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=-10.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 AB510C433DF for ; Wed, 13 May 2020 21:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C13A204EF for ; Wed, 13 May 2020 21:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589405134; bh=jycA+VHeU/fcuDEk+08oeZlp+rfDD0wO1CCwDXKTgCs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=vQUSncYiFA1go6BaCOLWGuBsXcSbdYmvW1Xp5pLEGxSNgjXJOInXpfE1lw2sWLjYM XOYZt4iqM0N5mIxLzFDTW19TOYVqPlNwa5TKS7mOnKgHLX8zZZ9whD78ZJ7XYwVoCv cC03ro0n8C2nhAh/Jc2AMItijOnDtysOtpU0cK0M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729230AbgEMVZd (ORCPT ); Wed, 13 May 2020 17:25:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:40018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728341AbgEMVZc (ORCPT ); Wed, 13 May 2020 17:25:32 -0400 Received: from embeddedor (unknown [189.207.59.248]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02A9120693; Wed, 13 May 2020 21:25:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589405132; bh=jycA+VHeU/fcuDEk+08oeZlp+rfDD0wO1CCwDXKTgCs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Yv/nqBozvT81+uOIvowsGAwB+C6wCVSZzE4RTQtDOelNwytDn4S/SQWGWL5s6BrkI ovIVQffFNazxGnZ3QpY/GRGX5WpzTAyAQgCThRB7hqmVR6JD+iyPaYoJveEGL0RY92 Emy/E5oAhSGM0G3PRYSeNnGCZvkdRDHF+UIrIJYo= Date: Wed, 13 May 2020 16:30:07 -0500 From: "Gustavo A. R. Silva" To: Ian Rogers Cc: clang-built-linux , Peter Zijlstra , Arnaldo Melo , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , LKML , "Gustavo A. R. Silva" Subject: Re: [PATCH] perf tools: Replace zero-length array with flexible-array Message-ID: <20200513213007.GP4897@embeddedor> References: <20200511195643.GA9850@embeddedor> <0C076F02-CEB7-4DBC-8337-CCEBC0870E44@gmail.com> <20200512000404.GA4897@embeddedor> <20200512080607.GD2978@hirez.programming.kicks-ass.net> <20200512180352.GB4897@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2020 at 02:03:56PM -0700, Ian Rogers wrote: > On Tue, May 12, 2020 at 10:59 AM Gustavo A. R. Silva > wrote: > > > > On Tue, May 12, 2020 at 10:06:07AM +0200, Peter Zijlstra wrote: > > > On Mon, May 11, 2020 at 07:04:04PM -0500, Gustavo A. R. Silva wrote: > > > > On Mon, May 11, 2020 at 05:20:08PM -0300, Arnaldo Melo wrote: > > > > > > > > > > Thanks, applied > > > > > > > > > > > > > Thanks, Arnaldo. > > > > > > > > I wonder if could also take the other two: > > > > > > > > https://lore.kernel.org/lkml/20200511200911.GA13149@embeddedor/ > > > > https://lore.kernel.org/lkml/20200511201227.GA14041@embeddedor/ > > > > > > I think I have those, but let me make sure. > > > > Great. :) > > > Thanks for the cleanup! It has yielded a clang compiler warning/error > for me in kernel/git/acme/linux.git branch perf/core: > > util/intel-pt.c:1802:24: error: field 'br_stack' with variable sized > type 'struct branch_stack' not > at the end of a struct or class is a GNU extension > [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct branch_stack br_stack; > > I think this can be resolved by reordering the members of the struct, > and may have been a latent bug exposed by this change. It's > unfortunate it has broken this build. > Yep. The following should resolve the issue: diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index f17b1e769ae4..b34179e3926f 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -1799,8 +1799,8 @@ static int intel_pt_synth_pebs_sample(struct intel_pt_queue *ptq) if (sample_type & PERF_SAMPLE_BRANCH_STACK) { struct { - struct branch_stack br_stack; struct branch_entry entries[LBRS_MAX]; + struct branch_stack br_stack; } br; if (items->mask[INTEL_PT_LBR_0_POS] || I'll send a proper patch. Thanks for the report! -- Gustavo