Bug#11761576 54082: HANDLE_SEGFAULT MAKES USE OF UNSAFE FUNCTIONS

handle_segfault is the signal handler code of mysqld.  however, it makes
calls to potentially unsafe functions localtime_r, fprintf, fflush.



include/my_stacktrace.h:
  Add safe versions of itoa() write() and snprintf().
libmysqld/CMakeLists.txt:
  Move signal handler to separate file.
mysys/stacktrace.c:
  Remove unsafe function calls.
sql/CMakeLists.txt:
  Move signal handler to separate file.
sql/Makefile.am:
  Move signal handler to separate file.
sql/mysqld.cc:
  Move signal handler to separate file.
sql/signal_handler.cc:
  Remove unsafe function calls.

4 files changed, 278 insertions, 173 deletions

diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index c050b329787..8f6e9cc7b32 100755
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -65,6 +65,7 @@ SET (SQL_SOURCE
                sql_list.cc sql_load.cc sql_manager.cc sql_map.cc sql_parse.cc 
                sql_partition.cc sql_plugin.cc sql_prepare.cc sql_rename.cc 
                debug_sync.cc debug_sync.h
+               signal_handler.cc
                sql_repl.cc sql_select.cc sql_show.cc sql_state.c sql_string.cc 
                sql_table.cc sql_test.cc sql_trigger.cc sql_udf.cc sql_union.cc
                sql_update.cc sql_view.cc strfunc.cc table.cc thr_malloc.cc 
@@ -113,7 +114,7 @@ IF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)
   ADD_CUSTOM_COMMAND(TARGET mysqld PRE_LINK
     COMMAND cscript ARGS //nologo ${PROJECT_SOURCE_DIR}/win/create_def_file.js
                   ${PLATFORM}  ${LIB_LOCATIONS} > mysqld.def 
-    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/sql)
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 ENDIF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)
 
 ADD_DEPENDENCIES(sql GenError)
diff --git a/sql/Makefile.am b/sql/Makefile.am
index 6040e4d498d..829523c7ba3 100644
--- a/sql/Makefile.am
+++ b/sql/Makefile.am
@@ -103,6 +103,7 @@ mysqld_SOURCES =	sql_lex.cc sql_handler.cc sql_partition.cc \
 		   	records.cc filesort.cc handler.cc \
 		        ha_partition.cc \
 			debug_sync.cc \
+			signal_handler.cc \
 			sql_db.cc sql_table.cc sql_rename.cc sql_crypt.cc \
 			sql_load.cc mf_iocache.cc field_conv.cc sql_show.cc \
 			sql_udf.cc sql_analyse.cc sql_analyse.h sql_cache.cc \
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 37eb6d95ce8..73b107e4746 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -122,13 +122,6 @@ extern "C" {					// Because of SCO 3.2V4.2
 #include <sys/mman.h>
 #endif
 
-#ifdef __WIN__ 
-#include <crtdbg.h>
-#define SIGNAL_FMT "exception 0x%x"
-#else
-#define SIGNAL_FMT "signal %d"
-#endif
-
 #ifdef __NETWARE__
 #define zVOLSTATE_ACTIVE 6
 #define zVOLSTATE_DEACTIVE 2
@@ -269,7 +262,7 @@ inline void setup_fpu()
 extern "C" int gethostname(char *name, int namelen);
 #endif
 
-extern "C" sig_handler handle_segfault(int sig);
+extern "C" sig_handler handle_fatal_signal(int sig);
 
 #if defined(__linux__)
 #define ENABLE_TEMP_POOL 1
@@ -415,6 +408,10 @@ TYPELIB log_output_typelib= {array_elements(log_output_names)-1,"",
 
 /* static variables */
 
+#ifdef HAVE_NPTL
+volatile sig_atomic_t ld_assume_kernel_is_set= 0;
+#endif
+
 /* the default log output is log tables */
 static bool lower_case_table_names_used= 0;
 static bool max_long_data_size_used= false;
@@ -424,7 +421,7 @@ static my_bool opt_debugging= 0, opt_external_locking= 0, opt_console= 0;
 static my_bool opt_short_log_format= 0;
 static uint kill_cached_threads, wake_thread;
 static ulong killed_threads, thread_created;
-static ulong max_used_connections;
+       ulong max_used_connections;
 static ulong my_bind_addr;			/**< the address we bind to */
 static volatile ulong cached_thread_count= 0;
 static const char *sql_mode_str= "OFF";
@@ -553,7 +550,7 @@ TYPELIB binlog_format_typelib=
 ulong opt_binlog_format_id= (ulong) BINLOG_FORMAT_UNSPEC;
 const char *opt_binlog_format= binlog_format_names[opt_binlog_format_id];
 #ifdef HAVE_INITGROUPS
-static bool calling_initgroups= FALSE; /**< Used in SIGSEGV handler. */
+volatile sig_atomic_t calling_initgroups= 0; /**< Used in SIGSEGV handler. */
 #endif
 uint mysqld_port, test_flags, select_errors, dropping_tables, ha_open_options;
 uint mysqld_port_timeout;
@@ -727,7 +724,7 @@ char *opt_logname, *opt_slow_logname;
 
 /* Static variables */
 
-static bool kill_in_progress, segfaulted;
+static volatile sig_atomic_t kill_in_progress;
 #ifdef HAVE_STACK_TRACE_ON_SEGV
 static my_bool opt_do_pstack;
 #endif /* HAVE_STACK_TRACE_ON_SEGV */
@@ -1616,9 +1613,9 @@ static void set_user(const char *user, struct passwd *user_info_arg)
     calling_initgroups as a flag to the SIGSEGV handler that is then used to
     output a specific message to help the user resolve this problem.
   */
-  calling_initgroups= TRUE;
+  calling_initgroups= 1;
   initgroups((char*) user, user_info_arg->pw_gid);
-  calling_initgroups= FALSE;
+  calling_initgroups= 0;
 #endif
   if (setgid(user_info_arg->pw_gid) == -1)
   {
@@ -2170,7 +2167,7 @@ LONG WINAPI my_unhandler_exception_filter(EXCEPTION_POINTERS *ex_pointers)
   __try
   {
     my_set_exception_pointers(ex_pointers);
-    handle_segfault(ex_pointers->ExceptionRecord->ExceptionCode);
+    handle_fatal_signal(ex_pointers->ExceptionRecord->ExceptionCode);
   }
   __except(EXCEPTION_EXECUTE_HANDLER)
   {
@@ -2481,161 +2478,6 @@ extern "C" char *my_demangle(const char *mangled_name, int *status)
 #endif
 
