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=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 8D0AEC433EF for ; Fri, 24 Sep 2021 14:14:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2256961212 for ; Fri, 24 Sep 2021 14:14:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2256961212 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id B3434940007; Fri, 24 Sep 2021 10:14:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ABB68900002; Fri, 24 Sep 2021 10:14:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95D47940007; Fri, 24 Sep 2021 10:14:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 83FC9900002 for ; Fri, 24 Sep 2021 10:14:26 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3FA4B2FD7B for ; Fri, 24 Sep 2021 14:14:26 +0000 (UTC) X-FDA: 78622662132.13.2A0A0AD Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf14.hostedemail.com (Postfix) with ESMTP id D77426001994 for ; Fri, 24 Sep 2021 14:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632492865; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vURCDQqb490vrVUUKxyIgtPmCzQpFb9HmiIOhgqiCwU=; b=UYmyaoLgsmAzsp/Eb2U649hatWDPnLmfyVI/zMBHA2OMkVYWNbO2VJDxcr4J7zytk6z6o4 Sd4GfhtPQYBToBGNvZ+ojw+LNCwvfBUdkA2wtlCN8UWEHY1FNlBRNEj3rgUTHIOdzsSTL5 l/DGXS5JYO82VAYEh3Y9sVJFRgDdS4c= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-488-yMs-DL3kOA-H_BtJDjgLGw-1; Fri, 24 Sep 2021 10:14:24 -0400 X-MC-Unique: yMs-DL3kOA-H_BtJDjgLGw-1 Received: by mail-qv1-f72.google.com with SMTP id r18-20020a056214069200b0037a291a6081so30307058qvz.18 for ; Fri, 24 Sep 2021 07:14:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=vURCDQqb490vrVUUKxyIgtPmCzQpFb9HmiIOhgqiCwU=; b=5FneTGaLIfrHP6Ma0SowTX830wQNwOLs5rsP+jJR0vK6ksRZ9leegkn5WVUw8MXhWl V0aQtXjKw5OO/2+mchWDMOmCojLKrj3zI0z8m8f0yF9JfkFcX7phngl/vAdTrZfD3SMb ndngJOc/GJh+2w9kvvzdkhcXzubCFmtj+9bQCoKb4fmkfvpVOmJnylehcSHK9ZqRNGh9 t6U3CxSBbkonWLYPlIzxXhGtvCbeBYXCy10WWsjIOAzVdZ/+FJ8GitA6jnWwHWu3BMx1 K8DumBAS2Tf8fkfEmqaiULvYcIPZY0T/F4L8oItDX9XJQDdqrzyWZjDfwCtrtyBxBeMQ X+sA== X-Gm-Message-State: AOAM532YrhDkZ+1SmnRx7rkNqQVe33HJeTMNDAkQPflmU9zqeSgynlZ9 CNZ0/6KNHFW2/HTrxsXyFaMFVmyfuq5OMGe2pr+dfL6OyLX43OAHXAZfMEzRrnBKKK/pxY4p+aH Vfi8S4jLDeyA= X-Received: by 2002:a37:6658:: with SMTP id a85mr10875025qkc.34.1632492863541; Fri, 24 Sep 2021 07:14:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx/FAo093naG96wtcJ0fkUoyMpB/ZaTO5SeisakJVzb4CYFdg7k3z6NELRzuk4IUhVd9yK71g== X-Received: by 2002:a37:6658:: with SMTP id a85mr10874997qkc.34.1632492863209; Fri, 24 Sep 2021 07:14:23 -0700 (PDT) Received: from t490s ([2607:fea8:56a2:9100::d3ec]) by smtp.gmail.com with ESMTPSA id v8sm5214030qtk.49.2021.09.24.07.14.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Sep 2021 07:14:22 -0700 (PDT) Date: Fri, 24 Sep 2021 10:14:21 -0400 From: Peter Xu To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrea Arcangeli , Axel Rasmussen , Nadav Amit , Li Wang Subject: Re: [PATCH] mm/userfaultfd: selftests: Fix memory corruption with thp enabled Message-ID: References: <20210923232512.210092-1-peterx@redhat.com> <20210923191941.da28da4400c11a3241a07acf@linux-foundation.org> MIME-Version: 1.0 In-Reply-To: <20210923191941.da28da4400c11a3241a07acf@linux-foundation.org> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D77426001994 X-Stat-Signature: jq6cbcus8xcgkmttsg3zwdt7hmbhkg7a Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=UYmyaoLg; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf14.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com X-HE-Tag: 1632492865-731700 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 23, 2021 at 07:19:41PM -0700, Andrew Morton wrote: > On Thu, 23 Sep 2021 19:25:12 -0400 Peter Xu wrote: > > > In RHEL's gating selftests we've encountered memory corruption in the uffd > > event test even with upstream kernel: > > > > ... > > > > > > We can mark the Fixes tag upon 0db282ba2c12 as it's reported to only happen > > there, however the real "Fixes" IMHO should be 8ba6e8640844, as before that > > commit we'll always do explicit release_pages() before registration of uffd, > > and 8ba6e8640844 changed that logic by adding extra unmap/map and we didn't > > release the pages at the right place. Meanwhile I don't have a solid glue > > anyway on whether posix_memalign() could always avoid triggering this bug, > > hence it's safer to attach this fix to commit 8ba6e8640844. > > > > Thanks. I added a cc:stable to this. I don't think we want selftests > in older kernels to be falsely reporting kernel bugs? Not sure how we normally handle such case for selftests, but I agree. Btw, 8ba6e8640844 is merged in 5.14, so the only stable branch that will need it will be 5.14.y; it can be applied cleanly there. Thanks, -- Peter Xu