From patchwork Tue Jun 20 23:57:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 110717 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp4022071vqr; Tue, 20 Jun 2023 17:11:45 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ7Hn5zPi1+6pCA6pAe8eB0f+e6ZqjK3nIzkg3Z8pX3L866pNGmR165gSvrcc8WY2jdatjv2 X-Received: by 2002:a05:6a20:2588:b0:11d:2764:d9c1 with SMTP id k8-20020a056a20258800b0011d2764d9c1mr17680416pzd.51.1687306304934; Tue, 20 Jun 2023 17:11:44 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1687306304; cv=none; d=google.com; s=arc-20160816; b=iRzpy3WdgiMYL/LmfJV+DJQHuaE/KtRYBfAD3/rKwJMeiNLRtqsL9BdicEjRX/oCSq WvIsr2zdZLoE/nr0RBuD690Qu+/RZ9njEJVpXBc8hq3xXCn4dO8SiqznZ7B41X1/+q4s DgVY56SOvYLIZWrrd3y45+HDlGIETq5ilLh2xsXdoYrVr/D6yO7ghwY6kVj5qRoBsoRo +vtqsm4Hl8kwcgigGy9/Y1SpgyApMxDrcYnOrPGRg5+DhTLpPN8t6C9iCjML8zWnQfOT 4GbEaLc9bBK/W0x5o1zHL/PhbippuSa0vgRlrAnVLZGI3VOLjRTtb0MLSXp8zZo75gWh ioSg== 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:mime-version:date :dkim-signature; bh=6My5zaxRwCubM/znAlFWMrzsQs0o4/hMLfIyqDwIdCM=; b=fVOCNIae4ROODCePGMr+EbgpumNLIvQ2IX1KHRViVn8IYEpj5FWtWncz7qypkRllmp 7zE1bvTRQVE3FX9Bi0Vz9swiFJYTOI9PrDImiFBC7iEhgfi784/kWaTHWkYpEM6+FUXG iRnXqBfn9uAHrAa4UK3TZVe79FY1Z24KnmZtBd5ITljTgtn7aW+n5GkBBunkEXz+mWXl X42ur/eaXtB0Q55NGH7gqT81S8ACrjUPDcVf3qh1Ewbqp08JmUikDy0ZCGiYaNoYKSC+ /rozlSsBZhPU1qOJ/Rx9Xk0paa7G7UaJ+S02Di/qeNIyuXU1l5TuWeYTFNZ3TdJb2/a/ WuMw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=CSSYpE6o; 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 y16-20020a63b510000000b00547a1922957si2639071pge.407.2023.06.20.17.11.31; Tue, 20 Jun 2023 17:11:44 -0700 (PDT) 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=20221208 header.b=CSSYpE6o; 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 S229684AbjFTX5c (ORCPT + 99 others); Tue, 20 Jun 2023 19:57:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229490AbjFTX5b (ORCPT ); Tue, 20 Jun 2023 19:57:31 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91636184 for ; Tue, 20 Jun 2023 16:57:30 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-be7e1d31646so4685638276.0 for ; Tue, 20 Jun 2023 16:57:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687305450; x=1689897450; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=6My5zaxRwCubM/znAlFWMrzsQs0o4/hMLfIyqDwIdCM=; b=CSSYpE6o2vAYB+EczjNxHQoW9ZZEIQkPp00UpPzxbzxvXBVI4La9GGnHYy8QOAimev sfzfDqWb0009TEU/RKdrkDPXynJU93p0tuZD9SmZGHcLexKdiOKqZWJHOqcUGvtktcrY 6STtqvnsGmXhMto4nbyL6fX0OZ5Mm8HfxnS/LYv9XTquxzNy8LHbClyPaVrhoICYyZ/2 g7WkUN6m7pcrbGPcMrAUVmt45VALmV9NtE5bNAkafpbx7TM/rk6YC/Ke8TslHhaYfECz 8sS3IXfjPcEJnj01RFYOknIlwJz0+ih21+BBteNcARxJv49L9w0p5ZwII+bz34K/JCZ/ JX1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687305450; x=1689897450; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=6My5zaxRwCubM/znAlFWMrzsQs0o4/hMLfIyqDwIdCM=; b=fTP2dqNH0Qu7La1q98t1+3nzBVN642i2q5U6p5/75d1RieybWwialCmzZ5hzWtCbkt CAmwdpOlGRq3I5NvoQT++1lh1h5zRv5JDPvrLrv3i3u9deduzctweLzOfGp2rmmS5HX+ diJMRAJXBiZZfBniZIpU1s6hjOwZeJaAtIwcM4MMX2R6aZKvUlDATACIZIRZq5L7eb14 2GncxBl2M1ghttmHjKlEEh6W6+IvDCOX71WWsnR2e+5FR4rdft9rFmKSpmLc+EJPj6V2 RZeF1VU9fcOzc2rN0TN+i6HS3G1qo7GlPbdNlh5pFttDm3uFOE6vx+M18MpJ63L57ym1 oI0Q== X-Gm-Message-State: AC+VfDxYLaKjnr6gBZpLriNFpQeRYmi7GiQGNI4YhQOOxk6G6gdwx+0y