/*- * Copyright (c) 1986, 1992, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#) Copyright (c) 1986, 1992, 1993 The Regents of the University of California. All rights reserved. * @(#)savecore.c 8.3 (Berkeley) 1/2/94 * $FreeBSD: src/sbin/savecore/savecore.c,v 1.28.2.14 2005/01/05 09:14:34 maxim Exp $ * $DragonFly: src/sbin/savecore/savecore.c,v 1.15 2007/05/19 06:54:29 dillon Exp $ */ #define _KERNEL_STRUCTURES #include #undef _KERNEL_STRUCTURES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern FILE *zopen(const char *fname, const char *mode); #define ok(number) ((number) - kernbase) struct nlist current_nl[] = { /* Namelist for currently running system. */ #define X_DUMPLO 0 { "_dumplo64", 0, 0, 0, 0 }, #define X_TIME 1 { "_time_second", 0, 0, 0, 0 }, #define X_DUMPSIZE 2 { "_dumpsize", 0, 0, 0, 0 }, #define X_VERSION 3 { "_version", 0, 0, 0, 0 }, #define X_PANICSTR 4 { "_panicstr", 0, 0, 0, 0 }, #define X_DUMPMAG 5 { "_dumpmag", 0, 0, 0, 0 }, #define X_KERNBASE 6 { "_kernbase", 0, 0, 0, 0 }, #define X_MAXMEM 7 { "_Maxmem", 0, 0, 0, 0 }, { "", 0, 0, 0, 0 }, }; int cursyms[] = { X_DUMPLO, X_VERSION, X_DUMPMAG, -1 }; int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 }; struct nlist dump_nl[] = { /* Name list for dumped system. */ { "_dumplo64", 0, 0, 0, 0 }, /* Entries MUST be the same as */ { "_time_second", 0, 0, 0, 0 }, /* those in current_nl[]. */ { "_dumpsize", 0, 0, 0, 0 }, { "_version", 0, 0, 0, 0 }, { "_panicstr", 0, 0, 0, 0 }, { "_dumpmag", 0, 0, 0, 0 }, { "_kernbase", 0, 0, 0, 0 }, { "_Maxmem", 0, 0, 0, 0 }, { "", 0, 0, 0, 0 }, }; /* Types match kernel declarations. */ u_long dumpmag; /* magic number in dump */ /* Based on kernel variables, but with more convenient types. */ off_t dumplo; /* where dump starts on dumpdev */ off_t dumpsize; /* amount of memory dumped */ char *kernel; /* user-specified kernel */ char *savedir; /* directory to save dumps in */ char ddname[MAXPATHLEN]; /* name of dump device */ dev_t dumpdev; /* dump device */ int dumpfd; /* read/write descriptor on char dev */ time_t now; /* current date */ char panic_mesg[1024]; /* panic message */ int panicstr; /* flag: dump was caused by panic */ char vers[1024]; /* version of kernel that crashed */ char *physmem; /* physmem value used with dumped session */ u_int64_t dkdumplo; /* directly specified kernel dumplo value */ u_long kernbase; /* offset of kvm to core file */ static int clear, compress, force, verbose, directdumplo; /* flags */ static int keep; /* keep dump on device */ static void check_kmem(void); static int check_space(void); static void clear_dump(void); static void DumpRead(int fd, void *bp, int size, off_t off, int flag); static void DumpWrite(int fd, void *bp, int size, off_t off, int flag); static int dump_exists(void); static void find_dev(dev_t); static int get_crashtime(void); static void get_dumpsize(void); static void kmem_setup(void); static void Lseek(int, off_t, int); static int Open(const char *, int rw); static int Read(int, void *, int); static void save_core(void); static void usage(void); static int verify_dev(char *, dev_t); static void Write(int, void *, int); static void kdumplo_adjust(char *cp, int kmem, u_int64_t *kdumplop); int main(int argc, char **argv) { int ch; char *ep; openlog("savecore", LOG_PERROR, LOG_DAEMON); while ((ch = getopt(argc, argv, "cD:dfkN:vzP:B:")) != -1) switch(ch) { case 