arch/tile: support new info op generated by compiler

This just syncs the backtracing support in the kernel to the
upstream backtrace library.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/include/asm/backtrace.h

@@ -146,7 +146,10 @@ enum {
 
 	CALLER_SP_IN_R52_BASE = 4,
 
-	CALLER_SP_OFFSET_BASE = 8
+	CALLER_SP_OFFSET_BASE = 8,
+
+	/* Marks the entry point of certain functions. */
+	ENTRY_POINT_INFO_OP = 16
 };
 
 

arch/tile/kernel/backtrace.c

@@ -369,6 +369,10 @@ static void find_caller_pc_and_caller_sp(CallerLocation *location,
 					/* Weird; reserved value, ignore it. */
 					continue;
 				}
+				if (info_operand & ENTRY_POINT_INFO_OP)	{
+					/* This info op is ignored by the backtracer. */
+					continue;
+				}
 
 				/* Skip info ops which are not in the
 				 * "one_ago" mode we want right now.