[PATCH 1/2] x86: make save_stack_address() !CONFIG_FRAME_POINTER friendly

[Oleg Nesterov <oleg@redhat.com>]

If CONFIG_FRAME_POINTER=n, print_context_stack() shouldn't neglect the
non-reliable addresses on stack, this is all we have if dump_trace(bp)
is called with the wrong or zero bp.

For example, /proc/pid/stack doesn't work if CONFIG_FRAME_POINTER=n.

This patch obviously has no effect if CONFIG_FRAME_POINTER=y, otherwise
it reverts 1650743c "x86: don't save unreliable stack trace entries".

Also, remove the unnecessary type-cast.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---

 arch/x86/kernel/stacktrace.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- 34-rc1/arch/x86/kernel/stacktrace.c~SAVE_STACK_WO_FP	2010-06-03 18:43:27.000000000 +0200
+++ 34-rc1/arch/x86/kernel/stacktrace.c	2010-06-03 21:29:52.000000000 +0200
@@ -26,8 +26,10 @@ static int save_stack_stack(void *data, 
 static void save_stack_address(void *data, unsigned long addr, int reliable)
 {
 	struct stack_trace *trace = data;
+#ifdef CONFIG_FRAME_POINTER
 	if (!reliable)
 		return;
+#endif
 	if (trace->skip > 0) {
 		trace->skip--;
 		return;
@@ -39,9 +41,11 @@ static void save_stack_address(void *dat
 static void
 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
 {
-	struct stack_trace *trace = (struct stack_trace *)data;
+	struct stack_trace *trace = data;
+#ifdef CONFIG_FRAME_POINTER
 	if (!reliable)
 		return;
+#endif
 	if (in_sched_functions(addr))
 		return;
 	if (trace->skip > 0) {