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Commit d435d862 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
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cpu hotplug: mce: fix cpu hotplug error handling 



- Clear kobject in percpu device_mce before calling sysdev_register() with

  Because mce_create_device() may fail and it leaves kobject filled with
  junk. It will be the problem when mce_create_device() will be called
  next time.

- Fix error handling in mce_create_device()

  Error handling should not do sysdev_remove_file() with not yet added
  attributes.

- Don't register hotcpu notifier when mce_create_device() returns error

- Do mce_create_device() in CPU_UP_PREPARE instead of CPU_ONLINE

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 881a841f

arch/x86/kernel/mce_64.c

+29 −10
Original line number Diff line number Diff line
@@ -802,16 +802,29 @@ static __cpuinit int mce_create_device(unsigned int cpu) 
	if (!mce_available(&cpu_data[cpu]))

		return -EIO;



	memset(&per_cpu(device_mce, cpu).kobj, 0, sizeof(struct kobject));

	per_cpu(device_mce,cpu).id = cpu;

	per_cpu(device_mce,cpu).cls = &mce_sysclass;



	err = sysdev_register(&per_cpu(device_mce,cpu));

	if (err)

		return err;



	if (!err) {

		for (i = 0; mce_attributes[i]; i++)

			sysdev_create_file(&per_cpu(device_mce,cpu),

	for (i = 0; mce_attributes[i]; i++) {

		err = sysdev_create_file(&per_cpu(device_mce,cpu),

					 mce_attributes[i]);

		if (err)

			goto error;

	}



	return 0;

error:

	while (i--) {

		sysdev_remove_file(&per_cpu(device_mce,cpu),

				   mce_attributes[i]);

	}

	sysdev_unregister(&per_cpu(device_mce,cpu));



	return err;

}
@@ -823,7 +836,6 @@ static void mce_remove_device(unsigned int cpu) 
		sysdev_remove_file(&per_cpu(device_mce,cpu),

			mce_attributes[i]);

	sysdev_unregister(&per_cpu(device_mce,cpu));

	memset(&per_cpu(device_mce, cpu).kobj, 0, sizeof(struct kobject));

}



/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -831,18 +843,21 @@ static int 
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)

{

	unsigned int cpu = (unsigned long)hcpu;

	int err = 0;



	switch (action) {

	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

		mce_create_device(cpu);

	case CPU_UP_PREPARE:

	case CPU_UP_PREPARE_FROZEN:

		err = mce_create_device(cpu);

		break;

	case CPU_UP_CANCELED:

	case CPU_UP_CANCELED_FROZEN:

	case CPU_DEAD:

	case CPU_DEAD_FROZEN:

		mce_remove_device(cpu);

		break;

	}

	return NOTIFY_OK;

	return err ? NOTIFY_BAD : NOTIFY_OK;

}



static struct notifier_block mce_cpu_notifier = {
@@ -857,9 +872,13 @@ static __init int mce_init_device(void) 
	if (!mce_available(&boot_cpu_data))

		return -EIO;

	err = sysdev_class_register(&mce_sysclass);

	if (err)

		return err;



	for_each_online_cpu(i) {

		mce_create_device(i);

		err = mce_create_device(i);

		if (err)

			return err;

	}



	register_hotcpu_notifier(&mce_cpu_notifier);