From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 893EB7B for ; Wed, 23 Nov 2022 08:58:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CAD05C433D6; Wed, 23 Nov 2022 08:58:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669193921; bh=t3hXwQq3L5B9fTd44C0XuYf3XzSZpJ5EgT9h6MXqXwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GrR7s4VcrR39yRJplMzUbZGiw6ySiyIpTrc6/vUYbFZt4oD24LHJs982qtdlJ4MCr 4KgZ5rLkQ81Cc6/NHhJ6t6xwm8SFE0KGbU+GxzoKapqnTIxxx5MvbZEUVa/sbOPiCl TEPMrL950UqGrmMw74CKOF4EHa2CQdk2fDqBr5qo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuan Can , Maxime Ripard , Sasha Levin Subject: [PATCH 4.14 08/88] drm/vc4: Fix missing platform_unregister_drivers() call in vc4_drm_register() Date: Wed, 23 Nov 2022 09:50:05 +0100 Message-Id: <20221123084548.817692871@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084548.535439312@linuxfoundation.org> References: <20221123084548.535439312@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yuan Can [ Upstream commit cf53db768a8790fdaae2fa3a81322b080285f7e5 ] A problem about modprobe vc4 failed is triggered with the following log given: [ 420.327987] Error: Driver 'vc4_hvs' is already registered, aborting... [ 420.333904] failed to register platform driver vc4_hvs_driver [vc4]: -16 modprobe: ERROR: could not insert 'vc4': Device or resource busy The reason is that vc4_drm_register() returns platform_driver_register() directly without checking its return value, if platform_driver_register() fails, it returns without unregistering all the vc4 drivers, resulting the vc4 can never be installed later. A simple call graph is shown as below: vc4_drm_register() platform_register_drivers() # all vc4 drivers are registered platform_driver_register() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without unregister drivers Fixing this problem by checking the return value of platform_driver_register() and do platform_unregister_drivers() if error happened. Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.") Signed-off-by: Yuan Can Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20221103014705.109322-1-yuancan@huawei.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/vc4/vc4_drv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 028dc2819a36..ad9e1fdf9fc8 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -364,7 +364,12 @@ static int __init vc4_drm_register(void) if (ret) return ret; - return platform_driver_register(&vc4_platform_driver); + ret = platform_driver_register(&vc4_platform_driver); + if (ret) + platform_unregister_drivers(component_drivers, + ARRAY_SIZE(component_drivers)); + + return ret; } static void __exit vc4_drm_unregister(void) -- 2.35.1