From patchwork Thu Feb 16 05:17:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 57866 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp117550wrn; Wed, 15 Feb 2023 21:21:58 -0800 (PST) X-Google-Smtp-Source: AK7set8e2YaGYYdGMGdW+BskZ/osK2QrvyJL5xo5waveTjGTof7W0B0+4IcT+gvHKTB8yNvGxKkP X-Received: by 2002:a05:6402:1209:b0:4ab:ed5:dd46 with SMTP id c9-20020a056402120900b004ab0ed5dd46mr4503383edw.6.1676524918434; Wed, 15 Feb 2023 21:21:58 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1676524918; cv=none; d=google.com; s=arc-20160816; b=lc5WfhZIlGxJow/Bb0xLgXdfcdBRHbKoroEkbiy3raLpyM8AJyG5iTvsJ06oFOMLU2 +ATQyoNelrUK5SOYSvcCiwvYCeIHflRlGMwvZVmAI2iNKZx+X59bYOJZdJwyG6zq+jIk dRbU+EfWSsFDHVRbCxJqwdR3C69UE6uL+vPv1DeKF2aojvY0IcEgx5TcqYr658PeHbrq dQtyyQ686fXi/ALbhCE/yzMOP9K0jwBXMa/c134RC3RK6gcIgufl+BjIgKvi+kHYAPRB zJbFDsHBnK45GlFpnHUKQ+jI1n3G4bojz+t3hA0LJaBcU+emmSY7XEQQCUznnExBT555 aKyQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:dkim-signature; bh=2G5AxmmOVrsRnXlCrW6/hvh5FUxSjD+0mS6LSWzYfho=; b=TljBfmPRnHisxsPCABwPl4uXb/WLvcc/g1q6o/7HA6Q5LXIjg1m2geIYo2wqKzyC+b 7WsyBtC9rPdjj+whpVfZaqIkYJWp6gdhOCU3+aYlsgNrVbdA/js8bcQFhRhCJHMrTLVp j9SD+Rc9BflrsPeUPjMkJmRdvBstgn0IWfXb+O2aleEPNTB3AopNqRlGWFX1jt2vBOYH oa/YrhH+vzHpvqNIaMv5KsQ2rkzzLl+2OcCy6OVcWL88m0VpWWPd3izKcdO9ZZjk0Zsg NgpnJkmT+KUR4Ljc6HIpbpdUE6JOCwAG13hmCnnF6VLvViz+ANWfF1UITu2rS+LZELx9 jLFA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=sqrDU+BC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ca8-20020aa7cd68000000b004acbf1d6be0si1079821edb.107.2023.02.15.21.21.35; Wed, 15 Feb 2023 21:21:58 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=sqrDU+BC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229808AbjBPFVD (ORCPT + 99 others); Thu, 16 Feb 2023 00:21:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbjBPFT7 (ORCPT ); Thu, 16 Feb 2023 00:19:59 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3886A47435 for ; Wed, 15 Feb 2023 21:19:05 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-52f1641b79aso8473097b3.16 for ; Wed, 15 Feb 2023 21:19:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=2G5AxmmOVrsRnXlCrW6/hvh5FUxSjD+0mS6LSWzYfho=; b=sqrDU+BCO7AIuj2EKpC5JjJjchpfs4e7nICzmha43sQtLyfoiEZwLUOwsCD209H5Ui lu0l/EwT0lWrDRHYoglaYWRXNYPJ1g8O+GpgkaLO5UTCsF2sShD98xQNq7PDWtH66r6g ZsB+oua1JfA0KymwRm2/PgdgPfreEDDqnwQyHLX1ndmfndQgCQh8neVqDDo8QNluQIit psaYv9QythR+X2eyBbc1tAjHl/fZRS54lIuiB1Ux7odRjp5k2KlmRL+IIzajgpgWcCV1 agKdJl/mJ1QtI4UVDWAjmp+dEFlVMZYnML3DG7HfRey4EeaADk1hZvmemdIk3Yb/sCoK 4MXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2G5AxmmOVrsRnXlCrW6/hvh5FUxSjD+0mS6LSWzYfho=; b=qcvcJ7dngs44avmgN2LjXdG3axYwu76OjwEDxZMCxitMtZmyibKsvEieuLyIaDIgMT Ux9wBggc/OxN5ps3xj4qIVEzv1iLEt8Qj2FkAkXpspsWYuaSL6zSiuSy1ab/2sS0RNXb KM8f6tyGsD//Z+eT5vtsJJZHDI95ML/IT6riKW13ChKKyTuOOIWwCg2EBjdrN5fsf7X7 KFPkdUlkTBooBc9ux+B4zvNL3AttzdcrIlMsXsBTk7UZsNHeES0g3T5g5Q4W+eThqu4U zFCmeMyvQazWW1qHwvKxGempdmVRABGpRMde9dpQKLqTV8u2UVG+zyhPM5SRK/rgR1R9 esGw== X-Gm-Message-State: AO0yUKXlruymgF53lwLGKjQnHxo2z7Ccm+A2u2ihQPj9RIP0GdTT2KRm 8gFlMHt/odByyC+J98YaIDEquQxG4zw= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:f781:d5ed:1806:6ebb]) (user=surenb job=sendgmr) by 2002:a05:6902:13c6:b0:8da:3163:224 with SMTP id y6-20020a05690213c600b008da31630224mr7ybu.0.1676524744013; Wed, 15 Feb 2023 21:19:04 -0800 (PST) Date: Wed, 15 Feb 2023 21:17:44 -0800 In-Reply-To: <20230216051750.3125598-1-surenb@google.com> Mime-Version: 1.0 References: <20230216051750.3125598-1-surenb@google.com> X-Mailer: git-send-email 2.39.1.581.gbfd45094c4-goog Message-ID: <20230216051750.3125598-30-surenb@google.com> Subject: [PATCH v3 29/35] mm: prevent userfaults to be handled under per-vma lock From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, chriscli@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, rppt@kernel.org, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, leewalsh@google.com, posk@google.com, michalechner92@googlemail.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, Suren Baghdasaryan X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1757963793025781724?= X-GMAIL-MSGID: =?utf-8?q?1757963793025781724?= Due to the possibility of handle_userfault dropping mmap_lock, avoid fault handling under VMA lock and retry holding mmap_lock. This can be handled more gracefully in the future. Signed-off-by: Suren Baghdasaryan Suggested-by: Peter Xu --- mm/memory.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 555612d153ad..751aebc1b29f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5254,6 +5254,15 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, if (!vma_start_read(vma)) goto inval; + /* + * Due to the possibility of userfault handler dropping mmap_lock, avoid + * it for now and fall back to page fault handling under mmap_lock. + */ + if (userfaultfd_armed(vma)) { + vma_end_read(vma); + goto inval; + } + /* Check since vm_start/vm_end might change before we lock the VMA */ if (unlikely(address < vma->vm_start || address >= vma->vm_end)) { vma_end_read(vma);