stack_trace: Add weak save_stack_trace_regs()

Add weak symbol of save_stack_trace_regs() as same as
save_stack_trace_tsk() since that is not implemented
except x86 yet.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@gmail.com>
Link: http://lkml.kernel.org/r/20110608070927.17777.37895.stgit@fedora15Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/stacktrace.c

@@ -26,12 +26,18 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
 EXPORT_SYMBOL_GPL(print_stack_trace);
 
 /*
- * Architectures that do not implement save_stack_trace_tsk get this
- * weak alias and a once-per-bootup warning (whenever this facility
- * is utilized - for example by procfs):
+ * Architectures that do not implement save_stack_trace_tsk or
+ * save_stack_trace_regs get this weak alias and a once-per-bootup warning
+ * (whenever this facility is utilized - for example by procfs):
  */
 __weak void
 save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
 }
+
+__weak void
+save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
+}