[ARM] Add ability to dump exception stacks to kernel backtraces

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h
index 69134c7..63b3080 100644
--- a/include/asm-arm/system.h
+++ b/include/asm-arm/system.h
@@ -76,6 +76,8 @@
 #include <linux/linkage.h>
 #include <linux/irqflags.h>
 
+#define __exception	__attribute__((section(".exception.text")))
+
 struct thread_info;
 struct task_struct;