I think the only concern with this is it still adds more checks and conditionals to the thread switching code. Whilst minimal, these can add up with enough features like these, so would want some decent motivation. That said, having the support be a build time option would somewhat circumvent that whole problem.

Once more people are back from holidays I can bring up this discussion internally, although it might be useful to have a more detailed use case and threat model that you are trying to defend against.

Adrian

On Fri 23-Dec-2016 10:38 PM, Corey Richardson wrote:

How do people feel about exposing the TSD (time-stamp disable) bit as a
piece of state on the TCB? Ideally it'd be lazily switched. I vaguely
want this in Robigalia for disabling access to real time in
non-sufficiently-privileged processes.

Best,

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