From mboxrd@z Thu Jan  1 00:00:00 1970
From: Corey Minyard <minyard@acm.org>
Subject: Re: [PATCH][RT] x86: Fix an RT MCE crash
Date: Thu, 30 Jun 2016 12:18:01 -0500
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Cc: "Luck, Tony" <tony.luck@intel.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	"linux-rt-users@vger.kernel.org" <linux-rt-users@vger.kernel.org>,
	Corey Minyard <cminyard@mvista.com>
To: Borislav Petkov <bp@alien8.de>
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On 06/30/2016 12:01 PM, Borislav Petkov wrote:
> On Thu, Jun 30, 2016 at 11:40:17AM -0500, Corey Minyard wrote:
>> I'm not sure.  I've included the entire boot log below...
> ...
>
>> [    0.164185]  [<ffffffff8106dcd8>] try_to_wake_up+0x28/0x320
>> [    0.164188]  [<ffffffff8106dfe0>] wake_up_process+0x10/0x20
>> [    0.164207]  [<ffffffff8101c548>] mce_notify_irq+0x28/0x30
>> [    0.164210]  [<ffffffff8101df35>] intel_threshold_interrupt+0xb5/0xd0
>> [    0.164213]  [<ffffffff8101e88c>] smp_threshold_interrupt+0x1c/0x40
>> [    0.164221]  [<ffffffff816f9b5a>] threshold_interrupt+0x6a/0x70
>> [    0.164223]  <EOI>
>> [    0.164226]  [<ffffffff8101dda7>] ? cmci_recheck+0x67/0x70
>> [    0.164241]  [<ffffffff816e9777>] setup_local_APIC+0x276/0x283
>> [    0.164259]  [<ffffffff81caf010>] native_smp_prepare_cpus+0x379/0x43b
>> [    0.164266]  [<ffffffff81ca3e4f>] kernel_init_freeable+0xd7/0x21a
>> [    0.164270]  [<ffffffff816df1f0>] ? rest_init+0x90/0x90
>> [    0.164272]  [<ffffffff816df1f9>] kernel_init+0x9/0x180
>> [    0.164275]  [<ffffffff816f8dc8>] ret_from_fork+0x58/0x90
>> [    0.164277]  [<ffffffff816df1f0>] ? rest_init+0x90/0x90
>> [    0.164295] Code: e7 ff ff 48 8b 7d 08 e8 02 1a 95 ff 5d c3 55 48 89 e5
>> 41 54 53 48 89 fb 9c 41 5c fa bf 01 00 00 00 e8 a8 38 00 00 ba 00 01 00 00
>> <f0> 66 0f c1 13 0f b6 ce 38 d1 74 10 0f 1f 80 00 00 00 00 f3 90
>> [    0.164298] RIP  [<ffffffff816f344d>] _raw_spin_lock_irqsave+0x1d/0x50
>> [    0.164298]  RSP <ffff88017fa03f00>
>> [    0.164299] CR2: 0000000000000600
>> [    0.656225] ---[ end trace 0000000000000001 ]---
>> [    0.656233] Kernel panic - not syncing: Fatal exception in interrupt
> Hmm, we have that setup_local_APIC -> cmci_recheck path on latest kernel
> too. However, we do init CMCI earlier, down the start_kernel() path.
>
> Would it be possible to boot latest upstream kernel on it to see whether
> it explodes the same way?
>
> Thanks.

This is on 3.10-rt with PREEMPT_RT enabled.  It appears that from 3.18-rt
and later it has code like the change I have proposed, so it does not crash.

I could add a something to see if the interrupt is coming in early to 
4.6-rt,
is that what you are looking for?

-corey