From: David Rientjes Date: Mon, 7 Feb 2011 22:08:53 +0000 (-0800) Subject: x86, numa: Add error handling for bad cpu-to-node mappings X-Git-Tag: v2.6.39-rc1~499^2~54^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=14392fd329eca9b59d51c0aa5d0acfb4965424d1;p=linux.git x86, numa: Add error handling for bad cpu-to-node mappings CONFIG_DEBUG_PER_CPU_MAPS may return NUMA_NO_NODE when an early_cpu_to_node() mapping hasn't been initialized. In such a case, it emits a warning and continues without an issue but callers may try to use the return value to index into an array. We can catch those errors and fail silently since a warning has already been emitted. No current user of numa_add_cpu() requires this error checking to avoid a crash, but it's better to be proactive in case a future user happens to have a bug and a user tries to diagnose it with CONFIG_DEBUG_PER_CPU_MAPS. Reported-by: Jesper Juhl Signed-off-by: David Rientjes Cc: Tejun Heo LKML-Reference: Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index bf60715bd1b7..9559d360fde7 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -219,6 +219,10 @@ struct cpumask __cpuinit *debug_cpumask_set_cpu(int cpu, int enable) struct cpumask *mask; char buf[64]; + if (node == NUMA_NO_NODE) { + /* early_cpu_to_node() already emits a warning and trace */ + return NULL; + } mask = node_to_cpumask_map[node]; if (!mask) { pr_err("node_to_cpumask_map[%i] NULL\n", node); diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index f548fbf75f44..3f9411ed3cdc 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -709,6 +709,10 @@ static void __cpuinit numa_set_cpumask(int cpu, int enable) struct cpumask *mask; int i; + if (node == NUMA_NO_NODE) { + /* early_cpu_to_node() already emits a warning and trace */ + return; + } for_each_online_node(i) { unsigned long addr;