Re: [linus:master] BUILD REGRESSION a2e5790d841658485d642196dbb0927303d6c22f

[Linus Torvalds]

On Wed, Feb 7, 2018 at 10:49 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> Right, we picked UD0 because we _thought_ everybody agreed it being 2
> bytes, just like UD2. This is now not true anymore?

Both UD0 and UD1 are documented to have modrm in the latest Intel SDM
I can find (Order number 325462-065US, December 2017):

  https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf

for the direct link.

           Linus