From patchwork Fri Aug 7 09:45:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 262661 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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 3ED70C433DF for ; Fri, 7 Aug 2020 09:47:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 037FA221E5 for ; Fri, 7 Aug 2020 09:47:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596793620; bh=TElq2iDLIWPnpZTsVRK7uTiZ+vQTXYN26Q6K19aA+1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=z9E/gHxNi9NMBU7ZHVEwSzfj8OOUiEIGF/gV74RNr3pzma8wz5OzELlR1qVJEoJj5 jwAIooZ3eG4W4A4UXSplrZNcp2Jkmsh8PyhjvWqXi6fWcz8D+BLu8ZzUyJkas33ZzF XEtza+FryMohszTCC1JJJQIP7cJOX7ZqgJnr4VG4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728183AbgHGJq7 convert rfc822-to-8bit (ORCPT ); Fri, 7 Aug 2020 05:46:59 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:37871 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727820AbgHGJq6 (ORCPT ); Fri, 7 Aug 2020 05:46:58 -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-300-dp9Td0yUN-CSRuKWcwB76w-1; Fri, 07 Aug 2020 05:46:51 -0400 X-MC-Unique: dp9Td0yUN-CSRuKWcwB76w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 74C13101C8A5; Fri, 7 Aug 2020 09:46:49 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.194.188]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1714D6932A; Fri, 7 Aug 2020 09:46:45 +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 v10 bpf-next 11/14] bpf: Update .BTF_ids section in btf.rst with sets info Date: Fri, 7 Aug 2020 11:45:56 +0200 Message-Id: <20200807094559.571260-12-jolsa@kernel.org> In-Reply-To: <20200807094559.571260-1-jolsa@kernel.org> References: <20200807094559.571260-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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.