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@ -182,6 +182,12 @@ static int openPerfEvent(perf_event_attr *hw_event, pid_t pid, int cpu, int grou
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return static_cast<int>(syscall(SYS_perf_event_open, hw_event, pid, cpu, group_fd, flags));
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}
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// cat /proc/sys/kernel/perf_event_paranoid
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// -1: Allow use of (almost) all events by all users
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// >=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
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// >=1: Disallow CPU event access by users without CAP_SYS_ADMIN
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// >=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
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// >=3: Disallow all event access by users without CAP_SYS_ADMIN
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static bool getPerfEventParanoid(Int32 & result)
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{
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// the longest possible variant: "-1\0"
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@ -185,19 +185,6 @@ struct PerfEventsCounters
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// must be unsigned to not cause undefined behaviour on increment
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typedef UInt64 Id;
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// cat /proc/sys/kernel/perf_event_paranoid - if perf_event_paranoid is set to 3, all calls to `perf_event_open` are rejected (even for the current process)
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// https://lwn.net/Articles/696234/
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// -1: Allow use of (almost) all events by all users
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// >=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
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// >=1: Disallow CPU event access by users without CAP_SYS_ADMIN
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// >=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
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// >=3: Disallow all event access by users without CAP_SYS_ADMIN
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// https://lwn.net/Articles/696216/
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// It adds a another value that can be set for the sysctl parameter (i.e. kernel.perf_event_paranoid=3)
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// that restricts perf_event_open() to processes with the CAP_SYS_ADMIN capability
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// todo: check whether perf_event_open() is available with CAP_SYS_ADMIN
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static constexpr size_t NUMBER_OF_RAW_EVENTS = 18;
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static const PerfEventInfo raw_events_info[PerfEventsCounters::NUMBER_OF_RAW_EVENTS];
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