Messages in this thread | | | From | Alexander Shishkin <> | Subject | Re: [PATCH v5 12/20] x86: perf: intel_pt: Intel PT PMU driver | Date | Fri, 24 Oct 2014 10:52:05 +0300 |
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Peter Zijlstra <peterz@infradead.org> writes:
> On Mon, Oct 13, 2014 at 04:45:40PM +0300, Alexander Shishkin wrote: >> +static bool pt_event_valid(struct perf_event *event) >> +{ >> + u64 config = event->attr.config; >> + >> + /* admin can set any packet generation parameters */ >> + if (capable(CAP_SYS_ADMIN) && (config & PT_BYPASS_MASK) == config) >> + return true; >> + >> + if ((config & PT_CONFIG_MASK) != config) >> + return false; >> + >> + return true; >> +} > > This seems to suggest PT is available to !priv users, is this right?
Yes, that's the intention. PT does CPL-based filtering in hardware and unlike previous attempts at branch tracing, does not leak out-of-context addresses (or any other information for that matter).
Regards, -- Alex
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