'c': clear = 1; break; case 'D': strncpy(ddname, optarg, sizeof(ddname)); break; case 'd': /* Not documented. */ case 'v': verbose = 1; break; case 'f': force = 1; break; case 'k': keep = 1; break; case 'N': kernel = optarg; break; case 'z': compress = 1; break; case 'P': physmem = optarg; break; case 'B': directdumplo = 1; dkdumplo = strtouq(optarg, &ep, 10); if (*ep != '\0') errx(1, "invalid offset: '%s'", optarg); break; case '?': default: usage(); } argc -= optind; argv += optind; if (!clear) { if (argc != 1 && argc != 2) usage(); savedir = argv[0]; } if (argc == 2) kernel = argv[1]; time(&now); kmem_setup(); if (clear) { clear_dump(); exit(0); } if (!dump_exists() && !force) exit(1); check_kmem(); if (panicstr) syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg); else syslog(LOG_ALERT, "reboot"); get_dumpsize(); if ((!get_crashtime() || !check_space()) && !force) exit(1); save_core(); if (!keep) clear_dump(); exit(0); } static void kmem_setup(void) { int kmem, i; const char *dump_sys; size_t len; u_int64_t kdumplo; /* block number where dump starts on dumpdev */ char *p; /* * Some names we need for the currently running system, others for * the system that was running when the dump was made. The values * obtained from the current system are used to look for things in * /dev/kmem that cannot be found in the dump_sys namelist, but are * presumed to be the same (since the disk partitions are probably * the same!) */ if ((nlist(getbootfile(), current_nl)) == -1) syslog(LOG_ERR, "%s: nlist: %m", getbootfile()); for (i = 0; cursyms[i] != -1; i++) if (current_nl[cursyms[i]].n_value == 0) { syslog(LOG_ERR, "%s: %s not in namelist", getbootfile(), current_nl[cursyms[i]].n_name); exit(1); } dump_sys = kernel ? kernel : getbootfile(); if ((nlist(dump_sys, dump_nl)) == -1) syslog(LOG_ERR, "%s: nlist: %m", dump_sys); for (i = 0; dumpsyms[i] != -1; i++) if (dump_nl[dumpsyms[i]].n_value == 0) { syslog(LOG_ERR, "%s: %s not in namelist", dump_sys, dump_nl[dumpsyms[i]].n_name); exit(1); } if (dump_nl[X_KERNBASE].n_value != 0) kernbase = dump_nl[X_KERNBASE].n_value; else kernbase = KERNBASE; if (*ddname == 0) { len = sizeof dumpdev; if (sysctlbyname("kern.dumpdev", &dumpdev, &len, NULL, 0) == -1) { syslog(LOG_ERR, "sysctl: kern.dumpdev: %m"); exit(1); } if (dumpdev == NODEV) { syslog(LOG_WARNING, "no core dump (no dumpdev)"); exit(1); } find_dev(dumpdev); } kmem = Open(_PATH_KMEM, O_RDONLY); if (directdumplo) { kdumplo = dkdumplo; } else { Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET); Read(kmem, &kdumplo, sizeof(kdumplo)); if (physmem) kdumplo_adjust(physmem, kmem, &kdumplo); } dumplo = kdumplo * DEV_BSIZE; if (verbose) printf("dumplo = %lld (%lld * %d)\n", (long long)dumplo, kdumplo, DEV_BSIZE); Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET); Read(kmem, &dumpmag, sizeof(dumpmag)); dumpfd = Open(ddname, O_RDWR); if (kernel) return; lseek(kmem, (off_t)current_nl[X_VERSION].n_value, SEEK_SET); Read(kmem, vers, sizeof(vers)); vers[sizeof(vers) - 1] = '\0'; p = strchr(vers, '\n'); if (p) p[1] = '\0'; /* Don't fclose(fp), we use kmem later. */ } static void check_kmem(void) { char core_vers[1024], *p; DumpRead(dumpfd, core_vers, sizeof(core_vers), (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET); core_vers[sizeof(core_vers) - 1] = '\0'; p = strchr(core_vers, '\n'); if (p) p[1] = '\0'; if (strcmp(vers, core_vers) && kernel == 0) syslog(LOG_WARNING, "warning: %s version mismatch:\n\t\"%s\"\nand\t\"%s\"\n", getbootfile(), vers, core_vers); DumpRead(dumpfd, &panicstr, sizeof(panicstr), (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET); if (panicstr) { DumpRead(dumpfd, panic_mesg, sizeof(panic_mesg), (off_t)(dumplo + ok(panicstr)), L_SET); } } /* * Clear the magic number in the dump header. */ static void clear_dump(void) { u_long newdumpmag; newdumpmag = 0; DumpWrite(dumpfd, &newdumpmag, sizeof(newdumpmag), (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); close(dumpfd); } /* * Check if a dump exists by looking for a magic number in the dump * header. */ static int dump_exists(void) { u_long newdumpmag; DumpRead(dumpfd, &newdumpmag, sizeof(newdumpmag), (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); if (newdumpmag != dumpmag) { if (verbose) syslog(LOG_WARNING, "magic number mismatch (%lx != %lx)", newdumpmag, dumpmag); syslog(LOG_WARNING, "no core dump"); return (0); } return (1); } char buf[1024 * 1024]; #define BLOCKSIZE (1<<12) #define BLOCKMASK (~(BLOCKSIZE-1)) /* * Save the core dump. */ static void save_core(void) { FILE *fp; int bounds, ifd, nr, nw; int hs, he = 0; /* start and end of hole */ char path[MAXPATHLEN]; mode_t oumask; /* * Get the current number and update the bounds file. Do the update * now, because may fail later and don't want to overwrite anything. */ snprintf(path, sizeof(path), "%s/bounds", savedir); if ((fp = fopen(path, "r")) == NULL) goto err1; if (fgets(buf, sizeof(buf), fp) == NULL) { if (ferror(fp)) err1: syslog(LOG_WARNING, "%s: %m", path); bounds = 0; } else bounds = atoi(buf); if (fp != NULL) fclose(fp); if ((fp = fopen(path, "w")) == NULL) syslog(LOG_ERR, "%s: %m", path); else { fprintf(fp, "%d\n", bounds + 1); fclose(fp); } /* Create the core file. */ oumask = umask(S_IRWXG|S_IRWXO); /* Restrict access to the core file.*/ snprintf(path, sizeof(path), "%s/vmcore.%d%s", savedir, bounds, compress ? ".gz" : ""); if (compress) fp = zopen(path, "w"); else fp = fopen(path, "w"); if (fp == NULL) { syslog(LOG_ERR, "%s: %m", path); exit(1); } umask(oumask); /* Seek to the start of the core. */ Lseek(dumpfd, (off_t)dumplo, L_SET); /* Copy the core file. */ syslog(LOG_NOTICE, "writing %score to %s", compress ? "compressed " : "", path); for (; dumpsize > 0; dumpsize -= nr) { printf("%6ldK\r", (long)(dumpsize / 1024)); fflush(stdout); nr = read(dumpfd, buf, MIN(dumpsize, sizeof(buf))); if (nr <= 0) { if (nr == 0) syslog(LOG_WARNING, "WARNING: EOF on dump device"); else syslog(LOG_ERR, "%s: %m", ddname); goto err2; } if (compress) { nw = fwrite(buf, 1, nr, fp); } else { for (nw = 0; nw < nr; nw = he) { /* find a contiguous block of zeroes */ for (hs = nw; hs < nr; hs += BLOCKSIZE) { for (he = hs; he < nr && buf[he] == 0; ++he) /* nothing */ ; /* is the hole long enough to matter? */ if (he >= hs + BLOCKSIZE) break; } /* back down to a block boundary */ he &= BLOCKMASK; /* * 1) Don't go beyond the end of the buffer. * 2) If the end of the buffer is less than * BLOCKSIZE bytes away, we're at the end * of the file, so just grab what's left. */ if (hs + BLOCKSIZE > nr) hs = he = nr; /* * At this point, we have a partial ordering: * nw <= hs <= he <= nr * If hs > nw, buf[nw..hs] contains non-zero data. * If he > hs, buf[hs..he] is all zeroes. */ if (hs > nw) if (fwrite(buf + nw, hs - nw, 1, fp) != 1) break; if (he > hs) if (fseeko(fp, he - hs, SEEK_CUR) == -1) break; } } if (nw != nr) { syslog(LOG_ERR, "%s: %m", path); err2: syslog(LOG_WARNING, "WARNING: vmcore may be incomplete"); printf("\n"); exit(1); } } fclose(fp); /* Copy the kernel. */ ifd = Open(kernel ? kernel : getbootfile(), O_RDONLY); snprintf(path, sizeof(path), "%s/kernel.