Message ID | 20190426045151.19556-4-peterx@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show
Return-Path: <owner-linux-mm@kvack.org> Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6234E933 for <patchwork-linux-mm@patchwork.kernel.org>; Fri, 26 Apr 2019 04:52:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 50DE1289B1 for <patchwork-linux-mm@patchwork.kernel.org>; Fri, 26 Apr 2019 04:52:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 446AF28CDD; Fri, 26 Apr 2019 04:52:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C155F289B1 for <patchwork-linux-mm@patchwork.kernel.org>; Fri, 26 Apr 2019 04:52:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D873E6B000C; Fri, 26 Apr 2019 00:52:33 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id D37506B000D; Fri, 26 Apr 2019 00:52:33 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C26B66B000E; Fri, 26 Apr 2019 00:52:33 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by kanga.kvack.org (Postfix) with ESMTP id A3EE26B000C for <linux-mm@kvack.org>; Fri, 26 Apr 2019 00:52:33 -0400 (EDT) Received: by mail-qk1-f198.google.com with SMTP id u66so1847799qkh.9 for <linux-mm@kvack.org>; Thu, 25 Apr 2019 21:52:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references; bh=vKNT6GfdSA2RaFRR5Rx6tafrEcvehh1DQki77hDcefA=; b=K7qrCrNOFAAlg5J8Z8/SgEww+z3jp2+ybQFL4gr/PgkL2ak4QY0lMpODUNllxKGGxu oQ8Ry6rvjyxVdxpt9Oy3XdPKnTBU5dzrTTALD2DBG0ICQoTvXiPPaMnAQJKZfG/HaKWl 7SEXgSEukUJnXgZUrG/8cdUmQABiqSRL419QWBMBCN0XGAfn+WWWpXB3VWpaIdmA9IQ2 E+GGt9tlNkUBDjN1aazRhzZcuJtnrsRKHzUrTVDPS988C7+vl4349p05DoVOWnaHCxyf p5nnTxFtbmBeZNSE+A6ATn4xcd2d5KHz9zJImrkLrAjFJfN5S7qQhUcbnqZkMXNr23cE 2uLg== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of peterx@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Gm-Message-State: APjAAAWC/AJv/5vARCfii4taqUvasqWQhnKL+C78bMqBYRqtugN39KX9 JXXlFRr6CZidcWSQI/om8tFZyOGkONVaGrwSiCYPQPBur7FRcAkNMTaq9ov1zg/08qa6ZXtkvb4 k/l6tVqmS1FZJaPh5LSSeFESh3BdDuvp++yX615vpl1OrptEgmzP47up5iAKH3FlPMg== X-Received: by 2002:a37:e119:: with SMTP id c25mr10607017qkm.75.1556254353440; Thu, 25 Apr 2019 21:52:33 -0700 (PDT) X-Google-Smtp-Source: APXvYqzldQgP8IQzyw1tWgp4He77GLfMOjGVlMA5aNOQnRT9md+DDPb+aCsWeEPLErOpUaoOyqL/ X-Received: by 2002:a37:e119:: with SMTP id c25mr10606982qkm.75.1556254352737; Thu, 25 Apr 2019 21:52:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556254352; cv=none; d=google.com; s=arc-20160816; b=FUvsmF4F2T4XPSmZeweGg0xbGxJZXTxQF1h3LXtQgoHD/RgWj/4QLPs+D+FKox1bF1 HzkiqWN0IQK+t46ko7S0T3/BcJVVee2Qb7AIm4guGCUm9cOqkHOU1J/UkZKOKSp14ocv 3KzMpe1StXlWNlvayWkzJx+mzgaP8UdZeR526YnVdF5C6WPFRGW945R41FcjIG5uJHAU /Zyp80u0p/meU5kJFAPHYlfOze6PWwyA+HpThpmeml1DA6syUU8iRyGotHpd02lSlhtF aEWBMAPLESUVNFGWWjb/y32ElKhJTaN3oHtihClUqGocuY1D7qScSb6vlXtZOXxIwTBv og7w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from; bh=vKNT6GfdSA2RaFRR5Rx6tafrEcvehh1DQki77hDcefA=; b=Ze9XzA7UbXEP07DSSDekhtwiEWlGp0cf3W5suBMQWh/lyViBGOSTDKQmzztrvitlmB +/h3mJAnCJTJa0EhHzWMfhZdZ/KDcv5Ak77Rjbw//Qk59bCdcxzSIyOp5Y5k1+NmcdiP iEYlUuVCqox4vMFgHRHiYo0mrPze9Tpu43ctBknyKkkQwo5wAffHNC9Xv6uKJ6/kJ9g2 RVbM1xfuMgVDcBFScMecOASNePUudHEj2hP0R+J8TcM5hhppGeJZjGNZ/VCNaWF24E9Q