From mboxrd@z Thu Jan 1 00:00:00 1970 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 15BE241A88 for ; Wed, 20 Sep 2023 21:31:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A70FC433C7; Wed, 20 Sep 2023 21:31:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695245510; bh=F/lk7KBzky7ybhGLC7FUC31ndjpQ/6UfQh3yYpW+cgM=; h=From:To:Cc:Subject:Date:From; b=bpACIvLsbtWsj7lW/Lyts2Hl2NQ09NLir9H+OMg4nN0owOhsjP6dFsfsn3BKcLyH5 y8r784r2g/BHVSUa5tEnP1Xn+aNuWi9KXxT3dgC5IMrBwIU7A1SxYbFlLM8j0rje47 QHKosCyPnrD3D6lGCi8QuODp9WQYOe5uxFb5wpvbpHvg0luzdl+/XiOT3AwaOVSRTE +P4yU1SQpHaJmmVc0Mdl+J15jFKv9t9aFz6iYZqnEhs0JPAJxhyQeVwq2486cq1bdk F6zAPkoBcR9VP7iOJqGpusIHKD0c1ilsqM0z5+i7hJ495zIXHJmvUCz9pLpvp+pGmD mdFR33Ge73QhQ== 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: [PATCHv3 bpf-next 0/9] bpf: Add missed stats for kprobes Date: Wed, 20 Sep 2023 23:31:36 +0200 Message-ID: <20230920213145.1941596-1-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 Content-Transfer-Encoding: 8bit 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 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. v3 changes: - added acks [Song] - make test_missed not serial [Andrii] Also available at: https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/missed_stats thanks, jirka --- Jiri Olsa (9): 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 bpftool: Display missed count for kprobe_multi link bpftool: Display missed count for kprobe perf link selftests/bpf: Add test for missed counts of perf event link kprobe selftests/bpf: Add test for recursion counts of perf event link kprobe selftests/bpf: Add test for recursion counts of perf event link tracepoint include/linux/bpf.h | 16 +++++++++++ include/linux/trace_events.h | 6 ++-- include/uapi/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 14 ++++++---- kernel/trace/bpf_trace.c | 10 +++++-- kernel/trace/trace_kprobe.c | 14 ++++++++-- tools/bpf/bpftool/link.c | 6 ++++ 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 | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_kprobe.c | 30 ++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c | 48 ++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_tp_recursion.c | 41 +++++++++++++++++++++++++++ 15 files changed, 322 insertions(+), 13 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 create mode 100644 tools/testing/selftests/bpf/progs/missed_tp_recursion.c