 
-extern "C" sig_handler handle_segfault(int sig)
-{
-  time_t curr_time;
-  struct tm tm;
-
-  /*
-    Strictly speaking, one needs a mutex here
-    but since we have got SIGSEGV already, things are a mess
-    so not having the mutex is not as bad as possibly using a buggy
-    mutex - so we keep things simple
-  */
-  if (segfaulted)
-  {
-    fprintf(stderr, "Fatal " SIGNAL_FMT " while backtracing\n", sig);
-    exit(1);
-  }
-
-  segfaulted = 1;
-
-  curr_time= my_time(0);
-  localtime_r(&curr_time, &tm);
-
-  fprintf(stderr,"\
-%02d%02d%02d %2d:%02d:%02d - mysqld got " SIGNAL_FMT " ;\n\
-This could be because you hit a bug. It is also possible that this binary\n\
-or one of the libraries it was linked against is corrupt, improperly built,\n\
-or misconfigured. This error can also be caused by malfunctioning hardware.\n",
-          tm.tm_year % 100, tm.tm_mon+1, tm.tm_mday,
-          tm.tm_hour, tm.tm_min, tm.tm_sec,
-	  sig);
-  fprintf(stderr, "\
-We will try our best to scrape up some info that will hopefully help diagnose\n\
-the problem, but since we have already crashed, something is definitely wrong\n\
-and this may fail.\n\n");
-  fprintf(stderr, "key_buffer_size=%lu\n",
-          (ulong) dflt_key_cache->key_cache_mem_size);
-  fprintf(stderr, "read_buffer_size=%ld\n", (long) global_system_variables.read_buff_size);
-  fprintf(stderr, "max_used_connections=%lu\n", max_used_connections);
-  fprintf(stderr, "max_threads=%u\n", thread_scheduler.max_threads);
-  fprintf(stderr, "threads_connected=%u\n", thread_count);
-  fprintf(stderr, "It is possible that mysqld could use up to \n\
-key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = %lu K\n\
-bytes of memory\n", ((ulong) dflt_key_cache->key_cache_mem_size +
-		     (global_system_variables.read_buff_size +
-		      global_system_variables.sortbuff_size) *
-		     thread_scheduler.max_threads +
-                     max_connections * sizeof(THD)) / 1024);
-  fprintf(stderr, "Hope that's ok; if not, decrease some variables in the equation.\n\n");
-
-#if defined(HAVE_LINUXTHREADS)
-  if (sizeof(char*) == 4 && thread_count > UNSAFE_DEFAULT_LINUX_THREADS)
-  {
-    fprintf(stderr, "\
-You seem to be running 32-bit Linux and have %d concurrent connections.\n\
-If you have not changed STACK_SIZE in LinuxThreads and built the binary \n\
-yourself, LinuxThreads is quite likely to steal a part of the global heap for\n\
-the thread stack. Please read http://dev.mysql.com/doc/mysql/en/linux.html\n\n",
-	    thread_count);
-  }
-#endif /* HAVE_LINUXTHREADS */
-
-#ifdef HAVE_STACKTRACE
-  THD *thd=current_thd;
-
-  if (!(test_flags & TEST_NO_STACKTRACE))
-  {
-    fprintf(stderr, "Thread pointer: 0x%lx\n", (long) thd);
-    fprintf(stderr, "Attempting backtrace. You can use the following "
-                    "information to find out\nwhere mysqld died. If "
-                    "you see no messages after this, something went\n"
-                    "terribly wrong...\n");
-    my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
-                        my_thread_stack_size);
-  }
-  if (thd)
-  {
-    const char *kreason= "UNKNOWN";
-    switch (thd->killed) {
-    case THD::NOT_KILLED:
-      kreason= "NOT_KILLED";
-      break;
-    case THD::KILL_BAD_DATA:
-      kreason= "KILL_BAD_DATA";
-      break;
-    case THD::KILL_CONNECTION:
