linux-kernel - Re: [PATCH] arch: m68k: math-emu: unsigned issue, 'unsigned long' will never be less than zero.

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: <m2a9ndndu5.fsf@linux-m68k.org>
Date:	Thu, 30 May 2013 09:09:38 +0200
From:	Andreas Schwab <schwab@...ux-m68k.org>
To:	Chen Gang <gang.chen@...anux.com>
Cc:	Geert Uytterhoeven <geert@...ux-m68k.org>,
	linux-m68k@...ts.linux-m68k.org,
	"linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>,
	Linux-Arch <linux-arch@...r.kernel.org>
Subject: Re: [PATCH] arch: m68k: math-emu: unsigned issue, 'unsigned long' will never be less than zero.

Chen Gang <gang.chen@...anux.com> writes:

> 'oldmant.m32[1]' is 'unsigned long' which never '< 0', and the original
> author wanted to check the highest bit whether set.
>
> So need type cast form 'unsigned long' to 'long'.

Better to make the bit test explicit, since it is not a sign bit.

> diff --git a/arch/m68k/math-emu/fp_arith.c b/arch/m68k/math-emu/fp_arith.c
> index 08f286d..ef013c5 100644
> --- a/arch/m68k/math-emu/fp_arith.c
> +++ b/arch/m68k/math-emu/fp_arith.c
> @@ -519,7 +519,7 @@ static void fp_roundint(struct fp_ext *dest, int mode)
>  				return;
>  			break;
>  		case 0x401e:
> -			if (!(oldmant.m32[1] >= 0))
> +			if (!((long)oldmant.m32[1] >= 0))

			if (oldmant.m32[1] & 0x80000000)

Andreas.

-- 
Andreas Schwab, schwab@...ux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."
--
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/