From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S932573AbbJPOEY (ORCPT <rfc822;w@1wt.eu>);
	Fri, 16 Oct 2015 10:04:24 -0400
Received: from relay1.mentorg.com ([192.94.38.131]:45056 "EHLO
	relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S932327AbbJPOEW (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 16 Oct 2015 10:04:22 -0400
Subject: Re: [PATCH v4] ARM: fix vdsomunge not to depend on glibc specific
 byteswap.h
To: "H. Nikolaus Schaller" <hns@goldelico.com>
References: <4436b0dbf72aa409613ec4c7407b017d085e40ac.1444977518.git.hns@goldelico.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Will Deacon <will.deacon@arm.com>,
        <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <marek@goldelico.com>
From: Nathan Lynch <Nathan_Lynch@mentor.com>
Message-ID: <5621038E.9080406@mentor.com>
Date: Fri, 16 Oct 2015 09:02:54 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.3.0
MIME-Version: 1.0
In-Reply-To: <4436b0dbf72aa409613ec4c7407b017d085e40ac.1444977518.git.hns@goldelico.com>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 10/16/2015 01:38 AM, H. Nikolaus Schaller wrote:
> diff --git a/arch/arm/vdso/vdsomunge.c b/arch/arm/vdso/vdsomunge.c
> index aedec81..0cebd98 100644
> --- a/arch/arm/vdso/vdsomunge.c
> +++ b/arch/arm/vdso/vdsomunge.c
> @@ -45,7 +45,6 @@
>   * it does.
>   */
>  
> -#include <byteswap.h>
>  #include <elf.h>
>  #include <errno.h>
>  #include <fcntl.h>
> @@ -59,6 +58,16 @@
>  #include <sys/types.h>
>  #include <unistd.h>
>  
> +#define swab16(x) \
> +	((((x) & 0x00ff) << 8) | \
> +	 (((x) & 0xff00) >> 8))
> +
> +#define swab32(x) \
> +	((((x) & 0x000000ff) << 24) | \
> +	 (((x) & 0x0000ff00) <<  8) | \
> +	 (((x) & 0x00ff0000) >>  8) | \
> +	 (((x) & 0xff000000) << 24))
> +
>  #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
>  #define HOST_ORDER ELFDATA2LSB
>  #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
> @@ -104,17 +113,17 @@ static void cleanup(void)
>  
>  static Elf32_Word read_elf_word(Elf32_Word word, bool swap)
>  {
> -	return swap ? bswap_32(word) : word;
> +	return swap ? swab32(word) : word;
>  }
>  
>  static Elf32_Half read_elf_half(Elf32_Half half, bool swap)
>  {
> -	return swap ? bswap_16(half) : half;
> +	return swap ? swab16(half) : half;
>  }
>  
>  static void write_elf_word(Elf32_Word val, Elf32_Word *dst, bool swap)
>  {
> -	*dst = swap ? bswap_32(val) : val;
> +	*dst = swap ? swab32(val) : val;
>  }

I think this looks good now and it checks out in my local testing.
Thanks for your persistence.

Assuming Russell has no further comments I'll put this in his patch
system later today.