lib/util/fault.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Critical Fault handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Tim Prouty 2009
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/filesys.h"
  23 #include "version.h"
  24
  25 #ifdef HAVE_SYS_SYSCTL_H
  26 #include <sys/sysctl.h>
  27 #endif
  28
  29
  30 #ifdef HAVE_SYS_PRCTL_H
  31 #include <sys/prctl.h>
  32 #endif
  33
  34 static struct {
  35         bool disabled;
  36         smb_panic_handler_t panic_handler;
  37 } fault_state;
  38
  39
  40 /*******************************************************************
  41 setup variables used for fault handling
  42 ********************************************************************/
  43 void fault_configure(smb_panic_handler_t panic_handler)
  44 {
  45         fault_state.panic_handler = panic_handler;
  46 }
  47
  48
  49 /**
  50    disable setting up fault handlers
  51    This is used for the bind9 dlz module, as we
  52    don't want a Samba module in bind9 to override the bind
  53    fault handling
  54 **/
  55 _PUBLIC_ void fault_setup_disable(void)
  56 {
  57         fault_state.disabled = true;
  58 }
  59
  60
  61 /*******************************************************************
  62 report a fault
  63 ********************************************************************/
  64 static void fault_report(int sig)
  65 {
  66         static int counter;
  67
  68         if (counter) _exit(1);
  69
  70         counter++;
  71
  72         DEBUGSEP(0);
  73         DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)getpid(),SAMBA_VERSION_STRING));
  74         DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba HOWTO\n"));
  75         DEBUGSEP(0);
  76
  77         smb_panic("internal error");
  78
  79         /* smb_panic() never returns, so this is really redundant */
  80         exit(1);
  81 }
  82
  83 /****************************************************************************
  84 catch serious errors
  85 ****************************************************************************/
  86 static void sig_fault(int sig)
  87 {
  88         fault_report(sig);
  89 }
  90
  91 /*******************************************************************
  92 setup our fault handlers
  93 ********************************************************************/
  94 void fault_setup(void)
  95 {
  96         if (fault_state.disabled) {
  97                 return;
  98         }
  99 #if !defined(HAVE_DISABLE_FAULT_HANDLING)
 100 #ifdef SIGSEGV
 101         CatchSignal(SIGSEGV, sig_fault);
 102 #endif
 103 #ifdef SIGBUS
 104         CatchSignal(SIGBUS, sig_fault);
 105 #endif
 106 #ifdef SIGABRT
 107         CatchSignal(SIGABRT, sig_fault);
 108 #endif
 109 #endif
 110 }
 111
 112 _PUBLIC_ const char *panic_action = NULL;
 113
 114 /*
 115    default smb_panic() implementation
 116 */
 117 static void smb_panic_default(const char *why)
 118 {
 119 #if defined(HAVE_PRCTL) && defined(PR_SET_PTRACER)
 120         /*
 121          * Make sure all children can attach a debugger.
 122          */
 123         prctl(PR_SET_PTRACER, getpid(), 0, 0, 0);
 124 #endif
 125
 126         if (panic_action && *panic_action) {
 127                 char cmdstring[200];
 128                 if (strlcpy(cmdstring, panic_action, sizeof(cmdstring)) < sizeof(cmdstring)) {
 129                         int result;
 130                         char pidstr[20];
 131                         snprintf(pidstr, sizeof(pidstr), "%d", (int) getpid());
 132                         all_string_sub(cmdstring, "%d", pidstr, sizeof(cmdstring));
 133                         DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmdstring));
 134                         result = system(cmdstring);
 135
 136                         if (result == -1)
 137                                 DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
 138                                           strerror(errno)));
 139                         else
 140                                 DEBUG(0, ("smb_panic(): action returned status %d\n",
 141                                           WEXITSTATUS(result)));
 142                 }
 143         }
 144         DEBUG(0,("PANIC: %s\n", why));
 145
 146 #ifdef SIGABRT
 147         CatchSignal(SIGABRT, SIG_DFL);
 148 #endif
 149         abort();
 150 }
 151
 152
 153 /**
 154    Something really nasty happened - panic !
 155 **/
 156 _PUBLIC_ void smb_panic(const char *why)
 157 {
 158         if (fault_state.panic_handler) {
 159                 fault_state.panic_handler(why);
 160                 _exit(1);
 161         }
 162         smb_panic_default(why);
 163 }