From patchwork Mon Dec 7 08:17:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 11955003 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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9D309C433FE for ; Mon, 7 Dec 2020 08:45:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D6C32151B for ; Mon, 7 Dec 2020 08:45:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726087AbgLGIpX (ORCPT ); Mon, 7 Dec 2020 03:45:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726024AbgLGIpX (ORCPT ); Mon, 7 Dec 2020 03:45:23 -0500 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [IPv6:2a01:37:1000::53df:5f64:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46E35C0613D0 for ; Mon, 7 Dec 2020 00:44:43 -0800 (PST) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 9A16930000CF4; Mon, 7 Dec 2020 09:44:05 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 18AF710DB; Mon, 7 Dec 2020 09:44:42 +0100 (CET) Message-Id: <1d58367d74d55741e0c2730a51a2b65012c8ab33.1607286887.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Mon, 7 Dec 2020 09:17:15 +0100 Subject: [PATCH 15/17] spi: ar934x: Don't leak SPI master in probe error path To: Mark Brown Cc: linux-spi@vger.kernel.org, Chuanhong Guo Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org If the call to devm_spi_register_controller() fails on probe of the Qualcomm Atheros AR934x/QCA95xx SPI driver, the spi_controller struct is erroneously not freed. Fix by switching over to the new devm_spi_alloc_master() helper. Moreover, the controller's clock is enabled on probe but not disabled if any of the subsequent probe steps fail. Finally, there's an ordering issue in ar934x_spi_remove() wherein the clock is disabled even though the controller is not yet unregistered. It is unregistered after ar934x_spi_remove() by the devres framework. As long as it is not unregistered, SPI transfers may still be ongoing and disabling the clock may break them. It is not possible to use devm_spi_register_controller() in this case, so move to the non-devm variant. All of these bugs have existed since the driver was first introduced, so it seems fair to fix them together in a single commit. Fixes: 047980c582af ("spi: add driver for ar934x spi controller") Signed-off-by: Lukas Wunner Cc: # v5.7+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: # v5.7+ Cc: Chuanhong Guo --- drivers/spi/spi-ar934x.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-ar934x.c b/drivers/spi/spi-ar934x.c index d08dec09d423..def32e0aaefe 100644 --- a/drivers/spi/spi-ar934x.c +++ b/drivers/spi/spi-ar934x.c @@ -176,10 +176,11 @@ static int ar934x_spi_probe(struct platform_device *pdev) if (ret) return ret; - ctlr = spi_alloc_master(&pdev->dev, sizeof(*sp)); + ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*sp)); if (!ctlr) { dev_info(&pdev->dev, "failed to allocate spi controller\n"); - return -ENOMEM; + ret = -ENOMEM; + goto err_clk_disable; } /* disable flash mapping and expose spi controller registers */ @@ -202,7 +203,13 @@ static int ar934x_spi_probe(struct platform_device *pdev) sp->clk_freq = clk_get_rate(clk); sp->ctlr = ctlr; - return devm_spi_register_controller(&pdev->dev, ctlr); + ret = spi_register_controller(ctlr); + if (!ret) + return 0; + +err_clk_disable: + clk_disable_unprepare(clk); + return ret; } static int ar934x_spi_remove(struct platform_device *pdev) @@ -213,6 +220,7 @@ static int ar934x_spi_remove(struct platform_device *pdev) ctlr = dev_get_drvdata(&pdev->dev); sp = spi_controller_get_devdata(ctlr); + spi_unregister_controller(ctlr); clk_disable_unprepare(sp->clk); return 0;