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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19760C433F5 for ; Mon, 23 May 2022 17:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240495AbiEWRRw (ORCPT ); Mon, 23 May 2022 13:17:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239986AbiEWRRU (ORCPT ); Mon, 23 May 2022 13:17:20 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D1346B653; Mon, 23 May 2022 10:17:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2872BB81210; Mon, 23 May 2022 17:16:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91F54C385AA; Mon, 23 May 2022 17:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653326182; bh=qNsw8UK5s/gGHb4MLQDTHi7UXjBbR34W4sjFr7+B9qs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2UFbfb3dYSUY+BUpaAltX4NFS937S+Q3GiW4gXZ5IgbyqsYG5cnaSYt8cnTP3Ry5C 0W8P+Mk/Mr497H4We+NqWrVtGDqSN0RiPgS8zcuAejzd+a1qAlPVFEaGjYQ9R2lmtd ugn8uXWWKGJkQIBmtQPwHjKY2bOj6eP6QRyrjE4A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sasha Levin Subject: [PATCH 5.10 31/97] Revert "swiotlb: fix info leak with DMA_FROM_DEVICE" Date: Mon, 23 May 2022 19:05:35 +0200 Message-Id: <20220523165817.160571252@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220523165812.244140613@linuxfoundation.org> References: <20220523165812.244140613@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This reverts commit d4d975e7921079f877f828099bb8260af335508f. Upstream had a follow-up fix, revert, and a semi-reverted-revert. Instead of going through this chain which is more painful to backport, I'm just going to revert this original commit and pick the final one. Signed-off-by: Sasha Levin --- Documentation/core-api/dma-attributes.rst | 8 -------- include/linux/dma-mapping.h | 8 -------- kernel/dma/swiotlb.c | 3 +-- 3 files changed, 1 insertion(+), 18 deletions(-) diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 17706dc91ec9..1887d92e8e92 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -130,11 +130,3 @@ accesses to DMA buffers in both privileged "supervisor" and unprivileged subsystem that the buffer is fully accessible at the elevated privilege level (and ideally inaccessible or at least read-only at the lesser-privileged levels). - -DMA_ATTR_OVERWRITE ------------------- - -This is a hint to the DMA-mapping subsystem that the device is expected to -overwrite the entire mapped size, thus the caller does not require any of the -previous buffer contents to be preserved. This allows bounce-buffering -implementations to optimise DMA_FROM_DEVICE transfers. diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index a9361178c5db..a7d70cdee25e 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -61,14 +61,6 @@ */ #define DMA_ATTR_PRIVILEGED (1UL << 9) -/* - * This is a hint to the DMA-mapping subsystem that the device is expected - * to overwrite the entire mapped size, thus the caller does not require any - * of the previous buffer contents to be preserved. This allows - * bounce-buffering implementations to optimise DMA_FROM_DEVICE transfers. - */ -#define DMA_ATTR_OVERWRITE (1UL << 10) - /* * A dma_addr_t can hold any valid DMA or bus address for the platform. It can * be given to a device to use as a DMA source or target. It is specific to a diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 62b1e5fa8673..0ed0e1f215c7 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -598,8 +598,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, tlb_addr = slot_addr(io_tlb_start, index) + offset; if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - (!(attrs & DMA_ATTR_OVERWRITE) || dir == DMA_TO_DEVICE || - dir == DMA_BIDIRECTIONAL)) + (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); return tlb_addr; } -- 2.35.1