hotplug / x86: Add hotplug lock to missing places
lock_device_hotplug[_sysfs]() 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.kani@hp.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 848ebbd..51f5d7f 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -93,7 +93,17 @@
const char *buf,
size_t count)
{
- return arch_cpu_probe(buf, count);
+ ssize_t cnt;
+ int ret;
+
+ ret = lock_device_hotplug_sysfs();
+ if (ret)
+ return ret;
+
+ cnt = arch_cpu_probe(buf, count);
+
+ unlock_device_hotplug();
+ return cnt;
}
static ssize_t cpu_release_store(struct device *dev,
@@ -101,7 +111,17 @@
const char *buf,
size_t count)
{
- return arch_cpu_release(buf, count);
+ ssize_t cnt;
+ int ret;
+
+ ret = lock_device_hotplug_sysfs();
+ if (ret)
+ return ret;
+
+ cnt = arch_cpu_release(buf, count);
+
+ unlock_device_hotplug();
+ return cnt;
}
static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);