From patchwork Mon Aug 28 07:55:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13367637 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 256BEEC2 for ; Mon, 28 Aug 2023 07:55:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 940C4C433C7; Mon, 28 Aug 2023 07:55:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693209342; bh=+KomhCliNwatsQyfrHWximXXsPIfKu8TgSw0Q3b/dOE=; h=From:To:Cc:Subject:Date:From; b=qC4guuZIgT97GAiMVBgvu5Tj8x9/8GGYIoclDoqXjGUF/UCsR2AsdgxTj3UWfK1Wf PhT2VfbuLrZ15qj49DGldS3UM2VMBbjWYhV6AfV0WZaO8NlsXxn4/olWTHCV0QUhVK Dply7jW4oP9puiQZiGVugl5Qnky9/GYG12okrMJOUQFhN0ZFJEDH0kCTA7wPcgaAoT zCzv6ZxZbMKtpgnnp1EZ0sCPOatxv6fnMOaxBj06nLm/C9qY4Nq+Sp2qmjuDWrWfoK O/jDtvzaQE3gXWuiD+A5A3FiOK63z951wSyLDw0sKyHOJJVWVQx9HqPR/a/hqjeIzZ ZOosfE9jqPf8g== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Hou Tao , Daniel Xu Subject: [PATCH bpf-next 00/12] bpf: Add missed stats for kprobes Date: Mon, 28 Aug 2023 09:55:25 +0200 Message-ID: <20230828075537.194192-1-jolsa@kernel.org> X-Mailer: git-send-email 2.41.0 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net hi, at the moment we can't retrieve the number of missed kprobe executions and subsequent execution of BPF programs. This patchset adds: - counting of missed execution on attach layer for: . kprobes attached through perf link (kprobe/ftrace) . kprobes attached through kprobe.multi link (fprobe) - counting of recursion_misses for BPF kprobe programs - counting runtime stats (kernel.bpf_stats_enabled=1) for BPF programs executed through bpf_prog_run_array - kprobes, perf events, trace syscall probes It's still technically possible to create kprobe without perf link (using SET_BPF perf ioctl) in which case we don't have a way to retrieve the kprobe's 'missed' count. However both libbpf and cilium/ebpf libraries use perf link if it's available, and for old kernels without perf link support we can use BPF program to retrieve the kprobe missed count. Also available at: https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/missed_stats thanks, jirka --- Jiri Olsa (12): bpf: Move update_prog_stats to syscall object bpf: Move bpf_prog_start_time to linux/filter.h bpf: Count stats for kprobe_multi programs bpf: Add missed value to kprobe_multi link info bpf: Add missed value to kprobe perf link info bpf: Count missed stats in trace_call_bpf bpf: Move bpf_prog_run_array down in the header file bpf: Count run stats in bpf_prog_run_array bpftool: Display missed count for kprobe_multi link bpftool: Display missed count for kprobe perf link selftests/bpf: Add test missed counts of perf event link kprobe elftests/bpf: Add test recursion stats of perf event link kprobe include/linux/bpf.h | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------- include/linux/trace_events.h | 6 ++++-- include/uapi/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 36 +++++++++++++++++++++++++------ kernel/bpf/trampoline.c | 45 +++++---------------------------------- kernel/trace/bpf_trace.c | 17 ++++++++++++--- kernel/trace/trace_kprobe.c | 5 ++++- tools/bpf/bpftool/link.c | 8 ++++++- tools/include/uapi/linux/bpf.h | 2 ++ tools/testing/selftests/bpf/DENYLIST.aarch64 | 1 + tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 5 +++++ tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h | 2 ++ tools/testing/selftests/bpf/prog_tests/missed.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_kprobe.c | 30 ++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c | 48 +++++++++++++++++++++++++++++++++++++++++ 15 files changed, 327 insertions(+), 83 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/missed.c create mode 100644 tools/testing/selftests/bpf/progs/missed_kprobe.c create mode 100644 tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c