From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 7662E315AD; Fri, 15 Dec 2023 14:22:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="R1ZuomwB" Received: from pps.filterd (m0279864.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 3BFCTfXJ010194; Fri, 15 Dec 2023 14:22:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= message-id:date:mime-version:subject:to:cc:references:from :in-reply-to:content-type:content-transfer-encoding; s= qcppdkim1; bh=oRRArLvECVGH55PpYZXpIucjWY4MTvMDV/T4hZ4cdvQ=; b=R1 ZuomwBwZwiFQKCEqhwVy3LKiOvdaLGGeAmE4KjQ4yiOiFf7IDdb/0T9bDQb36bRX B/5UICe7M0Wh/cj7SL6HnwiJv78nLOHs7sXs+tbiXKLMX+NPXKjAVLKNAlmvzKHe 2sBctIM7vBWDLurqwmkAAHM2PDIidZUvwUk4JyGlhqjteuIj2Ne9akqGlkIHEF4w 4AHlDzFGDmfXDS/kbq6jLPgef14owFndVQoc63eLN8Nlrix2o97kMV0tZlT6y7zi 9kvh0AxwsgmXtq0NWwcdMvS0nDP+n7OVjvafRF8/GX0AHPzKggCpz3oVRP6L/6zj JodtXB78ePysFTdSCGGw== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3v0hqch58d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 15 Dec 2023 14:22:45 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3BFEMjVq002341 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 15 Dec 2023 14:22:45 GMT Received: from [10.218.15.57] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Fri, 15 Dec 2023 06:22:42 -0800 Message-ID: Date: Fri, 15 Dec 2023 19:49:34 +0530 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v2] tty: Add comments for tty-ldisc module loading logic Content-Language: en-CA To: Zijun Hu , , , , , , CC: , References: <1702640236-22824-1-git-send-email-quic_zijuhu@quicinc.com> <1702647690-6787-1-git-send-email-quic_zijuhu@quicinc.com> From: Vijaya Krishna Nivarthi In-Reply-To: <1702647690-6787-1-git-send-email-quic_zijuhu@quicinc.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: S3hyn1q1ttcdaf_ODB0WyucHyIpk_vD6 X-Proofpoint-GUID: S3hyn1q1ttcdaf_ODB0WyucHyIpk_vD6 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_01,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 mlxscore=0 phishscore=0 adultscore=0 priorityscore=1501 impostorscore=0 lowpriorityscore=0 mlxlogscore=999 clxscore=1011 suspectscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2312150098 Hi, On 12/15/2023 7:11 PM, Zijun Hu wrote: > Current tty-ldisc module loading logic within tty_ldisc_get() > is prone to mislead beginner that the module is able to be loaded > by a user without capability CAP_SYS_MODULE, add comments to make > the logic easy to undertand. > > Signed-off-by: Zijun Hu > --- > Changes in v2: > - Remove condition checking changes > > drivers/tty/tty_ldisc.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c > index 3f68e213df1f..34526ffaccbc 100644 > --- a/drivers/tty/tty_ldisc.c > +++ b/drivers/tty/tty_ldisc.c > @@ -150,6 +150,10 @@ static struct tty_ldisc *tty_ldisc_get(struct tty_struct *tty, int disc) > */ > ldops = get_ldops(disc); > if (IS_ERR(ldops)) { > + /* > + * Always request tty-ldisc module regardless of user's > + * CAP_SYS_MODULE if autoload is enabled. > + */ Without much knowledge of this file... What the if condition below accomplishes is evident, it probably doesn't require a comment. A more useful comment would be why it does so? Thank you... -Vijay/ > if (!capable(CAP_SYS_MODULE) && !tty_ldisc_autoload) > return ERR_PTR(-EPERM); > request_module("tty-ldisc-%d", disc);