On Wed, Feb 7, 2018 at 10:49 AM, Peter Zijlstra <pet...@infradead.org> 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
