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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 44F9AC2BA83 for ; Fri, 14 Feb 2020 16:58:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 0C605206CC for ; Fri, 14 Feb 2020 16:58:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="i7g82/mh"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="uB0vlkpd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C605206CC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7NqU98F9usIcU3Qe9aUsqPHmFQCS9ToVsWtV1sd1WaQ=; b=i7g82/mhCerQ26 6b+j6LmTLNxiE+VbpsP16poX2i4yZEohYpu4o+ZtNN9oQdYtCcwW92O+McJSL1UD0BNxg5zBfrv/l 3GZ8gXDuKXLIwFcukPe+tgyyCkLJ7HkWX9szWVR/dTKrtW32TQcUsssv0tfvWz4SMN9VTp3dT9HNU U0OwkfjdwKcgFeRra9oMhO6McLsANPrjiAjDORpg76Qn3FMQCrrYA8d8Ut6HaGun3wZXNm8ytmT8r Lbw2DRXBf2gN9PumET1tMIjlXWcERtLy1DXwuxFpNjr3EVL4ON4vgu0rqOhc3YxildejE2uWsyMks WaiA1u36BP5xMtxuRQwA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j2eIV-0007Wt-VG; Fri, 14 Feb 2020 16:58:35 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j2dmt-0001zy-47 for linux-arm-kernel@lists.infradead.org; Fri, 14 Feb 2020 16:25:59 +0000 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 CBB76247C2; Fri, 14 Feb 2020 16:25:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581697554; bh=L9YoM++4KqetkkdG8Hj3b00h//mi3AFRw2kcEv8YIP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uB0vlkpd51d/xWlnjWw6Raz8nx5Zr20eMZ6t0jlNdDDjjZWoIW7RBbbp/lLamGgNT VbbJOAvwgrDLKIMUemdyTK6l1Ejf/luNyS7m4xGfDBFUNTCqdruBhqM4qgUQY80GLZ jAHcRC57Wreyru+ZnbuNmf9XGdZqG3y7cxDXldgs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 072/100] iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE Date: Fri, 14 Feb 2020 11:23:56 -0500 Message-Id: <20200214162425.21071-72-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214162425.21071-1-sashal@kernel.org> References: <20200214162425.21071-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200214_082555_226956_2D7BA132 X-CRM114-Status: GOOD ( 10.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Jean-Philippe Brucker , iommu@lists.linux-foundation.org, Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 eb9937225d645..6c10f307a1c98 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1090,7 +1090,8 @@ 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel