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=-8.7 required=3.0 tests=DATE_IN_PAST_06_12, DKIM_INVALID,DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 2D65EC4740A for ; Mon, 9 Sep 2019 22:16:56 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 F283D21D7B for ; Mon, 9 Sep 2019 22:16:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="D3m8qC90" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F283D21D7B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 6D147A80; Mon, 9 Sep 2019 22:16:54 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id DFDB0AD0 for ; Mon, 9 Sep 2019 22:16:53 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 92F20EC for ; Mon, 9 Sep 2019 22:16:53 +0000 (UTC) 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 39A1C222BD; Mon, 9 Sep 2019 22:16:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067413; bh=rbeWn0IPTd+TWEds9YFtOWj5EmQqVblA0ypZpXd4tiw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D3m8qC90I9xmd2fNQSDpJd5r0A+ZBOUj4j7g776mfVTmoO/JeoDk+kZhb8TrHxIOD sakDNQuPM1BnwaZT9bIm51Vgs+jVCv2M80uPFAolNZjcx2shnEKfn41ckc3CfB6BSe Lu/OElj5YfV4cwV6jYy3g/rpfZFqT3FPrZLDW/68= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 8/8] iommu/amd: Fix race in increase_address_space() Date: Mon, 9 Sep 2019 11:41:23 -0400 Message-Id: <20190909154124.31146-8-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190909154124.31146-1-sashal@kernel.org> References: <20190909154124.31146-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Cc: Sasha Levin , iommu@lists.linux-foundation.org, Joerg Roedel X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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 Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.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 8b79e2b32d378..69c269dc4f1bf 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1340,18 +1340,21 @@ 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)); @@ -1359,7 +1362,10 @@ 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu