From patchwork Sat Aug 1 17:03:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1339812 X-Patchwork-Delegate: bpf@iogearbox.net 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=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BJr8v10s4z9s1x for ; Sun, 2 Aug 2020 03:04:15 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728024AbgHAREO convert rfc822-to-8bit (ORCPT ); Sat, 1 Aug 2020 13:04:14 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:34338 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728020AbgHAREO (ORCPT ); Sat, 1 Aug 2020 13:04:14 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-332-YkLXQObwPdKdBFeOrHc6Qg-1; Sat, 01 Aug 2020 13:04:08 -0400 X-MC-Unique: YkLXQObwPdKdBFeOrHc6Qg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A49E418839E0; Sat, 1 Aug 2020 17:04:05 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.39]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7E4C67C10C; Sat, 1 Aug 2020 17:04:02 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , Martin KaFai Lau , David Miller , John Fastabend , Wenbo Zhang , KP Singh , Brendan Gregg , Florent Revest , Al Viro Subject: [PATCH v9 bpf-next 11/14] bpf: Update .BTF_ids section in btf.rst with sets info Date: Sat, 1 Aug 2020 19:03:19 +0200 Message-Id: <20200801170322.75218-12-jolsa@kernel.org> In-Reply-To: <20200801170322.75218-1-jolsa@kernel.org> References: <20200801170322.75218-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Updating btf.rst doc with info about BTF_SET_START/END macros. Signed-off-by: Jiri Olsa --- Documentation/bpf/btf.rst | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index b5361b8621c9..44dc789de2b4 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -724,6 +724,31 @@ want to define unused entry in BTF_ID_LIST, like:: BTF_ID_UNUSED BTF_ID(struct, task_struct) +The ``BTF_SET_START/END`` macros pair defines sorted list of BTF ID values +and their count, with following syntax:: + + BTF_SET_START(set) + BTF_ID(type1, name1) + BTF_ID(type2, name2) + BTF_SET_END(set) + +resulting in following layout in .BTF_ids section:: + + __BTF_ID__set__set: + .zero 4 + __BTF_ID__type1__name1__3: + .zero 4 + __BTF_ID__type2__name2__4: + .zero 4 + +The ``struct btf_id_set set;`` variable is defined to access the list. + +The ``typeX`` name can be one of following:: + + struct, union, typedef, func + +and is used as a filter when resolving the BTF ID value. + All the BTF ID lists and sets are compiled in the .BTF_ids section and resolved during the linking phase of kernel build by ``resolve_btfids`` tool.