On Wed, Feb 12, 2020 at 08:51:06AM +0100, Torsten Hilbrich wrote:
> This caused compile problems in user-space application using that
> header. Seen with systemd:
> 
> In file included from /build/client/devel/kernel/_/usr/include/linux/byteorder/little_endian.h:13,
>                  from /build/client/devel/kernel/_/usr/include/asm/byteorder.h: ,
>                  from /build/client/devel/kernel/_/usr/include/linux/icmpv6.h:6,
>                  from ../src/network/networkd-route.c:3:
> /build/client/devel/kernel/_/usr/include/linux/swab.h: In function ‘__swab’:
> /build/client/devel/kernel/_/usr/include/linux/swab.h:138:5: error: "BITS_PER_LONG" is not defined, evaluates to 0 [-Werror=undef]
>  #if BITS_PER_LONG == 64
>      ^~~~~~~~~~~~~
> cc1: some warnings being treated as errors
> [181/1207] Generating sys with a custom command.
> ninja: build stopped: subcommand failed.
> 
> Signed-off-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
> ---
>  include/uapi/linux/swab.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/swab.h b/include/uapi/linux/swab.h
> index fa7f97da5b76..7272f85d6d6a 100644
> --- a/include/uapi/linux/swab.h
> +++ b/include/uapi/linux/swab.h
> @@ -135,9 +135,9 @@ static inline __attribute_const__ __u32 __fswahb32(__u32 val)
> 
>  static __always_inline unsigned long __swab(const unsigned long y)
>  {
> -#if BITS_PER_LONG == 64
> +#if __BITS_PER_LONG == 64
>  	return __swab64(y);
> -#else /* BITS_PER_LONG == 32 */
> +#else /* __BITS_PER_LONG == 32 */
>  	return __swab32(y);
>  #endif
>  }
> -- 
> 2.20.1

Acked-by: Yury Norov <yury.norov@gmail.com>