Re: [PATCH 4.4 15/50] s390/alternative: use a copy of the facility bit mask

[Jiri Slaby]

On 05/04/2018, 09:37 AM, Jiri Slaby wrote:
> On 04/27/2018, 03:58 PM, Greg Kroah-Hartman wrote:
>> 4.4-stable review patch.  If anyone has any objections, please let me know.
>>
>> ------------------
>>
>> From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
>>
>>
>> [ Upstream commit cf1489984641369611556bf00c48f945c77bcf02 ]
>>
>> To be able to switch off specific CPU alternatives with kernel parameters
>> make a copy of the facility bit mask provided by STFLE and use the copy
>> for the decision to apply an alternative.
> ...
>> --- a/arch/s390/include/asm/facility.h
>> +++ b/arch/s390/include/asm/facility.h
>> @@ -13,6 +13,24 @@
>>  
>>  #define MAX_FACILITY_BIT (256*8)	/* stfle_fac_list has 256 bytes */
> 
> I wonder if the below (plus __test_facility) is correct in 4.4, given
> MAX_FACILITY_BIT is defined as such and not as sizeof(stfle_fac_list *
> 8) as in upstream?

IOW, we should include this 4.12-commit in 4.4 too:
commit 6f5165e864d240d15675cc2fb5a369d57e1f60d0
Author: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Date:   Mon Mar 20 14:29:50 2017 +0100

    s390/facilites: use stfle_fac_list array size for MAX_FACILITY_BIT

thanks,
-- 
js
suse labs