Remove stack unwinder for now

It has caused more problems than it ever really solved, and is
apparently not getting cleaned up and fixed.  We can put it back when
it's stable and isn't likely to make warning or bug events worse.

In the meantime, enable frame pointers for more readable stack traces.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index d143c0f..b5a90fc 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -55,37 +55,7 @@
 
 #define MAX_STACK_TRACE_DEPTH 32
 
-#ifdef CONFIG_STACK_UNWIND
-
-static asmlinkage int fail_stacktrace_callback(struct unwind_frame_info *info,
-						void *arg)
-{
-	int depth;
-	struct fault_attr *attr = arg;
-	bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
-
-	for (depth = 0; depth < attr->stacktrace_depth
-			&& unwind(info) == 0 && UNW_PC(info); depth++) {
-		if (arch_unw_user_mode(info))
-			break;
-		if (attr->reject_start <= UNW_PC(info) &&
-			       UNW_PC(info) < attr->reject_end)
-			return false;
-		if (attr->require_start <= UNW_PC(info) &&
-			       UNW_PC(info) < attr->require_end)
-			found = true;
-	}
-	return found;
-}
-
-static bool fail_stacktrace(struct fault_attr *attr)
-{
-	struct unwind_frame_info info;
-
-	return unwind_init_running(&info, fail_stacktrace_callback, attr);
-}
-
-#elif defined(CONFIG_STACKTRACE)
+#if defined(CONFIG_STACKTRACE)
 
 static bool fail_stacktrace(struct fault_attr *attr)
 {