linux-kernel - Re: [PATCH] qnx4: Use hweight8

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1258104305l.9440l.0l@i-dmzi_al.realan.de>
Date:	Fri, 13 Nov 2009 10:25:05 +0100
From:	Anders Larsen <al@...rsen.net>
To:	Akinobu Mita <akinobu.mita@...il.com>
Cc:	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	Akinobu Mita <akinobu.mita@...il.com>,
	Al Viro <viro@...iv.linux.org.uk>
Subject: Re: [PATCH] qnx4: Use hweight8

On 2009-11-13 08:06:18, Akinobu Mita wrote:
> Use hweight8 instead of counting for each bit
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@...il.com>
> Cc: Anders Larsen <al@...rsen.net>
> Cc: Al Viro <viro@...iv.linux.org.uk>

The original code counted the number of zeroes whereas hweight8() counts ones, so

NAK

(hint: "tot += 8 - hweight8(b)" should do the trick)

Cheers
Anders

> ---
>  fs/qnx4/bitmap.c |   17 +----------------
>  1 files changed, 1 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/qnx4/bitmap.c b/fs/qnx4/bitmap.c
> index 0afba06..b913e3d 100644
> --- a/fs/qnx4/bitmap.c
> +++ b/fs/qnx4/bitmap.c
> @@ -35,22 +35,7 @@ static void count_bits(register const char *bmPart, register int size,
>  	}
>  	do {
>  		b = *bmPart++;
> -		if ((b & 1) == 0)
> -			tot++;
> -		if ((b & 2) == 0)
> -			tot++;
> -		if ((b & 4) == 0)
> -			tot++;
> -		if ((b & 8) == 0)
> -			tot++;
> -		if ((b & 16) == 0)
> -			tot++;
> -		if ((b & 32) == 0)
> -			tot++;
> -		if ((b & 64) == 0)
> -			tot++;
> -		if ((b & 128) == 0)
> -			tot++;
> +		tot += hweight8(b);
>  		size--;
>  	} while (size != 0);
>  	*tf = tot;
> -- 
> 1.6.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/