Re: [PATCH v3 1/1] cxl/pmem: debug invalid serial number data

[Fan Ni <nifan.cxl@gmail.com>]

On Tue, Feb 18, 2025 at 09:47:46AM +0800, Yuquan Wang wrote:
> In a nvdimm interleave-set each device with an invalid or zero
> serial number may cause pmem region initialization to fail, but in
> cxl case such device could still set cookies of nd_interleave_set
> and create a nvdimm pmem region.
> 
> This adds the validation of serial number in cxl pmem region creation.
> The event of no serial number would cause to fail to set the cookie
> and pmem region.
> 
> For cxl-test to work properly, always +1 on mock device's serial
> number.
> 
> Signed-off-by: Yuquan Wang <wangyuquan1236@phytium.com.cn>
> ---
>  drivers/cxl/pmem.c           | 8 ++++++++
>  tools/testing/cxl/test/mem.c | 2 +-
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
> index f9c95996e937..73787afe1b9d 100644
> --- a/drivers/cxl/pmem.c
> +++ b/drivers/cxl/pmem.c
> @@ -383,6 +383,14 @@ static int cxl_pmem_region_probe(struct device *dev)
>  			.position = i,
>  		};
>  		info[i].offset = m->start;
> +
> +		if (cxlds->serial == 0) {
> +			/* include missing alongside invalid in this error message. */
> +			dev_err(dev, "%s: invalid or missing serial number\n",
> +				dev_name(&cxlmd->dev));
> +			rc = -ENXIO;
> +			goto out_nvd;
> +		}

Should we do the check earlier in the code? 
For example, right below if (!nvdimm) {}

Fan

>  		info[i].serial = cxlds->serial;
>  	}
>  	ndr_desc.num_mappings = cxlr_pmem->nr_mappings;
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index 8d731bd63988..9e098cf06603 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -1533,7 +1533,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
>  	mds->event.buf = (struct cxl_get_event_payload *) mdata->event_buf;
>  	INIT_DELAYED_WORK(&mds->security.poll_dwork, cxl_mockmem_sanitize_work);
>  
> -	cxlds->serial = pdev->id;
> +	cxlds->serial = pdev->id + 1;
>  	if (is_rcd(pdev))
>  		cxlds->rcd = true;
>  
> -- 
> 2.34.1
>