linux-kernel - RE: [PATCH 1/8] cxl: Add helper function to retrieve a feature entry

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e8e33d46aa1b478db601de29e047cb5f@huawei.com>
Date: Mon, 10 Mar 2025 18:15:38 +0000
From: Shiju Jose <shiju.jose@...wei.com>
To: Alison Schofield <alison.schofield@...el.com>
CC: "linux-cxl@...r.kernel.org" <linux-cxl@...r.kernel.org>,
	"dan.j.williams@...el.com" <dan.j.williams@...el.com>, "dave@...olabs.net"
	<dave@...olabs.net>, Jonathan Cameron <jonathan.cameron@...wei.com>,
	"dave.jiang@...el.com" <dave.jiang@...el.com>, "vishal.l.verma@...el.com"
	<vishal.l.verma@...el.com>, "ira.weiny@...el.com" <ira.weiny@...el.com>,
	"david@...hat.com" <david@...hat.com>, "Vilas.Sridharan@....com"
	<Vilas.Sridharan@....com>, "linux-edac@...r.kernel.org"
	<linux-edac@...r.kernel.org>, "linux-acpi@...r.kernel.org"
	<linux-acpi@...r.kernel.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "bp@...en8.de"
	<bp@...en8.de>, "tony.luck@...el.com" <tony.luck@...el.com>,
	"rafael@...nel.org" <rafael@...nel.org>, "lenb@...nel.org" <lenb@...nel.org>,
	"mchehab@...nel.org" <mchehab@...nel.org>, "leo.duran@....com"
	<leo.duran@....com>, "Yazen.Ghannam@....com" <Yazen.Ghannam@....com>,
	"rientjes@...gle.com" <rientjes@...gle.com>, "jiaqiyan@...gle.com"
	<jiaqiyan@...gle.com>, "Jon.Grimm@....com" <Jon.Grimm@....com>,
	"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
	"naoya.horiguchi@....com" <naoya.horiguchi@....com>, "james.morse@....com"
	<james.morse@....com>, "jthoughton@...gle.com" <jthoughton@...gle.com>,
	"somasundaram.a@....com" <somasundaram.a@....com>, "erdemaktas@...gle.com"
	<erdemaktas@...gle.com>, "pgonda@...gle.com" <pgonda@...gle.com>,
	"duenwen@...gle.com" <duenwen@...gle.com>, "gthelen@...gle.com"
	<gthelen@...gle.com>, "wschwartz@...erecomputing.com"
	<wschwartz@...erecomputing.com>, "dferguson@...erecomputing.com"
	<dferguson@...erecomputing.com>, "wbs@...amperecomputing.com"
	<wbs@...amperecomputing.com>, "nifan.cxl@...il.com" <nifan.cxl@...il.com>,
	tanxiaofei <tanxiaofei@...wei.com>, "Zengtao (B)" <prime.zeng@...ilicon.com>,
	Roberto Sassu <roberto.sassu@...wei.com>, "kangkang.shen@...urewei.com"
	<kangkang.shen@...urewei.com>, wanghuiqiang <wanghuiqiang@...wei.com>,
	Linuxarm <linuxarm@...wei.com>
Subject: RE: [PATCH 1/8] cxl: Add helper function to retrieve a feature entry

>-----Original Message-----
>From: Alison Schofield <alison.schofield@...el.com>
>Sent: 07 March 2025 19:20
>To: Shiju Jose <shiju.jose@...wei.com>
[...]
>> +struct cxl_feat_entry *cxl_get_feature_entry(struct cxl_dev_state *cxlds,
>> +					     const uuid_t *feat_uuid)
>> +{
>> +	struct cxl_features_state *cxlfs = to_cxlfs(cxlds);
>> +	struct cxl_feat_entry *feat_entry;
>> +	int count;
>> +
>> +	/*
>> +	 * Retrieve the feature entry from the supported features list,
>> +	 * if the feature is supported.
>> +	 */
>> +	feat_entry = cxlfs->entries->ent;
>
>Do we need some NULL checking here on cxlfs, entries

Hi Alison,

Thanks for the feedbacks.
We had check on cxlfs before
https://lore.kernel.org/all/20250122235159.2716036-5-dave.jiang@intel.com/
but removed because of the following comment.
https://lore.kernel.org/all/20250124150150.GZ5556@nvidia.com/
>
>
>> +	for (count = 0; count < cxlfs->entries->num_features; count++,
>> +feat_entry++) {
>
>Was num_features previously validated?
Not in the caller. Had check for num_features here before in cxl_get_feature_entry()
as seen in the above link.
>
>> +		if (uuid_equal(&feat_entry->uuid, feat_uuid))
>> +			return feat_entry;
>> +	}
>> +
>> +	return ERR_PTR(-ENOENT);
>
>Why not just return NULL?
Will do.
>
>
>> +}
>> +
>>  size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
>>  		       enum cxl_get_feat_selection selection,
>>  		       void *feat_out, size_t feat_out_size, u16 offset,
>> --
>> 2.43.0
>>

Thanks,
Shiju