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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 AE0E6C2BA83 for ; Fri, 14 Feb 2020 16:23:34 +0000 (UTC) Received: from hemlock.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 7C1DA24772 for ; Fri, 14 Feb 2020 16:23:34 +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="u7O2o9pt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C1DA24772 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 localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 4473487FD8; Fri, 14 Feb 2020 16:23:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6NX5DRjVBOdV; Fri, 14 Feb 2020 16:23:33 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 9B31A87FC3; Fri, 14 Feb 2020 16:23:33 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8901BC08A4; Fri, 14 Feb 2020 16:23:33 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 07A3BC0177 for ; Fri, 14 Feb 2020 16:23:32 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id EA9B92214F for ; Fri, 14 Feb 2020 16:23:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZgonPaFVlaRg for ; Fri, 14 Feb 2020 16:23:30 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by silver.osuosl.org (Postfix) with ESMTPS id BB93E204D1 for ; Fri, 14 Feb 2020 16:23:30 +0000 (UTC) Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 7703A24776; Fri, 14 Feb 2020 16:23:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581697410; bh=zg6Uq7ArT0C+WyG4FP67wrVc7ANAPFZHEsRcL6m0R6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u7O2o9pt8U4bwIJB2bBN42fv7kVC+tBRtcngVnxRe920X0lPEKQf5tUWj4XYxbkbR 72rDkaMgf9R9+9oXydNhrFZ77t0COvOdbRWy3BV4argW+4ZuM2NyBoJSMyunHTDm3D 50quqgDZcsKAhLeedWqOH2uPrOVY6ampY5O8A41A= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 102/141] iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE Date: Fri, 14 Feb 2020 11:20:42 -0500 Message-Id: <20200214162122.19794-102-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214162122.19794-1-sashal@kernel.org> References: <20200214162122.19794-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Cc: Sasha Levin , Jean-Philippe Brucker , iommu@lists.linux-foundation.org, Will Deacon , linux-arm-kernel@lists.infradead.org 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" From: Will Deacon [ Upstream commit d71e01716b3606a6648df7e5646ae12c75babde4 ] If, for some bizarre reason, the compiler decided to split up the write of STE DWORD 0, we could end up making a partial structure valid. Although this probably won't happen, follow the example of the context-descriptor code and use WRITE_ONCE() to ensure atomicity of the write. Reported-by: Jean-Philippe Brucker Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/arm-smmu-v3.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 7bd98585d78d2..48d3820087881 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1103,7 +1103,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid, } arm_smmu_sync_ste_for_sid(smmu, sid); - dst[0] = cpu_to_le64(val); + /* See comment in arm_smmu_write_ctx_desc() */ + WRITE_ONCE(dst[0], cpu_to_le64(val)); arm_smmu_sync_ste_for_sid(smmu, sid); /* It's likely that we'll want to use the new STE soon */ -- 2.20.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu