From patchwork Fri Feb 23 08:46:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 775408 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 301E112E5E for ; Fri, 23 Feb 2024 08:46:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708677980; cv=none; b=I4ofig32+rgOD0UKkQahcbgipQr0wdgZNpwohWJmc/MdkmxEM9S9GO0DlevlqlH/n/VtQkPQshzW0HLXTb0bIQu0hKLaoT2jCobOBqOKldsZEEK1ph/BoZ2gx2d2y4Se+Z6QZxmLMDE+rIBRBFNXBqKIT3nCse4MHeUjpTgyTcM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708677980; c=relaxed/simple; bh=+tecb2uIztWTL9hVxhFEv1SVlGIs3l+RJPoqi46FZeI=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=HegZZHwmbntDQ9JyMYFaD//SmLnIPiC6xp3l8Cok/ewHy+cBeeRjkvI8loubJoQ5nqCPWx43BNNhdYVHcG+gJuY+wjie0jEFXAPJkjz3hmmokBSbsTgqItLfXNI88IYZiy9bv+5kG/0D6LLgFEZg5A0RmP9k9moOaL/2fugqrCw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E06AC433C7; Fri, 23 Feb 2024 08:46:19 +0000 (UTC) Message-ID: Date: Fri, 23 Feb 2024 09:46:19 +0100 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US, nl To: Linux Media Mailing List Cc: Laurent Pinchart , Sakari Ailus From: Hans Verkuil Subject: [PATCH] media: mc: mark the media devnode as registered from the, start First the media device node was created, and if successful it was marked as 'registered'. This leaves a small race condition where an application can open the device node and get an error back because the 'registered' flag was not yet set. Change the order: first set the 'registered' flag, then actually register the media device node. If that fails, then clear the flag. Signed-off-by: Hans Verkuil Acked-by: Sakari Ailus Reviewed-by: Laurent Pinchart --- drivers/media/mc/mc-devnode.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c index 7f67825c8757..318e267e798e 100644 --- a/drivers/media/mc/mc-devnode.c +++ b/drivers/media/mc/mc-devnode.c @@ -245,15 +245,14 @@ int __must_check media_devnode_register(struct media_device *mdev, kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor); /* Part 3: Add the media and char device */ + set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); ret = cdev_device_add(&devnode->cdev, &devnode->dev); if (ret < 0) { + clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); pr_err("%s: cdev_device_add failed\n", __func__); goto cdev_add_error; } - /* Part 4: Activate this minor. The char device can now be used. */ - set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); - return 0; cdev_add_error: