From patchwork Thu Sep 10 13:09:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 1362057 Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=fJDny9+B; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BnXN04GLZz9sVC for ; Fri, 11 Sep 2020 07:39:28 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728111AbgIJVjZ (ORCPT ); Thu, 10 Sep 2020 17:39:25 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59929 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730532AbgIJNKq (ORCPT ); Thu, 10 Sep 2020 09:10:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599743396; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=umfS176nchuA3M5Cp4HyehVZfx3cPoV3pIXcITPig4A=; b=fJDny9+Byu55s5XpbB5BLsE1GsPPAgMkGq22Za2tv1pyBLA/R6xZsEwhLrKuNCXMS5aGHf 39oz9ekri7S9wORKwhLGnErLfVT9Z7pPBefwCaxiZ0dTT5GeqLN+TaryNkQT5FLZE1ubql Tntd55gItWq/vwvyl/2fmDc+2rjxKFk= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-573-YQPL09DKPH-JQ8rIE_a1ug-1; Thu, 10 Sep 2020 09:09:53 -0400 X-MC-Unique: YQPL09DKPH-JQ8rIE_a1ug-1 Received: by mail-wr1-f72.google.com with SMTP id l15so2238964wro.10 for ; Thu, 10 Sep 2020 06:09:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:user-agent :mime-version:content-transfer-encoding; bh=umfS176nchuA3M5Cp4HyehVZfx3cPoV3pIXcITPig4A=; b=IBQiT9BbNBrpWlw87Cq5BbesUAuTqeSdomNJKw700kesauJLtRdpubHurA7clmFrP5 ZaP/hJZBEO4wEn744Op7HKj6Lh2YqC0WQpqEFHkL8cIQ18wmDeoQ/3x1KrvOY55Fciw3 euswe6L0nJEQRRoMyCvaMly3AjROEtHdUlWLhf2wlH8D7Z3f1ZZLcRh0UHUjALoJHtBP EHwyJDpi7UfHpln4YzHJd8oUtAcF/CbClslm3CUlt5mrmPXyj7jfMkSDvTPehc+Ybf9d hmaSBj4rObB8nrfBYxp8zBxz5xtZorMAbCB9qlNTnJOSi1iFyECmAAGOvtL4/qpyKgk8 w+Kg== X-Gm-Message-State: AOAM5309e+w57955nInHMw0dR0Byw3Nbg7VCPlm/xLq0tsR7uV1fBPuz mMqMpmwzfdkbRNnKqwdSgui/w1ucB37bX8dvT1FZuZ8MO/vuuWdK8OjH0/nAYbi5hg00M6WqIbu BfGBKnY5mBNV7 X-Received: by 2002:a1c:3bd7:: with SMTP id i206mr10415wma.162.1599743391940; Thu, 10 Sep 2020 06:09:51 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxNfbP6KU9EsTxXYCrEhqUa8divHNQ8kxj/t4XAG4PPuM1wcZVf3Y3H9oMpETHBfaqLmYON+w== X-Received: by 2002:a1c:3bd7:: with SMTP id i206mr10392wma.162.1599743391622; Thu, 10 Sep 2020 06:09:51 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id t6sm10030836wre.30.2020.09.10.06.09.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Sep 2020 06:09:51 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 935201829D4; Thu, 10 Sep 2020 15:09:49 +0200 (CEST) Subject: [PATCH bpf-next v3 0/9] bpf: Support multi-attach for freplace programs From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , Jiri Olsa , Eelco Chaudron , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org Date: Thu, 10 Sep 2020 15:09:49 +0200 Message-ID: <159974338947.129227.5610774877906475683.stgit@toke.dk> User-Agent: StGit/0.23 MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This series adds support attaching freplace BPF programs to multiple targets. This is needed to support incremental attachment of multiple XDP programs using the libxdp dispatcher model. The first three patches are refactoring patches: The first one is a trivial change to the logging in the verifier, split out to make the subsequent refactor easier to read. Patch 2 refactors check_attach_btf_id() so that the checks on program and target compatibility can be reused when attaching to a secondary location. Patch 3 changes prog_aux->linked_prog to be an embedded bpf_tracing_link that is initialised at program load time. This nicely encapsulates both the trampoline and the prog reference, and moves the release of these references into bpf_link teardown. At raw_tracepoint_open() time (i.e., when the link is attached), it will be removed from the extension prog, and primed as a regular bpf_link. Based on these refactorings, it becomes pretty straight-forward to support multiple-attach for freplace programs (patch 4). This is simply a matter of creating a second bpf_tracing_link if a target is supplied to raw_tracepoint_open(). Patch 5 is a port of Jiri Olsa's patch to support fentry/fexit on freplace programs. His approach of getting the target type from the target program reference no longer works after we've gotten rid of linked_prog (because the bpf_tracing_link reference disappears on attach). Instead, we used the saved reference to the target prog type that is also used to verify compatibility on secondary freplace attachment. Patches 6-7 are tools and libbpf updates, and patches 8-9 are selftests, the first one for the multi-freplace functionality itself, and the second one is Jiri's previous selftest for the fentry-to-freplace fix. With this series, libxdp and xdp-tools can successfully attach multiple programs one at a time. To play with this, use the 'freplace-multi-attach' branch of xdp-tools: $ git clone --recurse-submodules --branch freplace-multi-attach https://github.com/xdp-project/xdp-tools $ cd xdp-tools $ make $ sudo ./xdp-loader/xdp-loader load veth0 lib/testing/xdp_drop.o $ sudo ./xdp-loader/xdp-loader load veth0 lib/testing/xdp_pass.o $ sudo ./xdp-loader/xdp-loader status The series is also available here: https://git.kernel.org/pub/scm/linux/kernel/git/toke/linux.git/log/?h=bpf-freplace-multi-attach-alt-03 Changelog: v3: - Get rid of prog_aux->linked_prog entirely in favour of a bpf_tracing_link - Incorporate Jiri's fix for attaching fentry to freplace programs v2: - Drop the log arguments from bpf_raw_tracepoint_open - Fix kbot errors - Rebase to latest bpf-next --- Jiri Olsa (1): selftests/bpf: Adding test for arg dereference in extension trace Toke Høiland-Jørgensen (8): bpf: change logging calls from verbose() to bpf_log() and use log pointer bpf: verifier: refactor check_attach_btf_id() bpf: wrap prog->aux->linked_prog in a bpf_tracing_link bpf: support attaching freplace programs to multiple attach points bpf: Fix context type resolving for extension programs tools: add new members to bpf_attr.raw_tracepoint in bpf.h libbpf: add support for supplying target to bpf_raw_tracepoint_open() selftests: add test for multiple attachments of freplace program include/linux/bpf.h | 33 ++- include/linux/bpf_verifier.h | 9 + include/uapi/linux/bpf.h | 6 +- kernel/bpf/btf.c | 22 +- kernel/bpf/core.c | 5 +- kernel/bpf/syscall.c | 161 +++++++++-- kernel/bpf/trampoline.c | 34 ++- kernel/bpf/verifier.c | 251 ++++++++++-------- tools/include/uapi/linux/bpf.h | 6 +- tools/lib/bpf/bpf.c | 13 +- tools/lib/bpf/bpf.h | 9 + tools/lib/bpf/libbpf.map | 1 + .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 171 +++++++++--- .../selftests/bpf/prog_tests/trace_ext.c | 93 +++++++ .../bpf/progs/freplace_get_constant.c | 15 ++ .../selftests/bpf/progs/test_trace_ext.c | 18 ++ .../bpf/progs/test_trace_ext_tracing.c | 25 ++ 17 files changed, 683 insertions(+), 189 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/trace_ext.c create mode 100644 tools/testing/selftests/bpf/progs/freplace_get_constant.c create mode 100644 tools/testing/selftests/bpf/progs/test_trace_ext.c create mode 100644 tools/testing/selftests/bpf/progs/test_trace_ext_tracing.c