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=-9.0 required=3.0 tests=DATE_IN_PAST_06_12, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 DC1EAC4740C for ; Mon, 9 Sep 2019 22:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFFAF21A4A for ; Mon, 9 Sep 2019 22:17:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067479; bh=jiWQb9vIJcyuQQYnH8FA+Q2/8IDnSEMWoxN1zIuW1pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OtEXfQwCFFSqy7lAXbqZnN9vlQ2clHjxxh0ui0Eus1rv1kVFD41Y4My+N6gdHnMLv nQdznJuCLTwN3rDRjOuKhWS5SKSaVxmzJ75Wr0YHXf22KaREiTs4QDE7b+aMiKLLKU b/n1YOj2udg390rdG8Ic3qiYUZ9FtigSblBrt5mI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392185AbfIIWRO (ORCPT ); Mon, 9 Sep 2019 18:17:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:46298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392165AbfIIWRO (ORCPT ); Mon, 9 Sep 2019 18:17:14 -0400 Received: from sasha-vm.mshome.net (unknown [62.28.240.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5327A222C4; Mon, 9 Sep 2019 22:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067433; bh=jiWQb9vIJcyuQQYnH8FA+Q2/8IDnSEMWoxN1zIuW1pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OCWtE/BIlTET/6L6gVPOKYO4uI+0J7lIYNAShZdrat8cx5k3NeT6KFWQRrFDLAdTO KHa7hvKoov1MYGShdHwDjYuU0QnwR4Mfd0NLmO8CCZQym5avidpIjWc8ST8h6kuoGF AGgYJ4Z7wFwlRbctAYBHR36hRDFPi+9cWQFLbz9s= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Joerg Roedel , Qian Cai , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 4.14 8/8] iommu/amd: Fix race in increase_address_space() Date: Mon, 9 Sep 2019 11:41:45 -0400 Message-Id: <20190909154145.31263-8-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190909154145.31263-1-sashal@kernel.org> References: <20190909154145.31263-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Joerg Roedel [ Upstream commit 754265bcab78a9014f0f99cd35e0d610fcd7dfa7 ] After the conversion to lock-less dma-api call the increase_address_space() function can be called without any locking. Multiple CPUs could potentially race for increasing the address space, leading to invalid domain->mode settings and invalid page-tables. This has been happening in the wild under high IO load and memory pressure. Fix the race by locking this operation. The function is called infrequently so that this does not introduce a performance regression in the dma-api path again. Reported-by: Qian Cai Fixes: 256e4621c21a ('iommu/amd: Make use of the generic IOVA allocator') Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd_iommu.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 822c85226a29f..a1174e61daf4e 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1337,18 +1337,21 @@ static void domain_flush_devices(struct protection_domain *domain) * another level increases the size of the address space by 9 bits to a size up * to 64 bits. */ -static bool increase_address_space(struct protection_domain *domain, +static void increase_address_space(struct protection_domain *domain, gfp_t gfp) { + unsigned long flags; u64 *pte; - if (domain->mode == PAGE_MODE_6_LEVEL) + spin_lock_irqsave(&domain->lock, flags); + + if (WARN_ON_ONCE(domain->mode == PAGE_MODE_6_LEVEL)) /* address space already 64 bit large */ - return false; + goto out; pte = (void *)get_zeroed_page(gfp); if (!pte) - return false; + goto out; *pte = PM_LEVEL_PDE(domain->mode, iommu_virt_to_phys(domain->pt_root)); @@ -1356,7 +1359,10 @@ static bool increase_address_space(struct protection_domain *domain, domain->mode += 1; domain->updated = true; - return true; +out: + spin_unlock_irqrestore(&domain->lock, flags); + + return; } static u64 *alloc_pte(struct protection_domain *domain, -- 2.20.1