[PATCH] x86_64: reliable stack trace support

These are the generic bits needed to enable reliable stack traces based
on Dwarf2-like (.eh_frame) unwind information. Subsequent patches will
enable x86-64 and i386 to make use of this.

Thanks to Andi Kleen and Ingo Molnar, who pointed out several possibilities
for improvement.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/init/main.c b/init/main.c
index f715b9b..f556fd0 100644
--- a/init/main.c
+++ b/init/main.c
@@ -47,6 +47,7 @@
 #include <linux/rmap.h>
 #include <linux/mempolicy.h>
 #include <linux/key.h>
+#include <linux/unwind.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -482,6 +483,7 @@
 		   __stop___param - __start___param,
 		   &unknown_bootoption);
 	sort_main_extable();
+	unwind_init();
 	trap_init();
 	rcu_init();
 	init_IRQ();