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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2647DC433DB for ; Wed, 3 Mar 2021 02:42:43 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 652BF64EBB for ; Wed, 3 Mar 2021 02:42:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 652BF64EBB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D46104B714; Tue, 2 Mar 2021 21:42:41 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 2Xkh2ILurEIs; Tue, 2 Mar 2021 21:42:40 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id BB20F4B709; Tue, 2 Mar 2021 21:42:40 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4DF974B707 for ; Tue, 2 Mar 2021 21:42:40 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tSmRKDhWcanL for ; Tue, 2 Mar 2021 21:42:39 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 10F0A4B67B for ; Tue, 2 Mar 2021 21:42:39 -0500 (EST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8D8B71FB; Tue, 2 Mar 2021 18:42:38 -0800 (PST) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.110]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A34EE3F73B; Tue, 2 Mar 2021 18:42:34 -0800 (PST) From: Jia He To: Marc Zyngier , kvmarm@lists.cs.columbia.edu Subject: [PATCH] KVM: arm64: Fix unaligned addr case in mmu walking Date: Wed, 3 Mar 2021 10:42:25 +0800 Message-Id: <20210303024225.2591-1-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 Cc: Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jia He , Will Deacon X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu If the start addr is not aligned with the granule size of that level. loop step size should be adjusted to boundary instead of simple kvm_granual_size(level) increment. Otherwise, some mmu entries might miss the chance to be walked through. E.g. Assume the unmap range [data->addr, data->end] is [0xff00ab2000,0xff00cb2000] in level 2 walking and NOT block mapping. And the 1st part of that pmd entry is [0xff00ab2000,0xff00c00000]. The pmd value is 0x83fbd2c1002 (not valid entry). In this case, data->addr should be adjusted to 0xff00c00000 instead of 0xff00cb2000. Without this fix, userspace "segment fault" error can be easily triggered by running simple gVisor runsc cases on an Ampere Altra server: docker run --runtime=runsc -it --rm ubuntu /bin/bash In container: for i in `seq 1 100`;do ls;done Reported-by: Howard Zhang Signed-off-by: Jia He --- arch/arm64/kvm/hyp/pgtable.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index bdf8e55ed308..4d99d07c610c 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -225,6 +225,7 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data, goto out; if (!table) { + data->addr = ALIGN_DOWN(data->addr, kvm_granule_size(level)); data->addr += kvm_granule_size(level); goto out; } -- 2.17.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm