<keescook@xxxxxxxxxxxx>,Jann Horn <jannh@xxxxxxxxxx>,Thomas Gleixner <tglx@xxxxxxxxxxxxx>,Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>,Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>,linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>,"linux-security-module@xxxxxxxxxxxxxxx" <linux-security-module@xxxxxxxxxxxxxxx>,"selinux@xxxxxxxxxxxxxxx" <selinux@xxxxxxxxxxxxxxx>,"intel-gfx@xxxxxxxxxxxxxxxxxxxxx" <intel-gfx@xxxxxxxxxxxxxxxxxxxxx>,"bpf@xxxxxxxxxxxxxxx" <bpf@xxxxxxxxxxxxxxx>,"linux-parisc@xxxxxxxxxxxxxxx" <linux-parisc@xxxxxxxxxxxxxxx>,"linuxppc-dev@xxxxxxxxxxxxxxxx" <linuxppc-dev@xxxxxxxxxxxxxxxx>,"linux-perf-users@xxxxxxxxxxxxxxx" <linux-perf-users@xxxxxxxxxxxxxxx>,"linux-arm-kernel@xxxxxxxxxxxxxxxxxxx" <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>,"oprofile-list@xxxxxxxxxxxx" <oprofile-list@xxxxxxxxxxxx> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Message-ID: <A7F0BF73-9189-44BA-9264-C88F2F51CBF3@xxxxxxxxxx> On January 10, 2020 9:23:27 PM GMT-03:00, Song Liu <songliubraving@xxxxxx> wrote: > > >> On Jan 10, 2020, at 3:47 PM, Masami Hiramatsu <mhiramat@xxxxxxxxxx> >wrote: >> >> On Fri, 10 Jan 2020 13:45:31 -0300 >> Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> 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 ><peterz@xxxxxxxxxxxxx> 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 ... You took the words from my mouth, exactly, that is a perfect use case, an alternative to the 'perf probe' one of making a disabled event that then gets activated via record/stat/trace, in many cases it's better, removes the explicit probe setup case. Regards, - Arnaldo > >Thanks, >Song _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