IH1brXTnH2Qsumz/RAmoEasfaZCQIFaXGTNoOT0bWqzQtc+vsnxFux4Vpxg5Xrx2vG1a fAsQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of peterx@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id o45si5188qta.395.2019.04.25.21.52.32 for <linux-mm@kvack.org> (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Apr 2019 21:52:32 -0700 (PDT) Received-SPF: pass (google.com: domain of peterx@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of peterx@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E1F71308A9E1; Fri, 26 Apr 2019 04:52:31 +0000 (UTC) Received: from xz-x1.nay.redhat.com (dhcp-15-205.nay.redhat.com [10.66.15.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5407A18500; Fri, 26 Apr 2019 04:52:26 +0000 (UTC) From: Peter Xu <peterx@redhat.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: David Hildenbrand <david@redhat.com>, Hugh Dickins <hughd@google.com>, Maya Gokhale <gokhale2@llnl.gov>, Jerome Glisse <jglisse@redhat.com>, Pavel Emelyanov <xemul@virtuozzo.com>, Johannes Weiner <hannes@cmpxchg.org>, peterx@redhat.com, Martin Cracauer <cracauer@cons.org>, Shaohua Li <shli@fb.com>, Denis Plotnikov <dplotnikov@virtuozzo.com>, Andrea Arcangeli <aarcange@redhat.com>, Mike Kravetz <mike.kravetz@oracle.com>, Marty McFadden <mcfadden8@llnl.gov>, Mike Rapoport <rppt@linux.vnet.ibm.com>, Mel Gorman <mgorman@suse.de>, "Kirill A . Shutemov" <kirill@shutemov.name>, "Dr . David Alan Gilbert" <dgilbert@redhat.com> Subject: [PATCH v4 03/27] userfaultfd: don't retake mmap_sem to emulate NOPAGE Date: Fri, 26 Apr 2019 12:51:27 +0800 Message-Id: <20190426045151.19556-4-peterx@redhat.com> In-Reply-To: <20190426045151.19556-1-peterx@redhat.com> References: <20190426045151.19556-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Fri, 26 Apr 2019 04:52:32 +0000 (UTC) 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: <linux-mm.kvack.org> X-Virus-Scanned: ClamAV using ClamSMTP |
Series |
userfaultfd: write protection support
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expand
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diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 89800fc7dc9d..b397bc3b954d 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -514,30 +514,6 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) __set_current_state(TASK_RUNNING); - if (return_to_userland) { - if (signal_pending(current) && - !fatal_signal_pending(current)) { - /* - * If we got a SIGSTOP or SIGCONT and this is - * a normal userland page fault, just let - * userland return so the signal will be - * handled and gdb debugging works. The page - * fault code immediately after we return from - * this function is going to release the - * mmap_sem and it's not depending on it - * (unlike gup would if we were not to return - * VM_FAULT_RETRY). - * - * If a fatal signal is pending we still take - * the streamlined VM_FAULT_RETRY failure path - * and there's no need to retake the mmap_sem - * in such case. - */ - down_read(&mm->mmap_sem); - ret = VM_FAULT_NOPAGE; - } - } - /* * Here we race with the list_del; list_add in * userfaultfd_ctx_read(), however because we don't ever run