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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 A2329C04A6B for ; Mon, 6 May 2019 21:36:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7292020675 for ; Mon, 6 May 2019 21:36:13 +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="sJbXTmKW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbfEFVgI (ORCPT ); Mon, 6 May 2019 17:36:08 -0400 Received: from mail-qk1-f178.google.com ([209.85.222.178]:44980 "EHLO mail-qk1-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726425AbfEFVgI (ORCPT ); Mon, 6 May 2019 17:36:08 -0400 Received: by mail-qk1-f178.google.com with SMTP id w25so2798199qkj.11 for ; Mon, 06 May 2019 14:36:07 -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=92TBfP6AEPchZTUan2PXByAVCV5aHVWIiftraVkfuME=; b=sJbXTmKWQtTUvSTjBLV8yxJbuWsvKCzinYgYM9jzzePYPBlyRDT472Idhg8AJRsTIp VvtWAXo35X3sxsyeOCd1zUQb4vAN0aDSc1qpgvX/qm3bAUoaboUb5+slDl6RMvC49iZF Q7aHjibqVnCe/z65zstTmDxnrC4n+C8Pcnb5L4oaPaFk88kxkLi2IrwuAei/MPYDejLV FFAoLi5UeZysxbLgHvvFXzRdF+pd1a9Y6wuDF0N5P6nV7d4m5GDZCmJglOOcGBGYTCdp T+7XOYc5KekyfJA/mLX0CNmXIubsziv+9pR05T1lRPCajYZoL47ihAlN3zebS2hmZpkW ybnA== 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=92TBfP6AEPchZTUan2PXByAVCV5aHVWIiftraVkfuME=; b=L18jpHvMlouZHOOv0ZNYfkTmpZixcAhG86EsZWjZ9UqQP8VtvYKyP0mbDlV/uBO8rt j2KUyauXxkx/4fwuaCsavO9cPTzGvRqkLMvqKmlrsBMC1gmwQj+GyUpq7F56AQ9xDUDk ydiH7JrN0Acf43IbF72cd/mz9Wkl9WhpcLAH0ghpV31shlfZMJYfSDryNwyYLIrSKMZq ZuPDeISxeJJI43R1t3JIqD2UOC8T3jZJaiTjsj4lnc5359is+GOOz2ubzpdFM2gLEJXH 0vAIHd4HREBRT9AjctW9ZDKjnHgJUvU5S8sJa5vbFq60vb9BNn4y5SIpu2CQ55ObXw2+ A6yQ== X-Gm-Message-State: APjAAAXAPgiNL6isFTV2BpSx1EUjKfHeVRwB2AfhL7wZEEyPhsrfiMrZ AiNuWRsGHglBqOcPo4qsieb6JV4v/JE= X-Google-Smtp-Source: APXvYqyLwlgu7HVcFCJ0Pc3G1IGsUKEkaPJ5gyvmRH0D9bffD/7Uges8jlJx5u3fNd8mUrgrQ+IRDA== X-Received: by 2002:a37:b8c:: with SMTP id 134mr3793391qkl.121.1557178567283; Mon, 06 May 2019 14:36:07 -0700 (PDT) Received: from cakuba.hsd1.ca.comcast.net ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id z38sm7641658qtz.13.2019.05.06.14.36.05 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 06 May 2019 14:36:07 -0700 (PDT) Date: Mon, 6 May 2019 14:35:59 -0700 From: Jakub Kicinski To: Oleksandr Natalenko Cc: "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, bpf@vger.kernel.org, oss-drivers@netronome.com, linux-kernel@vger.kernel.org, xdp-newbies@vger.kernel.org, valdis@vt.edu Subject: Re: netronome/nfp/bpf/jit.c cannot be build with -O3 Message-ID: <20190506143559.31e7c968@cakuba.hsd1.ca.comcast.net> In-Reply-To: <2a3761669e4ec13847205d30384c0a17@natalenko.name> References: <673b885183fb64f1cbb3ed2387524077@natalenko.name> <20190506140022.188d2b84@cakuba.hsd1.ca.comcast.net> <2a3761669e4ec13847205d30384c0a17@natalenko.name> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 06 May 2019 23:24:39 +0200, Oleksandr Natalenko wrote: > Hi. > > On 06.05.2019 23:00, Jakub Kicinski wrote: > > Any chance you could try different compiler versions? The code in > > question does not look too unusual. Could you try if removing > > FIELD_FIT() on line 326 makes a difference? > > If building with gcc from CentOS 7: > > gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36) > > the issue is not reproducible. I just did a make CC=gcc-8 CFLAGS=-O3 with GCC 8.2 here, and doesn't seem to trigger either. > Also, commenting out the whole "if" block with FIELD_FIT() prevents the > issue from occurring too. Hm, could it be that GCC 8.3 has some constant propagation bug which breaks BUILD_BUG_ON()? My uneducated guess it tries to pull the mask validation out of FIELD_FIT() and FIELD_PREP() into one place but in doing so loses some information.