From: David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>
To: Jon Loeliger <jdl-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Cc: devicetree-discuss
<devicetree-discuss-mnsaURCQ41sdnm+yROfE0A@public.gmane.org>,
Stephen Papacharalambous
<SteveP-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Subject: Re: [PATCH] Fix an overflow case in fdt_offset_ptr() detected by GCC 4.3.
Date: Fri, 26 Sep 2008 11:29:34 +1000 [thread overview]
Message-ID: <20080926012934.GD13228@yookeroo.seuss> (raw)
In-Reply-To: <1222358537.25112.7.camel@ld0161-tx32>
On Thu, Sep 25, 2008 at 11:02:17AM -0500, Jon Loeliger wrote:
>
> Using Gcc 4.3 detected this problem:
>
> ../dtc/libfdt/fdt.c: In function 'fdt_next_tag':
> ../dtc/libfdt/fdt.c:82: error: assuming signed overflow does not
> occur when assuming that (X + c) < X is always false
Um... I'm a little baffled by this warning, given that the line in
question is actually testing that (X+c) < X is false..
> To fix the problem, treat the offset as an unsigned int.
Nor am I entirely sure how that's supposed to help, since an unsigned
overflow is also possible.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
next prev parent reply other threads:[~2008-09-26 1:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-25 16:02 [PATCH] Fix an overflow case in fdt_offset_ptr() detected by GCC 4.3 Jon Loeliger
2008-09-26 1:29 ` David Gibson [this message]
2008-09-29 21:13 ` Jon Loeliger
[not found] ` <E1KkQ3b-0000uT-6H-CYoMK+44s/E@public.gmane.org>
2008-09-30 1:15 ` David Gibson
[not found] ` <20080930011525.GB6189-787xzQ0H9iRg7VrjXcPTGA@public.gmane.org>
2008-09-30 1:51 ` Jon Loeliger
[not found] ` <E1KkUOE-0001OX-EF-CYoMK+44s/E@public.gmane.org>
2008-09-30 2:39 ` David Gibson
[not found] ` <20080930023934.GB8939-787xzQ0H9iRg7VrjXcPTGA@public.gmane.org>
2008-09-30 8:03 ` Steve Papacharalambous
2008-09-30 16:28 ` Scott Wood
[not found] ` <48E253A2.1090702-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2008-10-01 1:19 ` David Gibson
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