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 752C3C61DA4 for ; Thu, 16 Feb 2023 05:20:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229819AbjBPFUV (ORCPT ); Thu, 16 Feb 2023 00:20:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229623AbjBPFTW (ORCPT ); Thu, 16 Feb 2023 00:19:22 -0500 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 5931636FC0 for ; Wed, 15 Feb 2023 21:18:47 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id n20-20020a25da14000000b008fa1d22bd55so840318ybf.21 for ; Wed, 15 Feb 2023 21:18:47 -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=zeEKIs6RouZ3NeHI7ZJ8m5Jmv1yLdTyFBRJo2pt5tCE=; b=Hd3NZlonbpCzy5K7Z5feVeMneevLupNr2wIBk8xrF2F0FeVHuTW7v0p8Iwz465OudO Kz/cwziHnFST/NwsyYv9H1NpjXxfHSGLxO5ukc+3xsoPYXaSl8+RA3RdmvmM4fbLpXN9 gimJ3OxJZ4Ep64JmtioAuz7PGMRMavPtJuthlMhEIfRvRDzYwwXEt+kIY/UhQ/1ohnXV Mp7Yg73p6F/OdwNe1qmUkwSe8yYAoyBy/8c1r/0Zsdj45B+B6DEhDKlW7MvfqHG54uOt TWogzsTy9UemTUaeFAzTdpALJEgq+fwHHnoe+QVimQT+Dp4bg9S2kMJXbPj9+Gb2VnGT o48A== 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=zeEKIs6RouZ3NeHI7ZJ8m5Jmv1yLdTyFBRJo2pt5tCE=; b=FV5sNiMFzNHCNtvK23N/vPhSa88H749KUN2uP8iGhzQx7K+wYFs1fqloQJUvbcXwwg R6OKWNFPaTzj3aQ2TYOncfxBOFMPMgNgy26wQgmT1raRUN6gkZDZsu+ISTS/H0Z67FfD y//3p7Ht8NcQcJOsE0R5EKGDQBbSVAmN5Jp5V/fIvBJFu7WIKaMjqfJeR/XbsZ3ugZ9O Gf7cNJgPhJhHE/ssF9UCDaxtENN77oeH8NbNvBolB80oYXxW+QFw3sgRU+bDxqDmkptv Y19RdCjRxtkZZRhGP3oFjspef3lPMMBzFiMjQ+Cl8BTrRAWDnCYOqQo8/9RKAG8c+PBs lGKA== X-Gm-Message-State: AO0yUKXXbwg/WF7QEdet7cIP1MfWQvGumGsRur2t0XDBnuXUE5A3xB82 /BFlWIVTGqFtpiO7QVMvyvvaD8FvLws= X-Google-Smtp-Source: AK7set9EG6pwKD6Qe8/WGqDgk7Um8RE2RvPxkguhsK1CKP8nzrHSAEE/Znnb7/ves5IDs/PTEla86+djibg= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:f781:d5ed:1806:6ebb]) (user=surenb job=sendgmr) by 2002:a5b:604:0:b0:859:2acc:deb6 with SMTP id d4-20020a5b0604000000b008592accdeb6mr561571ybq.79.1676524725671; Wed, 15 Feb 2023 21:18:45 -0800 (PST) Date: Wed, 15 Feb 2023 21:17:36 -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: <20230216051750.3125598-22-surenb@google.com> Subject: [PATCH v3 21/35] mm/mmap: write-lock adjacent VMAs if they can grow into unmapped area 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While unmapping VMAs, adjacent VMAs might be able to grow into the area being unmapped. In such cases write-lock adjacent VMAs to prevent this growth. Signed-off-by: Suren Baghdasaryan --- mm/mmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 118b2246bba9..00f8c5798936 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2399,11 +2399,13 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, * down_read(mmap_lock) and collide with the VMA we are about to unmap. */ if (downgrade) { - if (next && (next->vm_flags & VM_GROWSDOWN)) + if (next && (next->vm_flags & VM_GROWSDOWN)) { + vma_start_write(next); downgrade = false; - else if (prev && (prev->vm_flags & VM_GROWSUP)) + } else if (prev && (prev->vm_flags & VM_GROWSUP)) { + vma_start_write(prev); downgrade = false; - else + } else mmap_write_downgrade(mm); } -- 2.39.1