From mboxrd@z Thu Jan 1 00:00:00 1970 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 549FAC3F2D1 for ; Wed, 4 Mar 2020 15:21:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 287E721739 for ; Wed, 4 Mar 2020 15:21:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727930AbgCDPVg (ORCPT ); Wed, 4 Mar 2020 10:21:36 -0500 Received: from www62.your-server.de ([213.133.104.62]:37718 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727024AbgCDPVg (ORCPT ); Wed, 4 Mar 2020 10:21:36 -0500 Received: from sslproxy06.your-server.de ([78.46.172.3]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1j9Vq1-0006ZB-Sb; Wed, 04 Mar 2020 16:21:34 +0100 Received: from [2001:1620:665:0:5795:5b0a:e5d5:5944] (helo=linux.fritz.box) by sslproxy06.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j9Vq1-000ReH-JH; Wed, 04 Mar 2020 16:21:33 +0100 Subject: Re: [PATCH v3 bpf-next 0/3] Convert BPF UAPI constants into enum values To: Andrii Nakryiko , bpf@vger.kernel.org, netdev@vger.kernel.org, ast@fb.com Cc: andrii.nakryiko@gmail.com, kernel-team@fb.com References: <20200303003233.3496043-1-andriin@fb.com> From: Daniel Borkmann Message-ID: <47bbaa27-a112-b4a5-6251-d8aad31937a5@iogearbox.net> Date: Wed, 4 Mar 2020 16:21:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20200303003233.3496043-1-andriin@fb.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.2/25741/Wed Mar 4 15:15:26 2020) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 3/3/20 1:32 AM, Andrii Nakryiko wrote: > Convert BPF-related UAPI constants, currently defined as #define macro, into > anonymous enums. This has no difference in terms of usage of such constants in > C code (they are still could be used in all the compile-time contexts that > `#define`s can), but they are recorded as part of DWARF type info, and > subsequently get recorded as part of kernel's BTF type info. This allows those > constants to be emitted as part of vmlinux.h auto-generated header file and be > used from BPF programs. Which is especially convenient for all kinds of BPF > helper flags and makes CO-RE BPF programs nicer to write. > > libbpf's btf_dump logic currently assumes enum values are signed 32-bit > values, but that doesn't match a typical case, so switch it to emit unsigned > values. Once BTF encoding of BTF_KIND_ENUM is extended to capture signedness > properly, this will be made more flexible. > > As an immediate validation of the approach, runqslower's copy of > BPF_F_CURRENT_CPU #define is dropped in favor of its enum variant from > vmlinux.h. > > v2->v3: > - convert only constants usable from BPF programs (BPF helper flags, map > create flags, etc) (Alexei); > > v1->v2: > - fix up btf_dump test to use max 32-bit unsigned value instead of negative one. > > > Andrii Nakryiko (3): > bpf: switch BPF UAPI #define constants used from BPF program side to > enums > libbpf: assume unsigned values for BTF_KIND_ENUM > tools/runqslower: drop copy/pasted BPF_F_CURRENT_CPU definiton > > include/uapi/linux/bpf.h | 175 ++++++++++------- > tools/bpf/runqslower/runqslower.bpf.c | 3 - > tools/include/uapi/linux/bpf.h | 177 +++++++++++------- > tools/lib/bpf/btf_dump.c | 8 +- > .../bpf/progs/btf_dump_test_case_syntax.c | 2 +- > 5 files changed, 224 insertions(+), 141 deletions(-) > Applied, thanks!