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

From: Adrian Hunter
Date: Thu Mar 26 2020 - 01:10:36 EST


On 26/03/20 3:31 am, Masami Hiramatsu wrote:
> Hi,
>
> On Mon, 2 Mar 2020 23:50:30 -0500
> Mingbo Zhang <whensungoes@xxxxxxxxx> 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.
>>
>
> This looks good to me. BTW, wouldn't we need to add decode test cases to perf?
>
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
>
> Thank you,
>

We have correct patches that you ack'ed for CET here:

https://lore.kernel.org/lkml/20200204171425.28073-1-yu-cheng.yu@xxxxxxxxx/

But they have not yet been applied.

Sorry for the confusion.