Re: [PATCH v1 1/3] tools: allocate bitmaps in units of unsigned long

[Wei Liu <wl@xxxxxxx>]

On Wed, Dec 09, 2020 at 04:54:49PM +0100, Olaf Hering wrote:
> Allocate enough memory so that the returned pointer can be safely
> accessed as an array of unsigned long.
> 
> The actual bitmap size in units of bytes, as returned by bitmap_size,
> remains unchanged.
> 
> Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>

Acked-by: Wei Liu <wl@xxxxxxx>

I can see where you're coming from. This (internal) API's returned
pointer is being assigned to unsigned long *.

> ---
>  tools/libs/ctrl/xc_bitops.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h
> index 3d3a09772a..d6c5ea5138 100644
> --- a/tools/libs/ctrl/xc_bitops.h
> +++ b/tools/libs/ctrl/xc_bitops.h
> @@ -21,7 +21,10 @@ static inline unsigned long bitmap_size(unsigned long 
> nr_bits)
>  
>  static inline void *bitmap_alloc(unsigned long nr_bits)
>  {
> -    return calloc(1, bitmap_size(nr_bits));
> +    unsigned long longs;
> +
> +    longs = (nr_bits + BITS_PER_LONG - 1) / BITS_PER_LONG;
> +    return calloc(longs, sizeof(unsigned long));
>  }
>  
>  static inline void bitmap_set(void *addr, unsigned long nr_bits)