From patchwork Mon Aug 8 14:06:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12938822 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C438BC00140 for ; Mon, 8 Aug 2022 14:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237709AbiHHOGi (ORCPT ); Mon, 8 Aug 2022 10:06:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233230AbiHHOGi (ORCPT ); Mon, 8 Aug 2022 10:06:38 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63E80D73 for ; Mon, 8 Aug 2022 07:06:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id CEB76CE1104 for ; Mon, 8 Aug 2022 14:06:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75D3DC433D6; Mon, 8 Aug 2022 14:06:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659967593; bh=Jyjb2iG67Yw0o4r6uFbUuzn6Wo+JpgR0EElmyAz04xw=; h=From:To:Cc:Subject:Date:From; b=Js0losBOJTOS1bBK5AQTNsY8OjBEinXKOAfBojiVu0mldpsxBpPRPtkz0MZAFn6hy ic+6CCIIjjFoZW9Hj8PB0DbuedxA+LC1raf4v0sfR20SmsZ36qAYDDajSJvLT8Ifqu 9WgdJCvdwXOvpD4eg8PXnsiN2oweSNQ22NZQQ+HXHomycVwar/7bDcqUbaMJtX1t3b z8Bw/P4MjQIzeoa3tTafXcfKmuQN5YTBtO13AwMPzwHXau22PHMYJ9yFMtXSGZ5mHU cGdrcQROfS8ze9rQs1wP26v+ltPzeqeGC26usiEU7YSNlcA+zzVF4VYMSZD2wDTRzt eF4q+6vhEt4eQ== 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 Subject: [RFC PATCH bpf-next 00/17] bpf: Add tracing multi link Date: Mon, 8 Aug 2022 16:06:09 +0200 Message-Id: <20220808140626.422731-1-jolsa@kernel.org> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net X-Patchwork-State: RFC hi, this is another attempt to add batch attachment support for trampolines. The patchset adds support to create 'multi' trampoline that is attached to set of functions represented by BTF IDs. Previous post [0] tried to implement multi trampolines overlapping, but it turned out too complex, so I got back to simpler rules: (we can discuss possible overlapping changes on top this change) - multi trampoline can attach on top of existing single trampolines, which creates 2 types of function IDs: 1) single-IDs - functions that are attached within existing single trampolines 2) multi-IDs - functions that were 'not used' and are now taken by new 'multi' trampoline - we allow overlapping of 2 'multi' trampolines if they are attached to same IDs - we do now allow any other overlapping of 2 'multi' trampolines - any new 'single' trampoline cannot attach to existing multi-IDs IDs Maybe better explained on following example: - you want to attach program P to functions A,B,C,D,E,F via bpf_trampoline_multi_attach - D,E,F already have standard trampoline attached - the bpf_trampoline_multi_attach will create new 'multi' trampoline which spans over A,B,C functions and attach program P to single trampolines D,E,F - another program can be attached to A,B,C,D,E,F multi trampoline - A,B,C functions are now 'not attachable' by any trampoline until the above 'multi' trampoline is released - D,E,F functions are still attachable by any new trampoline Also now that we have trampoline helpers for function arguments, we can just simply use function declaration with maximum arguments for any multi trampoline or related single trampoline. There are couple of things missing in this post (that I know of), which I'll add when we agree that this is the way to go: - attaching by functions names - cookies support - find out better way of locking trampolines in bpf_trampoline_multi_attach and bpf_trampoline_multi_detach - bpf_tramp_update_set logic of calling multiple times register_ftrace_direct_multi function can be replaced by calling single update ftrace function that I have prototype for, but I will send it out separately to ftrace for review - arm trampoline code changes (won't compile now) - tests for error paths thanks, jirka [0] - https://lore.kernel.org/bpf/20211118112455.475349-1-jolsa@kernel.org/ --- Jiri Olsa (17): bpf: Link shimlink directly in trampoline bpf: Replace bpf_tramp_links with bpf_tramp_progs bpf: Store trampoline progs in arrays bpf: Add multi tracing attach types bpf: Add bpf_tramp_id object bpf: Pass image struct to reg/unreg/modify fentry functions bpf: Add support to postpone trampoline update bpf: Factor bpf_trampoline_lookup function bpf: Factor bpf_trampoline_put function bpf: Add support to attach program to multiple trampolines bpf: Add support to create tracing multi link libbpf: Add btf__find_by_glob_kind function libbpf: Add support to create tracing multi link selftests/bpf: Add fentry tracing multi func test selftests/bpf: Add fexit tracing multi func test selftests/bpf: Add fentry/fexit tracing multi func test selftests/bpf: Add mixed tracing multi func test arch/x86/net/bpf_jit_comp.c | 38 ++--- include/linux/bpf.h | 98 ++++++++---- include/linux/trace_events.h | 5 + include/uapi/linux/bpf.h | 7 + kernel/bpf/bpf_struct_ops.c | 30 ++-- kernel/bpf/syscall.c | 56 +++++-- kernel/bpf/trampoline.c | 723 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------- kernel/bpf/verifier.c | 8 +- kernel/trace/bpf_trace.c | 240 +++++++++++++++++++++++++++++ net/bpf/bpf_dummy_struct_ops.c | 16 +- net/bpf/test_run.c | 2 + tools/include/uapi/linux/bpf.h | 7 + tools/lib/bpf/bpf.c | 7 + tools/lib/bpf/bpf.h | 4 + tools/lib/bpf/btf.c | 41 +++++ tools/lib/bpf/btf.h | 3 + tools/lib/bpf/libbpf.c | 91 ++++++++++- tools/lib/bpf/libbpf.h | 14 ++ tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_internal.h | 1 + tools/testing/selftests/bpf/Makefile | 9 +- tools/testing/selftests/bpf/prog_tests/tracing_multi.c | 158 ++++++++++++++++++++ tools/testing/selftests/bpf/progs/tracing_multi_check.c | 158 ++++++++++++++++++++ tools/testing/selftests/bpf/progs/tracing_multi_fentry.c | 17 +++ tools/testing/selftests/bpf/progs/tracing_multi_fentry_fexit.c | 28 ++++ tools/testing/selftests/bpf/progs/tracing_multi_fexit.c | 20 +++ tools/testing/selftests/bpf/progs/tracing_multi_mixed.c | 43 ++++++ 27 files changed, 1624 insertions(+), 201 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/tracing_multi.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_check.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_fentry.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_fentry_fexit.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_fexit.c create mode 100644 tools/testing/selftests/bpf/progs/tracing_multi_mixed.c