From d435d862baca3e25e5eec236762a43251b1e7ffc Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Thu, 18 Oct 2007 03:05:15 -0700 Subject: [PATCH] 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 Signed-off-by: Akinobu Mita Cc: Gautham R Shenoy Cc: Oleg Nesterov Cc: Andi Kleen Cc: Jan Beulich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/mce_64.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/mce_64.c b/arch/x86/kernel/mce_64.c index 8ca8f8648969..66e6b797b2cb 100644 --- a/arch/x86/kernel/mce_64.c +++ b/arch/x86/kernel/mce_64.c @@ -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), - 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 @@ 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);