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=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 79F33C433DB for ; Thu, 4 Mar 2021 12:19:51 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 C68D164F11 for ; Thu, 4 Mar 2021 12:19:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C68D164F11 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 84566431D0; Thu, 4 Mar 2021 12:19:50 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iEYXOou5oKl5; Thu, 4 Mar 2021 12:19:49 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTP id 64FA342FBA; Thu, 4 Mar 2021 12:19:49 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3F1EDC000A; Thu, 4 Mar 2021 12:19:49 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0FF18C0001 for ; Thu, 4 Mar 2021 12:19:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E4F3F4EBCE for ; Thu, 4 Mar 2021 12:19:47 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Dmdaawvf9mF5 for ; Thu, 4 Mar 2021 12:19:45 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp4.osuosl.org (Postfix) with ESMTPS id B2CAD4EBCD for ; Thu, 4 Mar 2021 12:19:45 +0000 (UTC) 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 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-Disposition: inline In-Reply-To: <20210217181002.GC4304@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: valesini@yandex-team.ru, linux-kernel@vger.kernel.org, stable@vger.kernel.org, iommu@lists.linux-foundation.org, Qian Cai , Will Deacon X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu