From patchwork Thu Jul 16 18:21:36 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 6810101 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 1E053C05AC for ; Thu, 16 Jul 2015 18:22:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3538A20684 for ; Thu, 16 Jul 2015 18:22:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 214CE20674 for ; Thu, 16 Jul 2015 18:22:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755270AbbGPSWI (ORCPT ); Thu, 16 Jul 2015 14:22:08 -0400 Received: from andre.telenet-ops.be ([195.130.132.53]:36524 "EHLO andre.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756217AbbGPSWF (ORCPT ); Thu, 16 Jul 2015 14:22:05 -0400 Received: from ayla.of.borg ([84.193.93.87]) by andre.telenet-ops.be with bizsmtp id t6N21q00U1t5w8s016N2Uz; Thu, 16 Jul 2015 20:22:03 +0200 Received: from ramsan.of.borg ([192.168.97.29] helo=ramsan) by ayla.of.borg with esmtp (Exim 4.82) (envelope-from ) id 1ZFnnF-000084-OT; Thu, 16 Jul 2015 20:22:02 +0200 Received: from geert by ramsan with local (Exim 4.82) (envelope-from ) id 1ZFnnG-0007KL-Sa; Thu, 16 Jul 2015 20:22:02 +0200 From: Geert Uytterhoeven To: Magnus Damm , Laurent Pinchart , Nobuhiro Iwamatsu , Yoshihiro Kaneko , Kazuya Mizuguchi , Koji Matsuoka , Wolfram Sang , Guennadi Liakhovetski Cc: linux-sh@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH/RFC v2 05/29] serial: sh-sci: Fix scatterlist mapping leak Date: Thu, 16 Jul 2015 20:21:36 +0200 Message-Id: <1437070920-28069-6-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437070920-28069-1-git-send-email-geert+renesas@glider.be> References: <1437070920-28069-1-git-send-email-geert+renesas@glider.be> Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Spam-Status: No, score=-8.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The mapped scatterlist is never unmapped. This leaks quite some mappings, as the mapping is done in uart_ops.startup(), i.e. every time the device is opened. Unmap the scatterlist on device close. Note that we have to restore the original DMA entry length and DMA address, as it has been modified in work_fn_tx(). Else warnings are printed if CONFIG_DMA_API_DEBUG=y: WARNING: CPU: 0 PID: 20 at lib/dma-debug.c:1103 check_unmap+0x24c/0x85c() rcar-dmac e6700000.dma-controller: DMA-API: device driver frees DMA memory with different size [device address=0x000000006e15f000] [map size=4096 bytes] [unmap size=3 bytes] and: WARNING: CPU: 0 PID: 1364 at lib/dma-debug.c:1093 check_unmap+0x178/0x85c() rcar-dmac e6700000.dma-controller: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000006e16b006] [size=4096 bytes] TODO: Simplify by switching to dma_map_single(), as the transmit scatterlist contains one single entry, which is reused and modified. Signed-off-by: Geert Uytterhoeven --- v2: - Add TODO --- drivers/tty/serial/sh-sci.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 6431b1fb9c162e77..8ffc6320ff0a8448 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1390,6 +1390,14 @@ static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) s->chan_tx = NULL; s->cookie_tx = -EINVAL; + if (s->sg_len_tx) { + /* Restore sg_dma_len() and sg_dma_address() */ + sg_dma_len(&s->sg_tx) = UART_XMIT_SIZE; + sg_dma_address(&s->sg_tx) = sg_dma_address(&s->sg_tx) & + ~(UART_XMIT_SIZE - 1); + dma_unmap_sg(chan->device->dev, &s->sg_tx, 1, DMA_TO_DEVICE); + s->sg_len_tx = 0; + } dma_release_channel(chan); if (enable_pio) sci_start_tx(port);