From patchwork Sun Nov 5 09:34:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 13445679 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 79D57C4167D for ; Sun, 5 Nov 2023 09:35:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=iHl+XHKZ6mGVXjpDFEBwKsCC2V3uJNfJMQEY5muiCMs=; b=AM18ZBWHsimQ8w dEac7ZpKFLEyPTGKJFvignVjvJgFza4D2izOl0wp8+3tQ0/wORYbdPqur9KbrjS2vkAb6qAW56HsA GO5lRsOBoewKnnLPH2EjMykZ9zKZnquAiIWMJ2sD4iDm0twU3zXJPUcmQ9en8h/GanypVU6VhDyE+ jdKheYk6eOZSAUcQgA7vzznh9i8H7BaIFzofDT4ItQIqP4RmDvgyx0gOFnMkDoTFyjZlVbzP/TfXs zIPZYlFK4Fzwars+XQmyg8Ar/85qZCVK2uPa/7t0xEcnBCBCnIoS+iRKG9eEi4tvSzeYC1Db130+H Gh/NkrxQKKPZEX8bUCuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qzZWo-00EfnW-1h; Sun, 05 Nov 2023 09:34:46 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qzZWl-00EfmE-2P for linux-arm-kernel@lists.infradead.org; Sun, 05 Nov 2023 09:34:45 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qzZWd-0000Pg-T9; Sun, 05 Nov 2023 10:34:35 +0100 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qzZWc-006l7R-Hl; Sun, 05 Nov 2023 10:34:34 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1qzZWc-00D8nr-8c; Sun, 05 Nov 2023 10:34:34 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Vinod Koul Cc: Kunihiko Hayashi , Masami Hiramatsu , dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de Subject: [PATCH 4/4] dmaengine: uniphier-xdmac: Convert to platform remove callback returning void Date: Sun, 5 Nov 2023 10:34:20 +0100 Message-ID: <20231105093415.3704633-10-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231105093415.3704633-6-u.kleine-koenig@pengutronix.de> References: <20231105093415.3704633-6-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2604; i=u.kleine-koenig@pengutronix.de; h=from:subject; bh=Wsv/SCBHHBOzEUfGKUTR96iDjLgTDVwgqqZx8UGatP8=; b=owEBbQGS/pANAwAKAY+A+1h9Ev5OAcsmYgBlR2Gc9/4L+wKj/bFGGeUlDQohLCMOow4pA/CO+ 7vLAdGsk1uJATMEAAEKAB0WIQQ/gaxpOnoeWYmt/tOPgPtYfRL+TgUCZUdhnAAKCRCPgPtYfRL+ TmXXCACx8B/yk11rm8+3h9qfsjq5+yW6EpK/1olvOKBg0lRSjNXwixyw8zlSPXzQQgGS8rUyNKl xkckt8x8XsfPi0qgDxJxxVrdIC/6y+chfwaerRjzvO+u3LIJaDtb9SuD9DlVO9hDGZZQJtro/R9 LHQ6AocPWjDbi8FWiLhvnURNNVqGQibcOXmPlY8glS+IM+/lr2HNrBR+g/mUD0gAyYe1jr/tw96 HIESy72063wNt8fqrmWgk+3g4kFFVgEAY0iL/CEiMNJStXw5ZpjkbqqYaOq5ysAWi+xMxfEPkqZ qm9bROZ3Lt//0qpfE0QQ70zIbOkFOI1/Yo/MzA+z3ZKwpHqS X-Developer-Key: i=u.kleine-koenig@pengutronix.de; a=openpgp; fpr=0D2511F322BFAB1C1580266BE2DCDD9132669BD6 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231105_013443_784316_30032A5E X-CRM114-Status: GOOD ( 19.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). There is an error path that has the above mentioned problem. This patch only adds a more drastic error message. To properly fix it, dmaengine_terminate_sync() must be known to have succeeded (or that it's safe to not call it as other drivers seem to assume). Signed-off-by: Uwe Kleine-König --- drivers/dma/uniphier-xdmac.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/dma/uniphier-xdmac.c b/drivers/dma/uniphier-xdmac.c index 3a8ee2b173b5..3ce2dc2ad9de 100644 --- a/drivers/dma/uniphier-xdmac.c +++ b/drivers/dma/uniphier-xdmac.c @@ -563,7 +563,7 @@ static int uniphier_xdmac_probe(struct platform_device *pdev) return ret; } -static int uniphier_xdmac_remove(struct platform_device *pdev) +static void uniphier_xdmac_remove(struct platform_device *pdev) { struct uniphier_xdmac_device *xdev = platform_get_drvdata(pdev); struct dma_device *ddev = &xdev->ddev; @@ -579,15 +579,20 @@ static int uniphier_xdmac_remove(struct platform_device *pdev) */ list_for_each_entry(chan, &ddev->channels, device_node) { ret = dmaengine_terminate_sync(chan); - if (ret) - return ret; + if (ret) { + /* + * This results in resource leakage and maybe also + * use-after-free errors as e.g. *xdev is kfreed. + */ + dev_alert(&pdev->dev, "Failed to terminate channel %d (%pe)\n", + chan->chan_id, ERR_PTR(ret)); + return; + } uniphier_xdmac_free_chan_resources(chan); } of_dma_controller_free(pdev->dev.of_node); dma_async_device_unregister(ddev); - - return 0; } static const struct of_device_id uniphier_xdmac_match[] = { @@ -598,7 +603,7 @@ MODULE_DEVICE_TABLE(of, uniphier_xdmac_match); static struct platform_driver uniphier_xdmac_driver = { .probe = uniphier_xdmac_probe, - .remove = uniphier_xdmac_remove, + .remove_new = uniphier_xdmac_remove, .driver = { .name = "uniphier-xdmac", .of_match_table = uniphier_xdmac_match,