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>

diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index f1e1232..9a8228a 100644 (file)
--- 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;