From patchwork Tue Mar 12 10:34:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 779891 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (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 8D22A79DDD for ; Tue, 12 Mar 2024 10:34:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710239685; cv=none; b=HOz+nGi52Wgd4pWbZOrUaRJsN/CIaxrCGaJ///UWr4eF0Cg3TlCkP8KCgPL8exZVE9ddOYBfu6vnyVrPXlLGnq0IehhKiRYgppVcOETNP+TQKtti8OVq6tqK2GGO4d+QDze/YipBgLKiYasVqFdyzVAldUeo5zFk0kqZxJ8tYpY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710239685; c=relaxed/simple; bh=GnXZ+uykzjm2yeKEIqJ8UlgN7XyR0uSitA/90So7sNo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=k482UfG4ROZx2Qm73Qp2f+MKZnrLITPeiOC1GPugeFA/+plf1GqVyoiveC3Dz2c1FzQwDER5aNOCLkaupYL3u5wj4BG8sw2kByGfTDJws7D/z2xjQ7dSm+TQKFcT/yAt20bCxHzqwmCz/lGoHDErUn8vULIv8Fn3GOs7Xc21j5E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=F8RYpnuZ; arc=none smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="F8RYpnuZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710239684; x=1741775684; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GnXZ+uykzjm2yeKEIqJ8UlgN7XyR0uSitA/90So7sNo=; b=F8RYpnuZqBgb7/2AY7cQodIrBEY3i8Kjl4knWBmJ9OfpdBBr0oaNPYN2 bZ90vhXTitVytaHajSoCl6j+JQPnN3QWSJGrpbE/ltZ/x/WXakt2I0SrY PBMmpjHYR6BKP3o1rtUkIAh9ZrQNRPYb5noxcf8ZydbB+fBaADhEwwdCS KUUWXbNtkfHRMJFisyQQnvVBFgsHz8BH8APUlm3ba/0DAbMwbEpa8AOK8 RvmQhm6Ca69Hg9DTVr9LQW68rkt2eDqO5ocBar/avJUf55iZ1ATS16GLw x1q5VCeaykvlgaGvozIV2X2y+FhCqmMQakemPB+GycCJIDC82IxuAE8AX A==; X-IronPort-AV: E=McAfee;i="6600,9927,11010"; a="4794346" X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="4794346" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 03:34:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="16194119" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 03:34:43 -0700 Received: from svinhufvud.ger.corp.intel.com (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with ESMTP id D0A8A11F819; Tue, 12 Mar 2024 12:34:39 +0200 (EET) From: Sakari Ailus To: linux-media@vger.kernel.org Cc: laurent.pinchart@ideasonboard.com, hverkuil@xs4all.nl Subject: [PATCH v3 25/26] media: mc: Enforce one-time registration Date: Tue, 12 Mar 2024 12:34:21 +0200 Message-Id: <20240312103422.216484-26-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240312103422.216484-1-sakari.ailus@linux.intel.com> References: <20240312103422.216484-1-sakari.ailus@linux.intel.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 A media devnode may be registered only once. Enforce this by setting the minor to -1 in init. Registration initialises the character device and sets up the device name. These should take place only once during the lifetime of the media device. Signed-off-by: Sakari Ailus --- drivers/media/mc/mc-devnode.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c index e2a30b21e6c8..8742bd7a3521 100644 --- a/drivers/media/mc/mc-devnode.c +++ b/drivers/media/mc/mc-devnode.c @@ -240,6 +240,7 @@ void media_devnode_init(struct media_devnode *devnode) { device_initialize(&devnode->dev); devnode->dev.release = media_devnode_release; + devnode->minor = -1; } int __must_check media_devnode_register(struct media_devnode *devnode, @@ -251,6 +252,9 @@ int __must_check media_devnode_register(struct media_devnode *devnode, int minor; int ret; + if (devnode->minor != -1) + return -EINVAL; + /* Part 1: Find a free minor number */ mutex_lock(&media_devnode_lock); minor = find_first_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES);