);
    851 		}
    852 		dumptime = dtime.tv_sec;
    853 	}
    854 	if (dumptime == 0) {
    855 		syslog(LOG_WARNING, "dump time is zero");
    856 		return (0);
    857 	}
    858 	syslog(LOG_INFO, "system went down at %s", ctime(&dumptime));
    859 #define	LEEWAY	(60 * SECSPERDAY)
    860 	if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
    861 		syslog(LOG_WARNING, "dump time is unreasonable");
    862 		return (0);
    863 	}
    864 	return (1);
    865 }
    866 
    867 static int
    868 check_space(void)
    869 {
    870 	FILE *fp;
    871 	off_t minfree, spacefree, kernelsize, needed;
    872 	struct stat st;
    873 	struct statvfs fsbuf;
    874 	char mbuf[100], path[MAXPATHLEN];
    875 
    876 	/* XXX assume a reasonable default, unless we find a kernel. */
    877 	kernelsize = 20 * 1024 * 1024;
    878 	if (!stat(kernel, &st)) kernelsize = st.st_blocks * S_BLKSIZE;
    879 	if (statvfs(dirname, &fsbuf) < 0) {
    880 		syslog(LOG_ERR, "%s: %m", dirname);
    881 		exit(1);
    882 	}
    883 	spacefree = fsbuf.f_bavail;
    884 	spacefree *= fsbuf.f_frsize;
    885 	spacefree /= 1024;
    886 
    887 	(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
    888 	if ((fp = fopen(path, "r")) == NULL)
    889 		minfree = 0;
    890 	else {
    891 		if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
    892 			minfree = 0;
    893 		else
    894 			minfree = atoi(mbuf);
    895 		(void)fclose(fp);
    896 	}
    897 
    898 	needed = (dumpbytes + kernelsize) / 1024;
    899  	if (minfree > 0 && spacefree - needed < minfree) {
    900 		syslog(LOG_WARNING,
    901 		    "no dump, not enough free space in %s", dirname);
    902 		return (0);
    903 	}
    904 	if (spacefree - needed < minfree)
    905 		syslog(LOG_WARNING,
    906 		    "dump performed, but free space threshold crossed");
    907 	return (1);
    908 }
    909 
    910 static int
    911 Open(const char *name, int rw)
    912 {
    913 	int fd;
    914 
    915 	if ((fd = open(name, rw, 0)) < 0) {
    916 		syslog(LOG_ERR, "%s: %m", name);
    917 		exit(1);
    918 	}
    919 	return (fd);
    920 }
    921 
    922 static void
    923 Lseek(int fd, off_t off, int flag)
    924 {
    925 	off_t ret;
    926 
    927 	ret = lseek(fd, off, flag);
    928 	if (ret == -1) {
    929 		syslog(LOG_ERR, "lseek: %m");
    930 		exit(1);
    931 	}
    932 }
    933 
    934 static int
    935 Create(char *file, int mode)
    936 {
    937 	int fd;
    938 
    939 	fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
    940 	if (fd < 0) {
    941 		syslog(LOG_ERR, "%s: %m", file);
    942 		exit(1);
    943 	}
    944 	return (fd);
    945 }
    946 
    947 static void
    948 usage(const char *fmt, ...)
    949 {
    950 	va_list ap;
    951 	va_start(ap, fmt);
    952 	(void)vsyslog(LOG_ERR, fmt, ap);
    953 	va_end(ap);
    954 	(void)syslog(LOG_ERR,
    955 	    "Usage: %s [-cfnvz] [-N system] [-Z level] [directory]",
    956 	    getprogname());
    957 	exit(1);
    958 }
    959