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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1DDD5C2BB55 for ; Thu, 16 Apr 2020 12:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F22FF21973 for ; Thu, 16 Apr 2020 12:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2635574AbgDPMa6 (ORCPT ); Thu, 16 Apr 2020 08:30:58 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:30432 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2635398AbgDPMap (ORCPT ); Thu, 16 Apr 2020 08:30:45 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03GC4YFd004188 for ; Thu, 16 Apr 2020 08:30:44 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 30epxn141p-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 16 Apr 2020 08:30:44 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 16 Apr 2020 13:30:19 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 03GCTVFA35520776 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Apr 2020 12:29:31 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D5B87A4062; Thu, 16 Apr 2020 12:30:37 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 359DCA4060; Thu, 16 Apr 2020 12:30:37 +0000 (GMT) Received: from oc7455500831.ibm.com (unknown [9.145.77.31]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 16 Apr 2020 12:30:37 +0000 (GMT) Subject: Re: [PATCH v3 00/12] Rework READ_ONCE() to improve codegen To: Will Deacon , linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, kernel-team@android.com, Michael Ellerman , Peter Zijlstra , Linus Torvalds , Segher Boessenkool , Luc Van Oostenryck , Arnd Bergmann , Peter Oberparleiter , Masahiro Yamada , Nick Desaulniers References: <20200415165218.20251-1-will@kernel.org> From: Christian Borntraeger Autocrypt: addr=borntraeger@de.ibm.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200415165218.20251-1-will@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 20041612-0012-0000-0000-000003A58FFD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20041612-0013-0000-0000-000021E2CFF7 Message-Id: <809e006e-6641-c252-53a1-cc4479d2ca89@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-16_03:2020-04-14,2020-04-16 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 priorityscore=1501 mlxscore=0 malwarescore=0 phishscore=0 bulkscore=0 impostorscore=0 suspectscore=0 mlxlogscore=999 spamscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004160082 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15.04.20 18:52, Will Deacon wrote: > Hi everyone, > > This is version three of the patches I previously posted for improving > the code generation of READ_ONCE() and moving the minimum GCC version > to 4.8: > > RFC: https://lore.kernel.org/lkml/20200110165636.28035-1-will@kernel.org > v2: https://lore.kernel.org/lkml/20200123153341.19947-1-will@kernel.org > > Although v2 was queued up by Peter in -tip, it was found to break the > build for m68k and sparc32. We fixed m68k during the merge window and > I've since posted patches to fix sparc32 here: > > https://lore.kernel.org/lkml/20200414214011.2699-1-will@kernel.org > > This series is a refresh on top of 5.7-rc1, the main changes being: > > * Fix another issue where 'const' is assigned to non-const via > WRITE_ONCE(), this time in the tls code > > * Fix READ_ONCE_NOCHECK() abuse in arm64 checksum code > > * Added Reviewed-bys and Acks from v2 > > Hopefully this can be considered for 5.8, along with the sparc32 changes. > > Cheers, > > Will > > Cc: Michael Ellerman > Cc: Peter Zijlstra > Cc: Linus Torvalds > Cc: Segher Boessenkool > Cc: Christian Borntraeger > Cc: Luc Van Oostenryck > Cc: Arnd Bergmann > Cc: Peter Oberparleiter > Cc: Masahiro Yamada > Cc: Nick Desaulniers > I gave this series a try and s390 seems to compile fine and it also seems to properly compile the the ipte_unlock_siif function in arch/s390/kvm/gaccess.c This function was miscompiled with gcc4.6 and the trigger for replacing ACCESS_ONCE with READ_ONCE