Re: [PATCH v6 12/17] lib/bootconfig: fix signed comparison in xbc_node_get_data()

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Sun, 15 Mar 2026 12:20:10 +0000
Josh Law <objecting@objecting.org> wrote:

>   lib/bootconfig.c:188:28: warning: comparison of integer expressions
>   of different signedness: 'int' and 'size_t' [-Wsign-compare]
> 
> The local variable 'offset' is declared as int, but xbc_data_size is
> size_t.  Using ~XBC_VALUE as the mask also involves integer promotion
> rules that obscure intent.
> 
> Change the type to unsigned int and mask with XBC_DATA_MAX (which is
> the 15-bit data mask) instead of ~XBC_VALUE, making the expression
> self-documenting and eliminating the signed/unsigned comparison.

Please follow the warning message and use size_t instead.

Thanks,

> 
> Signed-off-by: Josh Law <objecting@objecting.org>
> ---
>  lib/bootconfig.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/bootconfig.c b/lib/bootconfig.c
> index 182d9d9bc5a6..806a8f038d24 100644
> --- a/lib/bootconfig.c
> +++ b/lib/bootconfig.c
> @@ -183,7 +183,7 @@ struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
>   */
>  const char * __init xbc_node_get_data(struct xbc_node *node)
>  {
> -	int offset = node->data & ~XBC_VALUE;
> +	unsigned int offset = node->data & XBC_DATA_MAX;
>  
>  	if (WARN_ON(offset >= xbc_data_size))
>  		return NULL;
> -- 
> 2.34.1
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>