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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31947C433FE for ; Mon, 3 Oct 2022 21:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229658AbiJCVAo (ORCPT ); Mon, 3 Oct 2022 17:00:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229556AbiJCVAk (ORCPT ); Mon, 3 Oct 2022 17:00:40 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A08A62F017 for ; Mon, 3 Oct 2022 14:00:38 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id c7so10673031pgt.11 for ; Mon, 03 Oct 2022 14:00:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date; bh=HLHdFxoJHk5RJojcM4EF6YsKjsuNbBptwhJEME2CxZk=; b=H4nriSy95wk6Qjxo385ChG3lW6IR50a3hRFZgLW/U4eSlUw9UHf7JiaJfu8T750lgf I60xaN+8fYvIuZ6Eo+f63T6Wr2/DQq01d/tTLMTLMgZzjEU0BgurmruMu+IRBF3IRPtS ciCASHG2v74dN+99t8uKYgORu5psgSTC1lmQD23ChB27JRFaGrl39VKORh9+plhS9JiB aSvsxgl+CAsIPkpLXk159jRiYhY1ANxqr8iDUBp5i3obisXEgxD27wG8SKygixYpWfeK LujI1EJ2Qnw9kGaXtQymZzYtltsjrsBt2UAj1vh2DHHH62R3yTkoDXGiGq88g64l7bwS Yqzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date; bh=HLHdFxoJHk5RJojcM4EF6YsKjsuNbBptwhJEME2CxZk=; b=jrcBoZMCqtHb+9IGwK9/Fq40Efh47lsaqBJ9D7E82rizeCoCMYZIPc1YF1w81ay0nI MxVBQHxtHaP1WGOWIADNX3uwDZoPqIcXYlHTWuz3/mGUfNTRjoqBmSwZkp7xT3orPM9f OD0VDKz7KdJMm/rI8S3+ZsXATm2xI1zsPK0YNiOQQ9W+1zlKGnM4RUyktZBqEq6g1ZSE eG5DnfPtZ0Oby8HXj3iVijG5/+uKdRo9pfSY1VmJbPWOZSX6kUeC9YqASLtVsK907Ism h931YrPhHm1og5oI4SgH+yNrEKP/KXFyIXyd7ZLpbGMpzUlbOa8XBYwtrZiusn53HM5e jdTA== X-Gm-Message-State: ACrzQf3G0XCcf0iHSODR9YxdlwQ2SLBG9YwETUi4k89MK9cjX+Vdm49d tQ5k7jlm2AJuZumrv/bf8Bs= X-Google-Smtp-Source: AMsMyM7vgqQKCY6Yuu8k4Ya6DEkma/pgiSnECZBHfwhpHKA51cT6YTqEXiiEyPJC/CFmbwtjgI7udQ== X-Received: by 2002:a05:6a00:1747:b0:55c:b475:5f74 with SMTP id j7-20020a056a00174700b0055cb4755f74mr17723187pfc.68.1664830837787; Mon, 03 Oct 2022 14:00:37 -0700 (PDT) Received: from smtpclient.apple ([66.170.99.2]) by smtp.gmail.com with ESMTPSA id u5-20020a170902e80500b00177faf558b5sm7366289plg.250.2022.10.03.14.00.36 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 03 Oct 2022 14:00:37 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\)) Subject: Re: [PATCH 1/3] mm/hugetlb: Fix race condition of uffd missing/minor handling From: Nadav Amit In-Reply-To: <20221003155630.469263-2-peterx@redhat.com> Date: Mon, 3 Oct 2022 14:00:36 -0700 Cc: LKML , Linux MM , Andrea Arcangeli , Mike Rapoport , David Hildenbrand , Andrew Morton , Axel Rasmussen , Mike Kravetz Content-Transfer-Encoding: quoted-printable Message-Id: References: <20221003155630.469263-1-peterx@redhat.com> <20221003155630.469263-2-peterx@redhat.com> To: Peter Xu X-Mailer: Apple Mail (2.3696.120.41.1.1) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Oct 3, 2022, at 8:56 AM, Peter Xu wrote: >=20 > + */ > + if (hugetlb_pte_stable(h, mm, ptep, old_pte)) > + ret =3D hugetlb_handle_userfault( > + vma, mapping, idx, flags, haddr, > + address, VM_UFFD_MISSING); > + else > + /* Retry the fault */ > + ret =3D 0; Might be unrelated, but at least for the sake of consistency if not potential GUP issues, don=E2=80=99t you want to return VM_FAULT_RETRY ?