| Subject | Re: [PATCH 00/11 v3] x86: load FPU registers on return to userland | From | Andy Lutomirski <> | Date | Thu, 4 Oct 2018 09:50:51 -0700 |
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> On Oct 4, 2018, at 9:45 AM, Rik van Riel <riel@surriel.com> wrote: > > On Thu, 2018-10-04 at 16:05 +0200, Sebastian Andrzej Siewior wrote: > > >> In v3 I dropped that decouple idea. I also learned that the wrpkru >> instruction is not privileged and so caching it in kernel does not >> work. > > Wait, so any thread can bypass its memory protection > keys, even if there is a seccomp filter preventing > it from calling the PKRU syscalls? > > Is that intended? > > Is that simply a hardware limitation, or something > where we can set a flag somewhere to force tasks to > go through the kernel? > >
Hardware limitation.
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