-      kreason= "KILL_CONNECTION";
-      break;
-    case THD::KILL_QUERY:
-      kreason= "KILL_QUERY";
-      break;
-    case THD::KILLED_NO_VALUE:
-      kreason= "KILLED_NO_VALUE";
-      break;
-    }
-    fprintf(stderr, "\nTrying to get some variables.\n"
-                    "Some pointers may be invalid and cause the dump to abort.\n");
-    fprintf(stderr, "Query (%p): ", thd->query());
-    my_safe_print_str(thd->query(), min(1024, thd->query_length()));
-    fprintf(stderr, "Connection ID (thread ID): %lu\n", (ulong) thd->thread_id);
-    fprintf(stderr, "Status: %s\n", kreason);
-    fputc('\n', stderr);
-  }
-  fprintf(stderr, "\
-The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains\n\
-information that should help you find out what is causing the crash.\n");
-  fflush(stderr);
-#endif /* HAVE_STACKTRACE */
-
-#ifdef HAVE_INITGROUPS
-  if (calling_initgroups)
-    fprintf(stderr, "\n\
-This crash occured while the server was calling initgroups(). This is\n\
-often due to the use of a mysqld that is statically linked against glibc\n\
-and configured to use LDAP in /etc/nsswitch.conf. You will need to either\n\
-upgrade to a version of glibc that does not have this problem (2.3.4 or\n\
-later when used with nscd), disable LDAP in your nsswitch.conf, or use a\n\
-mysqld that is not statically linked.\n");
-#endif
-
-#ifdef HAVE_NPTL
-  if (thd_lib_detected == THD_LIB_LT && !getenv("LD_ASSUME_KERNEL"))
-    fprintf(stderr,"\n\
-You are running a statically-linked LinuxThreads binary on an NPTL system.\n\
-This can result in crashes on some distributions due to LT/NPTL conflicts.\n\
-You should either build a dynamically-linked binary, or force LinuxThreads\n\
-to be used with the LD_ASSUME_KERNEL environment variable. Please consult\n\
-the documentation for your distribution on how to do that.\n");
-#endif
-  
-  if (locked_in_memory)
-  {
-    fprintf(stderr, "\n\
-The \"--memlock\" argument, which was enabled, uses system calls that are\n\
-unreliable and unstable on some operating systems and operating-system\n\
-versions (notably, some versions of Linux).  This crash could be due to use\n\
-of those buggy OS calls.  You should consider whether you really need the\n\
-\"--memlock\" parameter and/or consult the OS distributer about \"mlockall\"\n\
-bugs.\n");
-  }
-
-#ifdef HAVE_WRITE_CORE
-  if (test_flags & TEST_CORE_ON_SIGNAL)
-  {
-    fprintf(stderr, "Writing a core file\n");
-    fflush(stderr);
-    my_write_core(sig);
-  }
-#endif
-
-#ifndef __WIN__
-  /* On Windows, do not terminate, but pass control to exception filter */
-  exit(1);
-#endif
-}
-
 #if !defined(__WIN__) && !defined(__NETWARE__)
 #ifndef SA_RESETHAND
 #define SA_RESETHAND 0
@@ -2664,9 +2506,9 @@ static void init_signals(void)
     my_init_stacktrace();
 #endif
 #if defined(__amiga__)
-    sa.sa_handler=(void(*)())handle_segfault;
+    sa.sa_handler=(void(*)())handle_fatal_signal;
 #else
-    sa.sa_handler=handle_segfault;
+    sa.sa_handler=handle_fatal_signal;
 #endif
     sigaction(SIGSEGV, &sa, NULL);
     sigaction(SIGABRT, &sa, NULL);
@@ -4363,6 +4205,10 @@ int win_main(int argc, char **argv)
 int main(int argc, char **argv)
 #endif
 {
+#ifdef HAVE_NPTL
+  ld_assume_kernel_is_set= (getenv("LD_ASSUME_KERNEL") != 0);
+#endif
+
   MY_INIT(argv[0]);		// init my_sys library & pthreads
   /* nothing should come before this line ^^^ */
 
