x86: add debug of invalid per_cpu map accesses

dont crash survivable situations.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index f1e12329078e..9a8228a177c7 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -66,14 +66,15 @@ static inline int early_cpu_to_node(int cpu)
 
 static inline int cpu_to_node(int cpu)
 {
-#ifdef  CONFIG_DEBUG_PER_CPU_MAPS
-        if(x86_cpu_to_node_map_early_ptr) {
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+        if (x86_cpu_to_node_map_early_ptr) {
                 printk("KERN_NOTICE cpu_to_node(%d): usage too early!\n",
                         (int)cpu);
-                BUG();
+                dump_stack();
+                return ((int *)x86_cpu_to_node_map_early_ptr)[cpu];
         }
 #endif
-        if(per_cpu_offset(cpu))
+        if (per_cpu_offset(cpu))
                 return per_cpu(x86_cpu_to_node_map, cpu);
         else
                 return NUMA_NO_NODE;