viT3fQJOkjsoxNWY7ukaGE5VidBl7Rk= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:3f57:9854:e19:8906]) (user=surenb job=sendgmr) by 2002:a05:6902:91:b0:ba8:6dc0:cacf with SMTP id h17-20020a056902009100b00ba86dc0cacfmr1731864ybs.12.1687305449890; Tue, 20 Jun 2023 16:57:29 -0700 (PDT) Date: Tue, 20 Jun 2023 16:57:24 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <20230620235726.3873043-1-surenb@google.com> Subject: [PATCH 1/3] mm: change vma_start_read to fail if VMA got detached from under it From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, torvalds@linuxfoundation.org, vegard.nossum@oracle.com, mpe@ellerman.id.au, Liam.Howlett@oracle.com, lrh2000@pku.edu.cn, mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com 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,T_SCC_BODY_TEXT_LINE,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?1769268895647196409?= X-GMAIL-MSGID: =?utf-8?q?1769268895647196409?= Current implementation of vma_start_read() checks VMA for being locked before taking vma->vm_lock and then checks that again. This mechanism fails to detect a case when the VMA gets write-locked, modified and unlocked after the first check but before the vma->vm_lock is obtained. While this is not strictly a problem (vma_start_read would not produce a false unlocked result), this allows it to successfully lock a VMA which got detached from the VMA tree while vma_start_read was locking it. New condition checks for any change in vma->vm_lock_seq after we obtain vma->vm_lock and will cause vma_start_read() to fail if the above race occurs. Fixes: 5e31275cc997 ("mm: add per-VMA lock and helper functions to control it") Suggested-by: Matthew Wilcox Signed-off-by: Suren Baghdasaryan --- include/linux/mm.h | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 27ce77080c79..8410da79c570 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -639,23 +639,24 @@ static inline void vma_numab_state_free(struct vm_area_struct *vma) {} */ static inline bool vma_start_read(struct vm_area_struct *vma) { - /* Check before locking. A race might cause false locked result. */ - if (vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq)) + int vm_lock_seq = READ_ONCE(vma->vm_lock_seq); + + /* + * Check if VMA is locked before taking vma->vm_lock. A race or + * mm_lock_seq overflow might cause false locked result. + */ + if (vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq)) return false; if (unlikely(down_read_trylock(&vma->vm_lock->lock) == 0)) return false; - /* - * Overflow might produce false locked result. - * False unlocked result is impossible because we modify and check - * vma->vm_lock_seq under vma->vm_lock protection and mm->mm_lock_seq - * modification invalidates all existing locks. - */ - if (unlikely(vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq))) { + /* Fail if VMA was write-locked after we checked it earlier */ + if (unlikely(vm_lock_seq != READ_ONCE(vma->vm_lock_seq))) { up_read(&vma->vm_lock->lock); return false; } + return true; } From patchwork Tue Jun 20 23:57:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 110718 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp4022944vqr; Tue, 20 Jun 2023 17:13:35 