Re: [PATCH ndctl 2/3] cxl/monitor: retain error code in monitor_event()

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

On 2/17/23 5:40 PM, Vishal Verma wrote:
> Static analysis reports that the error unwinding path in monitor_event()
> overwrites 'rc' with the return from cxl_event_tracing_disable(). This
> masks the actual error code from either epoll_wait() or
> cxl_parse_events() which is the one that should be propagated.
> 
> Print a spot error in case there's an error while disabling tracing, but
> otherwise retain the rc from the main body of the function.
> 
> Fixes: 299f69f974a6 ("cxl/monitor: add a new monitor command for CXL trace events")
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>   cxl/monitor.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/cxl/monitor.c b/cxl/monitor.c
> index 31e6f98..749f472 100644
> --- a/cxl/monitor.c
> +++ b/cxl/monitor.c
> @@ -130,7 +130,8 @@ static int monitor_event(struct cxl_ctx *ctx)
>   	}
>   
>   parse_err:
> -	rc = cxl_event_tracing_disable(inst);
> +	if (cxl_event_tracing_disable(inst) < 0)
> +		err(&monitor, "failed to disable tracing\n");
>   event_en_err:
>   epoll_ctl_err:
>   	close(fd);
>