Re: [PATCH] libcrc32c: keep intermediate crc state in cpu order

[Dave Jiang <djiang@mvista.com>]

Resolved my issue with BE open-iscsi initiator and LE IET target. Thanks!

Benny Halevy wrote:
> crypto/crc32.c:chksum_final() is computing the digest as
> *(__le32 *)out = ~cpu_to_le32(mctx->crc);
> so the low-level crc32c_le routines should just keep
> the crc in cpu order, otherwise it is getting swabbed
> one too many times on big-endian machines.
> 
> Signed-off-by: Benny Halevy <bhalevy@fs1.bhalevy.com>
> ---
>  lib/libcrc32c.c |    7 ++-----
>  1 files changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c
> index 802f11f..b5c3287 100644
> --- a/lib/libcrc32c.c
> +++ b/lib/libcrc32c.c
> @@ -33,7 +33,6 @@
>  #include <linux/crc32c.h>
>  #include <linux/compiler.h>
>  #include <linux/module.h>
> -#include <asm/byteorder.h>
>  
>  MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
>  MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
> @@ -161,15 +160,13 @@ static const u32 crc32c_table[256] = {
>   */
>  
>  u32 __pure
> -crc32c_le(u32 seed, unsigned char const *data, size_t length)
> +crc32c_le(u32 crc, unsigned char const *data, size_t length)
>  {
> -	u32 crc = __cpu_to_le32(seed);
> -	
>  	while (length--)
>  		crc =
>  		    crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
>  
> -	return __le32_to_cpu(crc);
> +	return crc;
>  }
>  
>  #endif	/* CRC_LE_BITS == 8 */


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Dave Jiang
Software Engineer
MontaVista Software, Inc.
http://www.mvista.com
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