On January 10, 2019 9:42:57 AM PST, Sean Christopherson <sean.j.christopher...@intel.com> wrote: >On Thu, Jan 10, 2019 at 12:32:43PM -0500, Steven Rostedt wrote: >> On Thu, 10 Jan 2019 11:20:04 -0600 >> Josh Poimboeuf <jpoim...@redhat.com> wrote: >> >> >> > > While I can't find a reason for hypervisors to emulate this >instruction, >> > > smarter people might find ways to turn it into a security >exploit. >> > >> > Interesting point... but I wonder if it's a realistic concern. >BTW, >> > text_poke_bp() also relies on undocumented behavior. >> >> But we did get an official OK from Intel that it will work. Took a >bit >> of arm twisting to get them to do so, but they did. And it really is >> pretty robust. > >Did we (they?) list any caveats for this behavior? E.g. I'm fairly >certain atomicity guarantees go out the window if WC memtype is used.
If you run code from non-WB memory, all bets are off and you better not be doing cross-modifying code. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
