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| author | Borislav Petkov <bp@suse.de> | 2014-06-20 23:16:45 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2014-06-24 15:17:01 +0200 |
| commit | 27c934158c5be0bebfb2970da521b9d9efc0058b (patch) | |
| tree | e943e5c07306850caca97f81c8c387b826c7e2f8 | |
| parent | 38356c1fbd8cd0f44a32ede2c97f0eb639d06613 (diff) | |
| download | op-kernel-dev-27c934158c5be0bebfb2970da521b9d9efc0058b.zip op-kernel-dev-27c934158c5be0bebfb2970da521b9d9efc0058b.tar.gz | |
x86, MCE: Robustify mcheck_init_device
BorisO reports that misc_register() fails often on xen. The current code
unregisters the CPU hotplug notifier in that case. If then a CPU is
offlined and onlined back again, we end up with a second timer running
on that CPU, leading to soft lockups and system hangs.
So let's leave the hotcpu notifier always registered - even if
mce_device_create failed for some cores and never unreg it so that we
can deal with the timer handling accordingly.
Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 8fecdd3..4fc5797 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -2450,6 +2450,12 @@ static __init int mcheck_init_device(void) for_each_online_cpu(i) { err = mce_device_create(i); if (err) { + /* + * Register notifier anyway (and do not unreg it) so + * that we don't leave undeleted timers, see notifier + * callback above. + */ + __register_hotcpu_notifier(&mce_cpu_notifier); cpu_notifier_register_done(); goto err_device_create; } @@ -2470,10 +2476,6 @@ static __init int mcheck_init_device(void) err_register: unregister_syscore_ops(&mce_syscore_ops); - cpu_notifier_register_begin(); - __unregister_hotcpu_notifier(&mce_cpu_notifier); - cpu_notifier_register_done(); - err_device_create: /* * We didn't keep track of which devices were created above, but |
