[PATCH 1/2] topology: Check for missing CPU devices

Ben Hutchings
2012-01-08T20:48:46Z

Commit ccbc60d3e19a1b6ae66ca0d89b3da02dde62088b ('topology: Provide
CPU topology in sysfs in !SMP configurations') causes a crash at boot
on a several architectures. The topology sysfs code assumes that
there is a CPU device for each online CPU whereas some architectures
that do not support SMP or cpufreq do not register any CPU devices.
Check for this before trying to use a device.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/base/topology.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index ae989c5..4467c85 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -147,6 +147,8 @@ static int __cpuinit topology_add_dev(unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);

+ if (!dev)
+ return -ENODEV;
return sysfs_create_group(&dev->kobj, &topology_attr_group);
}

@@ -154,7 +156,8 @@ static void __cpuinit topology_remove_dev(unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);

- sysfs_remove_group(&dev->kobj, &topology_attr_group);
+ if (dev)
+ sysfs_remove_group(&dev->kobj, &topology_attr_group);
}

static int __cpuinit topology_cpu_callback(struct notifier_block *nfb,
--
1.7.8.2