[PATCH] powerpc: Fix dl-procinfo HWCAP

[Adhemerval Zanella]

LGTM but it does not characterize a critical bug or CVE to lift the
freeze.  Please apply when 2.24 open and we can backport to 2.23
after release.

On 03-02-2016 12:02, Carlos Eduardo Seo wrote:
> Ping
> 
> Is this OK for 2.23?
> 
> Thanks
> 
> On 1/25/16 4:15 PM, Carlos Eduardo Seo wrote:
>>
>>
>> On 1/25/16 4:04 PM, Adhemerval Zanella wrote:
>>>
>>> I think you should not it might be wrong for hwcap2, since the logic
>>> is correct for hwcap1 (I assume this hitting the new fields for
>>> POWER9).
>>>
>>
>> No, this actually hits HWCAP1. If you look at hwcap.h, you will see:
>>
>> #define PPC_FEATURE_PSERIES_PERFMON_COMPAT  0x00000040
>> #define PPC_FEATURE_TRUE_LE        0x00000002
>>
>> There's a 4 bit gap between PPC_FEATURE_PSERIES_PERFMON_COMPAT and
>> PPC_FEATURE_TRUE_LE that has to be padded in _dl_powerpc_cap_flags.
>>
>> The patch also assumes HWCAP1 is 64-bit long and all bits are filled,
>> which is true now (if you pad those vacant 4 bits).
>>
>