From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753383AbbE1BpT (ORCPT ); Wed, 27 May 2015 21:45:19 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:33105 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752605AbbE1BpM (ORCPT ); Wed, 27 May 2015 21:45:12 -0400 Date: Wed, 27 May 2015 18:45:10 -0700 From: Alexei Starovoitov To: Wang Nan Cc: paulus@samba.org, a.p.zijlstra@chello.nl, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, jolsa@kernel.org, dsahern@gmail.com, daniel@iogearbox.net, brendan.d.gregg@gmail.com, masami.hiramatsu.pt@hitachi.com, lizefan@huawei.com, linux-kernel@vger.kernel.org, pi3orama@163.com Subject: Re: [RFC PATCH v4 07/29] bpf tools: Check endianess and make libbpf fail early Message-ID: <20150528014509.GB20764@Alexeis-MacBook-Pro.local> References: <1432704004-171454-1-git-send-email-wangnan0@huawei.com> <1432704004-171454-8-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1432704004-171454-8-git-send-email-wangnan0@huawei.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2015 at 05:19:42AM +0000, Wang Nan wrote: > Check endianess according to EHDR. Code is taken from > tools/perf/util/symbol-elf.c. > > Libbpf doesn't magically convert missmatched endianess. See discussion > on https://lkml.org/lkml/2015/5/18/650 that, even if we swap > eBPF instructions to correct byte order, we are unable to deal with > endianess in code logical generated by LLVM. > > Therefore, libbpf should simply reject missmatched ELF object, and let > LLVM to create good code. > > Signed-off-by: Wang Nan lgtm Acked-by: Alexei Starovoitov