From patchwork Fri Jan 13 22:52:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Khoroshilov X-Patchwork-Id: 9516601 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4E98C601E5 for ; Fri, 13 Jan 2017 22:53:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3EC812877D for ; Fri, 13 Jan 2017 22:53:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3179D2878B; Fri, 13 Jan 2017 22:53:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F296F2877D for ; Fri, 13 Jan 2017 22:53:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751442AbdAMWxP (ORCPT ); Fri, 13 Jan 2017 17:53:15 -0500 Received: from mail.ispras.ru ([83.149.199.45]:60480 "EHLO mail.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751378AbdAMWxP (ORCPT ); Fri, 13 Jan 2017 17:53:15 -0500 Received: from localhost.localdomain (ppp85-140-188-91.pppoe.mtu-net.ru [85.140.188.91]) by mail.ispras.ru (Postfix) with ESMTPSA id 09D54540068; Sat, 14 Jan 2017 01:53:10 +0300 (MSK) From: Alexey Khoroshilov To: Ulf Hansson Cc: Alexey Khoroshilov , Pierre Ossman , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] mmc: wbsd: safer check if dma_addr is valid DMA address Date: Sat, 14 Jan 2017 01:52:51 +0300 Message-Id: <1484347971-30829-1-git-send-email-khoroshilov@ispras.ru> X-Mailer: git-send-email 2.7.4 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP host->dma_addr can store a value that is not returned by the DMA API, so it is safer to check if is a valid DMA address indirectly. Signed-off-by: Alexey Khoroshilov --- drivers/mmc/host/wbsd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c index 80a3b11f3217..bd04e8bae010 100644 --- a/drivers/mmc/host/wbsd.c +++ b/drivers/mmc/host/wbsd.c @@ -1437,11 +1437,14 @@ static void wbsd_request_dma(struct wbsd_host *host, int dma) static void wbsd_release_dma(struct wbsd_host *host) { - if (!dma_mapping_error(mmc_dev(host->mmc), host->dma_addr)) { + /* + * host->dma_addr is valid here iff host->dma_buffer is not NULL. + */ + if (host->dma_buffer) { dma_unmap_single(mmc_dev(host->mmc), host->dma_addr, WBSD_DMA_SIZE, DMA_BIDIRECTIONAL); + kfree(host->dma_buffer); } - kfree(host->dma_buffer); if (host->dma >= 0) free_dma(host->dma);