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ79FJlnaCOaq1qxYExgXkQzY0Wrf4fQ8pxyCbFU5QxJgZ4d/natf5Y0IM7XvqxVRkOMskMp X-Received: by 2002:a05:6808:1250:b0:39e:ac75:8a09 with SMTP id o16-20020a056808125000b0039eac758a09mr10949876oiv.50.1687306415305; Tue, 20 Jun 2023 17:13:35 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1687306415; cv=none; d=google.com; s=arc-20160816; b=N6TLp0BNf6kFoDUHWFhrD+oWaBq+iRbXfsu8swiyT00HTTAwohyPDcA3nBhd8c+++G fH61aytSiQVUNzm3bw7Js1A598H8ZKFeeyRDX2PGXNNTkjPQuBoe9egyYk23dNfvPVl7 gcwAe4iq/c/wVyK1lVwWgIm1mlgomFJRcUGwz1HYREYSml+QZ3xNBWTHNkVYaGyQSGmN Q1sddFp9qILPmod+XE+WzAbpSRED3UI9PrcLKVc9atG3Qie4stTwm2NEU5FYraow7jDl Qn3RuOOYn96dRIjTgiOLVCBwdQ05h+3Is9jAPsVEnP8xmEmXj+oy8YmEQDSGpWMjY7Wa zNDw== 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=a/KyKqe8FdTi+g9/IKt8G5I/SC33PtSDDTh0FPFRaVQ=; b=yXMJ4Pc0odRVYDy2QRUT/wqyRNiqMGqObKkqPxkKapMhuBe+ujCFlmr+cVA6T52oFu Ys532HrhG0fd5mq6EvlYm7I3YrOmtgVdy1dO0Ty6OLEfb8rEZFVJCJNIARUE5fnemzGH aNHsHf/vUrhhTNNF0ebHYwgTnhTFlnGbaAA7TvD0mIJFJsf8awbxYiWRqp6FHaRV7+uw +Se7OiXfCxGNIwWmtAlDUgbbLGsDef+Ikgm7YU0V82GGgfN8LkV0ATBCOAl4S24PZEnN v4mAZMKOP/2ltGM7hOYjSshScQhm7wy1F8ZRpP7A0TOScy2LbQIDPyzAxqX2Y1V9joXX vWfA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=djOCkf7s; 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 j190-20020a636ec7000000b005572b563e5esi652140pgc.160.2023.06.20.17.13.22; Tue, 20 Jun 2023 17:13:35 -0700 (PDT) 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=20221208 header.b=djOCkf7s; 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 S229743AbjFTX5h (ORCPT + 99 others); Tue, 20 Jun 2023 19:57:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbjFTX5d (ORCPT ); Tue, 20 Jun 2023 19:57:33 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A47F4184 for ; Tue, 20 Jun 2023 16:57:32 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-bfee66a6398so214603276.3 for ; Tue, 20 Jun 2023 16:57:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687305452; x=1689897452; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=a/KyKqe8FdTi+g9/IKt8G5I/SC33PtSDDTh0FPFRaVQ=; b=djOCkf7sRmJEOqkBFJ1FAWr8LXWtr4BdpV1egpT43a8UfDOVBoBIuOCLxFedXjFa5b 1QOybvoapiGbw4NqKAvUWz+Fu19NBYstRwQlaC9K679sBdbRylerMVN2GPJl6f40HGRd jkUzOBouUCpguF36dwOGv4Mqx54tXxWhHGK35MaM5gY/XnL1tOp4MMdkKJjbjpszTSXG +MmeKpVWaqVgIGvTyv3WvYXc4kg3IolRfClLe0BDvx9p80AJntMQZuo8Dm0Z5JpwnDBm eulTjrH/K/rDevjtJ8yQo2HNk4iADzua7QHUx9I7o9do4iwPamwNMonQ11jiZ1XTlxGC ivrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687305452; x=1689897452; 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=a/KyKqe8FdTi+g9/IKt8G5I/SC33PtSDDTh0FPFRaVQ=; b=ILxhMeoka364MTW8DlMmduAN6PS8plGVx+/66KdujYXbGkF2A+mHD6p0pV96PZeY9l zJyn0rzky+sh/c62el62FOTp2hVt+2qLp8r88M0+AEgpSp6Hz6MdmyKd046pJ78i7iao TAnoSrUojGyP9QOrkgxCBIiTNDtPPFZYbNJPbXOZqrxnW27vEkJcKKTbmO9ZHsVucYno 7zu4uHXY5X+qW67PRgWPJz8fRrLld72cBSf3+AQzTinlNGZYOIodoQuadUM3V+WGddBY 1NrM7+6YkcvI6wmQrqlOXfWo1ZJeqadCucUalBHnVrzVronGDWOrcxeKIkNaUerhU2ZI Sxrw== X-Gm-Message-State: AC+VfDyQjNRB9Yx+B17nRlQXRFTn1L+sPTk5Co7SY0nBr3hGAGzlu4z2 rgE5AcZisQXQD5td0tGSZlEUQ3HQGeU= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:3f57:9854:e19:8906]) (user=surenb job=sendgmr) by 2002:a25:fc28:0:b0:ba8:5bc9:80fe with SMTP id