On Wed, Nov 21, 2018 at 10:44 AM Linus Torvalds <[email protected]> wrote: > > On Wed, Nov 21, 2018 at 10:26 AM Andy Lutomirski <[email protected]> wrote: > > > > Can we maybe use this as an excuse to ask for some reasonable instructions > > to access user memory? > > I did that long ago. It's why we have CLAC/STAC today. I was told that > what I actually asked for (get an instruction to access user space - I > suggested using a segment override prefix) was not viable. >
Maybe it wasn't viable *then*, but WRUSS really does write to userspace with user privilege. Surely the same mechanism with some of the weirdness removed would do what we want.
