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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 65C1CC433DF for ; Tue, 16 Jun 2020 10:05:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 433D320786 for ; Tue, 16 Jun 2020 10:05:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592301943; bh=tFQki4ywcUOfIk4VfrY8g66I/2LRHfYMnaNLoGO2tNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lT9oOAJ7mjH4w4pAu8tOM7sdqlcNstHzpAGH232RUW56l+VVtdHAX77aWopsFWxqW bXZp4SG/RInslztvfLaqq/+SwcSTu65nh2AeQPQmXrftgfSFVYfRNaWNrxTDCyF06D AGtf7UTaAupkZNO46xKuL2R6+T01tFzCFZdqUALY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728282AbgFPKFm convert rfc822-to-8bit (ORCPT ); Tue, 16 Jun 2020 06:05:42 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:50673 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728279AbgFPKFm (ORCPT ); Tue, 16 Jun 2020 06:05:42 -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-455-8mdyV8RgP5S6h5xXJWpPuw-1; Tue, 16 Jun 2020 06:05:38 -0400 X-MC-Unique: 8mdyV8RgP5S6h5xXJWpPuw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 52A231083E88; Tue, 16 Jun 2020 10:05:35 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.195.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 488BA5D9DD; Tue, 16 Jun 2020 10:05:30 +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 03/11] bpf: Add btf_ids object Date: Tue, 16 Jun 2020 12:05:04 +0200 Message-Id: <20200616100512.2168860-4-jolsa@kernel.org> In-Reply-To: <20200616100512.2168860-1-jolsa@kernel.org> References: <20200616100512.2168860-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Adding support to generate .BTF_ids section that would hold various BTF IDs list for verifier. Adding 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. Following defines list of one BTF ID that is accessible within kernel code as bpf_skb_output_btf_ids array. extern int bpf_skb_output_btf_ids[]; BTF_ID_LIST(bpf_skb_output_btf_ids) BTF_ID(struct, sk_buff) Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- include/asm-generic/vmlinux.lds.h | 4 ++ kernel/bpf/Makefile | 2 +- kernel/bpf/btf_ids.c | 3 ++ kernel/bpf/btf_ids.h | 70 +++++++++++++++++++++++++++++++ 4 files changed, 78 insertions(+), 1 deletion(-) create mode 100644 kernel/bpf/btf_ids.c create mode 100644 kernel/bpf/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/kernel/bpf/Makefile b/kernel/bpf/Makefile index 1131a921e1a6..21e4fc7c25ab 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -7,7 +7,7 @@ obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o obj-$(CONFIG_BPF_JIT) += trampoline.o -obj-$(CONFIG_BPF_SYSCALL) += btf.o +obj-$(CONFIG_BPF_SYSCALL) += btf.o btf_ids.o obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o diff --git a/kernel/bpf/btf_ids.c b/kernel/bpf/btf_ids.c new file mode 100644 index 000000000000..e7f9d94ad293 --- /dev/null +++ b/kernel/bpf/btf_ids.c @@ -0,0 +1,3 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "btf_ids.h" diff --git a/kernel/bpf/btf_ids.h b/kernel/bpf/btf_ids.h new file mode 100644 index 000000000000..68aa5c38a37f --- /dev/null +++ b/kernel/bpf/btf_ids.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __BTF_IDS_H__ +#define __BTF_IDS_H__ + +#include +#include +#include + + +/* + * 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 SECTION ".BTF_ids" + +#define ____BTF_ID(symbol) \ +asm( \ +".pushsection " SECTION ",\"a\"; \n" \ +".local " #symbol " ; \n" \ +".type " #symbol ", @object; \n" \ +".size " #symbol ", 4; \n" \ +#symbol ": \n" \ +".zero 4 \n" \ +".popsection; \n"); + +#define __BTF_ID(...) \ + ____BTF_ID(__VA_ARGS__) + +#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 " SECTION ",\"a\"; \n" \ +".global " #name "; \n" \ +#name ":; \n" \ +".popsection; \n"); + +#endif -- 2.25.4