Commit-ID: 14392fd329eca9b59d51c0aa5d0acfb4965424d1
Gitweb: http://git.kernel.org/tip/14392fd329eca9b59d51c0aa5d0acfb4965424d1
Author: David Rientjes <rientjes@xxxxxxxxxx>
AuthorDate: Mon, 7 Feb 2011 14:08:53 -0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Mon, 14 Feb 2011 13:29:27 +0100
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 <jj@xxxxxxxxxxxxx>
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
LKML-Reference: <alpine.DEB.2.00.1102071407250.7812@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/mm/numa.c | 4 ++++
arch/x86/mm/numa_64.c | 4 ++++
2 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index bf60715..9559d36 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 f548fbf..3f9411e 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;
--
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