v40-20020a25fc28000000b00ba85bc980femr5330222ybd.1.1687305451896; Tue, 20 Jun 2023 16:57:31 -0700 (PDT) Date: Tue, 20 Jun 2023 16:57:25 -0700 In-Reply-To: <20230620235726.3873043-1-surenb@google.com> Mime-Version: 1.0 References: <20230620235726.3873043-1-surenb@google.com> X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <20230620235726.3873043-2-surenb@google.com> Subject: [PATCH 2/3] mm: change vma_start_read to fail to lock a detached VMA From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, torvalds@linuxfoundation.org, vegard.nossum@oracle.com, mpe@ellerman.id.au, Liam.Howlett@oracle.com, lrh2000@pku.edu.cn, mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com 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,T_SCC_BODY_TEXT_LINE,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?1769269011757292539?= X-GMAIL-MSGID: =?utf-8?q?1769269011757292539?= vma_start_read can successfully lock a detached VMA relying on its caller to check for vma->detached. Change vma_start_read to include that check and fail if the VMA got detached. Suggested-by: Linus Torvalds Signed-off-by: Suren Baghdasaryan --- include/linux/mm.h | 4 ++-- include/linux/vm_event_item.h | 1 - mm/memory.c | 10 +--------- mm/vmstat.c | 1 - 4 files changed, 3 insertions(+), 13 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8410da79c570..74e3033c9fc2 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -651,8 +651,8 @@ static inline bool vma_start_read(struct vm_area_struct *vma) if (unlikely(down_read_trylock(&vma->vm_lock->lock) == 0)) return false; - /* Fail if VMA was write-locked after we checked it earlier */ - if (unlikely(vm_lock_seq != READ_ONCE(vma->vm_lock_seq))) { + /* Fail if VMA is detached or was write-locked after we checked it earlier */ + if (unlikely(vma->detached || vm_lock_seq != READ_ONCE(vma->vm_lock_seq))) { up_read(&vma->vm_lock->lock); return false; } diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 8abfa1240040..e741098954ff 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -154,7 +154,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, VMA_LOCK_SUCCESS, VMA_LOCK_ABORT, VMA_LOCK_RETRY, - VMA_LOCK_MISS, #endif NR_VM_EVENT_ITEMS }; diff --git a/mm/memory.c b/mm/memory.c index f69fbc251198..bd666fa20748 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5275,7 +5275,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, struct vm_area_struct *vma; rcu_read_lock(); -retry: + vma = mas_walk(&mas); if (!vma) goto inval; @@ -5306,14 +5306,6 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, goto inval; } - /* Check if the VMA got isolated after we found it */ - if (vma->detached) { - vma_end_read(vma); - count_vm_vma_lock_event(VMA_LOCK_MISS); - /* The area was replaced with another one */ - goto retry; - } - rcu_read_unlock(); return vma; inval: diff --git a/mm/vmstat.c b/mm/vmstat.c index c28046371b45..5d6acdb1b611 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1403,7 +1403,6 @@ const char * const vmstat_text[] = { "vma_lock_success", "vma_lock_abort", "vma_lock_retry", - "vma_lock_miss", #endif #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */ }; From patchwork Tue Jun 20 23:57:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 110720 