hotplug / x86: Add hotplug lock to missing places (574b851e) · Commits · 戴 / test

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>

arch/x86/kernel/topology.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

drivers/base/cpu.c

+22 −2

Original line number	Diff line number	Diff line
		@@ -93,7 +93,17 @@ static ssize_t cpu_probe_store(struct device *dev,
		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 @@ static ssize_t cpu_release_store(struct device *dev,
		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);

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