Re: [PATCH 1/2] xen/common: llc-coloring: clear color count on parse failure

[dmukhin@xxxxxxxx]

On Sat, May 16, 2026 at 06:03:11PM +0300, Mykola Kvach wrote:
> From: Mykola Kvach <mykola_kvach@xxxxxxxx>
> 
> parse_color_config() updates the caller-provided color count while
> parsing. If parsing later fails, leave the count at zero so callers
> do not consume a partially parsed configuration.
> 
> Fixes: 6cdea3444eaf ("xen/arm: add Dom0 cache coloring support")
> Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>

Please consider

Reviewed-by: Denis Mukhin <dmukhin@xxxxxxxx> 

> ---
>  xen/common/llc-coloring.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/common/llc-coloring.c b/xen/common/llc-coloring.c
> index 6dc614739a..2606cb0977 100644
> --- a/xen/common/llc-coloring.c
> +++ b/xen/common/llc-coloring.c
> @@ -79,7 +79,7 @@ static int __init parse_color_config(const char *buf, 
> unsigned int colors[],
>          if ( end >= NR_LLC_COLORS || start > end ||
>               (end - start) >= (UINT_MAX - *num_colors) ||
>               (*num_colors + (end - start)) >= max_num_colors )
> -            return -EINVAL;
> +            goto fail;
>  
>          /* Colors are range checked in check_colors() */
>          for ( color = start; color <= end; color++ )
> @@ -91,7 +91,14 @@ static int __init parse_color_config(const char *buf, 
> unsigned int colors[],
>              break;
>      }
>  
> -    return *s ? -EINVAL : 0;
> +    if ( *s )
> +        goto fail;
> +
> +    return 0;
> +
> + fail:
> +    *num_colors = 0;
> +    return -EINVAL;
>  }
>  
>  static int __init parse_dom0_colors(const char *s)
> -- 
> 2.43.0
> 
>