From patchwork Thu Jun 13 04:47:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 1115396 Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45PqSV3sxjz9s5c for ; Fri, 14 Jun 2019 02:48:42 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730221AbfFMQsk convert rfc822-to-8bit (ORCPT ); Thu, 13 Jun 2019 12:48:40 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:43298 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730214AbfFMErm (ORCPT ); Thu, 13 Jun 2019 00:47:42 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5D4h12u001517 for ; Wed, 12 Jun 2019 21:47:40 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2t3cu6ge22-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 12 Jun 2019 21:47:40 -0700 Received: from mx-out.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 12 Jun 2019 21:47:39 -0700 Received: by devbig007.ftw2.facebook.com (Postfix, from userid 572438) id A067B760C2A; Wed, 12 Jun 2019 21:47:38 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Alexei Starovoitov Smtp-Origin-Hostname: devbig007.ftw2.facebook.com To: CC: , , , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 0/9] bpf: bounded loops and other features Date: Wed, 12 Jun 2019 21:47:29 -0700 Message-ID: <20190613044738.3858896-1-ast@kernel.org> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-13_02:, , signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=815 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906130037 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hi, this patch set introduces verifier support for bounded loops and adds several other improvements. Ideally they would be introduced one at a time, but to support bounded loop the verifier needs to 'step back' in the patch 1. That patch introduces tracking of spill/fill of constants through the stack. Though it's a useful feature it hurts cilium tests. Patch 3 introduces another feature by extending is_branch_taken logic to 'if rX op rY' conditions. This feature is also necessary to support bounded loops. Then patch 4 adds support for the loops while adding key heuristics with jmp_processed. Introduction of parentage chain of verifier states in patch 4 allows patch 9 to add backtracking of precise scalar registers which finally resolves degradation from patch 1. The end result is much faster verifier for existing programs and new support for loops. See patch 8 for many kinds of loops that are now validated. Patch 9 is the most tricky one and could be rewritten with a different algorithm in the future. Alexei Starovoitov (9): bpf: track spill/fill of constants selftests/bpf: fix tests due to const spill/fill bpf: extend is_branch_taken to registers bpf: introduce bounded loops bpf: fix callees pruning callers selftests/bpf: fix tests selftests/bpf: add basic verifier tests for loops selftests/bpf: add realistic loop tests bpf: precise scalar_value tracking include/linux/bpf_verifier.h | 69 +- kernel/bpf/verifier.c | 688 ++++++++++++++++-- .../bpf/prog_tests/bpf_verif_scale.c | 67 +- tools/testing/selftests/bpf/progs/loop1.c | 28 + tools/testing/selftests/bpf/progs/loop2.c | 28 + tools/testing/selftests/bpf/progs/loop3.c | 22 + tools/testing/selftests/bpf/progs/pyperf.h | 6 +- tools/testing/selftests/bpf/progs/pyperf600.c | 9 + .../selftests/bpf/progs/pyperf600_nounroll.c | 8 + .../testing/selftests/bpf/progs/strobemeta.c | 10 + .../testing/selftests/bpf/progs/strobemeta.h | 528 ++++++++++++++ .../bpf/progs/strobemeta_nounroll1.c | 9 + .../bpf/progs/strobemeta_nounroll2.c | 9 + .../selftests/bpf/progs/test_seg6_loop.c | 261 +++++++ .../selftests/bpf/progs/test_sysctl_loop1.c | 68 ++ .../selftests/bpf/progs/test_sysctl_loop2.c | 69 ++ .../selftests/bpf/progs/test_xdp_loop.c | 231 ++++++ tools/testing/selftests/bpf/test_verifier.c | 11 +- tools/testing/selftests/bpf/verifier/calls.c | 22 +- tools/testing/selftests/bpf/verifier/cfg.c | 11 +- .../bpf/verifier/direct_packet_access.c | 3 +- .../bpf/verifier/helper_access_var_len.c | 28 +- tools/testing/selftests/bpf/verifier/loops1.c | 161 ++++ 23 files changed, 2258 insertions(+), 88 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/loop1.c create mode 100644 tools/testing/selftests/bpf/progs/loop2.c create mode 100644 tools/testing/selftests/bpf/progs/loop3.c create mode 100644 tools/testing/selftests/bpf/progs/pyperf600.c create mode 100644 tools/testing/selftests/bpf/progs/pyperf600_nounroll.c create mode 100644 tools/testing/selftests/bpf/progs/strobemeta.c create mode 100644 tools/testing/selftests/bpf/progs/strobemeta.h create mode 100644 tools/testing/selftests/bpf/progs/strobemeta_nounroll1.c create mode 100644 tools/testing/selftests/bpf/progs/strobemeta_nounroll2.c create mode 100644 tools/testing/selftests/bpf/progs/test_seg6_loop.c create mode 100644 tools/testing/selftests/bpf/progs/test_sysctl_loop1.c create mode 100644 tools/testing/selftests/bpf/progs/test_sysctl_loop2.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_loop.c create mode 100644 tools/testing/selftests/bpf/verifier/loops1.c