2 * Copyright (c) 1986, 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
33 * @(#) Copyright (c) 1986, 1992, 1993 The Regents of the University of California. All rights reserved.
34 * @(#)savecore.c 8.3 (Berkeley) 1/2/94
35 * $FreeBSD: src/sbin/savecore/savecore.c,v 1.28.2.13 2002/04/07 21:17:50 asmodai Exp $
36 * $DragonFly: src/sbin/savecore/savecore.c,v 1.9 2005/02/02 07:00:47 cpressey Exp $
39 #include <sys/param.h>
41 #include <sys/mount.h>
42 #include <sys/syslog.h>
43 #include <sys/sysctl.h>
46 #include <vm/vm_param.h>
58 extern FILE *zopen(const char *fname, const char *mode);
61 #define ok(number) ALPHA_K0SEG_TO_PHYS(number)
65 #define ok(number) ((number) - kernbase)
68 struct nlist current_nl[] = { /* Namelist for currently running system. */
70 { "_dumplo", 0, 0, 0, 0 },
72 { "_time_second", 0, 0, 0, 0 },
74 { "_dumpsize", 0, 0, 0, 0 },
76 { "_version", 0, 0, 0, 0 },
78 { "_panicstr", 0, 0, 0, 0 },
80 { "_dumpmag", 0, 0, 0, 0 },
82 { "_kernbase", 0, 0, 0, 0 },
85 int cursyms[] = { X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
86 int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };
88 struct nlist dump_nl[] = { /* Name list for dumped system. */
89 { "_dumplo", 0, 0, 0, 0 }, /* Entries MUST be the same as */
90 { "_time_second", 0, 0, 0, 0 }, /* those in current_nl[]. */
91 { "_dumpsize", 0, 0, 0, 0 },
92 { "_version", 0, 0, 0, 0 },
93 { "_panicstr", 0, 0, 0, 0 },
94 { "_dumpmag", 0, 0, 0, 0 },
95 { "_kernbase", 0, 0, 0, 0 },
99 /* Types match kernel declarations. */
100 u_long dumpmag; /* magic number in dump */
102 /* Based on kernel variables, but with more convenient types. */
103 off_t dumplo; /* where dump starts on dumpdev */
104 off_t dumpsize; /* amount of memory dumped */
106 char *kernel; /* user-specified kernel */
107 char *savedir; /* directory to save dumps in */
108 char ddname[MAXPATHLEN]; /* name of dump device */
109 dev_t dumpdev; /* dump device */
110 int dumpfd; /* read/write descriptor on char dev */
111 time_t now; /* current date */
112 char panic_mesg[1024]; /* panic message */
113 int panicstr; /* flag: dump was caused by panic */
114 char vers[1024]; /* version of kernel that crashed */
117 u_long kernbase; /* offset of kvm to core file */
120 static int clear, compress, force, verbose; /* flags */
121 static int keep; /* keep dump on device */
123 static void check_kmem(void);
124 static int check_space(void);
125 static void clear_dump(void);
126 static void DumpRead(int fd, void *bp, int size, off_t off, int flag);
127 static void DumpWrite(int fd, void *bp, int size, off_t off, int flag);
128 static int dump_exists(void);
129 static void find_dev(dev_t);
130 static int get_crashtime(void);
131 static void get_dumpsize(void);
132 static void kmem_setup(void);
133 static void Lseek(int, off_t, int);
134 static int Open(const char *, int rw);
135 static int Read(int, void *, int);
136 static void save_core(void);
137 static void usage(void);
138 static int verify_dev(char *, dev_t);
139 static void Write(int, void *, int);
142 main(int argc, char **argv)
146 openlog("savecore", LOG_PERROR, LOG_DAEMON);
148 while ((ch = getopt(argc, argv, "cdfkN:vz")) != -1)
153 case 'd': /* Not documented. */
177 if (argc != 1 && argc != 2)
192 if (!dump_exists() && !force)
198 syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
200 syslog(LOG_ALERT, "reboot");
