Re: [PATCH] x86: perf: insn: Tweak opcode map for Intel CET instructions

From: Adrian Hunter
Date: Wed Mar 25 2020 - 02:11:32 EST


On 16/03/20 9:10 am, Adrian Hunter wrote:
> On 3/03/20 9:17 am, Adrian Hunter wrote:
>> On 3/03/20 6:50 am, Mingbo Zhang wrote:
>>> Intel CET instructions are not described in the Intel SDM. When trying to
>>> get the instruction length, the following instructions get wrong (missing
>>> ModR/M byte).
>>>
>>> RDSSPD r32
>>> RSDDPQ r64
>>> ENDBR32
>>> ENDBR64
>>> WRSSD r/m32, r32
>>> WRSSQ r/m64, r64
>>>
>>> RDSSPD/Q and ENDBR32/64 use the same opcode (f3 0f 1e) slot, which is
>>> described in SDM as Reserved-NOP with no encoding characters, and got an
>>> empty slot in the opcode map. WRSSD/Q (0f 38 f6) also got an empty slot.
>>
>> We have patches for that:
>>
>> https://lore.kernel.org/lkml/20200204171425.28073-1-yu-cheng.yu@xxxxxxxxx/
>>
>> But they have not yet been applied. Arnaldo, could you take them?
>>
>
> Any takers?
>

:-)