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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD89CC433EF for ; Tue, 5 Oct 2021 12:20:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A439B6117A for ; Tue, 5 Oct 2021 12:20:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234731AbhJEMW3 (ORCPT ); Tue, 5 Oct 2021 08:22:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233784AbhJEMW2 (ORCPT ); Tue, 5 Oct 2021 08:22:28 -0400 Received: from mail-wr1-x449.google.com (mail-wr1-x449.google.com [IPv6:2a00:1450:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F26C061749 for ; Tue, 5 Oct 2021 05:20:37 -0700 (PDT) Received: by mail-wr1-x449.google.com with SMTP id w2-20020a5d5442000000b0016061c95fb7so5651557wrv.12 for ; Tue, 05 Oct 2021 05:20:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=m/O1dgx/6dc/3G/WHpfSWl4EY1iI+ZyzOq/yOOojIvY=; b=OD7BHJzoRVq9YndsXgA6wM/uouP19YQUkJYZ8SUt7BtxMUEI+dl3vAXpdyo4nfKnWt Vsk3eSZrnL0Xe2Kf7qXbwwa9X56ZprMhgVUSz8+b4KMXu1kWFP2HjR5vgHXhPoy3q2uk X3Ii7WpVkiUK2r48b53wLkrH/4pqCMMwoVCZy/1d9SHnKai8GthwWqAm0kbbsLwMqyTZ L1rwzgHNArnHLbBPv0/S6y4EUzjDFknvyxBXSxWd2aNnJOK/6Th6VsFTHqsxAsWAuz5N 4/OkIdVv/6RiRMYvlaDGJumhw+2CBQPd+nv8BstqehoOILYGz0t1fie2R4BxE5Rh3G3V 6DuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=m/O1dgx/6dc/3G/WHpfSWl4EY1iI+ZyzOq/yOOojIvY=; b=LjWtRA988rxGOdPMVMAURGCob11WdRJy9kJ8Z3UrGO5QzK7hZyQGYt93gRVahOaCW/ UilprWbRt1DuJpPnWIDFJxAY9c006aJlV+aMkd+Nbewk8OT7gAhcKN/Ar3FArmqbwRHH rDLhXmlBCIwIIOryPxdq8ZCE0hOeRYFIDTpM1eVUxSynHie0+XLRBNnD3WWH37ybLDYd USrbX2173yVCvAQOj5xWFCePheOSQf8gMNLJwD24ZeyB6uGrWRTjKuemsIE7U0UgtdES HHA/sZ2uZC9FQrBlF1MFnHOUsv6m4E+DiMZBudqqSiUcGskyUAGacLJcZ/JSfgnevRWS 8e8w== X-Gm-Message-State: AOAM530K+ioPGeu6RWWsnMdXAUc9NmCZWyK62ACGe65jlBjfhhtWU+97 I4NX2TJclLhAV83cLlGsmnI7TuO5iiNH X-Google-Smtp-Source: ABdhPJwmuoUenb0uSWOlCBVEwk5H7f0VMu8HbnUjMB8fSNcFpLR024d7GwmK+6XLgt3zfreUU7OOwG2C8UMa X-Received: from luke.lon.corp.google.com ([2a00:79e0:d:210:c8bd:fb02:d32e:faa0]) (user=qperret job=sendgmr) by 2002:a05:600c:3b26:: with SMTP id m38mr612627wms.0.1633436435583; Tue, 05 Oct 2021 05:20:35 -0700 (PDT) Date: Tue, 5 Oct 2021 13:20:31 +0100 Message-Id: <20211005122031.809857-1-qperret@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.33.0.800.g4c38ced690-goog Subject: [PATCH] KVM: arm64: Release mmap_lock when using VM_SHARED with MTE From: Quentin Perret To: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , Steven Price , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Cc: kernel-team@android.com, Quentin Perret Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org VM_SHARED mappings are currently forbidden in a memslot with MTE to prevent two VMs racing to sanitise the same page. However, this check is performed while holding current->mm's mmap_lock, but fails to release it. Fix this by releasing the lock when needed. Fixes: ea7fc1bb1cd1 ("KVM: arm64: Introduce MTE VM feature") Signed-off-by: Quentin Perret --- arch/arm64/kvm/mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 1a94a7ca48f2..69bd1732a299 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1529,8 +1529,10 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, * when updating the PG_mte_tagged page flag, see * sanitise_mte_tags for more details. */ - if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) - return -EINVAL; + if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) { + ret = -EINVAL; + break; + } if (vma->vm_flags & VM_PFNMAP) { /* IO region dirty page logging not allowed */ -- 2.33.0.800.g4c38ced690-goog