linux-kernel - Re: [PATCH v2 2/3] scsi: ufs: Modulize ufs-bsg

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>] [day] [month] [year] [list]

Date:   Thu, 12 Dec 2019 11:10:15 +0530
From:   Vignesh Raghavendra <vigneshr@...com>
To:     Can Guo <cang@...eaurora.org>, <asutoshd@...eaurora.org>,
        <nguyenb@...eaurora.org>, <rnayak@...eaurora.org>,
        <linux-scsi@...r.kernel.org>, <kernel-team@...roid.com>,
        <saravanak@...gle.com>, <salyzyn@...gle.com>
CC:     Alim Akhtar <alim.akhtar@...sung.com>,
        Avri Altman <avri.altman@....com>,
        Pedro Sousa <pedrom.sousa@...opsys.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Evan Green <evgreen@...omium.org>,
        Kishon Vijay Abraham I <kishon@...com>,
        Stephen Boyd <swboyd@...omium.org>,
        Stanley Chu <stanley.chu@...iatek.com>,
        Bean Huo <beanhuo@...ron.com>,
        Bart Van Assche <bvanassche@....org>,
        Venkat Gopalakrishnan <venkatg@...eaurora.org>,
        Tomas Winkler <tomas.winkler@...el.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Arnd Bergmann <arnd@...db.de>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/3] scsi: ufs: Modulize ufs-bsg

Hi,

On 11/12/19 2:19 pm, Can Guo wrote:
> In order to improve the flexibility of ufs-bsg, modulizing it is a good
> choice. This change introduces tristate to ufs-bsg to allow users compile
> it as an external module.
> 
> Signed-off-by: Can Guo <cang@...eaurora.org>
> ---
[...]
> -int ufs_bsg_probe(struct ufs_hba *hba)
> +static int ufs_bsg_probe(struct ufs_hba *hba)
>  {
> -	struct device *bsg_dev = &hba->bsg_dev;
> +	struct device *bsg_dev;
>  	struct Scsi_Host *shost = hba->host;
>  	struct device *parent = &shost->shost_gendev;
>  	struct request_queue *q;
>  	int ret;
>  
> +	bsg_dev = kzalloc(sizeof(*bsg_dev), GFP_KERNEL);
> +	if (!bsg_dev)
> +		return -ENOMEM;
> +
> +	hba->bsg_dev = bsg_dev;
>  	device_initialize(bsg_dev);
>  
>  	bsg_dev->parent = get_device(parent);
> @@ -217,6 +225,41 @@ int ufs_bsg_probe(struct ufs_hba *hba)
>  
>  out:
>  	dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no);
> +	hba->bsg_dev = NULL;

Don't we need to free the associated memory before assigning to NULL?
Alternatively can allocation be made with devm_ APIs instead?

>  	put_device(bsg_dev);
>  	return ret;
>  }
> +
> +static int __init ufs_bsg_init(void)
> +{
> +	struct list_head *hba_list = NULL;
> +	struct ufs_hba *hba;
> +	int ret = 0;
> +
> +	ufshcd_get_hba_list_lock(&hba_list);
> +	list_for_each_entry(hba, hba_list, list) {
> +		ret = ufs_bsg_probe(hba);
> +		if (ret)
> +			break;
> +	}

So IIUC, if ufs_bsg_probe() fails for one of the hba instances in the
list, then we fail to create bsg device for all remaining instances that
follow, which seems too harsh.

Regards
Vignesh