bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jiri Olsa <jolsa@redhat.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andriin@fb.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@chromium.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Subject: [RFC bpf-next 0/5] bpf, x86: Add bpf_get_func_ip helper
Date: Tue, 29 Jun 2021 21:29:40 +0200	[thread overview]
Message-ID: <20210629192945.1071862-1-jolsa@kernel.org> (raw)

hi,
adding bpf_get_func_ip helper that returns IP address of the
caller function for trampoline and krobe programs.

There're 2 specific implementation of the bpf_get_func_ip
helper, one for trampoline progs and one for kprobe/kretprobe
progs.

The trampoline helper call is replaced/inlined by verifier
with simple move instruction. The kprobe/kretprobe is actual
helper call that returns prepared caller address.

The trampoline extra 3 instructions for storing IP address
is now optional, which I'm not completely sure is necessary,
so I plan to do some benchmarks, if it's noticeable, hence
the RFC. I'm also not completely sure about the kprobe/kretprobe
implementation.

Also available at:
  https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  bpf/get_func_ip

thanks,
jirka


---
Jiri Olsa (5):
      bpf, x86: Store caller's ip in trampoline stack
      bpf: Enable BPF_TRAMP_F_IP_ARG for trampolines with call_get_func_ip
      bpf: Add bpf_get_func_ip helper for tracing programs
      bpf: Add bpf_get_func_ip helper for kprobe programs
      selftests/bpf: Add test for bpf_get_func_ip helper

 arch/x86/net/bpf_jit_comp.c                               | 19 +++++++++++++++++++
 include/linux/bpf.h                                       |  5 +++++
 include/linux/filter.h                                    |  3 ++-
 include/uapi/linux/bpf.h                                  |  7 +++++++
 kernel/bpf/trampoline.c                                   | 12 +++++++++---
 kernel/bpf/verifier.c                                     | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/trace/bpf_trace.c                                  | 29 +++++++++++++++++++++++++++++
 kernel/trace/trace_kprobe.c                               | 20 ++++++++++++++++++--
 kernel/trace/trace_probe.h                                |  5 +++++
 tools/include/uapi/linux/bpf.h                            |  7 +++++++
 tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/get_func_ip_test.c      | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 12 files changed, 260 insertions(+), 6 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c
 create mode 100644 tools/testing/selftests/bpf/progs/get_func_ip_test.c


             reply	other threads:[~2021-06-29 19:29 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-29 19:29 Jiri Olsa [this message]
2021-06-29 19:29 ` [PATCH bpf-next 1/5] bpf, x86: Store caller's ip in trampoline stack Jiri Olsa
2021-06-29 19:29 ` [PATCH bpf-next 2/5] bpf: Enable BPF_TRAMP_F_IP_ARG for trampolines with call_get_func_ip Jiri Olsa
2021-06-29 19:29 ` [PATCH bpf-next 3/5] bpf: Add bpf_get_func_ip helper for tracing programs Jiri Olsa
2021-06-29 19:29 ` [PATCH bpf-next 4/5] bpf: Add bpf_get_func_ip helper for kprobe programs Jiri Olsa
2021-06-30 17:47   ` Yonghong Song
2021-06-30 23:58     ` Masami Hiramatsu
2021-07-01  1:45       ` Yonghong Song
2021-07-01  2:01         ` Masami Hiramatsu
2021-07-01  8:38       ` Jiri Olsa
2021-07-01 13:10         ` Masami Hiramatsu
2021-07-01  8:34     ` Jiri Olsa
2021-06-29 19:29 ` [PATCH bpf-next 5/5] selftests/bpf: Add test for bpf_get_func_ip helper Jiri Olsa
2021-07-01 17:22 ` [RFC bpf-next 0/5] bpf, x86: Add " Alan Maguire
2021-07-02  8:16   ` Jiri Olsa

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210629192945.1071862-1-jolsa@kernel.org \
    --to=jolsa@redhat.com \
    --cc=andriin@fb.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=john.fastabend@gmail.com \
    --cc=kafai@fb.com \
    --cc=kpsingh@chromium.org \
    --cc=mhiramat@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=yhs@fb.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).