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 62C81C77B75 for ; Mon, 8 May 2023 10:32:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234751AbjEHKcA (ORCPT ); Mon, 8 May 2023 06:32:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234755AbjEHKbd (ORCPT ); Mon, 8 May 2023 06:31:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CAB8327853 for ; Mon, 8 May 2023 03:31:20 -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 dfw.source.kernel.org (Postfix) with ESMTPS id C1EE1626D5 for ; Mon, 8 May 2023 10:31:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C58B2C433EF; Mon, 8 May 2023 10:31:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683541880; bh=iSQ0QSC3DzGnIMRRTKfOccPI+S6/B1s3mC+ZJFBhaKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qMyDVqtuYxnZ+coJXVddzIFSNiKNfwQh/kd0hg1or9Cc+YuPhsFnXRv3kRzq2tc55 u68Hv/s9bngYIPRYqueeCuU61tfi8HOVT319VfbeGQURJ1t/viEQnFmiL8Ap6RxpcA iq8G1fj1AOAJXZ7UuSw3t5Ga5llKQos+SM1MQaFA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Sasha Levin Subject: [PATCH 6.2 257/663] platform: Provide a remove callback that returns no value Date: Mon, 8 May 2023 11:41:23 +0200 Message-Id: <20230508094436.595003518@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094428.384831245@linuxfoundation.org> References: <20230508094428.384831245@linuxfoundation.org> User-Agent: quilt/0.67 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 From: Uwe Kleine-König [ Upstream commit 5c5a7680e67ba6fbbb5f4d79fa41485450c1985c ] struct platform_driver::remove returning an integer made driver authors expect that returning an error code was proper error handling. However the driver core ignores the error and continues to remove the device because there is nothing the core could do anyhow and reentering the remove callback again is only calling for trouble. So this is an source for errors typically yielding resource leaks in the error path. As there are too many platform drivers to neatly convert them all to return void in a single go, do it in several steps after this patch: a) Convert all drivers to implement .remove_new() returning void instead of .remove() returning int; b) Change struct platform_driver::remove() to return void and so make it identical to .remove_new(); c) Change all drivers back to .remove() now with the better prototype; d) drop struct platform_driver::remove_new(). While this touches all drivers eventually twice, steps a) and c) can be done one driver after another and so reduces coordination efforts immensely and simplifies review. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20221209150914.3557650-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman Stable-dep-of: c766c90faf93 ("media: rcar_fdp1: Fix refcount leak in probe and remove function") Signed-off-by: Sasha Levin --- drivers/base/platform.c | 4 +++- include/linux/platform_device.h | 11 +++++++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 968f3d71eeab2..a4938d1c8fe1d 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1416,7 +1416,9 @@ static void platform_remove(struct device *_dev) struct platform_driver *drv = to_platform_driver(_dev->driver); struct platform_device *dev = to_platform_device(_dev); - if (drv->remove) { + if (drv->remove_new) { + drv->remove_new(dev); + } else if (drv->remove) { int ret = drv->remove(dev); if (ret) diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index b0d5a253156ec..b845fd83f429b 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -207,7 +207,18 @@ extern void platform_device_put(struct platform_device *pdev); struct platform_driver { int (*probe)(struct platform_device *); + + /* + * Traditionally the remove callback returned an int which however is + * ignored by the driver core. This led to wrong expectations by driver + * authors who thought returning an error code was a valid error + * handling strategy. To convert to a callback returning void, new + * drivers should implement .remove_new() until the conversion it done + * that eventually makes .remove() return void. + */ int (*remove)(struct platform_device *); + void (*remove_new)(struct platform_device *); + void (*shutdown)(struct platform_device *); int (*suspend)(struct platform_device *, pm_message_t state); int (*resume)(struct platform_device *); -- 2.39.2