store pthread stack guard sizes for pthread_getattr_np
diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 34cd993..439ee36 100644
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -232,8 +232,8 @@
 			memset(stack, 0, need);
 		} else {
 			size = ROUND(need);
-			guard = 0;
 		}
+		guard = 0;
 	} else {
 		guard = ROUND(attr._a_guardsize);
 		size = guard + ROUND(attr._a_stacksize
@@ -265,6 +265,7 @@
 	new->map_size = size;
 	new->stack = stack;
 	new->stack_size = stack - stack_limit;
+	new->guard_size = guard;
 	new->start = entry;
 	new->start_arg = arg;
 	new->self = new;