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Diffstat (limited to 'lib/util/fault.c')
| -rw-r--r-- | lib/util/fault.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/util/fault.c b/lib/util/fault.c new file mode 100644 index 0000000000..2ffd5dbd6d --- /dev/null +++ b/lib/util/fault.c @@ -0,0 +1,380 @@ +/* + Unix SMB/CIFS implementation. + Critical Fault handling + Copyright (C) Andrew Tridgell 1992-1998 + Copyright (C) Tim Prouty 2009 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" + +#ifdef HAVE_SYS_SYSCTL_H +#include <sys/sysctl.h> +#endif + + +#ifdef HAVE_SYS_PRCTL_H +#include <sys/prctl.h> +#endif + +static char *corepath; + +/******************************************************************* +report a fault +********************************************************************/ +static void fault_report(int sig) +{ + static int counter; + + if (counter) _exit(1); + + counter++; + + DEBUGSEP(0); + DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)sys_getpid(),samba_version_string())); + DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba3-HOWTO\n")); + DEBUG(0,("\nFrom: http://www.samba.org/samba/docs/Samba3-HOWTO.pdf\n")); + DEBUGSEP(0); + + smb_panic("internal error"); + + /* smb_panic() never returns, so this is really redundent */ + exit(1); +} + +/**************************************************************************** +catch serious errors +****************************************************************************/ +static void sig_fault(int sig) +{ + fault_report(sig); +} + +/******************************************************************* +setup our fault handlers +********************************************************************/ +void fault_setup(void) +{ +#ifdef SIGSEGV + CatchSignal(SIGSEGV, sig_fault); +#endif +#ifdef SIGBUS + CatchSignal(SIGBUS, sig_fault); +#endif +#ifdef SIGABRT + CatchSignal(SIGABRT, sig_fault); +#endif +} + +/** + * Build up the default corepath as "<logbase>/cores/<progname>" + */ +static char *get_default_corepath(const char *logbase, const char *progname) +{ + char *tmp_corepath; + + /* Setup core dir in logbase. */ + tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase); + if (!tmp_corepath) + return NULL; + + if ((mkdir(tmp_corepath, 0700) == -1) && errno != EEXIST) + goto err_out; + + if (chmod(tmp_corepath, 0700) == -1) + goto err_out; + + talloc_free(tmp_corepath); + + /* Setup progname-specific core subdir */ + tmp_corepath = talloc_asprintf(NULL, "%s/cores/%s", logbase, progname); + if (!tmp_corepath) + return NULL; + + if (mkdir(tmp_corepath, 0700) == -1 && errno != EEXIST) + goto err_out; + + if (chown(tmp_corepath, getuid(), getgid()) == -1) + goto err_out; + + if (chmod(tmp_corepath, 0700) == -1) + goto err_out; + + return tmp_corepath; + + err_out: + talloc_free(tmp_corepath); + return NULL; +} + +/** + * Get the FreeBSD corepath. + * + * On FreeBSD the current working directory is ignored when creating a core + * file. Instead the core directory is controlled via sysctl. This consults + * the value of "kern.corefile" so the correct corepath can be printed out + * before dump_core() calls abort. + */ +#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME)) +static char *get_freebsd_corepath(void) +{ + char *tmp_corepath = NULL; + char *end = NULL; + size_t len = 128; + int ret; + + /* Loop with increasing sizes so we don't allocate too much. */ + do { + if (len > 1024) { + goto err_out; + } + + tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath, + char, len); + if (!tmp_corepath) { + return NULL; + } + + ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL, + 0); + if (ret == -1) { + if (errno != ENOMEM) { + DEBUG(0, ("sysctlbyname failed getting " + "kern.corefile %s\n", + strerror(errno))); + goto err_out; + } + + /* Not a large enough array, try a bigger one. */ + len = len << 1; + } + } while (ret == -1); + + /* Strip off the common filename expansion */ + if ((end = strrchr_m(tmp_corepath, '/'))) { + *end = '\0'; + } + + return tmp_corepath; + + err_out: + if (tmp_corepath) { + talloc_free(tmp_corepath); + } + return NULL; +} +#endif + +#if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN) + +/** + * Get the Linux corepath. + * + * On Linux the contents of /proc/sys/kernel/core_pattern indicates the + * location of the core path. + */ +static char *get_linux_corepath(void) +{ + char *end; + int fd; + char *result; + + fd = open("/proc/sys/kernel/core_pattern", O_RDONLY, 0); + if (fd == -1) { + return NULL; + } + + result = afdgets(fd, NULL, 0); + close(fd); + + if (result == NULL) { + return NULL; + } + + if (result[0] != '/') { + /* + * No absolute path, use the default (cwd) + */ + TALLOC_FREE(result); + return NULL; + } + /* Strip off the common filename expansion */ + + end = strrchr_m(result, '/'); + + if ((end != result) /* this would be the only / */ + && (end != NULL)) { + *end = '\0'; + } + return result; +} +#endif + + +/** + * Try getting system-specific corepath if one exists. + * + * If the system doesn't define a corepath, then the default is used. + */ +static char *get_corepath(const char *logbase, const char *progname) +{ +#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME)) + char *tmp_corepath = NULL; + tmp_corepath = get_freebsd_corepath(); + + /* If this has been set correctly, we're done. */ + if (tmp_corepath) { + return tmp_corepath; + } +#endif + +#if defined(HAVE_SYS_KERNEL_PROC_CORE_PATTERN) + char *tmp_corepath = NULL; + tmp_corepath = get_linux_corepath(); + + /* If this has been set correctly, we're done. */ + if (tmp_corepath) { + return tmp_corepath; + } +#endif + + /* Fall back to the default. */ + return get_default_corepath(logbase, progname); +} + +/******************************************************************* +make all the preparations to safely dump a core file +********************************************************************/ + +void dump_core_setup(const char *progname) +{ + char *logbase = NULL; + char *end = NULL; + + if (lp_logfile() && *lp_logfile()) { + if (asprintf(&logbase, "%s", lp_logfile()) < 0) { + return; + } + if ((end = strrchr_m(logbase, '/'))) { + *end = '\0'; + } + } else { + /* We will end up here if the log file is given on the command + * line by the -l option but the "log file" option is not set + * in smb.conf. + */ + if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) { + return; + } + } + + SMB_ASSERT(progname != NULL); + + corepath = get_corepath(logbase, progname); + if (!corepath) { + DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname, + strerror(errno))); + goto out; + } + + +#ifdef HAVE_GETRLIMIT +#ifdef RLIMIT_CORE + { + struct rlimit rlp; + getrlimit(RLIMIT_CORE, &rlp); + rlp.rlim_cur = MAX(16*1024*1024,rlp.rlim_cur); + setrlimit(RLIMIT_CORE, &rlp); + getrlimit(RLIMIT_CORE, &rlp); + DEBUG(3,("Maximum core file size limits now %d(soft) %d(hard)\n", + (int)rlp.rlim_cur,(int)rlp.rlim_max)); + } +#endif +#endif + + /* FIXME: if we have a core-plus-pid facility, configurably set + * this up here. + */ + out: + SAFE_FREE(logbase); +} + + void dump_core(void) +{ + static bool called; + + if (called) { + DEBUG(0, ("dump_core() called recursive\n")); + exit(1); + } + called = true; + + /* Note that even if core dumping has been disabled, we still set up + * the core path. This is to handle the case where core dumping is + * turned on in smb.conf and the relevant daemon is not restarted. + */ + if (!lp_enable_core_files()) { + DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n")); + exit(1); + } + +#if DUMP_CORE + /* If we're running as non root we might not be able to dump the core + * file to the corepath. There must not be an unbecome_root() before + * we call abort(). */ + if (geteuid() != sec_initial_uid()) { + become_root(); + } + + if (corepath == NULL) { + DEBUG(0, ("Can not dump core: corepath not set up\n")); + exit(1); + } + + if (*corepath != '\0') { + /* The chdir might fail if we dump core before we finish + * processing the config file. + */ + if (chdir(corepath) != 0) { + DEBUG(0, ("unable to change to %s\n", corepath)); + DEBUGADD(0, ("refusing to dump core\n")); + exit(1); + } + + DEBUG(0,("dumping core in %s\n", corepath)); + } + + umask(~(0700)); + dbgflush(); + +#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) + /* On Linux we lose the ability to dump core when we change our user + * ID. We know how to dump core safely, so let's make sure we have our + * dumpable flag set. + */ + prctl(PR_SET_DUMPABLE, 1); +#endif + + /* Ensure we don't have a signal handler for abort. */ +#ifdef SIGABRT + CatchSignal(SIGABRT, SIG_DFL); +#endif + + abort(); + +#else /* DUMP_CORE */ + exit(1); +#endif /* DUMP_CORE */ +} |