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| author | Borislav Petkov <bp@suse.de> | 2014-06-20 23:16:45 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2014-07-21 18:14:32 +0200 |
| commit | 51cbe7e7c400def749950ab6b2c120624dbe21a7 (patch) | |
| tree | 4dad4c11bc99e9596fa5e6c6d0bb426388ec957d | |
| parent | Linux 3.16-rc6 (diff) | |
| download | linux-51cbe7e7c400def749950ab6b2c120624dbe21a7.tar.xz linux-51cbe7e7c400def749950ab6b2c120624dbe21a7.zip | |
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 bb92f38153b2..9a79c8dbd8e8 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -2451,6 +2451,12 @@ 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; } @@ -2471,10 +2477,6 @@ 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 |