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=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 D8C8FC433E2 for ; Thu, 17 Sep 2020 13:13:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9354A2083B for ; Thu, 17 Sep 2020 13:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726897AbgIQNNL (ORCPT ); Thu, 17 Sep 2020 09:13:11 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60197 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727058AbgIQNMz (ORCPT ); Thu, 17 Sep 2020 09:12:55 -0400 X-Greylist: delayed 1070 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Sep 2020 09:12:55 EDT Received: from mail-ot1-f72.google.com ([209.85.210.72]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kItR7-0003qW-S0 for netdev@vger.kernel.org; Thu, 17 Sep 2020 12:54:54 +0000 Received: by mail-ot1-f72.google.com with SMTP id o3so413680otp.8 for ; Thu, 17 Sep 2020 05:54:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=qvtx1Dw39OYs5aOUHC+fg8agAEsZenZTX5vKZkyOU9s=; b=Jzibdkq5F7wZgUBcyI6pvrkG+2VqRWQfxr6DlQMIJT67uAlDmTqgh1famTfnA/ECl9 PIFpY+D8RG0Bk9A8XzLoBM8ImeCgdbaT9iCe8j6tWshaGU8PurAUoZdyTbyOtMoCW3xj 1fY92NKC9lChYs0uFnxF+CK/ZZSwyjCGZX9WXgNlL3UgDzPhvaJG9m+fHTaspWnRzCaN JckqHd8aa0wdxU3lK8ZuabcIqer1rvG1KiuXzD8h1IxUhVbRO3rBnJJynNFkU9k0qp48 TvAsGbeExJIaj7+icSLr9ERDRlGhHfycf6WONehMlC2Sm850So7kNLCwX1yODdcaER1V wh+A== X-Gm-Message-State: AOAM531YLimDewIuniXuwNpDOnCTE5ZqPgh4XJzzBMrqs+OeajwPIJ4K VsECXvvZhqHeqQxrZ6M4ldIuNKBUq/69IUJS40KIb3+rUn2EpEV1Hd2HqvNkxIzv4RE3QIkfEYb mDBX31QimtBoUrK5o2zfh1SdeMRGusTtdaQ== X-Received: by 2002:aca:843:: with SMTP id 64mr6229927oii.135.1600347292700; Thu, 17 Sep 2020 05:54:52 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwh6KjccBZl5W9X0X9YrClsArM7xybnlSW3VEUFeKIhv9qqHi6wD4If97szIyRO4rGFle9HYQ== X-Received: by 2002:aca:843:: with SMTP id 64mr6229907oii.135.1600347292463; Thu, 17 Sep 2020 05:54:52 -0700 (PDT) Received: from localhost ([2605:a601:ac0f:820:c48f:8c0b:cb29:e546]) by smtp.gmail.com with ESMTPSA id s196sm11797740oih.26.2020.09.17.05.54.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2020 05:54:51 -0700 (PDT) Date: Thu, 17 Sep 2020 07:54:50 -0500 From: Seth Forshee To: Jiri Olsa 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: <20200917125450.GC4820@ubuntu-x1> References: <20200916194733.GA4820@ubuntu-x1> <20200917080452.GB2411168@krava> <20200917083809.GE2411168@krava> <20200917091406.GF2411168@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200917091406.GF2411168@krava> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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. 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/ > >