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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 BCDF1C433E0 for ; Wed, 3 Mar 2021 16:22:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8215064EE7 for ; Wed, 3 Mar 2021 16:22:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1452739AbhCCQSm (ORCPT ); Wed, 3 Mar 2021 11:18:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:50678 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234416AbhCCLmM (ORCPT ); Wed, 3 Mar 2021 06:42:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0BE0D64EE3; Wed, 3 Mar 2021 11:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614770980; bh=X7znKVskg1MlkzK8CLsnoOUCSQ1ohITe7zhHreZVWvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y7Px4czelhdxpnQqPohTeAkivJu14CrWiCChoxyi1u+XEAGiMgtLkXZS9u39tk0iC l4/9e3Z4DXcJA0j3KX467gCLH+t8DTdunFYUD9ntLfXo5l55Om6BZL6ymwlb51i2iz 5zH6uKZVR5hWvP1Kw+nLxcrV/+YNwn505/gqmWjqTKerlDBA7YDc9UALsm2h1lyfhw zX4n2c5kvLYSWzATKD2Zi+r/6HIXXev+o8tcc8vSVaz+sXZzQUUXXxoE1/NOpvcHj8 wvoYNa9UeC/HIVOfHJvMsTXGdKb3mx75IkVg8DjaPUCupMuPFzGRPRA1JReXPzPiZd Xxk7dmhide6QQ== Date: Wed, 3 Mar 2021 11:29:34 +0000 From: Will Deacon To: Jia He Cc: Marc Zyngier , kvmarm@lists.cs.columbia.edu, James Morse , Julien Thierry , Suzuki K Poulose , Catalin Marinas , Gavin Shan , Yanan Wang , Quentin Perret , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: Fix unaligned addr case in mmu walking Message-ID: <20210303112934.GA18452@willie-the-truck> References: <20210303024225.2591-1-justin.he@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210303024225.2591-1-justin.he@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 03, 2021 at 10:42:25AM +0800, Jia He wrote: > 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); Can you replace both of these lines with: data->addr = ALIGN(data->addr, kvm_granule_size(level)); instead? Will 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=-15.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 44333C433DB for ; Wed, 3 Mar 2021 11:29:48 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 6D4A064EDF for ; Wed, 3 Mar 2021 11:29:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D4A064EDF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 E71224B498; Wed, 3 Mar 2021 06:29:46 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org 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 C79DXnYstXdE; Wed, 3 Mar 2021 06:29:45 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D3A7C4B329; Wed, 3 Mar 2021 06:29:45 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 36B2A4B329 for ; Wed, 3 Mar 2021 06:29:44 -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 18JXpDbE99Jr for ; Wed, 3 Mar 2021 06:29:43 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 3E7044B2C0 for ; Wed, 3 Mar 2021 06:29:43 -0500 (EST) Received: by mail.kernel.org (Postfix) with ESMTPSA id 0BE0D64EE3; Wed, 3 Mar 2021 11:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614770980; bh=X7znKVskg1MlkzK8CLsnoOUCSQ1ohITe7zhHreZVWvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y7Px4czelhdxpnQqPohTeAkivJu14CrWiCChoxyi1u+XEAGiMgtLkXZS9u39tk0iC l4/9e3Z4DXcJA0j3KX467gCLH+t8DTdunFYUD9ntLfXo5l55Om6BZL6ymwlb51i2iz 5zH6uKZVR5hWvP1Kw+nLxcrV/+YNwn505/gqmWjqTKerlDBA7YDc9UALsm2h1lyfhw zX4n2c5kvLYSWzATKD2Zi+r/6HIXXev+o8tcc8vSVaz+sXZzQUUXXxoE1/NOpvcHj8 wvoYNa9UeC/HIVOfHJvMsTXGdKb3mx75IkVg8DjaPUCupMuPFzGRPRA1JReXPzPiZd Xxk7dmhide6QQ== Date: Wed, 3 Mar 2021 11:29:34 +0000 From: Will Deacon To: Jia He Subject: Re: [PATCH] KVM: arm64: Fix unaligned addr case in mmu walking Message-ID: <20210303112934.GA18452@willie-the-truck> References: <20210303024225.2591-1-justin.he@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210303024225.2591-1-justin.he@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Marc Zyngier , kvmarm@lists.cs.columbia.edu 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: , 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 On Wed, Mar 03, 2021 at 10:42:25AM +0800, Jia He wrote: > 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); Can you replace both of these lines with: data->addr = ALIGN(data->addr, kvm_granule_size(level)); instead? Will _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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=-15.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 74F4AC433E0 for ; Wed, 3 Mar 2021 20:59:51 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 527DE64EF8 for ; Wed, 3 Mar 2021 20:59:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 527DE64EF8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yp+nFcOd5RkokXF9tJwecsb7PDPGBA6wxPHcLzUhEhw=; b=RcW5lEfOPIgEqm1dfouibAoHA Qxyjs4E9Y3nHjIu0/yD8L6XuEdr5u7hOlJa6rSAZroS++KT7guDXtCBdcrULie/HlSUmoT0dmqZaD zkQN55cvGgXKm7bPNQG4jU7vR71xn/JTWxsK+BX2wVpX8yXgYNxrtdKD1O0iLEo5hmiAx2jysafzF Qxp77yeZf6ec3pQbUksdg8uFZyoe7nUBF6yy/9RYSBujSvOurser32Rjjqd/2zc+oGRFBnzN80Fw4 D3SFBgXBIZpnORlppwF0TKB80szwq+iJim79/hQGT0n1spGlqFt6phlPUTrGJ2dewXmE1cc31x+t1 yrH+AFu7g==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lHYYV-006VY6-6B; Wed, 03 Mar 2021 20:57:15 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lHT7V-005JR1-9s for linux-arm-kernel@desiato.infradead.org; Wed, 03 Mar 2021 15:09:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=RriJq/n5sl8RSjiqndqo1qhf8YGldDu7mV+1BT37pjw=; b=fQIzksJZWTKy9VEAqWGzWc5RfU NuSQ1iARKGBBUafMZnNhrihCXJLmjeCsOGF/nmi6iLKqg7LiZYOlttRwIlPbT8GNjLftAjRREQNRT CwxELc8l0WKoZ9PhMakbS2oGFwgke0pLEAFT/rAPfVEitPP7L8fuUnbPRCh5SgLKq3aUBlo/hTbbR VXDxN6fYk4SDJCCzjV8WayddOWfyV3Sdd6k8lpjTNiGP+ctP2o1ffVs6tifuAWV699UwIL9BJ6JzY qRV/ssAYhVxdjDKjv9hrdy0zYwbZYR54aM9/r8A3yJAfjpmkmtU5Zlgd7s8+X5zc6W+Iq4cLolvLj mjZZAR3Q==; Received: from mail.kernel.org ([198.145.29.99]) by casper.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lHPsf-002OBZ-9H for linux-arm-kernel@lists.infradead.org; Wed, 03 Mar 2021 11:41:30 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0BE0D64EE3; Wed, 3 Mar 2021 11:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614770980; bh=X7znKVskg1MlkzK8CLsnoOUCSQ1ohITe7zhHreZVWvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y7Px4czelhdxpnQqPohTeAkivJu14CrWiCChoxyi1u+XEAGiMgtLkXZS9u39tk0iC l4/9e3Z4DXcJA0j3KX467gCLH+t8DTdunFYUD9ntLfXo5l55Om6BZL6ymwlb51i2iz 5zH6uKZVR5hWvP1Kw+nLxcrV/+YNwn505/gqmWjqTKerlDBA7YDc9UALsm2h1lyfhw zX4n2c5kvLYSWzATKD2Zi+r/6HIXXev+o8tcc8vSVaz+sXZzQUUXXxoE1/NOpvcHj8 wvoYNa9UeC/HIVOfHJvMsTXGdKb3mx75IkVg8DjaPUCupMuPFzGRPRA1JReXPzPiZd Xxk7dmhide6QQ== Date: Wed, 3 Mar 2021 11:29:34 +0000 From: Will Deacon To: Jia He Cc: Marc Zyngier , kvmarm@lists.cs.columbia.edu, James Morse , Julien Thierry , Suzuki K Poulose , Catalin Marinas , Gavin Shan , Yanan Wang , Quentin Perret , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: Fix unaligned addr case in mmu walking Message-ID: <20210303112934.GA18452@willie-the-truck> References: <20210303024225.2591-1-justin.he@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210303024225.2591-1-justin.he@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210303_114130_025206_4867B07B X-CRM114-Status: GOOD ( 17.86 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 03, 2021 at 10:42:25AM +0800, Jia He wrote: > 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); Can you replace both of these lines with: data->addr = ALIGN(data->addr, kvm_granule_size(level)); instead? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel