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=-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 7C7C0C433FB for ; Fri, 10 Jul 2020 19:38:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50FCB20748 for ; Fri, 10 Jul 2020 19:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594409914; bh=pvgj2bUwF2BGOpBeaHA8imWS0X9zBR6eNv4lbiJiUV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f1u8AJ+KTbs04gpM0Zyk+RAp+Y9iUiFOLArrqkhum+54tYjVQvOic2XI0vkLwdgn5 6zlWvE8UV5Y3/Z/JqmaNyqzyQdp4YbW7KuShs7Eq8qsVdy4ZidVC7fS9DzcsQUgr30 mf7QV39iUB9ZwtjQx9pkNg+1Us75Ckd1VQ/8tAz8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728378AbgGJTiJ convert rfc822-to-8bit (ORCPT ); Fri, 10 Jul 2020 15:38:09 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:24090 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728354AbgGJTiH (ORCPT ); Fri, 10 Jul 2020 15:38:07 -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-132-H_GURmi5O1aVilO0lgtFEg-1; Fri, 10 Jul 2020 15:38:04 -0400 X-MC-Unique: H_GURmi5O1aVilO0lgtFEg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 47914100CCC8; Fri, 10 Jul 2020 19:38:03 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.98]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD0EA1002391; Fri, 10 Jul 2020 19:38:01 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH v6 bpf-next 3/9] bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros Date: Fri, 10 Jul 2020 21:37:48 +0200 Message-Id: <20200710193754.3821104-4-jolsa@kernel.org> In-Reply-To: <20200710193754.3821104-1-jolsa@kernel.org> References: <20200710193754.3821104-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Adding support to generate .BTF_ids section that will hold BTF ID lists for verifier. Adding macros that will help to define lists of BTF ID values placed in .BTF_ids section. They are initially filled with zeros (during compilation) and resolved later during the linking phase by resolve_btfids tool. Following defines list of one BTF ID value: BTF_ID_LIST(bpf_skb_output_btf_ids) BTF_ID(struct, sk_buff) It also defines following variable to access the list: extern u32 bpf_skb_output_btf_ids[]; The BTF_ID_UNUSED macro defines 4 zero bytes. It's used when we want to define 'unused' entry in BTF_ID_LIST, like: BTF_ID_LIST(bpf_skb_output_btf_ids) BTF_ID(struct, sk_buff) BTF_ID_UNUSED BTF_ID(struct, task_struct) Suggested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- include/asm-generic/vmlinux.lds.h | 4 ++ include/linux/btf_ids.h | 87 +++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) create mode 100644 include/linux/btf_ids.h diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index db600ef218d7..0be2ee265931 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -641,6 +641,10 @@ __start_BTF = .; \ *(.BTF) \ __stop_BTF = .; \ + } \ + . = ALIGN(4); \ + .BTF_ids : AT(ADDR(.BTF_ids) - LOAD_OFFSET) { \ + *(.BTF_ids) \ } #else #define BTF diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h new file mode 100644 index 000000000000..fe019774f8a7 --- /dev/null +++ b/include/linux/btf_ids.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_BTF_IDS_H +#define _LINUX_BTF_IDS_H + +#include /* for __PASTE */ + +/* + * Following macros help to define lists of BTF IDs placed + * in .BTF_ids section. They are initially filled with zeros + * (during compilation) and resolved later during the + * linking phase by resolve_btfids tool. + * + * Any change in list layout must be reflected in resolve_btfids + * tool logic. + */ + +#define BTF_IDS_SECTION ".BTF_ids" + +#define ____BTF_ID(symbol) \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".local " #symbol " ; \n" \ +".type " #symbol ", @object; \n" \ +".size " #symbol ", 4; \n" \ +#symbol ": \n" \ +".zero 4 \n" \ +".popsection; \n"); + +#define __BTF_ID(symbol) \ + ____BTF_ID(symbol) + +#define __ID(prefix) \ + __PASTE(prefix, __COUNTER__) + +/* + * The BTF_ID defines unique symbol for each ID pointing + * to 4 zero bytes. + */ +#define BTF_ID(prefix, name) \ + __BTF_ID(__ID(__BTF_ID__##prefix##__##name##__)) + +/* + * The BTF_ID_LIST macro defines pure (unsorted) list + * of BTF IDs, with following layout: + * + * BTF_ID_LIST(list1) + * BTF_ID(type1, name1) + * BTF_ID(type2, name2) + * + * list1: + * __BTF_ID__type1__name1__1: + * .zero 4 + * __BTF_ID__type2__name2__2: + * .zero 4 + * + */ +#define __BTF_ID_LIST(name) \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".local " #name "; \n" \ +#name ":; \n" \ +".popsection; \n"); \ + +#define BTF_ID_LIST(name) \ +__BTF_ID_LIST(name) \ +extern u32 name[]; + +/* + * The BTF_ID_UNUSED macro defines 4 zero bytes. + * It's used when we want to define 'unused' entry + * in BTF_ID_LIST, like: + * + * BTF_ID_LIST(bpf_skb_output_btf_ids) + * BTF_ID(struct, sk_buff) + * BTF_ID_UNUSED + * BTF_ID(struct, task_struct) + */ + +#define BTF_ID_UNUSED \ +asm( \ +".pushsection " BTF_IDS_SECTION ",\"a\"; \n" \ +".zero 4 \n" \ +".popsection; \n"); + + +#endif -- 2.25.4