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From: fan <nifan.cxl@gmail.com>
Date: Tue, 19 Dec 2023 09:44:06 -0800
To: Ira Weiny <ira.weiny@intel.com>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>,
	Fan Ni <nifan.cxl@gmail.com>, Dave Jiang <dave.jiang@intel.com>,
	linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org,
	Huai-Cheng Kuo <hchkuo@avery-design.com.tw>
Subject: Re: [PATCH v2 1/2] cxl/cdat: Handle cdat table build errors
Message-ID: <ZYHWZjsnQwcBEDpd@debian>
References: <20231117-fix-cdat-cs-v2-0-715399976d4d@intel.com>
 <20231117-fix-cdat-cs-v2-1-715399976d4d@intel.com>
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In-Reply-To: <20231117-fix-cdat-cs-v2-1-715399976d4d@intel.com>

On Wed, Nov 29, 2023 at 05:33:03PM -0800, Ira Weiny wrote:
> The callback for building CDAT tables may return negative error codes.
> This was previously unhandled and will result in potentially huge
> allocations later on in ct3_build_cdat()
> 
> Detect the negative error code and defer cdat building.
> 
> Fixes: f5ee7413d592 ("hw/mem/cxl-type3: Add CXL CDAT Data Object Exchange")
> Cc: Huai-Cheng Kuo <hchkuo@avery-design.com.tw>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> ---
>  hw/cxl/cxl-cdat.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/cxl/cxl-cdat.c b/hw/cxl/cxl-cdat.c
> index 639a2db3e17b..24829cf2428d 100644
> --- a/hw/cxl/cxl-cdat.c
> +++ b/hw/cxl/cxl-cdat.c
> @@ -63,7 +63,7 @@ static void ct3_build_cdat(CDATObject *cdat, Error **errp)
>      cdat->built_buf_len = cdat->build_cdat_table(&cdat->built_buf,
>                                                   cdat->private);
>  
> -    if (!cdat->built_buf_len) {
> +    if (cdat->built_buf_len <= 0) {
>          /* Build later as not all data available yet */
>          cdat->to_update = true;
>          return;
> 

The fix looks good to me. Just curious how to really build cdat table
again when an error occurs, for example, the memory allocation fails.

Fan
> -- 
> 2.42.0
>