Messages in this thread | | | Date | Mon, 09 Sep 2019 12:56:18 +0100 | Subject | Re: [PATCH] x86/umip: Add emulation for 64-bit processes | From | hpa@zytor ... |
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On September 8, 2019 8:22:48 AM GMT+01:00, Borislav Petkov <bp@alien8.de> wrote: >On Sat, Sep 07, 2019 at 02:26:10PM -0700, Ricardo Neri wrote: >> > Wine users have encountered a number of 64-bit Windows games that >use >> > these instructions (particularly sgdt), and were crashing when run >on >> > UMIP-enabled systems. >> >> Emulation support for 64-bit processes was not initially included >> because no use cases had been identified. > >AFAIR, we said at the time that 64-bit doesn't need it because this is >legacy software only and 64-bit will get fixed properly not to use >those >insns. I can probably guess how that went ...
I don't think Windows games was something we considered. However, needing to simulate these instructions is not a huge surprise. The important thing is that by simulating them, we can plug the leak of some very high value kernel information – mainly the GDT, IDT and TSS addresses. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
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