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Commit 881a841f authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
Browse files

cpu hotplug: msr: fix cpu hotplug error handling 



Do msr_device_create() in CPU_UP_PREPARE instead of CPU_ONLINE.

Cc: "H. Peter Anvin" <hpa@zytor.com>
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 c7e38a9c

arch/x86/kernel/msr.c

+20 −15
Original line number Diff line number Diff line
@@ -133,37 +133,42 @@ static const struct file_operations msr_fops = { 
	.open = msr_open,

};



static int __cpuinit msr_device_create(int i)

static int msr_device_create(int cpu)

{

	int err = 0;

	struct device *dev;



	dev = device_create(msr_class, NULL, MKDEV(MSR_MAJOR, i), "msr%d",i);

	if (IS_ERR(dev))

		err = PTR_ERR(dev);

	return err;

	dev = device_create(msr_class, NULL, MKDEV(MSR_MAJOR, cpu),

			    "msr%d", cpu);

	return IS_ERR(dev) ? PTR_ERR(dev) : 0;

}



static void msr_device_destroy(int cpu)

{

	device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));

}



static int __cpuinit msr_class_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:

		msr_device_create(cpu);

	case CPU_UP_PREPARE:

	case CPU_UP_PREPARE_FROZEN:

		err = msr_device_create(cpu);

		break;

	case CPU_UP_CANCELED:

	case CPU_UP_CANCELED_FROZEN:

	case CPU_DEAD:

	case CPU_DEAD_FROZEN:

		device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));

		msr_device_destroy(cpu);

		break;

	}

	return NOTIFY_OK;

	return err ? NOTIFY_BAD : NOTIFY_OK;

}



static struct notifier_block __cpuinitdata msr_class_cpu_notifier =

{

static struct notifier_block __cpuinitdata msr_class_cpu_notifier = {

	.notifier_call = msr_class_cpu_callback,

};
@@ -196,7 +201,7 @@ static int __init msr_init(void) 
out_class:

	i = 0;

	for_each_online_cpu(i)

		device_destroy(msr_class, MKDEV(MSR_MAJOR, i));

		msr_device_destroy(i);

	class_destroy(msr_class);

out_chrdev:

	unregister_chrdev(MSR_MAJOR, "cpu/msr");
@@ -208,7 +213,7 @@ static void __exit msr_exit(void) 
{

	int cpu = 0;

	for_each_online_cpu(cpu)

		device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));

		msr_device_destroy(cpu);

	class_destroy(msr_class);

	unregister_chrdev(MSR_MAJOR, "cpu/msr");

	unregister_hotcpu_notifier(&msr_class_cpu_notifier);