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp4033838vqr; Tue, 20 Jun 2023 17:39:27 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5oFRxn6rlMn0ZW9dJ7HKbT8PL04DpwaTKVyNjV14xP9XR8rgFgXixoFDPZIRssL0M9byTx X-Received: by 2002:a05:620a:808b:b0:75d:4f25:29d1 with SMTP id ef11-20020a05620a808b00b0075d4f2529d1mr16764216qkb.66.1687307966831; Tue, 20 Jun 2023 17:39:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1687307966; cv=none; d=google.com; s=arc-20160816; b=RBk4PpAv8Vy037+TNEDTr902P+guvb9zpD7hSoxqtHjHq+ASSPghnxFtOoAxwbrdm9 oM11sy8WW2opMqocSOzIPEL2kOVAT0pauRllWvRRiGnMJliNO78P4ZKjpoZRs4xTAkw4 tfSkYOKopY77Fwp0EAO+RVOiZ7+8buEotVIOkQB3OLZUp8lQjQTGMgO4XF2NjONyv8fc fzqCjyxFsd79V5JRkn9d4542X9XbiwxCZCvKjQjdOvUE08O1bkKX7pubSuDLevM9WcZU R7wf9CW+AAcJgrPXyKxVeJz5m9jb4qx13R9VbtACjl9c1zP5TmZqvwXMXY/rjvtTpBV1 W3XA== 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=BGbrY/f1fvBNW9z8go6Nnz06u29111qaAGQndqYmZbI=; b=XvF51suGOLv5AfFy7+t2sUii310g+JwO4nGpl3X8GGqtMmSN/2vNJrzPgZ4NIocF8q vXzu0K/ufZ7dCRvAcVD4iMxeOaTUR4bHKB6EgIBgD7XQ0iRJoekiZjpvjhGImKj+egBF hd45sZkI8lWpOsaDwtGY6j7NdUtsD/9rWfO2leaGppmBvXE6v2QYlsjHJ9/AyK8sCD3b vMbPFCslP+HOQVV2wsjjBMWei63YE4xhYjI7zhemuNh21/IfyhJko+r2vDEvc5rdgEfw 4Ppi4O5lLitEndVab6wjMskaRnryBkf/G+7r80A/yvReLa33yvjBAaAYVw3+KiN2bXHo D3cA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=P9ZGKNT+; 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 y17-20020aa79e11000000b006642e5dd553si2766847pfq.221.2023.06.20.17.39.14; Tue, 20 Jun 2023 17:39:26 -0700 (PDT) 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=20221208 header.b=P9ZGKNT+; 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 S229852AbjFTX5j (ORCPT + 99 others); Tue, 20 Jun 2023 19:57:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229759AbjFTX5g (ORCPT ); Tue, 20 Jun 2023 19:57:36 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DDF819F for ; Tue, 20 Jun 2023 16:57:35 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-bf34588085bso3242704276.0 for ; Tue, 20 Jun 2023 16:57:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687305454; x=1689897454; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=BGbrY/f1fvBNW9z8go6Nnz06u29111qaAGQndqYmZbI=; b=P9ZGKNT+TEzfnNjgXfWsFMxrjrmo19InxA9Ltzw94eBOzcf0DrJjIadY39g5B1ARES UM8Tb66YAZoM1qvWyjNLmdfb7GBwdGln7qA5RgXbZWXGaZHvI0XHaH/HBL1QpJNOQgUm 6OloW5Gfvh2xzMIEA3ALlJsZDF0ta5gG6htWRcVitzaGC/HTclOzVZESltb69EPM+Vbp ulOrRqMr+3gQkWyLLTEaVyZRb1j645qYTNnqpW50MZl/4SibKrzjz7laJRB/LZnjYsyE XMOaY7sjsOrxZl8Y6VKGCVQZWc8BmHDWraN0TJszAdVqPx1QEoL6EPZTqJhDF1Ftewq7 eOYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687305454; x=1689897454; 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=BGbrY/f1fvBNW9z8go6Nnz06u29111qaAGQndqYmZbI=; b=IwOWlrT8F0vRn91nCBV0pb8nDFj7HfW3lUTIoN+Qc9c8g70aN19WpVI/Uuv/wVU0Dn igbSYKOdwDfxywZkAkvTxID9pcXAN1ZbCHZjKq3F+DcwZzD4UOZSyl00tWk8td8+je3W MRTXleCE0GVrYNbpFw0ReCPsVVzpEQJbdcSMmU1zU2V6sjw1XR3qSN/KzqG32EnrC1E+ aQHCyaqNoiI5tHOt7ft4QnfY3k0b21qVId+osLg7MA1PzotyMvFOnisoecDv3vOmdtVQ m9MK686vjDFE1mM6PHj1kw3NDegvJRrMgw43/JbhrHe63zusYMSzm7KA0oShbydpe6Y9 z6KQ== X-Gm-Message-State: AC+VfDxDaD6KJODSd+koF4j7p71HKxSB+gKkBSarZIyICUGE4RnmRK9m sAIHmEAH05yoUL5qh6WTmnDo++T0HZM= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:3f57:9854:e19:8906]) (user=surenb job=sendgmr) by 