[PATCH] x86, numa: exit early on numa_reset_distance()

[Yinghai Lu <yinghai@kernel.org>]

Do not call __pa(numa_distance), if it is not allocated before.

it will get BUG_ON if VIRTUAL_DEBUG is on.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/x86/mm/numa_64.c |    6 ++++++
 1 file changed, 6 insertions(+)

Index: linux-2.6/arch/x86/mm/numa_64.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/numa_64.c
+++ linux-2.6/arch/x86/mm/numa_64.c
@@ -371,6 +371,12 @@ static void __init numa_reset_distance(v
 {
 	size_t size;
 
+	if (!numa_distance_cnt) {
+		numa_distance = NULL;
+
+		return;
+	}
+
 	size = numa_distance_cnt * sizeof(numa_distance[0]);
 	memblock_x86_free_range(__pa(numa_distance),
 				__pa(numa_distance) + size);