Messages in this thread | | | Date | Mon, 19 Oct 2020 11:37:14 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH RFC V3 4/9] x86/pks: Preserve the PKRS MSR on context switch |
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On Fri, Oct 16, 2020 at 10:14:10PM -0700, Ira Weiny wrote: > > so it either needs to > > explicitly do so, or have an assertion that preemption is indeed > > disabled. > > However, I don't think I understand clearly. Doesn't [get|put]_cpu_ptr() > handle the preempt_disable() for us?
It does.
> Is it not sufficient to rely on that?
It is.
> Dave's comment seems to be the opposite where we need to eliminate preempt > disable before calling write_pkrs(). > > FWIW I think I'm mistaken in my response to Dave regarding the > preempt_disable() in pks_update_protection().
Dave's concern is that we're calling with with preemption already disabled so disabling it again is superfluous.
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