Re: [RFC v2 0/6] enable creating [k,u]probe with perf_event_open
- Date: Mon, 13 Nov 2017 22:52:49 +0000
- From: Song Liu <songliubraving@xxxxxx>
- Subject: Re: [RFC v2 0/6] enable creating [k,u]probe with perf_event_open
> On Nov 12, 2017, at 3:40 PM, Song Liu <songliubraving@xxxxxx> wrote:
> Changes v1 to v2:
> Fix build issue reported by kbuild test bot by adding ifdef of
> CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS.
> v1 cover letter:
> This is to follow up the discussion over "new kprobe api" at Linux
> Plumbers 2017:
> With current kernel, user space tools can only create/destroy [k,u]probes
> with a text-based API (kprobe_events and uprobe_events in tracefs). This
> approach relies on user space to clean up the [k,u]probe after using them.
> However, this is not easy for user space to clean up properly.
> To solve this problem, we introduce a file descriptor based API.
> Specifically, we extended perf_event_open to create [k,u]probe, and attach
> this [k,u]probe to the file descriptor created by perf_event_open. These
> [k,u]probe are associated with this file descriptor, so they are not
> available in tracefs.
> We reuse large portion of existing trace_kprobe and trace_uprobe code.
> Currently, the file descriptor API does not support arguments as the
> text-based API does. This should not be a problem, as user of the file
> decriptor based API read data through other methods (bpf, etc.).
> I also include a patch to to bcc, and a patch to man-page perf_even_open.
> Please see the list below. A fork of bcc with this patch is also available
> on github:
> man-pages patch:
> perf_event_open.2: add new type PERF_TYPE_PROBE
> bcc patch:
> bcc: Try use new API to create [k,u]probe with perf_event_open
> kernel patches:
> Song Liu (6):
> perf: Add new type PERF_TYPE_PROBE
> perf: copy new perf_event.h to tools/include/uapi
> perf: implement kprobe support to PERF_TYPE_PROBE
> perf: implement uprobe support to PERF_TYPE_PROBE
> bpf: add option for bpf_load.c to use PERF_TYPE_PROBE
> bpf: add new test test_many_kprobe
> include/linux/trace_events.h | 2 +
> include/uapi/linux/perf_event.h | 35 ++++++-
> kernel/events/core.c | 39 ++++++-
> kernel/trace/trace_event_perf.c | 127 +++++++++++++++++++++++
> kernel/trace/trace_kprobe.c | 91 +++++++++++++++--
> kernel/trace/trace_probe.h | 11 ++
> kernel/trace/trace_uprobe.c | 90 +++++++++++++++--
> samples/bpf/Makefile | 3 +
> samples/bpf/bpf_load.c | 61 ++++++-----
> samples/bpf/bpf_load.h | 12 +++
> samples/bpf/test_many_kprobe_user.c | 184 ++++++++++++++++++++++++++++++++++
> tools/include/uapi/linux/perf_event.h | 35 ++++++-
> 12 files changed, 643 insertions(+), 47 deletions(-)
> create mode 100644 samples/bpf/test_many_kprobe_user.c
Could you please share feedback about this set?
Thanks and Best Regards,