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=-13.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 3D705C47429 for ; Wed, 30 Sep 2020 04:28:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 031772074B for ; Wed, 30 Sep 2020 04:28:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="Je/jzJOo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725790AbgI3E2Y (ORCPT ); Wed, 30 Sep 2020 00:28:24 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:65126 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725497AbgI3E2Y (ORCPT ); Wed, 30 Sep 2020 00:28:24 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08U4QZ2E001887 for ; Tue, 29 Sep 2020 21:28:24 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=/wphFbtfizr247YhuIGvyoKb3Cenmq9hKVJ+Uk9uLzI=; b=Je/jzJOoaVqlLSw5fgNmtnWT1MRcyd0ZyoV4bb+jm/q/qz0CTRd9KDMnpkWPx/lhc1Sk 6iNRd1ft+8jUIpj5lg023ZEqhoSmTQDQpyKfU220Yseck4a1Ts5NIA9+GLc6zkAkehtU 1kz8OwHDwxJtyZ7a1kEw0aGUtjyhVrUWNd0= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 33v3vtvjj8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 29 Sep 2020 21:28:24 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 29 Sep 2020 21:28:23 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id ED1012EC77F1; Tue, 29 Sep 2020 21:28:15 -0700 (PDT) From: Andrii Nakryiko To: CC: , Andrii Nakryiko Subject: [PATCH dwarves 11/11] btf_encoder: support cross-compiled ELF binaries with different endianness Date: Tue, 29 Sep 2020 21:27:42 -0700 Message-ID: <20200930042742.2525310-12-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200930042742.2525310-1-andriin@fb.com> References: <20200930042742.2525310-1-andriin@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-30_01:2020-09-29,2020-09-30 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 suspectscore=13 phishscore=0 mlxlogscore=999 clxscore=1015 bulkscore=0 impostorscore=0 adultscore=0 priorityscore=1501 spamscore=0 mlxscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009300032 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: dwarves@vger.kernel.org Ensure that output BTF endianness corresponds to target ELF's endianness.= This makes it finally possible to use pahole to generate BTF for cross-compile= d kernels with different endianness. Signed-off-by: Andrii Nakryiko --- libbtf.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/libbtf.c b/libbtf.c index 4829651b76c4..6b0fb4e4c137 100644 --- a/libbtf.c +++ b/libbtf.c @@ -87,6 +87,8 @@ struct btf_elf *btf_elf__new(const char *filename, Elf = *elf) btfe->raw_btf =3D true; btfe->wordsize =3D sizeof(long); btfe->is_big_endian =3D BYTE_ORDER =3D=3D BIG_ENDIAN; + btf__set_endianness(btfe->btf, + btfe->is_big_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN); return btfe; } =20 @@ -117,8 +119,14 @@ struct btf_elf *btf_elf__new(const char *filename, E= lf *elf) } =20 switch (btfe->ehdr.e_ident[EI_DATA]) { - case ELFDATA2LSB: btfe->is_big_endian =3D false; break; - case ELFDATA2MSB: btfe->is_big_endian =3D true; break; + case ELFDATA2LSB: + btfe->is_big_endian =3D false; + btf__set_endianness(btfe->btf, BTF_LITTLE_ENDIAN); + break; + case ELFDATA2MSB: + btfe->is_big_endian =3D true; + btf__set_endianness(btfe->btf, BTF_BIG_ENDIAN); + break; default: fprintf(stderr, "%s: unknown elf endianness.\n", __func__); goto errout; @@ -701,6 +709,18 @@ static int btf_elf__write(const char *filename, stru= ct btf *btf) goto out; } =20 + switch (ehdr_mem.e_ident[EI_DATA]) { + case ELFDATA2LSB: + btf__set_endianness(btf, BTF_LITTLE_ENDIAN); + break; + case ELFDATA2MSB: + btf__set_endianness(btf, BTF_BIG_ENDIAN); + break; + default: + fprintf(stderr, "%s: unknown elf endianness.\n", __func__); + goto out; + } + /* * First we look if there was already a .BTF section to overwrite. */ --=20 2.24.1