From patchwork Tue May 25 03:59:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 12277765 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B37BC4707F for ; Tue, 25 May 2021 03:59:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF07B6141F for ; Tue, 25 May 2021 03:59:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230389AbhEYEBW convert rfc822-to-8bit (ORCPT ); Tue, 25 May 2021 00:01:22 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:48050 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230269AbhEYEBU (ORCPT ); Tue, 25 May 2021 00:01:20 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14P3jB08030678 for ; Mon, 24 May 2021 20:59:51 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 38rpf9gw62-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 24 May 2021 20:59:51 -0700 Received: from intmgw002.25.frc3.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 24 May 2021 20:59:50 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id D9FEB2EDBE05; Mon, 24 May 2021 20:59:40 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , , John Fastabend , =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?q?=C3=B8rgensen?= Subject: [PATCH v2 bpf-next 1/5] libbpf: add libbpf_set_strict_mode() API to turn on libbpf 1.0 behaviors Date: Mon, 24 May 2021 20:59:31 -0700 Message-ID: <20210525035935.1461796-2-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210525035935.1461796-1-andrii@kernel.org> References: <20210525035935.1461796-1-andrii@kernel.org> X-FB-Internal: Safe X-Proofpoint-GUID: BiO0QKRRuc9xKXBX2neJjX25nit6qdmw X-Proofpoint-ORIG-GUID: BiO0QKRRuc9xKXBX2neJjX25nit6qdmw X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-05-25_02:2021-05-24,2021-05-25 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0 adultscore=0 malwarescore=0 mlxlogscore=981 priorityscore=1501 lowpriorityscore=0 clxscore=1015 bulkscore=0 impostorscore=0 mlxscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105250024 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add libbpf_set_strict_mode() API that allows application to simulate libbpf 1.0 breaking changes before libbpf 1.0 is released. This will help users migrate gradually and with confidence. For now only ALL or NONE options are available, subsequent patches will add more flags. This patch is preliminary for selftests/bpf changes. Acked-by: John Fastabend Acked-by: Toke Høiland-Jørgensen Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/Makefile | 1 + tools/lib/bpf/libbpf.c | 17 +++++++++++++ tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 5 ++++ tools/lib/bpf/libbpf_legacy.h | 47 +++++++++++++++++++++++++++++++++++ 5 files changed, 71 insertions(+) create mode 100644 tools/lib/bpf/libbpf_legacy.h diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index e43e1896cb4b..15420303cf06 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -229,6 +229,7 @@ install_headers: $(BPF_HELPER_DEFS) $(call do_install,libbpf.h,$(prefix)/include/bpf,644); \ $(call do_install,btf.h,$(prefix)/include/bpf,644); \ $(call do_install,libbpf_common.h,$(prefix)/include/bpf,644); \ + $(call do_install,libbpf_legacy.h,$(prefix)/include/bpf,644); \ $(call do_install,xsk.h,$(prefix)/include/bpf,644); \ $(call do_install,bpf_helpers.h,$(prefix)/include/bpf,644); \ $(call do_install,$(BPF_HELPER_DEFS),$(prefix)/include/bpf,644); \ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b396e45b17ea..1425d7ed0f2f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -151,6 +151,23 @@ static inline __u64 ptr_to_u64(const void *ptr) return (__u64) (unsigned long) ptr; } +/* this goes away in libbpf 1.0 */ +enum libbpf_strict_mode libbpf_mode = LIBBPF_STRICT_NONE; + +int libbpf_set_strict_mode(enum libbpf_strict_mode mode) +{ + /* __LIBBPF_STRICT_LAST is the last power-of-2 value used + 1, so to + * get all possible values we compensate last +1, and then (2*x - 1) + * to get the bit mask + */ + if (mode != LIBBPF_STRICT_ALL + && (mode & ~((__LIBBPF_STRICT_LAST - 1) * 2 - 1))) + return errno = EINVAL, -EINVAL; + + libbpf_mode = mode; + return 0; +} + enum kern_feature_id { /* v4.14: kernel support for program & map names. */ FEAT_PROG_NAME, diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index d98523558f39..6e61342ba56c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -18,6 +18,7 @@ #include #include "libbpf_common.h" +#include "libbpf_legacy.h" #ifdef __cplusplus extern "C" { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 0229e01e8ccc..bbe99b1db1a9 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -370,3 +370,8 @@ LIBBPF_0.4.0 { bpf_tc_hook_destroy; bpf_tc_query; } LIBBPF_0.3.0; + +LIBBPF_0.5.0 { + global: + libbpf_set_strict_mode; +} LIBBPF_0.4.0; diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h new file mode 100644 index 000000000000..7482cfe22ab2 --- /dev/null +++ b/tools/lib/bpf/libbpf_legacy.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ + +/* + * Libbpf legacy APIs (either discouraged or deprecated, as mentioned in [0]) + * + * [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY + * + * Copyright (C) 2021 Facebook + */ +#ifndef __LIBBPF_LEGACY_BPF_H +#define __LIBBPF_LEGACY_BPF_H + +#include +#include +#include +#include +#include "libbpf_common.h" + +#ifdef __cplusplus +extern "C" { +#endif + +enum libbpf_strict_mode { + /* Turn on all supported strict features of libbpf to simulate libbpf + * v1.0 behavior. + * This will be the default behavior in libbpf v1.0. + */ + LIBBPF_STRICT_ALL = 0xffffffff, + + /* + * Disable any libbpf 1.0 behaviors. This is the default before libbpf + * v1.0. It won't be supported anymore in v1.0, please update your + * code so that it handles LIBBPF_STRICT_ALL mode before libbpf v1.0. + */ + LIBBPF_STRICT_NONE = 0x00, + + __LIBBPF_STRICT_LAST, +}; + +LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode); + + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __LIBBPF_LEGACY_BPF_H */