2002:a5b:bc9:0:b0:bad:41b:f343 with SMTP id c9-20020a5b0bc9000000b00bad041bf343mr5127082ybr.1.1687305454340; Tue, 20 Jun 2023 16:57:34 -0700 (PDT) Date: Tue, 20 Jun 2023 16:57:26 -0700 In-Reply-To: <20230620235726.3873043-1-surenb@google.com> Mime-Version: 1.0 References: <20230620235726.3873043-1-surenb@google.com> X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <20230620235726.3873043-3-surenb@google.com> Subject: [PATCH 3/3] mm: check for VMA being detached before destroying it From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, torvalds@linuxfoundation.org, vegard.nossum@oracle.com, mpe@ellerman.id.au, Liam.Howlett@oracle.com, lrh2000@pku.edu.cn, mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com 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,T_SCC_BODY_TEXT_LINE,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?1769270395609736634?= X-GMAIL-MSGID: =?utf-8?q?1769270638262782923?= By the time VMA is freed it has to be detached with the exception of exit_mmap which is destroying the whole VMA tree. Enforce this requirement before freeing the VMA. exit_mmap in the only user calling __vm_area_free directly, therefore it won't trigger the new check. Change VMA initialization to mark new VMAs as detached and change that flag once the VMA is added into a tree. Suggested-by: Linus Torvalds Signed-off-by: Suren Baghdasaryan --- include/linux/mm.h | 4 ++-- kernel/fork.c | 2 ++ mm/internal.h | 1 + 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 74e3033c9fc2..9a10fcdb134e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -247,7 +247,7 @@ void setup_initial_init_mm(void *start_code, void *end_code, struct vm_area_struct *vm_area_alloc(struct mm_struct *); struct vm_area_struct *vm_area_dup(struct vm_area_struct *); void vm_area_free(struct vm_area_struct *); -/* Use only if VMA has no other users */ +/* Use only if VMA has no other users and might still be attached to a tree */ void __vm_area_free(struct vm_area_struct *vma); #ifndef CONFIG_MMU @@ -751,7 +751,7 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) vma->vm_mm = mm; vma->vm_ops = &dummy_vm_ops; INIT_LIST_HEAD(&vma->anon_vma_chain); - vma_mark_detached(vma, false); + vma->detached = true; vma_numab_state_init(vma); } diff --git a/kernel/fork.c b/kernel/fork.c index 41c964104b58..000fc429345c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -540,6 +540,7 @@ static void vm_area_free_rcu_cb(struct rcu_head *head) /* The vma should not be locked while being destroyed. */ VM_BUG_ON_VMA(rwsem_is_locked(&vma->vm_lock->lock), vma); + WARN_ON_ONCE(!vma->detached); __vm_area_free(vma); } #endif @@ -549,6 +550,7 @@ void vm_area_free(struct vm_area_struct *vma) #ifdef CONFIG_PER_VMA_LOCK call_rcu(&vma->vm_rcu, vm_area_free_rcu_cb); #else + WARN_ON_ONCE(!vma->detached); __vm_area_free(vma); #endif } diff --git a/mm/internal.h b/mm/internal.h index 68410c6d97ac..728189e6c703 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1068,6 +1068,7 @@ static inline void vma_iter_store(struct vma_iterator *vmi, vmi->mas.index = vma->vm_start; vmi->mas.last = vma->vm_end - 1; mas_store_prealloc(&vmi->mas, vma); + vma_mark_detached(vma, false); } static inline int vma_iter_store_gfp(struct vma_iterator *vmi,