diff --git a/gdb-6.3-bt-past-zero-20051201.patch b/gdb-6.3-bt-past-zero-20051201.patch
new file mode 100644
index 0000000..5b6f5f7
--- /dev/null
+++ b/gdb-6.3-bt-past-zero-20051201.patch
@@ -0,0 +1,76 @@
+2005-12-01  Jeff Johnston  <jjohnstn@redhat.com>
+
+	* frame.c (backtrace_past_zero_pc): New static variable.
+	(get_prev_frame): Don't return NULL for zero pc value if
+	backtrace past-zero-frame option is turned on.
+	(_initialize_frame): Initialize new command to allow backtracing
+	past a zero pc value (set backtrace past-zero-pc).
+
+testsuite/gdb.base:
+2005-12-01  Jeff Johnston  <jjohnstn@redhat.com>
+
+	* setshow.exp: Add testing of "set backtrace past-zero-pc" option.
+
+--- gdb-6.3/gdb/testsuite/gdb.base/setshow.exp.fix	2005-12-01 14:43:02.000000000 -0500
++++ gdb-6.3/gdb/testsuite/gdb.base/setshow.exp	2005-12-01 14:43:20.000000000 -0500
+@@ -1,4 +1,4 @@
+-# Copyright 1992, 1994, 1996, 1997, 1998, 2001, 2003
++# Copyright 1992, 1994, 1996, 1997, 1998, 2001, 2003, 2005
+ # Free Software Foundation, Inc.
+ 
+ # This program is free software; you can redistribute it and/or modify
+@@ -106,6 +106,16 @@ if { ![target_info exists use_gdb_stub] 
+     delete_breakpoints
+     gdb_test "run" "Starting program:.*foo bar blup baz bubble.*" "passing args"
+ }
++#test show backtrace past-zero-pc
++gdb_test "show backtrace past-zero-pc" "Whether backtraces should continue past a zero pc value is off." "default show backtrace past-zero-pc (off)"
++#test set backtrace past-zero-pc on
++gdb_test "set backtrace past-zero-pc on" "" "set backtrace past-zero-pc on"
++#test show backtrace past-zero-pc
++gdb_test "show backtrace past-zero-pc" "Whether backtraces should continue past a zero pc value is on." "show backtrace past-zero-pc (on)"
++#test set backtrace past-zero-pc off
++gdb_test "set backtrace past-zero-pc off" "" "set backtrace past-zero-pc off"
++#test show backtrace past-zero-pc
++gdb_test "show backtrace past-zero-pc" "Whether backtraces should continue past a zero pc value is off." "show backtrace past-zero-pc (off)"
+ #test set check range on
+ gdb_test "set check range on" "" "set check range on" 
+ #test show check range on
+--- gdb-6.3/gdb/frame.c.fix	2005-12-01 14:42:47.000000000 -0500
++++ gdb-6.3/gdb/frame.c	2005-12-01 14:44:08.000000000 -0500
+@@ -115,6 +115,7 @@ static int frame_debug;
+ /* Flag to indicate whether backtraces should stop at main et.al.  */
+ 
+ static int backtrace_past_main;
++static int backtrace_past_zero_pc;
+ static unsigned int backtrace_limit = UINT_MAX;
+ 
+ static void
+@@ -1236,9 +1237,7 @@ get_prev_frame (struct frame_info *this_
+     }
+ 
+   if (this_frame->level > 0
+-#if 0
+-      && backtrace_past_zero_pc
+-#endif
++      && !backtrace_past_zero_pc
+       && get_frame_type (this_frame) == NORMAL_FRAME
+       && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME
+       && get_frame_pc (this_frame) == 0)
+@@ -1537,6 +1536,16 @@ Whether backtraces should continue past 
+ 			   NULL, NULL, &set_backtrace_cmdlist,
+ 			   &show_backtrace_cmdlist);
+ 
++  add_setshow_boolean_cmd ("past-zero-pc", class_obscure,
++			   &backtrace_past_zero_pc, "\
++Set whether backtraces should continue past a zero pc value.", "\
++Show whether backtraces should continue past a zero pc value..", "\
++Normally GDB stops backtracing when it finds a zero pc.\n\
++Set this variable if you need to see the rest of the stack trace.", "\
++Whether backtraces should continue past a zero pc value is %s.",
++			   NULL, NULL, &set_backtrace_cmdlist,
++			   &show_backtrace_cmdlist);
++
+   add_setshow_uinteger_cmd ("limit", class_obscure,
+ 			    &backtrace_limit, "\
+ Set an upper bound on the number of backtrace levels.", "\
diff --git a/gdb.spec b/gdb.spec
index 448f707..1294635 100644
--- a/gdb.spec
+++ b/gdb.spec
@@ -11,7 +11,7 @@ Name: gdb
 Version: 6.3.0.0
 
 # The release always contains a leading reserved number, start it at 0.
-Release: 1.89
+Release: 1.93
 
 License: GPL
 Group: Development/Debuggers
@@ -258,6 +258,9 @@ Patch168: gdb-6.3-attach-stop-20051011.patch
 # Fix ia64 gdb problem with user-specified SIGILL handling
 Patch169: gdb-6.3-ia64-sigill-20051115.patch
 
+# Allow option to continue backtracing past a zero pc value
+Patch170: gdb-6.3-bt-past-zero-20051201.patch
+
 %ifarch ia64
 BuildRequires: ncurses-devel glibc-devel gcc make gzip texinfo dejagnu libunwind >= 0.96-3
 %else
@@ -359,6 +362,7 @@ and printing their data.
 %patch167 -p1
 %patch168 -p1
 %patch169 -p1
+%patch170 -p1
 
 # Change the version that gets printed at GDB startup, so it is RedHat
 # specific.
@@ -527,6 +531,13 @@ fi
 # don't include the files in include, they are part of binutils
 
 %changelog
+* Thu Dec 01 2005 Jeff Johnston	<jjohnstn@redhat.com>	6.3.0.0-1.93
+- Bump up release number.
+
+* Thu Dec 01 2005 Jeff Johnston	<jjohnstn@redhat.com>	6.3.0.0-1.90
+- Add option to allow backtracing past zero pc value.
+- Bugzilla 170275
+
 * Tue Nov 15 2005 Jeff Johnston	<jjohnstn@redhat.com>	6.3.0.0-1.89
 - Bump up release number.