204 if ((!get_crashtime() || !check_space()) && !force)
219 const char *dump_sys;
221 long kdumplo; /* block number where dump starts on dumpdev */
225 * Some names we need for the currently running system, others for
226 * the system that was running when the dump was made. The values
227 * obtained from the current system are used to look for things in
228 * /dev/kmem that cannot be found in the dump_sys namelist, but are
229 * presumed to be the same (since the disk partitions are probably
232 if ((nlist(getbootfile(), current_nl)) == -1)
233 syslog(LOG_ERR, "%s: nlist: %m", getbootfile());
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 getbootfile(), current_nl[cursyms[i]].n_name);
241 dump_sys = kernel ? kernel : getbootfile();
242 if ((nlist(dump_sys, dump_nl)) == -1)
243 syslog(LOG_ERR, "%s: nlist: %m", dump_sys);
244 for (i = 0; dumpsyms[i] != -1; i++)
245 if (dump_nl[dumpsyms[i]].n_value == 0) {
246 syslog(LOG_ERR, "%s: %s not in namelist",
247 dump_sys, dump_nl[dumpsyms[i]].n_name);
252 if (dump_nl[X_KERNBASE].n_value != 0)
253 kernbase = dump_nl[X_KERNBASE].n_value;
258 len = sizeof dumpdev;
259 if (sysctlbyname("kern.dumpdev", &dumpdev, &len, NULL, 0) == -1) {
260 syslog(LOG_ERR, "sysctl: kern.dumpdev: %m");
263 if (dumpdev == NODEV) {
264 syslog(LOG_WARNING, "no core dump (no dumpdev)");
268 kmem = Open(_PATH_KMEM, O_RDONLY);
269 Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET);
270 Read(kmem, &kdumplo, sizeof(kdumplo));
271 dumplo = (off_t)kdumplo * DEV_BSIZE;
273 printf("dumplo = %lld (%ld * %d)\n",
274 (long long)dumplo, kdumplo, DEV_BSIZE);
275 Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET);
276 Read(kmem, &dumpmag, sizeof(dumpmag));
278 dumpfd = Open(ddname, O_RDWR);
282 lseek(kmem, (off_t)current_nl[X_VERSION].n_value, SEEK_SET);
283 Read(kmem, vers, sizeof(vers));
284 vers[sizeof(vers) - 1] = '\0';
285 p = strchr(vers, '\n');
289 /* Don't fclose(fp), we use kmem later. */
295 char core_vers[1024], *p;
297 DumpRead(dumpfd, core_vers, sizeof(core_vers),
298 (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET);
299 core_vers[sizeof(core_vers) - 1] = '\0';
300 p = strchr(core_vers, '\n');
303 if (strcmp(vers, core_vers) && kernel == 0)
305 "warning: %s version mismatch:\n\t\"%s\"\nand\t\"%s\"\n",
306 getbootfile(), vers, core_vers);
307 DumpRead(dumpfd, &panicstr, sizeof(panicstr),
308 (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET);
310 DumpRead(dumpfd, panic_mesg, sizeof(panic_mesg),
311 (off_t)(dumplo + ok(panicstr)), L_SET);
316 * Clear the magic number in the dump header.
324 DumpWrite(dumpfd, &newdumpmag, sizeof(newdumpmag),
325 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
330 * Check if a dump exists by looking for a magic number in the dump
338 DumpRead(dumpfd, &newdumpmag, sizeof(newdumpmag),
339 (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
340 if (newdumpmag != dumpmag) {
342 syslog(LOG_WARNING, "magic number mismatch (%lx != %lx)",
343 newdumpmag, dumpmag);
344 syslog(LOG_WARNING, "no core dump");
350 char buf[1024 * 1024];
351 #define BLOCKSIZE (1<<12)
352 #define BLOCKMASK (~(BLOCKSIZE-1))
355 * Save the core dump.
361 int bounds, ifd, nr, nw;
362 int hs, he = 0; /* start and end of hole */
363 char path[MAXPATHLEN];
367 * Get the current number and update the bounds file. Do the update
368 * now, because may fail later and don't want to overwrite anything.
370 snprintf(path, sizeof(path), "%s/bounds", savedir);
371 if ((fp = fopen(path, "r")) == NULL)
373 if (fgets(buf, sizeof(buf), fp) == NULL) {
375 err1: syslog(LOG_WARNING, "%s: %m", path);
381 if ((fp = fopen(path, "w")) == NULL)
382 syslog(LOG_ERR, "%s: %m", path);
384 fprintf(fp, "%d\n", bounds + 1);
388 /* Create the core file. */
389 oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/
390 snprintf(path, sizeof(path), "%s/vmcore.%d%s",
391 savedir, bounds, compress ? ".gz" : "");
393 fp = zopen(path, "w");
395 fp = fopen(path, "w");
397 syslog(LOG_ERR, "%s: %m", path);
402 /* Seek to the start of the core. */
403 Lseek(dumpfd, (off_t)dumplo, L_SET);
405 /* Copy the core file. */
406 syslog(LOG_NOTICE, "writing %score to %s",
407 compress ? "compressed " : "", path);
408 for (; dumpsize > 0; dumpsize -= nr) {
409 printf("%6ldK\r", (long)(dumpsize / 1024));
411 nr = read(dumpfd, buf, MIN(dumpsize, sizeof(buf)));
415 "WARNING: EOF on dump device");
417 syslog(LOG_ERR, "%s: %m", ddname);
420 for (nw = 0; nw < nr; nw = he) {
421 /* find a contiguous block of zeroes */
422 for (hs = nw; hs < nr; hs += BLOCKSIZE) {
423 for (he = hs; he < nr && buf[he] == 0; ++he)
426 /* is the hole long enough to matter? */
427 if (he >= hs + BLOCKSIZE)
431 /* back down to a block boundary */
435 * 1) Don't go beyond the end of the buffer.
436 * 2) If the end of the buffer is less than
437 * BLOCKSIZE bytes away, we're at the end
438 * of the file, so just grab what's left.
440 if (hs + BLOCKSIZE > nr)
444 * At this point, we have a partial ordering:
445 * nw <= hs <= he <= nr
446 * If hs > nw, buf[nw..hs] contains non-zero data.
447 * If he > hs, buf[hs..he] is all zeroes.
450 if (fwrite(buf + nw, hs - nw, 1, fp) != 1)
453 if (fseeko(fp, he - hs, SEEK_CUR) == -1)
457 syslog(LOG_ERR, "%s: %m", path);
458 err2: syslog(LOG_WARNING,
459 "WARNING: vmcore may be incomplete");
467 /* Copy the kernel. */
468 ifd = Open(kernel ? kernel : getbootfile(), O_RDONLY);
469 snprintf(path, sizeof(path), "%s/kernel.%d%s",
470 savedir, bounds, compress ? ".gz" : "");
472 fp = zopen(path, "w");
474 fp = fopen(path, "w");
476 syslog(LOG_ERR, "%s: %m", path);
479 syslog(LOG_NOTICE, "writing %skernel to %s",
480 compress ? "compressed " : "", path);
481 while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
482 nw = fwrite(buf, 1, nr, fp);
484 syslog(LOG_ERR, "%s: %m", path);
486 "WARNING: kernel may be incomplete");
491 syslog(LOG_ERR, "%s: %m", kernel ? kernel : getbootfile());
493 "WARNING: kernel may be incomplete");
501 * Verify that the specified device node exists and matches the
505 verify_dev(char *name, dev_t dev)
509 if (lstat(name, &sb) == -1)
511 if (!S_ISCHR(sb.st_mode) || sb.st_rdev != dev)
517 * Find the dump device.
519 * 1) try devname(3); see if it returns something sensible
520 * 2) scan /dev for the desired node
521 * 3) as a last resort, try to create the node we need
530 strcpy(ddname, _PATH_DEV);
531 dnp = ddname + sizeof _PATH_DEV - 1;
532 if ((dn = devname(dev, S_IFCHR)) != NULL) {
534 if (verify_dev(ddname, dev) == 0)
537 if ((d = opendir(_PATH_DEV)) != NULL) {
538 while ((ent = readdir(d))) {
539 strcpy(dnp, ent->d_name);
540 if (verify_dev(ddname, dev) == 0) {
548 if (mknod(ddname, S_IFCHR|S_IRUSR|S_IWUSR, dev) == 0)
550 syslog(LOG_ERR, "can't find device %d/%#x", major(dev), minor(dev));
555 * Extract the date and time of the crash from the dump header, and
556 * make sure it looks sane (within one week of current date and time).
561 time_t dumptime; /* Time the dump was taken. */
563 DumpRead(dumpfd, &dumptime, sizeof(dumptime),
564 (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET);
567 syslog(LOG_ERR, "dump time is zero");
570 printf("savecore: system went down at %s", ctime(&dumptime));
571 #define LEEWAY (7 * 86400)
572 if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
573 printf("dump time is unreasonable\n");
580 * Extract the size of the dump from the dump header.
585 int kdumpsize; /* Number of pages in dump. */
587 /* Read the dump size. */
588 DumpRead(dumpfd, &kdumpsize, sizeof(kdumpsize),
589 (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET);
590 dumpsize = (off_t)kdumpsize * getpagesize();
594 * Check that sufficient space is available on the disk that holds the
602 off_t minfree, spacefree, totfree, kernelsize, needed;
605 char mybuf[100], path[MAXPATHLEN];
607 tkernel = kernel ? kernel : getbootfile();
608 if (stat(tkernel, &st) < 0) {
609 syslog(LOG_ERR, "%s: %m", tkernel);
612 kernelsize = st.st_blocks * S_BLKSIZE;
614 if (statfs(savedir, &fsbuf) < 0) {
615 syslog(LOG_ERR, "%s: %m", savedir);
618 spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
619 totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024;
621 snprintf(path, sizeof(path), "%s/minfree", savedir);
622 if ((fp = fopen(path, "r")) == NULL)
625 if (fgets(mybuf, sizeof(mybuf), fp) == NULL)
628 minfree = atoi(mybuf);
632 needed = (dumpsize + kernelsize) / 1024;
633 if (((minfree > 0) ? spacefree : totfree) - needed < minfree) {
635 "no dump, not enough free space on device (%lld available, need %lld)",
636 (long long)(minfree > 0 ? spacefree : totfree),
640 if (spacefree - needed < 0)
642 "dump performed, but free space threshold crossed");
647 Open(const char *name, int rw)
651 if ((fd = open(name, rw, 0)) < 0) {
652 syslog(LOG_ERR, "%s: %m", name);
659 Read(int fd, void *bp, int size)
663 nr = read(fd, bp, size);
665 syslog(LOG_ERR, "read: %m");
672 Lseek(int fd, off_t off, int flag)
676 ret = lseek(fd, off, flag);
678 syslog(LOG_ERR, "lseek: %m");
684 * DumpWrite and DumpRead block io requests to the * dump device.
686 #define DUMPBUFSIZE 8192
688 DumpWrite(int fd, void *bp, int size, off_t off, int flag)
690 unsigned char mybuf[DUMPBUFSIZE], *p, *q;
695 syslog(LOG_ERR, "lseek: not LSET");
700 pos = off & ~(DUMPBUFSIZE - 1);
701 Lseek(fd, pos, flag);
702 Read(fd, mybuf, sizeof(mybuf));
703 j = off & (DUMPBUFSIZE - 1);
706 if (i > DUMPBUFSIZE - j)
709 Lseek(fd, pos, flag);
710 Write(fd, mybuf, sizeof(mybuf));
718 DumpRead(int fd, void *bp, int size, off_t off, int flag)
720 unsigned char mybuf[DUMPBUFSIZE], *p, *q;
725 syslog(LOG_ERR, "lseek: not LSET");
730 pos = off & ~(DUMPBUFSIZE - 1);
731 Lseek(fd, pos, flag);
732 Read(fd, mybuf, sizeof(mybuf));
733 j = off & (DUMPBUFSIZE - 1);
736 if (i > DUMPBUFSIZE - j)
746 Write(int fd, void *bp, int size)
750 if ((n = write(fd, bp, size)) < size) {
751 syslog(LOG_ERR, "write: %m");
759 syslog(LOG_ERR, "usage: savecore [-cfkvz] [-N system] directory");