Re: [PATCH] cxl/test: Assign overflow_err_count from log->nr_overflow

[Dave Jiang <dave.jiang@intel.com>]

On 11/15/25 6:30 PM, Alison Schofield wrote:
> mock_get_event() uses an uninitialized local variable, nr_overflow, to
> populate the overflow_err_count field. That results in incorrect
> overflow_err_count values in mocked cxl_overflow trace events, such as
> this case where the records are reported as 0 and should be non-zero:
> 
> [] cxl_overflow: memdev=mem7 host=cxl_mem.6 serial=7: log=Failure : 0 records from 1763228189130895685 to 1763228193130896180
> 
> Fix by using log->nr_overflow and remove the unused local variable.
> 
> A follow-up change was considered in cxl_mem_get_records_log() to
> confirm that the overflow_err_count is non-zero when the overflow flag
> is set [1]. Since the driver has no functional dependency on this
> constraint, and a device that violates this specific requirement does
> not cause incorrect driver behavior, no validation check is added.
> 
> [1] CXL 3.2, Table 8-65 Get Event Records Output Payload
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>> ---
>  tools/testing/cxl/test/mem.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index d533481672b7..9853bccfa185 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -256,7 +256,6 @@ static int mock_get_event(struct device *dev, struct cxl_mbox_cmd *cmd)
>  {
>  	struct cxl_get_event_payload *pl;
>  	struct mock_event_log *log;
> -	u16 nr_overflow;
>  	u8 log_type;
>  	int i;
>  
> @@ -299,7 +298,7 @@ static int mock_get_event(struct device *dev, struct cxl_mbox_cmd *cmd)
>  		u64 ns;
>  
>  		pl->flags |= CXL_GET_EVENT_FLAG_OVERFLOW;
> -		pl->overflow_err_count = cpu_to_le16(nr_overflow);
> +		pl->overflow_err_count = cpu_to_le16(log->nr_overflow);
>  		ns = ktime_get_real_ns();
>  		ns -= 5000000000; /* 5s ago */
>  		pl->first_overflow_timestamp = cpu_to_le64(ns);
> 
> base-commit: e9a6fb0bcdd7609be6969112f3fbfcce3b1d4a7c