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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,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 6CAADCA9EAF for ; Mon, 21 Oct 2019 23:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3963320679 for ; Mon, 21 Oct 2019 23:16:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="oHMv5HG1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730350AbfJUXQF (ORCPT ); Mon, 21 Oct 2019 19:16:05 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:46916 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730276AbfJUXQE (ORCPT ); Mon, 21 Oct 2019 19:16:04 -0400 Received: by mail-pf1-f196.google.com with SMTP id q5so9368824pfg.13 for ; Mon, 21 Oct 2019 16:16:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=SIazbGGrODWbrTu58S9RmN4EpuuCS7YJjAB2It/OA0k=; b=oHMv5HG1Ss7uQiQr0HZqS0JqLJqa6fUER36ipCFDLxHLr5wqqqBig5LpXYkdS6MhVE 8+RHZ10Q/KdNvZ/NMkZDmuXOanyMRkwpMF3js+0LP2Zxob4BAsSN/Ey6Kq29NdwMB3LN 8C2xdub6zuszZNLDjs9eu3crx9kpgd7yUflIIH160ThihJMPJ9DmBY70pNcm8unfl14y ++oi/35LtKt8bx4eM48LK6++0ZT14sstZGvuH757ZpXfBiUkma+GoV/kuhaYQe3k11sg WFUkYoElkLZwU21+jMvtZkpfIkVcdjh7EKoEYkG+9IioGUjnLXFOF09w6vUwjxOpeKmi PjwA== 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:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=SIazbGGrODWbrTu58S9RmN4EpuuCS7YJjAB2It/OA0k=; b=sx+6FhnxVZJYf8mCLvcP9+QY1avV2zp76ZazTvtaxGfEhnEDXEBiTgxSpAy5r+1kkn 84neR+AQQ5ItN8ghj4Qi7s8zOCPTE4S8L9fhdAFop0ENuOkPzWztC6ui2iw6xsPVXrz2 U0+zKJhSTsbGWrfaNUrdYWdlGzm9XTh9D956W/7qSL2ozwkQ4HQ5OCcug/mlcRXcZDVD RvNNdkYJJNiIe/BM+KdT1mot2d7HPSBTXh0dyLtxWEqe5cVLp7um3JDX22dv+x5P8rd9 KFbuEvdg98PZMj4FLN1a2t1QzofwYAwhUTVBXAMk8AeuzorPUIil40JMV8iq4VbX7Xkt 03gw== X-Gm-Message-State: APjAAAW5nmz0/iqm//PY5RrM22qMsdOA4I3NFgAhEXglwAjjE8XyNCGM 19n5s2QX/c3N+2BoIcabFiJIqQ== X-Google-Smtp-Source: APXvYqwUupoLUquBzzVqMXRG2rPQmVWyjAJrS7NMYXMcTAUeIZu/lU/4IiVC3ni9FdOQFFk7rsfT1g== X-Received: by 2002:a17:90a:a88e:: with SMTP id h14mr247045pjq.42.1571699763985; Mon, 21 Oct 2019 16:16:03 -0700 (PDT) Received: from cakuba.netronome.com (c-73-202-202-92.hsd1.ca.comcast.net. [73.202.202.92]) by smtp.gmail.com with ESMTPSA id n2sm17412294pgg.77.2019.10.21.16.16.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Oct 2019 16:16:03 -0700 (PDT) Date: Mon, 21 Oct 2019 16:16:00 -0700 From: Jakub Kicinski To: Jiri Olsa Cc: Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko , Yonghong Song , Martin KaFai Lau Subject: Re: [PATCH] bpftool: Try to read btf as raw data if elf read fails Message-ID: <20191021161600.282c04fb@cakuba.netronome.com> In-Reply-To: <20191021140227.GD32718@krava> References: <20191018103404.12999-1-jolsa@kernel.org> <20191018153905.600d7c8a@cakuba.netronome.com> <20191021140227.GD32718@krava> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, 21 Oct 2019 16:02:27 +0200, Jiri Olsa wrote: > > > static int do_dump(int argc, char **argv) > > > { > > > struct btf *btf = NULL; > > > @@ -397,7 +429,7 @@ static int do_dump(int argc, char **argv) > > > __u32 btf_id = -1; > > > const char *src; > > > int fd = -1; > > > - int err; > > > + int err = 0; > > > > This change looks unnecessary. > > I'm getting confusing warnings from gcc about this, > but there is a code path where do_dump would return > untouched err: > > do_dump > int err; > > } else if (is_prefix(src, "file")) { > btf = btf__parse_elf(*argv, NULL); // succeeds > > } > > while (argc) { > if (is_prefix(*argv, "format")) { > else { // in here > goto done; > } > > done: > return err; ugh, right those look legit, although unrelated to you change. err should always be set before jumping to 'done'. The error setting in this function looks super messy :( Sometimes is returns errno codes, sometimes positive values, sometimes negative, sometimes just -1. Sometimes it jumps to 'done' for no good reason, ahh :/