[patch, -rc5-mm1] lock validator: fix stacktrace on x86_64

[Ingo Molnar <mingo@elte.hu>]

replacement for lockdep-stacktrace-oops-workaround.patch:

------------------
Subject: lock validator: fix stacktrace on x86_64
From: Ingo Molnar <mingo@elte.hu>

after hours of hair-pulling by Arjan and me the "x86_64 crashes
on bootup" problem got traced back to a brown-paperbag 32/64-bit
mixup. Sign extension got us lucky, but that luck vanished in
2.6.17-rc5-mm1 ...

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 arch/x86_64/kernel/stacktrace.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux/arch/x86_64/kernel/stacktrace.c
===================================================================
--- linux.orig/arch/x86_64/kernel/stacktrace.c
+++ linux/arch/x86_64/kernel/stacktrace.c
@@ -115,9 +115,9 @@ save_context_stack(struct stack_trace *t
 	unsigned long addr;
 
 #ifdef CONFIG_FRAME_POINTER
-	unsigned prev_stack = 0;
+	unsigned long prev_stack = 0;
 
-	while (in_range(prev_stack, (unsigned long)stack, stack_end)) {
+	while (in_range(prev_stack, stack, stack_end)) {
 		pr_debug("stack:          %p\n", (void *)stack);
 		addr = (unsigned long)(((unsigned long *)stack)[1]);
 		pr_debug("addr:           %p\n", (void *)addr);