Messages in this thread | | | Date | Wed, 19 Oct 2016 07:26:02 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [kernel-hardening] [PATCH 1/2] security, perf: allow further restriction of perf_event_open |
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Em Wed, Oct 19, 2016 at 12:01:26PM +0200, Peter Zijlstra escreveu: > On Tue, Oct 18, 2016 at 05:15:01PM -0400, Daniel Micay wrote: > > It's also worth noting that fine-grained control via a scoped mechanism > > would likely only be used to implement *more restrictions* on Android, > > not to make the feature less aggressive.
> > It's desirable for perf events to be disabled by default for non-root > > across the board on Android.
> Right, but this is Android. The knob seems to now also live in Debian > (and derived) distros. And there it is utter crap.
> It completely defeats having perf for a fairly large segment of > corporate developers who do not get to have root on their own machines > (which is stupid policy but whatever).
> It similarly defeats development of self profiling JITs and whatnot.
> A capability would allow people to run perf (or another sanctioned > binary), even though in general they cannot do sys_perf_event_open().
But self profiling JITs would be useful for non-developers, on Android (anywhere, really), and for that it would require being able to at least, well, self profile, using sys_perf_event_open() by a normal process, limited to profiling itself, no?
This not being possible, self profiling will use some other means, its like sys_perf_event_open() never existed for them.
- Arnaldo
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