[PATCH v2 2/9] x86: numa: check the node id consistently for x86

[Yunsheng Lin]

According to Section 6.2.14 from ACPI spec 6.3 [1], the setting
of proximity domain is optional, as below:

This optional object is used to describe proximity domain
associations within a machine. _PXM evaluates to an integer
that identifies a device as belonging to a Proximity Domain
defined in the System Resource Affinity Table (SRAT).

This patch checks node id with the below case before returning
node_to_cpumask_map[node]:
1. if node_id >= nr_node_ids, return cpu_none_mask
2. if node_id < 0, return cpu_online_mask
3. if node_to_cpumask_map[node_id] is NULL, return cpu_online_mask

[1] https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
 arch/x86/include/asm/topology.h | 6 ++++++
 arch/x86/mm/numa.c              | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 4b14d23..f36e9c8 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -69,6 +69,12 @@ extern const struct cpumask *cpumask_of_node(int node);
 /* Returns a pointer to the cpumask of CPUs on Node 'node'. */
 static inline const struct cpumask *cpumask_of_node(int node)
 {
+	if (node >= nr_node_ids)
+		return cpu_none_mask;
+
+	if (node < 0 || !node_to_cpumask_map[node])
+		return cpu_online_mask;
+
 	return node_to_cpumask_map[node];
 }
 #endif
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index e6dad60..5e393d2 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -868,7 +868,7 @@ const struct cpumask *cpumask_of_node(int node)
 		dump_stack();
 		return cpu_none_mask;
 	}
-	if (node_to_cpumask_map[node] == NULL) {
+	if (node < 0 || !node_to_cpumask_map[node]) {
 		printk(KERN_WARNING
 			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
 			node);
-- 
2.8.1