[patch 2/6] alpha: cpumask_of_node() should handle -1 as a node

Anton Blanchard
2010-01-06T06:11:59Z

pcibus_to_node can return -1 if we cannot determine which node a pci bus
is on. If passed -1, cpumask_of_node will negatively index the lookup array
and pull in random data:

# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpus
00000000,00000003,00000000,00000000
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpulist
64-65

Change cpumask_of_node to check for -1 and return cpu_all_mask in this
case:

# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpus
ffffffff,ffffffff,ffffffff,ffffffff
# cat /sys/devices/pci0000:00/0000:00:01.0/local_cpulist
0-127

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-cpumask/arch/alpha/include/asm/topology.h
===================================================================
--- linux-cpumask.orig/arch/alpha/include/asm/topology.h 2010-01-06 15:20:22.952583839 +1100
+++ linux-cpumask/arch/alpha/include/asm/topology.h 2010-01-06 15:20:46.610083557 +1100
@@ -28,6 +28,9 @@ static const struct cpumask *cpumask_of_
{
int cpu;

+ if (node == -1)
+ return cpu_all_mask;
+
cpumask_clear(&node_to_cpumask_map[node]);

for_each_online_cpu(cpu) {

--