From patchwork Wed Jul 1 06:45:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1320269 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@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=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=XLLs9SHE; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49xWvL5LFLz9sTT for ; Wed, 1 Jul 2020 16:45:34 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbgGAGpd (ORCPT ); Wed, 1 Jul 2020 02:45:33 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:16778 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727943AbgGAGpc (ORCPT ); Wed, 1 Jul 2020 02:45:32 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 0616duob014756 for ; Tue, 30 Jun 2020 23:45:31 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=6ahtOnzc8oMo0v0y+QQ+BQUGjdqT6t2aJ6YMPMb9+KE=; b=XLLs9SHEE4XD4tlpdo7mmzIzTXM8y/J0RbsFXW/eY+Lj1DileaXdTCKpff6iDR44GlCZ jzSe7eTBbkGgIkINTENDxDaKkGLGZc8W0FzXnLmRbznzDgpnYK9EyqAMXkrVmHUa8YRZ BeOT6lpnZzkYVnfpk4RPyC2XNMN+8ApY4n8= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0089730.ppops.net with ESMTP id 320anf2gur-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 30 Jun 2020 23:45:31 -0700 Received: from intmgw001.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 30 Jun 2020 23:45:30 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 1A2D22EC3A2B; Tue, 30 Jun 2020 23:45:29 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko , Anton Protopopov Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 0/3] Strip away modifiers from BPF skeleton global variables Date: Tue, 30 Jun 2020 23:45:22 -0700 Message-ID: <20200701064527.3158178-1-andriin@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-01_03:2020-07-01,2020-07-01 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0 mlxlogscore=690 lowpriorityscore=0 adultscore=0 mlxscore=0 priorityscore=1501 cotscore=-2147483648 phishscore=0 impostorscore=0 spamscore=0 bulkscore=0 malwarescore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007010047 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Fix bpftool logic of stripping away const/volatile modifiers for all global variables during BPF skeleton generation. See patch #1 for details on when existing logic breaks and why it's important. Support special .strip_mods=true mode in btf_dump. Add selftests validating that everything works as expected. Recent example of when this has caused problems can be found in [0]. [0] https://github.com/iovisor/bcc/pull/2994#issuecomment-650588533 Cc: Anton Protopopov Andrii Nakryiko (3): libbpf: support stripping modifiers for btf_dump selftests/bpf: add selftest validating btf_dump's mod-stripping output tools/bpftool: strip away modifiers from global variables tools/bpf/bpftool/gen.c | 13 ++--- tools/lib/bpf/btf.h | 6 +++ tools/lib/bpf/btf_dump.c | 18 +++++-- .../selftests/bpf/prog_tests/btf_dump.c | 5 +- .../selftests/bpf/prog_tests/skeleton.c | 6 +-- .../bpf/progs/btf_dump_test_case_strip_mods.c | 50 +++++++++++++++++++ .../selftests/bpf/progs/test_skeleton.c | 6 ++- 7 files changed, 84 insertions(+), 20 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/btf_dump_test_case_strip_mods.c