[PATCH v1 0/3] Introduce CAP_SYS_PERFMON capability for secure Perf users groups
ak at linux.intel.com
Wed Dec 11 20:36:48 UTC 2019
> > In this circumstances CAP_SYS_PERFMON looks like smart balanced advancement that
> > trade-offs between perf_events subsystem extensions, required level of control
> > and configurability of perf_events, existing users adoption effort, and it brings
> > security hardening benefits of decreasing attack surface for the existing users
> > and use cases.
> I'm not 100% opposed to CAP_SYS_PERFMON. I am 100% opposed to new capabilities
> that have a single use. Surely there are other CAP_SYS_ADMIN users that [cs]ould
> be converted to CAP_SYS_PERFMON as well. If there is a class of system performance
> privileged operations, say a dozen or so, you may have a viable argument.
perf events is not a single use. It has a bazillion of sub functionalities,
including hardware tracing, software tracing, pmu counters, software counters,
uncore counters, break points and various other stuff in its PMU drivers.
See it more as a whole quite heterogenous driver subsystem.
I guess CAP_SYS_PERFMON is not a good name because perf is much more
than just Perfmon. Perhaps call it CAP_SYS_PERF_EVENTS
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