Subject: Re: [PATCH ethtool-next] Fixing boolean value output for Netlink reported values in JSON format

From: Simon Horman <[email-masked]>
Date: Thu, 5 Jan 2023 13:11:33 +0100

On Tue, Dec 27, 2022 at 10:36:20AM -0700, Maxim Georgiev wrote:
> Current implementation of show_bool_val() passes "val" parameter of pointer
> type as a last parameter to print_bool():
> https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/tree/netlink/netlink.h#n131
> ...
> static inline void show_bool_val(const char *key, const char *fmt, uint8_t *val)
> {
> 	if (is_json_context()) {
> 		if (val)
> >			print_bool(PRINT_JSON, key, NULL, val);
> 	} else {
> ...
> print_bool() expects the last parameter to be bool:
> https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/tree/json_print.c#n153
> ...
> void print_bool(enum output_type type,
> 		const char *key,
> 		const char *fmt,
> 		bool value)
> {
> ...
> Current show_bool_val() implementation converts "val" pointer to bool while
> calling show_bool_val(). As a result show_bool_val() always prints the value
> as "true" as long as it gets a non-null pointer to the boolean value, even if
> the referred boolean value is false.
> 
> Fixes: 7e5c1ddbe67d ("pause: add --json support")
> Signed-off-by: Maxim Georgiev <[email-masked]>

Reviewed-by: Simon Horman <[email-masked]>

I'm assuming that val is never NULL :)

> ---
>  netlink/netlink.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/netlink/netlink.h b/netlink/netlink.h
> index 3240fca..1274a3b 100644
> --- a/netlink/netlink.h
> +++ b/netlink/netlink.h
> @@ -128,7 +128,7 @@ static inline void show_bool_val(const char *key, const char *fmt, uint8_t *val)
>  {
>  	if (is_json_context()) {
>  		if (val)
> -			print_bool(PRINT_JSON, key, NULL, val);
> +			print_bool(PRINT_JSON, key, NULL, *val);
>  	} else {
>  		print_string(PRINT_FP, NULL, fmt, u8_to_bool(val));
>  	}
> -- 
> 2.38.1
>