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=-9.8 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,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 AA593C43465 for ; Fri, 18 Sep 2020 10:05:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F6C720665 for ; Fri, 18 Sep 2020 10:05:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="B5vjXDs1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726587AbgIRKFz (ORCPT ); Fri, 18 Sep 2020 06:05:55 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:57912 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726551AbgIRKFx (ORCPT ); Fri, 18 Sep 2020 06:05:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600423551; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WkpClEmXxT84vDpjsqvB+DVNHu1sfbMIG8xOfJiWTAw=; b=B5vjXDs1yeLh4Ew4xx+uFAIGu1+fqHOGTkiywxM5zcUNOKEXMdih/L5t8VsqRJ/VjC/yqq TfeiQl7X2kl6OtSrD8A7G95lf88RMvLLKA/maw4/GLPtFMzIuklo91hP8smHXv3twncQB6 osz0QqjJkSOonuYr2cxW2mHfJls6NtE= 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-379-pG7bMC-GPxaN-W1VdCndGg-1; Fri, 18 Sep 2020 06:05:47 -0400 X-MC-Unique: pG7bMC-GPxaN-W1VdCndGg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6FA621891E81; Fri, 18 Sep 2020 10:05:45 +0000 (UTC) Received: from krava (ovpn-114-24.ams2.redhat.com [10.36.114.24]) by smtp.corp.redhat.com (Postfix) with SMTP id 5A90D55771; Fri, 18 Sep 2020 10:05:43 +0000 (UTC) Date: Fri, 18 Sep 2020 12:05:42 +0200 From: Jiri Olsa To: Seth Forshee , Andrii Nakryiko Cc: Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: resolve_btfids breaks kernel cross-compilation Message-ID: <20200918100542.GD2514666@krava> References: <20200916194733.GA4820@ubuntu-x1> <20200917080452.GB2411168@krava> <20200917083809.GE2411168@krava> <20200917091406.GF2411168@krava> <20200917125450.GC4820@ubuntu-x1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200917125450.GC4820@ubuntu-x1> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Sep 17, 2020 at 07:54:50AM -0500, Seth Forshee wrote: > On Thu, Sep 17, 2020 at 11:14:06AM +0200, Jiri Olsa wrote: > > On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote: > > > On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote: > > > > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote: > > > > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF > > > > > is enabled breaks some cross builds. For example, when building a 64-bit > > > > > powerpc kernel on amd64 I get: > > > > > > > > > > Auto-detecting system features: > > > > > ... libelf: [ [32mon[m ] > > > > > ... zlib: [ [32mon[m ] > > > > > ... bpf: [ [31mOFF[m ] > > > > > > > > > > BPF API too old > > > > > make[6]: *** [Makefile:295: bpfdep] Error 1 > > > > > > > > > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output: > > > > > > > > > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11, > > > > > from /usr/include/asm-generic/int-ll64.h:12, > > > > > from /usr/include/asm-generic/types.h:7, > > > > > from /usr/include/x86_64-linux-gnu/asm/types.h:1, > > > > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10, > > > > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11, > > > > > from test-bpf.c:3: > > > > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h > > > > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h > > > > > | ^~~~~ > > > > > > > > > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets > > > > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__, > > > > > which is not defined by the host compiler. What can we do to get cross > > > > > builds working again? > > > > > > > > could you please share the command line and setup? > > > > > > I just reproduced.. checking on fix > > > > I still need to check on few things, but patch below should help > > It does help with the word size problem, thanks. > > > we might have a problem for cross builds with different endianity > > than the host because libbpf does not support reading BTF data > > with different endianity, and we get: > > > > BTFIDS vmlinux > > libbpf: non-native ELF endianness is not supported > > Yes, I see this now when cross building for s390. Andrii, I read you might be already working on this? https://lore.kernel.org/bpf/CAEf4Bza9tZ-Jj0dj9Ne0fmxa95t=9XxxJR+Ce=6hDmw_d8uVFA@mail.gmail.com/ thanks, jirka > > Thanks, > Seth > > > > > jirka > > > > > > --- > > diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile > > index a88cd4426398..d3c818b8d8d3 100644 > > --- a/tools/bpf/resolve_btfids/Makefile > > +++ b/tools/bpf/resolve_btfids/Makefile > > @@ -1,5 +1,6 @@ > > # SPDX-License-Identifier: GPL-2.0-only > > include ../../scripts/Makefile.include > > +include ../../scripts/Makefile.arch > > > > ifeq ($(srctree),) > > srctree := $(patsubst %/,%,$(dir $(CURDIR))) > > @@ -29,6 +30,7 @@ endif > > AR = $(HOSTAR) > > CC = $(HOSTCC) > > LD = $(HOSTLD) > > +ARCH = $(HOSTARCH) > > > > OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/ > > > > >