x86/MCE/AMD: Fix the thresholding machinery initialization order

[John Clemens <john@deater.net>]

On 11/27/18 3:38 PM, Rafał Miłecki wrote:
> On 27.11.2018 20:25, Borislav Petkov wrote:
>> Currently, the code sets up the thresholding interrupt vector and only
>> then goes about initializing the thresholding banks. Which is wrong,
>> because an early thresholding interrupt would cause a NULL pointer
>> dereference when accessing those banks and prevent the machine from
>> booting.
>>
>> Therefore, set the thresholding interrupt vector only *after* having
>> initialized the banks successfully.
>>
>> Fixes: 18807ddb7f88 ("x86/mce/AMD: Reset Threshold Limit after logging 
>> error")
>> Reported-by: Rafał Miłecki <rafal@milecki.pl>
>> Reported-by: John Clemens <clemej@gmail.com>
>> Signed-off-by: Borislav Petkov <bp@suse.de>
>> Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
>> Cc: linux-edac@vger.kernel.org
>> Cc: stable@vger.kernel.org
>> Cc: Tony Luck <tony.luck@intel.com>
>> Cc: x86@kernel.org
>> Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
>> Link: https://lkml.kernel.org/r/20181127101700.2964-1-zajec5@gmail.com
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=201291
> 
> Tested on top of 4.14.83 and 4.20-rc4. It fixed both kernels for me!
> 
> Tested-by: Rafał Miłecki <rafal@milecki.pl>

Not that anyone needs further verification at this point, but tested 
working on top of 4.19.5, on the HP EliteBook 745 G5, BIOS Q81 v01.03.01 
(same as bugzilla report).

Tested-by: John Clemens <john@deater.net>

> John: thanks a lot for bisecting this issue down and finding a
> workaround (mce=off). It allowed me to boot recent Linux & debug it
> further.

Thank you for taking it the rest of the way, life got in the way after 
the bisect.  I'm glad you were able to pick it up.

> Borislav: thank you for looking at my patch and coming with a nicer fix
> SO quickly!

My thanks as well, to all.

john.c