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: Akinobu 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/kernel/mce_64.c b/arch/x86/kernel/mce_64.c
index 8ca8f86..66e6b79 100644
--- a/arch/x86/kernel/mce_64.c
+++ b/arch/x86/kernel/mce_64.c
@@ -802,16 +802,29 @@
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),
- mce_attributes[i]);
+ 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 @@
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 @@
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 @@
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);
