diff options
Diffstat (limited to 'sbin/savecore/savecore.c')
| -rw-r--r-- | sbin/savecore/savecore.c | 73 |
1 files changed, 57 insertions, 16 deletions
diff --git a/sbin/savecore/savecore.c b/sbin/savecore/savecore.c index 188e01c..ccbd4b4 100644 --- a/sbin/savecore/savecore.c +++ b/sbin/savecore/savecore.c @@ -117,6 +117,7 @@ int panicstr; /* flag: dump was caused by panic */ char vers[1024]; /* version of kernel that crashed */ int clear, compress, force, verbose; /* flags */ +int keep; /* keep dump on device */ void check_kmem __P((void)); int check_space __P((void)); @@ -145,7 +146,7 @@ main(argc, argv) openlog("savecore", LOG_PERROR, LOG_DAEMON); - while ((ch = getopt(argc, argv, "cdfN:vz")) != -1) + while ((ch = getopt(argc, argv, "dfkN:vz")) != -1) switch(ch) { case 'c': clear = 1; @@ -157,6 +158,9 @@ main(argc, argv) case 'f': force = 1; break; + case 'k': + keep = 1; + break; case 'N': kernel = optarg; break; @@ -203,19 +207,20 @@ main(argc, argv) save_core(); - clear_dump(); + if (!keep) + clear_dump(); + exit(0); } void kmem_setup() { - FILE *fp; int kmem, i; const char *dump_sys; - int mib[2]; size_t len; long kdumplo; /* block number where dump starts on dumpdev */ + char *p; /* * Some names we need for the currently running system, others for @@ -244,10 +249,8 @@ kmem_setup() exit(1); } - mib[0] = CTL_KERN; - mib[1] = KERN_DUMPDEV; len = sizeof dumpdev; - if (sysctl(mib, 2, &dumpdev, &len, NULL, 0) == -1) { + if (sysctlbyname("kern.dumpdev", &dumpdev, &len, NULL, 0) == -1) { syslog(LOG_ERR, "sysctl: kern.dumpdev: %m"); exit(1); } @@ -267,17 +270,17 @@ kmem_setup() (void)Read(kmem, &dumpmag, sizeof(dumpmag)); find_dev(dumpdev); dumpfd = Open(ddname, O_RDWR); - fp = fdopen(kmem, "r"); - if (fp == NULL) { - syslog(LOG_ERR, "%s: fdopen: %m", _PATH_KMEM); - exit(1); - } if (kernel) return; - (void)fseek(fp, (off_t)current_nl[X_VERSION].n_value, L_SET); - (void)fgets(vers, sizeof(vers), fp); - /* Don't fclose(fp), we use dumpfd later. */ + 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. */ } void @@ -339,6 +342,8 @@ dump_exists() } char buf[1024 * 1024]; +#define BLOCKSIZE (1<<12) +#define BLOCKMASK (~(BLOCKSIZE-1)) /* * Save the core dump. @@ -348,6 +353,7 @@ save_core() { register FILE *fp; register int bounds, ifd, nr, nw; + int hs, he; /* start and end of hole */ char path[MAXPATHLEN]; mode_t oumask; @@ -405,7 +411,42 @@ err1: syslog(LOG_WARNING, "%s: %m", path); syslog(LOG_ERR, "%s: %m", ddname); goto err2; } - nw = fwrite(buf, 1, nr, fp); + 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 (fseek(fp, he - hs, SEEK_CUR) == -1) + break; + } if (nw != nr) { syslog(LOG_ERR, "%s: %m", path); err2: syslog(LOG_WARNING, |
