lock_device_hotplug() serializes CPU & Memory online/offline and hotplug
operations. However, this lock is not held in the debug interfaces below
that initiate CPU online/offline operations.
- _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by
CONFIG_DEBUG_HOTPLUG_CPU0.
- cpu_probe_store() and cpu_release_store(), cpu hotplug test interface
enabled by CONFIG_ARCH_CPU_PROBE_RELEASE.
This patch changes the above interfaces to hold lock_device_hotplug().
Signed-off-by: Toshi Kani <toshi.k...@hp.com>
---
arch/x86/kernel/topology.c | 2 ++
drivers/base/cpu.c | 16 ++++++++++++++--
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 5823bbd..a3f35eb 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -65,6 +65,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action)
if (!cpu_is_hotpluggable(cpu))
return -EINVAL;
+ lock_device_hotplug();
cpu_hotplug_driver_lock();
switch (action) {
@@ -91,6 +92,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action)
}
cpu_hotplug_driver_unlock();
+ unlock_device_hotplug();
return ret;
}
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 4c358bc..4cc6928 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -88,7 +88,13 @@ static ssize_t cpu_probe_store(struct device *dev,
const char *buf,
size_t count)
{
- return arch_cpu_probe(buf, count);
+ ssize_t ret;
+
+ lock_device_hotplug();
+ ret = arch_cpu_probe(buf, count);
+ unlock_device_hotplug();
+
+ return ret;
}
static ssize_t cpu_release_store(struct device *dev,
@@ -96,7 +102,13 @@ static ssize_t cpu_release_store(struct device *dev,
const char *buf,
size_t count)
{
- return arch_cpu_release(buf, count);
+ ssize_t ret;
+
+ lock_device_hotplug();
+ ret = arch_cpu_release(buf, count);
+ unlock_device_hotplug();
+
+ return ret;
}
static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
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