From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752645AbbE1Fvf (ORCPT ); Thu, 28 May 2015 01:51:35 -0400 Received: from mail-pa0-f54.google.com ([209.85.220.54]:35731 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752452AbbE1Fv0 (ORCPT ); Thu, 28 May 2015 01:51:26 -0400 Date: Wed, 27 May 2015 22:51:21 -0700 From: Alexei Starovoitov To: "Wangnan (F)" 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 09/29] bpf tools: Collect version and license from ELF sections Message-ID: <20150528055104.GA21006@Alexeis-MBP.westell.com> References: <1432704004-171454-1-git-send-email-wangnan0@huawei.com> <1432704004-171454-10-git-send-email-wangnan0@huawei.com> <20150528014818.GD20764@Alexeis-MacBook-Pro.local> <55668CCD.9040506@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55668CCD.9040506@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 Thu, May 28, 2015 at 11:34:37AM +0800, Wangnan (F) wrote: > >... > >>+static int > >>+bpf_object__init_kversion(struct bpf_object *obj, > >>+ void *data, size_t size) > >>+{ > >>+ u32 kver; > >>+ if (size < sizeof(kver)) { > >shouldn't it be '!=' ? > > Is it possible that LLVM pads 'version' section so the size of it becomes > longer than sizeof(u32)? llvm will not be padding a section unless user asks for it. Try objdump on *_kern.o