Re: [PATCH v4 2/9] perf/core: open access for CAP_SYS_PERFMON privileged process
Song Liu <[email protected]> Sat, 11 Jan 2020 00:23:27 +0000
| Newsgroups | gmane.linux.ports.arm.kernel,gmane.linux.oprofile,gmane.comp.freedesktop.xorg.drivers.intel,gmane.linux.ports.parisc,gmane.linux.kernel,gmane.linux.kernel.perf.user,gmane.linux.kernel.lsm,gmane.linux.ports.ppc64.devel |
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| Message-ID | <[email protected]> |
> On Jan 10, 2020, at 3:47 PM, Masami Hiramatsu <[email protected]> wrote: > > On Fri, 10 Jan 2020 13:45:31 -0300 > Arnaldo Carvalho de Melo <[email protected]> wrote: > >> Em Sat, Jan 11, 2020 at 12:52:13AM +0900, Masami Hiramatsu escreveu: >>> On Fri, 10 Jan 2020 15:02:34 +0100 Peter Zijlstra <[email protected]> wrote: >>>> Again, this only allows attaching to previously created kprobes, it does >>>> not allow creating kprobes, right? >> >>>> That is; I don't think CAP_SYS_PERFMON should be allowed to create >>>> kprobes. >> >>>> As might be clear; I don't actually know what the user-ABI is for >>>> creating kprobes. >> >>> There are 2 ABIs nowadays, ftrace and ebpf. perf-probe uses ftrace interface to >>> define new kprobe events, and those events are treated as completely same as >>> tracepoint events. On the other hand, ebpf tries to define new probe event >>> via perf_event interface. Above one is that interface. IOW, it creates new kprobe. >> >> Masami, any plans to make 'perf probe' use the perf_event_open() >> interface for creating kprobes/uprobes? > > Would you mean perf probe to switch to perf_event_open()? > No, perf probe is for setting up the ftrace probe events. I think we can add an > option to use perf_event_open(). But current kprobe creation from perf_event_open() > is separated from ftrace by design. I guess we can extend event parser to understand kprobe directly. Instead of perf probe kernel_func perf stat/record -e probe:kernel_func ... We can just do perf stat/record -e kprobe:kernel_func ... Thanks, Song