linux-kernel - Re: [PATCH v1 4/7] cxl/core: Use guard() to drop the goto pattern of cxl_dpa

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: <20250211173007.00001f26@huawei.com>
Date: Tue, 11 Feb 2025 17:30:07 +0000
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Li Ming <ming.li@...omail.com>
CC: <dave@...olabs.net>, <dave.jiang@...el.com>, <alison.schofield@...el.com>,
	<vishal.l.verma@...el.com>, <ira.weiny@...el.com>,
	<dan.j.williams@...el.com>, <linux-cxl@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 4/7] cxl/core: Use guard() to drop the goto pattern
 of cxl_dpa_free()

On Tue, 11 Feb 2025 15:57:24 +0800
Li Ming <ming.li@...omail.com> wrote:

> cxl_dpa_free() has a goto pattern to call up_write() for cxl_dpa_rwsem,
> it can be removed by using a guard() to replace the down_write() and
> up_write().
> 
> Signed-off-by: Li Ming <ming.li@...omail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>

> ---
>  drivers/cxl/core/hdm.c | 24 ++++++++----------------
>  1 file changed, 8 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 2bb2782a72ad..4d753520a79a 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -384,35 +384,27 @@ int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
>  {
>  	struct cxl_port *port = cxled_to_port(cxled);
>  	struct device *dev = &cxled->cxld.dev;
> -	int rc;
>  
> -	down_write(&cxl_dpa_rwsem);
> -	if (!cxled->dpa_res) {
> -		rc = 0;
> -		goto out;
> -	}
> +	guard(rwsem_write)(&cxl_dpa_rwsem);
> +	if (!cxled->dpa_res)
> +		return 0;
>  	if (cxled->cxld.region) {
>  		dev_dbg(dev, "decoder assigned to: %s\n",
>  			dev_name(&cxled->cxld.region->dev));
> -		rc = -EBUSY;
> -		goto out;
> +		return -EBUSY;
>  	}
>  	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
>  		dev_dbg(dev, "decoder enabled\n");
> -		rc = -EBUSY;
> -		goto out;
> +		return -EBUSY;
>  	}
>  	if (cxled->cxld.id != port->hdm_end) {
>  		dev_dbg(dev, "expected decoder%d.%d\n", port->id,
>  			port->hdm_end);
> -		rc = -EBUSY;
> -		goto out;
> +		return -EBUSY;
>  	}
> +
>  	devm_cxl_dpa_release(cxled);
> -	rc = 0;
> -out:
> -	up_write(&cxl_dpa_rwsem);
> -	return rc;
> +	return 0;
>  }
>  
>  int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,