Archer-upstreamed:
http://sourceware.org/ml/archer/2010-q2/msg00031.html

--- ./gdb/breakpoint.c	2010-05-29 01:12:32.000000000 +0200
+++ ./gdb/breakpoint.c	2010-05-29 01:22:21.000000000 +0200
@@ -1679,14 +1679,11 @@ create_exception_master_breakpoint (void
       debug_hook = lookup_minimal_symbol_text ("_Unwind_DebugHook", objfile);
       if (debug_hook != NULL)
 	{
-	  CORE_ADDR pc;
 	  struct breakpoint *b;
 
-	  pc = find_function_start_pc (get_objfile_arch (objfile),
-				       SYMBOL_VALUE_ADDRESS (debug_hook),
-				       SYMBOL_OBJ_SECTION (debug_hook));
 	  b = create_internal_breakpoint (get_objfile_arch (objfile),
-					  pc, bp_exception_master);
+					  SYMBOL_VALUE_ADDRESS (debug_hook),
+					  bp_exception_master);
 	  b->addr_string = xstrdup ("_Unwind_DebugHook");
 	  b->enable_state = bp_disabled;
 	}
--- ./gdb/testsuite/gdb.cp/cxxexec.cc	1970-01-01 01:00:00.000000000 +0100
+++ ./gdb/testsuite/gdb.cp/cxxexec.cc	2010-05-29 01:18:56.000000000 +0200
@@ -0,0 +1,25 @@
+/* This test script is part of GDB, the GNU debugger.
+
+   Copyright 2010 Free Software Foundation, Inc.
+
+   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 <unistd.h>
+
+int
+main()
+{
+  execlp ("true", "true", NULL);
+  return 1;
+}
--- ./gdb/testsuite/gdb.cp/cxxexec.exp	1970-01-01 01:00:00.000000000 +0100
+++ ./gdb/testsuite/gdb.cp/cxxexec.exp	2010-05-29 01:29:25.000000000 +0200
@@ -0,0 +1,51 @@
+# Copyright 2010 Free Software Foundation, Inc.
+
+# 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/>.
+
+if { [skip_cplus_tests] } { continue }
+
+set testfile cxxexec
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${testfile}.cc {c++ debug}] } {
+    return -1
+}
+
+runto_main
+
+# We could stop after `continue' again at `main'.
+delete_breakpoints
+
+set test "p _Unwind_DebugHook"
+gdb_test_multiple $test $test {
+    -re " = .* 0x\[0-9a-f\].*\r\n$gdb_prompt $" {
+	pass $test
+    }
+    -re "\r\nNo symbol .*\r\n$gdb_prompt $" {
+	xfail $test
+	untested ${testfile}.exp
+	return -1
+    }
+}
+
+set test continue
+gdb_test_multiple $test $test {
+    -re "Cannot access memory at address 0x\[0-9a-f\]+\r\n$gdb_prompt $" {
+	fail $test
+    }
+    -re "\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
+
+# `info inferiors' can show <null> on older GDBs.
+gdb_test "info threads" "info threads" "program finished"