ARC: warn on improper stack unwind FDE entries

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index a8d0222..e550b11 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -289,6 +289,8 @@
 			 * instead of the initial loc addr
 			 * return;
 			 */
+			WARN(1, "unwinder: FDE->initial_location NULL %p\n",
+				(const u8 *)(fde + 1) + *fde);
 		}
 		++n;
 	}