@@ -7876,7 +7722,7 @@ static int mysql_init_variables(void)
   opt_secure_file_priv= 0;
   opt_bootstrap= opt_myisam_log= 0;
   mqh_used= 0;
-  segfaulted= kill_in_progress= 0;
+  kill_in_progress= 0;
   cleanup_done= 0;
   defaults_argc= 0;
   defaults_argv= 0;
diff --git a/sql/signal_handler.cc b/sql/signal_handler.cc
new file mode 100644
index 00000000000..54b456ec2c4
--- /dev/null
+++ b/sql/signal_handler.cc
@@ -0,0 +1,257 @@
+/* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+
+   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; version 2 of the License.
+
+   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, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02111-1307  USA */
+
+#include "my_global.h"
+#include <signal.h>
+
+#include "mysql_priv.h"
+#include "my_stacktrace.h"
+
+#ifdef __WIN__
+#include <crtdbg.h>
+#define SIGNAL_FMT "exception 0x%x"
+#else
+#define SIGNAL_FMT "signal %d"
+#endif
+
+/*
+  We are handling signals in this file.
+  Any global variables we read should be 'volatile sig_atomic_t'
+  to guarantee that we read some consistent value.
+ */
+static volatile sig_atomic_t segfaulted= 0;
+extern ulong max_used_connections;
+extern volatile sig_atomic_t calling_initgroups;
+#ifdef HAVE_NPTL
+extern volatile sig_atomic_t ld_assume_kernel_is_set;
+#endif
+
+/**
+ * Handler for fatal signals
+ *
+ * Fatal events (seg.fault, bus error etc.) will trigger
+ * this signal handler.  The handler will try to dump relevant
+ * debugging information to stderr and dump a core image.
+ *
+ * Signal handlers can only use a set of 'safe' system calls
+ * and library functions.  A list of safe calls in POSIX systems
+ * are available at:
+ *  http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html
+ * For MS Windows, guidelines are available at:
+ *  http://msdn.microsoft.com/en-us/library/xdkz3x12(v=vs.71).aspx
+ *
+ * @param sig Signal number
+*/
+extern "C" sig_handler handle_fatal_signal(int sig)
+{
+  if (segfaulted)
+  {
+    my_safe_printf_stderr("Fatal " SIGNAL_FMT " while backtracing\n", sig);
+    _exit(1); /* Quit without running destructors */
+  }
+
+  segfaulted = 1;
+
+#ifdef __WIN__
+  SYSTEMTIME utc_time;
+  GetSystemTime(&utc_time);
+  const long hrs=  utc_time.wHour;
+  const long mins= utc_time.wMinute;
+  const long secs= utc_time.wSecond;
+#else
+  /* Using time() instead of my_time() to avoid looping */
+  const time_t curr_time= time(NULL);
+  /* Calculate time of day */
+  const long tmins = curr_time / 60;
+  const long thrs  = tmins / 60;
+  const long hrs   = thrs  % 24;
+  const long mins  = tmins % 60;
+  const long secs  = curr_time % 60;
+#endif
+
+  char hrs_buf[3]= "00";
+  char mins_buf[3]= "00";
+  char secs_buf[3]= "00";
+  my_safe_itoa(10, hrs, &hrs_buf[2]);
+  my_safe_itoa(10, mins, &mins_buf[2]);
+  my_safe_itoa(10, secs, &secs_buf[2]);
+
+  my_safe_printf_stderr("%s:%s:%s UTC - mysqld got " SIGNAL_FMT " ;\n",
+                        hrs_buf, mins_buf, secs_buf, sig);
+
+  my_safe_printf_stderr("%s",
+    "This could be because you hit a bug. It is also possible that this binary\n"
+    "or one of the libraries it was linked against is corrupt, improperly built,\n"
+    "or misconfigured. This error can also be caused by malfunctioning hardware.\n");
+
+  my_safe_printf_stderr("%s",
+    "We will try our best to scrape up some info that will hopefully help\n"
+    "diagnose the problem, but since we have already crashed, \n"
+    "something is definitely wrong and this may fail.\n\n");
+
+  my_safe_printf_stderr("key_buffer_size=%lu\n",
+                        (ulong) dflt_key_cache->key_cache_mem_size);
+
+  my_safe_printf_stderr("read_buffer_size=%ld\n",
+                        (long) global_system_variables.read_buff_size);
+
+  my_safe_printf_stderr("max_used_connections=%lu\n",
+                        (ulong) max_used_connections);
+
+  my_safe_printf_stderr("max_threads=%u\n",
+                        (uint) thread_scheduler.max_threads);
+
+  my_safe_printf_stderr("thread_count=%u\n", (uint) thread_count);
+
+  my_safe_printf_stderr("connection_count=%u\n", (uint) connection_count);
+
+  my_safe_printf_stderr("It is possible that mysqld could use up to \n"
+                        "key_buffer_size + "
+                        "(read_buffer_size + sort_buffer_size)*max_threads = "
+                        "%lu K  bytes of memory\n",
+                        ((ulong) dflt_key_cache->key_cache_mem_size +
+                         (global_system_variables.read_buff_size +
+                          global_system_variables.sortbuff_size) *
