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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 659A8C432BE for ; Mon, 30 Aug 2021 10:55:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 00887610FD for ; Mon, 30 Aug 2021 10:55:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 00887610FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 4C1806B006C; Mon, 30 Aug 2021 06:55:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 471D86B0071; Mon, 30 Aug 2021 06:55:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 339906B0072; Mon, 30 Aug 2021 06:55:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0078.hostedemail.com [216.40.44.78]) by kanga.kvack.org (Postfix) with ESMTP id 206366B006C for ; Mon, 30 Aug 2021 06:55:41 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4AAFD22893 for ; Mon, 30 Aug 2021 10:55:39 +0000 (UTC) X-FDA: 78531441198.39.66F228E Received: from mail-io1-f41.google.com (mail-io1-f41.google.com [209.85.166.41]) by imf24.hostedemail.com (Postfix) with ESMTP id 091A8B0000A2 for ; Mon, 30 Aug 2021 10:55:38 +0000 (UTC) Received: by mail-io1-f41.google.com with SMTP id n24so19174697ion.10 for ; Mon, 30 Aug 2021 03:55:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xS9SwSA6yuA1OafRoxLdXW0QKqukJZ/A3wgnuw8Qvtk=; b=MOINA1qJxLGoErdnA008+v6J478Ywvcb2I46ktSOzZcrNxQ4TBLvQJjZ46p3yajZSn NO50z2WRZE7Ur1KIil9k5pRT2+Jjg1EKbgE3xbjW0Fc5fMYhlK8p+F/EsybblYiq933S WBLqM1vxjU/SR0RAKLYRNCJKBrtCwEP/+KgH5f/VKXmlDFFZpc1Y+kohscZE8UWLHlgi VkheC3Mvf3bOOgzOIs3EDEGDunkR/11pa3eIfRanwq//hmzY78aWxG3vMMrcIkAQ82kU Hu4I9fyNmfM9fDKPVpwJw4U8tfeZUZK2XzgBulLKyezN4w8h1BoUrhCEiH/gh4p4Kg/y ceBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xS9SwSA6yuA1OafRoxLdXW0QKqukJZ/A3wgnuw8Qvtk=; b=N9pYcYZmEeSTqDFfaOYbJGMLNNCkp2AqpEnvXVCxjXSQqHj+QgKDuGiCps1ehdwmvt V4iKqBura5hzHc0JDRidbOqnuqAuSZ2QGjQaNkzVaw3ufgRdJLNN57Ttw68NdhCr5Ohb 36DScHY4u0GFM9aM1wNSxFfFsXLqA/D9W7bD0wjblARj2dXRBB2LTmoj32zYZ/WyCQJy rhGOazSLu0OCxUB10Ly63MEu46f4lcv74usNvAUatH1kBf1fsDpeZjQs7aLm4Ycb+gNb pyCHfi7mELb0OZuipU9xbitUkIqJ9KqAnSMYbPsq+DWj6jMu86bpfoL9O1qgVzu6kCyl tD+w== X-Gm-Message-State: AOAM531uB+XTZvZ3J6qmVtL2WowOtOwksIIdqIs2BfPtc8Pfl5MIkKxh mbYI4xanvACkubnN1ntJVd8jz4jWk5buWdL2XxM= X-Google-Smtp-Source: ABdhPJzQ0qsYTPzF4FV9dl5PwdCDnVWMxYzH0moSH4JmM3ESyqfZDHFY5Iel8KOeiBKo7lzxBB2A/DvCfCu7vY493j4= X-Received: by 2002:a5d:94c6:: with SMTP id y6mr18054486ior.202.1630320938386; Mon, 30 Aug 2021 03:55:38 -0700 (PDT) MIME-Version: 1.0 References: <20210829011953.9051-1-laoar.shao@gmail.com> In-Reply-To: From: Yafang Shao Date: Mon, 30 Aug 2021 18:55:02 +0800 Message-ID: Subject: Re: [PATCH] mm, gpu: fix error when FOLL_MLOCK an unpresent page To: Christoph Hellwig Cc: Andrew Morton , Linux MM , "Kirill A . Shutemov" Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=gmail.com header.s=20161025 header.b=MOINA1qJ; spf=pass (imf24.hostedemail.com: domain of laoarshao@gmail.com designates 209.85.166.41 as permitted sender) smtp.mailfrom=laoarshao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 091A8B0000A2 X-Stat-Signature: 44tkgrcyrqgf3hytc5mzioxhnyf4ztft X-HE-Tag: 1630320938-839433 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 Mon, Aug 30, 2021 at 6:08 PM Christoph Hellwig wrote: > > On Mon, Aug 30, 2021 at 05:12:32PM +0800, Yafang Shao wrote: > > > Which is not a valid way to call get_user_pages. What we need to do is > > > to reject that case. > > > > Do you mean below change ? > > Sory of. I think once touching this we should do a few more cleanups > including making many of the flags private to gup.c. I'll try to find > some time to post a more complete series. JFYI, below test case can also hit the bug I reported above. #define _GNU_SOURCE #include #include #define LEN 4096 int main() { char *addr; int ret; addr = mmap(NULL, LEN, PROT_READ|PROT_WRITE, MAP_PRIVATE | MAP_ANON , -1, 0); if (addr == MAP_FAILED) { perror("mmap"); return ret; } /* * MLOCK_ONFAULT will hit below if condition. * if ((*flags & (FOLL_POPULATE | FOLL_MLOCK)) == FOLL_MLOCK) * return -ENOENT; */ ret = mlock2(addr, LEN, MLOCK_ONFAULT); // ret = mlock2(addr, LEN, 0); if (ret < 0) { perror("mlock2"); return ret; } return 0; } -- Thanks Yafang