From patchwork Thu Jun 25 22:12:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1317218 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@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=netdev-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 49tDmt5DJhz9sQx for ; Fri, 26 Jun 2020 08:13:34 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407484AbgFYWNd convert rfc822-to-8bit (ORCPT ); Thu, 25 Jun 2020 18:13:33 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:24120 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2407471AbgFYWNc (ORCPT ); Thu, 25 Jun 2020 18:13:32 -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-263-F2LMeeI7NiyyW6_VCU0wHg-1; Thu, 25 Jun 2020 18:13:27 -0400 X-MC-Unique: F2LMeeI7NiyyW6_VCU0wHg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EFA8F1005513; Thu, 25 Jun 2020 22:13:22 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 11D7379303; Thu, 25 Jun 2020 22:13:18 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: Andrii Nakryiko , netdev@vger.kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , Martin KaFai Lau , David Miller , John Fastabend , Wenbo Zhang , KP Singh , Andrii Nakryiko , Brendan Gregg , Florent Revest , Al Viro Subject: [PATCH v4 bpf-next 03/14] bpf: Add BTF_ID_LIST/BTF_ID macros Date: Fri, 26 Jun 2020 00:12:53 +0200 Message-Id: <20200625221304.2817194-4-jolsa@kernel.org> In-Reply-To: <20200625221304.2817194-1-jolsa@kernel.org> References: <20200625221304.2817194-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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 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 int bpf_skb_output_btf_ids[]; Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Acked-by: Andrii Nakryiko --- include/asm-generic/vmlinux.lds.h | 4 ++ include/linux/btf_ids.h | 69 +++++++++++++++++++++++++++++++ 2 files changed, 73 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..a9b77a4314a8 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..f7f9dc4d9a9f --- /dev/null +++ b/include/linux/btf_ids.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_BTF_IDS_H +#define _LINUX_BTF_IDS_H 1 + +#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 btfid tool. + * + * Any change in list layout must be reflected in btfid + * 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 int name[]; + +#endif