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=-15.2 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_SANE_1 autolearn=unavailable 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 662EAC433DB for ; Thu, 4 Mar 2021 12:21:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25CEC64F1E for ; Thu, 4 Mar 2021 12:21:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240404AbhCDMUd (ORCPT ); Thu, 4 Mar 2021 07:20:33 -0500 Received: from 8bytes.org ([81.169.241.247]:57604 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240421AbhCDMUY (ORCPT ); Thu, 4 Mar 2021 07:20:24 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id A4A0722E; Thu, 4 Mar 2021 13:19:42 +0100 (CET) Date: Thu, 4 Mar 2021 13:19:41 +0100 From: Joerg Roedel To: Andrey Ryabinin Cc: Will Deacon , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Qian Cai , valesini@yandex-team.ru, stable@vger.kernel.org Subject: Re: [PATCH] iommu/amd: Fix sleeping in atomic in increase_address_space() Message-ID: <20210304121941.GB26414@8bytes.org> References: <20210217143004.19165-1-arbn@yandex-team.com> <20210217181002.GC4304@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217181002.GC4304@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Feb 17, 2021 at 06:10:02PM +0000, Will Deacon wrote: > > drivers/iommu/amd/iommu.c | 10 ++++++---- > > 1 file changed, 6 insertions(+), 4 deletions(-) > > Acked-by: Will Deacon Applied for v5.12, thanks. There were some conflicts which I resolved, can you please check the result, Andrey? The updated patch is attached. >From 140456f994195b568ecd7fc2287a34eadffef3ca Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 17 Feb 2021 17:30:04 +0300 Subject: [PATCH] iommu/amd: Fix sleeping in atomic in increase_address_space() increase_address_space() calls get_zeroed_page(gfp) under spin_lock with disabled interrupts. gfp flags passed to increase_address_space() may allow sleeping, so it comes to this: BUG: sleeping function called from invalid context at mm/page_alloc.c:4342 in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8 Call Trace: dump_stack+0x66/0x8b ___might_sleep+0xec/0x110 __alloc_pages_nodemask+0x104/0x300 get_zeroed_page+0x15/0x40 iommu_map_page+0xdd/0x3e0 amd_iommu_map+0x50/0x70 iommu_map+0x106/0x220 vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1] do_vfs_ioctl+0xa3/0x6f0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4e/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by moving get_zeroed_page() out of spin_lock/unlock section. Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()") Signed-off-by: Andrey Ryabinin Acked-by: Will Deacon Cc: Link: https://lore.kernel.org/r/20210217143004.19165-1-arbn@yandex-team.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/io_pgtable.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c index 1c4961e05c12..bb0ee5c9fde7 100644 --- a/drivers/iommu/amd/io_pgtable.c +++ b/drivers/iommu/amd/io_pgtable.c @@ -182,6 +182,10 @@ static bool increase_address_space(struct protection_domain *domain, bool ret = true; u64 *pte; + pte = (void *)get_zeroed_page(gfp); + if (!pte) + return false; + spin_lock_irqsave(&domain->lock, flags); if (address <= PM_LEVEL_SIZE(domain->iop.mode)) @@ -191,10 +195,6 @@ static bool increase_address_space(struct protection_domain *domain, if (WARN_ON_ONCE(domain->iop.mode == PAGE_MODE_6_LEVEL)) goto out; - pte = (void *)get_zeroed_page(gfp); - if (!pte) - goto out; - *pte = PM_LEVEL_PDE(domain->iop.mode, iommu_virt_to_phys(domain->iop.root)); domain->iop.root = pte; @@ -208,10 +208,12 @@ static bool increase_address_space(struct protection_domain *domain, */ amd_iommu_domain_set_pgtable(domain, pte, domain->iop.mode); + pte = NULL; ret = true; out: spin_unlock_irqrestore(&domain->lock, flags); + free_page((unsigned long)pte); return ret; } -- 2.26.2