%d%s", savedir, bounds, compress ? ".gz" : ""); if (compress) fp = zopen(path, "w"); else fp = fopen(path, "w"); if (fp == NULL) { syslog(LOG_ERR, "%s: %m", path); exit(1); } syslog(LOG_NOTICE, "writing %skernel to %s", compress ? "compressed " : "", path); while ((nr = read(ifd, buf, sizeof(buf))) > 0) { nw = fwrite(buf, 1, nr, fp); if (nw != nr) { syslog(LOG_ERR, "%s: %m", path); syslog(LOG_WARNING, "WARNING: kernel may be incomplete"); exit(1); } } if (nr < 0) { syslog(LOG_ERR, "%s: %m", kernel ? kernel : getbootfile()); syslog(LOG_WARNING, "WARNING: kernel may be incomplete"); exit(1); } fclose(fp); close(ifd); } /* * Verify that the specified device node exists and matches the * specified device. */ static int verify_dev(char *name, dev_t dev) { struct stat sb; if (lstat(name, &sb) == -1) return (-1); if (!S_ISCHR(sb.st_mode) || sb.st_rdev != dev) return (-1); return (0); } /* * Find the dump device. * * 1) try devname(3); see if it returns something sensible * 2) scan /dev for the desired node * 3) as a last resort, try to create the node we need */ static void find_dev(dev_t dev) { struct dirent *ent; char *dn, *dnp; DIR *d; strcpy(ddname, _PATH_DEV); dnp = ddname + sizeof _PATH_DEV - 1; if ((dn = devname(dev, S_IFCHR)) != NULL) { strcpy(dnp, dn); if (verify_dev(ddname, dev) == 0) return; } if ((d = opendir(_PATH_DEV)) != NULL) { while ((ent = readdir(d))) { strcpy(dnp, ent->d_name); if (verify_dev(ddname, dev) == 0) { closedir(d); return; } } closedir(d); } strcpy(dnp, "dump"); if (mknod(ddname, S_IFCHR|S_IRUSR|S_IWUSR, dev) == 0) return; syslog(LOG_ERR, "can't find device %d/%#x", major(dev), minor(dev)); exit(1); } /* * Extract the date and time of the crash from the dump header, and * make sure it looks sane (within one week of current date and time). */ static int get_crashtime(void) { time_t dumptime; /* Time the dump was taken. */ DumpRead(dumpfd, &dumptime, sizeof(dumptime), (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET); if (dumptime == 0) { if (verbose) syslog(LOG_ERR, "dump time is zero"); return (0); } printf("savecore: system went down at %s", ctime(&dumptime)); #define LEEWAY (7 * 86400) if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) { printf("dump time is unreasonable\n"); return (0); } return (1); } /* * Extract the size of the dump from the dump header. */ static void get_dumpsize(void) { int kdumpsize; /* Number of pages in dump. */ /* Read the dump size. */ DumpRead(dumpfd, &kdumpsize, sizeof(kdumpsize), (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET); dumpsize = (off_t)kdumpsize * getpagesize(); } /* * Check that sufficient space is available on the disk that holds the * save directory. */ static int check_space(void) { FILE *fp; const char *tkernel; off_t minfree, spacefree, totfree, kernelsize, needed; struct stat st; struct statfs fsbuf; char mybuf[100], path[MAXPATHLEN]; tkernel = kernel ? kernel : getbootfile(); if (stat(tkernel, &st) < 0) { syslog(LOG_ERR, "%s: %m", tkernel); exit(1); } kernelsize = st.st_blocks * S_BLKSIZE; if (statfs(savedir, &fsbuf) < 0) { syslog(LOG_ERR, "%s: %m", savedir); exit(1); } spacefree = ((off_t) fsbuf.f_bavail * fsbuf.f_bsize) / 1024; totfree = ((off_t) fsbuf.f_bfree * fsbuf.f_bsize) / 1024; snprintf(path, sizeof(path), "%s/minfree", savedir); if ((fp = fopen(path, "r")) == NULL) minfree = 0; else { if (fgets(mybuf, sizeof(mybuf), fp) == NULL) minfree = 0; else minfree = atoi(mybuf); fclose(fp); } needed = (dumpsize + kernelsize) / 1024; if (((minfree > 0) ? spacefree : totfree) - needed < minfree) { syslog(LOG_WARNING, "no dump, not enough free space on device (%lld available, need %lld)", (long long)(minfree > 0 ? spacefree : totfree), (long long)needed); return (0); } if (spacefree - needed < 0) syslog(LOG_WARNING, "dump performed, but free space threshold crossed"); return (1); } static int Open(const char *name, int rw) { int fd; if ((fd = open(name, rw, 0)) < 0) { syslog(LOG_ERR, "%s: %m", name); exit(1); } return (fd); } static int Read(int fd, void *bp, int size) { int nr; nr = read(fd, bp, size); if (nr != size) { syslog(LOG_ERR, "read: %m"); exit(1); } return (nr); } static void Lseek(int fd, off_t off, int flag) { off_t ret; ret = lseek(fd, off, flag); if (ret == -1) { syslog(LOG_ERR, "lseek: %m"); exit(1); } } /* * DumpWrite and DumpRead block io requests to the * dump device. */ #define DUMPBUFSIZE 8192 static void DumpWrite(int fd, void *bp, int size, off_t off, int flag) { unsigned char mybuf[DUMPBUFSIZE], *p, *q; off_t pos; int i, j; if (flag != L_SET) { syslog(LOG_ERR, "lseek: not LSET"); exit(2); } q = bp; while (size) { pos = off & ~(DUMPBUFSIZE - 1); Lseek(fd, pos, flag); Read(fd, mybuf, sizeof(mybuf)); j = off & (DUMPBUFSIZE - 1); p = mybuf + j; i = size; if (i > DUMPBUFSIZE - j) i = DUMPBUFSIZE - j; memcpy(p, q, i); Lseek(fd, pos, flag); Write(fd, mybuf, sizeof(mybuf)); size -= i; q += i; off += i; } } static void DumpRead(int fd, void *bp, int size, off_t off, int flag) { unsigned char mybuf[DUMPBUFSIZE], *p, *q; off_t pos; int i, j; if (flag != L_SET) { syslog(LOG_ERR, "lseek: not LSET"); exit(2); } q = bp; while (size) { pos = off & ~(DUMPBUFSIZE - 1); Lseek(fd, pos, flag); Read(fd, mybuf, sizeof(mybuf)); j = off & (DUMPBUFSIZE - 1); p = mybuf + j; i = size; if (i > DUMPBUFSIZE - j) i = DUMPBUFSIZE - j; memcpy(q, p, i); size -= i; q += i; off += i; } } static void Write(int fd, void *bp, int size) { int n; if ((n = write(fd, bp, size)) < size) { syslog(LOG_ERR, "write: %m"); exit(1); } } static void kdumplo_adjust(char *cp, int kmem, u_int64_t *kdumplop) { uint64_t AllowMem, sanity, Maxmem, CurrMaxmem; char *ep; /* based on getmemsize() in i386/i386/machdep.c */ sanity = AllowMem = strtouq(cp, &ep, 0); if ((ep != cp) && (*ep != 0)) { switch(*ep) { case 'g': case 'G': AllowMem <<= 10; case 'm': case 'M': AllowMem <<= 10; case 'k': case 'K': AllowMem <<= 10; break; default: AllowMem = 0; } if (AllowMem < sanity) AllowMem = 0; } if (AllowMem == 0) errx(1, "invalid memory size: '%s'\n", cp); else Maxmem = atop(AllowMem); Lseek(kmem, (off_t)current_nl[X_MAXMEM].n_value, L_SET); Read(kmem, &CurrMaxmem, sizeof(CurrMaxmem)); /* based on setdumpdev() in kern_shutdown.c */ *kdumplop += (u_int64_t)CurrMaxmem * PAGE_SIZE / DEV_BSIZE; *kdumplop -= (u_int64_t)Maxmem * PAGE_SIZE / DEV_BSIZE; } static void usage(void) { syslog(LOG_ERR, "usage: savecore [-cfkvz] [-N system] [-P physmem|-B blkno] directory"); exit(1); }