+                         thread_scheduler.max_threads +
+                         max_connections * sizeof(THD)) / 1024);
+
+  my_safe_printf_stderr("%s",
+    "Hope that's ok; if not, decrease some variables in the equation.\n\n");
+
+#if defined(HAVE_LINUXTHREADS)
+  if (sizeof(char*) == 4 && thread_count > UNSAFE_DEFAULT_LINUX_THREADS)
+  {
+    my_safe_printf_stderr(
+      "You seem to be running 32-bit Linux and have "
+      "%d concurrent connections.\n"
+      "If you have not changed STACK_SIZE in LinuxThreads "
+      "and built the binary \n"
+      "yourself, LinuxThreads is quite likely to steal "
+      "a part of the global heap for\n"
+      "the thread stack. Please read "
+      "http://dev.mysql.com/doc/mysql/en/linux-installation.html\n\n"
+      thread_count);
+  }
+#endif /* HAVE_LINUXTHREADS */
+
+#ifdef HAVE_STACKTRACE
+  THD *thd=current_thd;
+
+  if (!(test_flags & TEST_NO_STACKTRACE))
+  {
+    my_safe_printf_stderr("Thread pointer: 0x%p\n", thd);
+    my_safe_printf_stderr("%s",
+      "Attempting backtrace. You can use the following "
+      "information to find out\n"
+      "where mysqld died. If you see no messages after this, something went\n"
+      "terribly wrong...\n");
+    my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
+                        my_thread_stack_size);
+  }
+  if (thd)
+  {
+    const char *kreason= "UNKNOWN";
+    switch (thd->killed) {
+    case THD::NOT_KILLED:
+      kreason= "NOT_KILLED";
+      break;
+    case THD::KILL_BAD_DATA:
+      kreason= "KILL_BAD_DATA";
+      break;
+    case THD::KILL_CONNECTION:
+      kreason= "KILL_CONNECTION";
+      break;
+    case THD::KILL_QUERY:
+      kreason= "KILL_QUERY";
+      break;
+    case THD::KILLED_NO_VALUE:
+      kreason= "KILLED_NO_VALUE";
+      break;
+    }
+    my_safe_printf_stderr("%s", "\n"
+      "Trying to get some variables.\n"
+      "Some pointers may be invalid and cause the dump to abort.\n");
+
+    my_safe_printf_stderr("Query (%p): ", thd->query());
+    my_safe_print_str(thd->query(), min(1024U, thd->query_length()));
+    my_safe_printf_stderr("Connection ID (thread ID): %lu\n",
+                          (ulong) thd->thread_id);
+    my_safe_printf_stderr("Status: %s\n\n", kreason);
+  }
+  my_safe_printf_stderr("%s",
+    "The manual page at "
+    "http://dev.mysql.com/doc/mysql/en/crashing.html contains\n"
+    "information that should help you find out what is causing the crash.\n");
+
+#endif /* HAVE_STACKTRACE */
+
+#ifdef HAVE_INITGROUPS
+  if (calling_initgroups)
+  {
+    my_safe_printf_stderr("%s", "\n"
+      "This crash occured while the server was calling initgroups(). This is\n"
+      "often due to the use of a mysqld that is statically linked against \n"
+      "glibc and configured to use LDAP in /etc/nsswitch.conf.\n"
+      "You will need to either upgrade to a version of glibc that does not\n"
+      "have this problem (2.3.4 or later when used with nscd),\n"
+      "disable LDAP in your nsswitch.conf, or use a "
+      "mysqld that is not statically linked.\n");
+  }
+#endif
+
+#ifdef HAVE_NPTL
+  if (thd_lib_detected == THD_LIB_LT && !ld_assume_kernel_is_set)
+  {
+    my_safe_printf_stderr("%s",
+      "You are running a statically-linked LinuxThreads binary on an NPTL\n"
+      "system. This can result in crashes on some distributions due to "
+      "LT/NPTL conflicts.\n"
+      "You should either build a dynamically-linked binary, "
+      "or force LinuxThreads\n"
+      "to be used with the LD_ASSUME_KERNEL environment variable.\n"
+      "Please consult the documentation for your distribution "
+      "on how to do that.\n");
+  }
+#endif
+
+  if (locked_in_memory)
+  {
+    my_safe_printf_stderr("%s", "\n"
+      "The \"--memlock\" argument, which was enabled, "
+      "uses system calls that are\n"
+      "unreliable and unstable on some operating systems and "
+      "operating-system versions (notably, some versions of Linux).\n"
+      "This crash could be due to use of those buggy OS calls.\n"
+      "You should consider whether you really need the "
+      "\"--memlock\" parameter and/or consult the OS distributer about "
+      "\"mlockall\" bugs.\n");
+  }
+
+#ifdef HAVE_WRITE_CORE
+  if (test_flags & TEST_CORE_ON_SIGNAL)
+  {
+    my_safe_printf_stderr("%s", "Writing a core file\n");
+    my_write_core(sig);
+  }
+#endif
+
+#ifndef __WIN__
+  /*
+     Quit, without running destructors (etc.)
+     On Windows, do not terminate, but pass control to exception filter.
+  */
+  _exit(1);  // Using _exit(), since exit() is not async signal safe
+#endif
+}