Messages in this thread | | | Date | Fri, 12 Jan 2018 21:22:38 +0100 | From | Ingo Molnar <> | Subject | Re: [RFC PATCH v2 6/6] x86/entry/pti: don't switch PGD on when pti_disable is set |
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* Andy Lutomirski <luto@amacapital.net> wrote:
> > Oh, and yes, I think the npti flag should also break ptrace(). I do agree with > > Andy that it's a "capability", although I do not think it should actually be > > implemented as one. > > For all that Linux capabilities are crap, nopti walks like one and quacks like > one. It needs to affect ptrace() permissions, it needs a way to disable it > systemwide, it needs LSM integration, etc. Using CAP_DISABLE_PTI gives us all > of this without tons of churn, auditing, and a whole new configuration thingy > for each LSM. And I avoids permanently polluting ptrace checks, the LSM > interface, etc for what is, essentially, a performance hack to work around a > blatant error in the design of some CPUs. > > Plus, with ambient caps, we already did the nasty part of the with and finished > all the relevant bikeshedding. > > So I'd rather just hold my nose and add the new capability bit.
Those all seem pretty valid arguments to me.
Thanks,
Ingo
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