source/lib/fault.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Critical Fault handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 #ifdef HAVE_SYS_PRCTL_H
  24 #include <sys/prctl.h>
  25 #endif
  26
  27 static void (*cont_fn)(void *);
  28 static pstring corepath;
  29
  30 /*******************************************************************
  31 report a fault
  32 ********************************************************************/
  33 static void fault_report(int sig)
  34 {
  35         static int counter;
  36
  37         if (counter) _exit(1);
  38
  39         counter++;
  40
  41         DEBUGSEP(0);
  42         DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)sys_getpid(),SAMBA_VERSION_STRING));
  43         DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba3-HOWTO\n"));
  44         DEBUG(0,("\nFrom: http://www.samba.org/samba/docs/Samba3-HOWTO.pdf\n"));
  45         DEBUGSEP(0);
  46
  47         smb_panic("internal error");
  48
  49         if (cont_fn) {
  50                 cont_fn(NULL);
  51 #ifdef SIGSEGV
  52                 CatchSignal(SIGSEGV,SIGNAL_CAST SIG_DFL);
  53 #endif
  54 #ifdef SIGBUS
  55                 CatchSignal(SIGBUS,SIGNAL_CAST SIG_DFL);
  56 #endif
  57 #ifdef SIGABRT
  58                 CatchSignal(SIGABRT,SIGNAL_CAST SIG_DFL);
  59 #endif
  60                 return; /* this should cause a core dump */
  61         }
  62         exit(1);
  63 }
  64
  65 /****************************************************************************
  66 catch serious errors
  67 ****************************************************************************/
  68 static void sig_fault(int sig)
  69 {
  70         fault_report(sig);
  71 }
  72
  73 /*******************************************************************
  74 setup our fault handlers
  75 ********************************************************************/
  76 void fault_setup(void (*fn)(void *))
  77 {
  78         cont_fn = fn;
  79
  80 #ifdef SIGSEGV
  81         CatchSignal(SIGSEGV,SIGNAL_CAST sig_fault);
  82 #endif
  83 #ifdef SIGBUS
  84         CatchSignal(SIGBUS,SIGNAL_CAST sig_fault);
  85 #endif
  86 #ifdef SIGABRT
  87         CatchSignal(SIGABRT,SIGNAL_CAST sig_fault);
  88 #endif
  89 }
  90
  91 /*******************************************************************
  92 make all the preparations to safely dump a core file
  93 ********************************************************************/
  94
  95 void dump_core_setup(const char *progname)
  96 {
  97         pstring logbase;
  98         char * end;
  99
 100         if (lp_logfile() && *lp_logfile()) {
 101                 snprintf(logbase, sizeof(logbase), "%s", lp_logfile());
 102                 if ((end = strrchr_m(logbase, '/'))) {
 103                         *end = '\0';
 104                 }
 105         } else {
 106                 /* We will end up here is the log file is given on the command
 107                  * line by the -l option but the "log file" option is not set
 108                  * in smb.conf.
 109                  */
 110                 snprintf(logbase, sizeof(logbase), "%s", dyn_LOGFILEBASE);
 111         }
 112
 113         SMB_ASSERT(progname != NULL);
 114
 115         snprintf(corepath, sizeof(corepath), "%s/cores", logbase);
 116         mkdir(corepath,0700);
 117
 118         snprintf(corepath, sizeof(corepath), "%s/cores/%s",
 119                 logbase, progname);
 120         mkdir(corepath,0700);
 121
 122         sys_chown(corepath,getuid(),getgid());
 123         chmod(corepath,0700);
 124
 125 #ifdef HAVE_GETRLIMIT
 126 #ifdef RLIMIT_CORE
 127         {
 128                 struct rlimit rlp;
 129                 getrlimit(RLIMIT_CORE, &rlp);
 130                 rlp.rlim_cur = MAX(16*1024*1024,rlp.rlim_cur);
 131                 setrlimit(RLIMIT_CORE, &rlp);
 132                 getrlimit(RLIMIT_CORE, &rlp);
 133                 DEBUG(3,("Maximum core file size limits now %d(soft) %d(hard)\n",
 134                          (int)rlp.rlim_cur,(int)rlp.rlim_max));
 135         }
 136 #endif
 137 #endif
 138
 139 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
 140         /* On Linux we lose the ability to dump core when we change our user
 141          * ID. We know how to dump core safely, so let's make sure we have our
 142          * dumpable flag set.
 143          */
 144         prctl(PR_SET_DUMPABLE, 1);
 145 #endif
 146
 147         /* FIXME: if we have a core-plus-pid facility, configurably set
 148          * this up here.
 149          */
 150 }
 151
 152  void dump_core(void)
 153 {
 154         /* Note that even if core dumping has been disabled, we still set up
 155          * the core path. This is to handle the case where core dumping is
 156          * turned on in smb.conf and the relevant daemon is not restarted.
 157          */
 158         if (!lp_enable_core_files()) {
 159                 DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
 160                 exit(1);
 161         }
 162
 163 #if DUMP_CORE
 164         /* If we're running as non root we might not be able to dump the core
 165          * file to the corepath.  There must not be an unbecome_root() before
 166          * we call abort(). */
 167         if (geteuid() != 0) {
 168                 become_root();
 169         }
 170
 171         if (*corepath != '\0') {
 172                 /* The chdir might fail if we dump core before we finish
 173                  * processing the config file.
 174                  */
 175                 if (chdir(corepath) != 0) {
 176                         DEBUG(0, ("unable to change to %s\n", corepath));
 177                         DEBUGADD(0, ("refusing to dump core\n"));
 178                         exit(1);
 179                 }
 180
 181                 DEBUG(0,("dumping core in %s\n", corepath));
 182         }
 183
 184         umask(~(0700));
 185         dbgflush();
 186
 187         /* Ensure we don't have a signal handler for abort. */
 188 #ifdef SIGABRT
 189         CatchSignal(SIGABRT,SIGNAL_CAST SIG_DFL);
 190 #endif
 191
 192         abort();
 193
 194 #else /* DUMP_CORE */
 195         exit(1);
 196 #endif /* DUMP_CORE */
 197 }
 198