From: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
To: Jim Rees <rees@umich.edu>
Cc: Bruce Fields <bfields@fieldses.org>, linux-nfs@vger.kernel.org
Subject: Re: [PATCH v2] nfsd: avoid undefined signed overflow
Date: Sat, 18 May 2013 17:49:11 +0200 [thread overview]
Message-ID: <1368892155.11003.39.camel@thorin> (raw)
In-Reply-To: <20130518145808.GA3670@umich.edu>
On Sam, 2013-05-18 at 10:58 -0400, Jim Rees wrote:
> Bernd Petrovitsch wrote:
>
> Hmm, what is actually wrong with plain-old
> ---- snip ----
> static bool stateid_generation_after(stateid_t *a, stateid_t *b)
> {
> return a->si_generation > b->si_generation;
> }
> ---- snip ----
> ?
>
> It doesn't account for wraparound. Try this:
>
> unsigned int a = 0xffff0000, b = 0x7fff0000;
> printf("%d %d\n", a > b, (int)(a - b) > 0);
>
> I just realized that I said this needed a comment, then didn't provide one.
Ooops, yes, thx.
Sry for the noise;-)
Bernd
--
Bernd Petrovitsch Email : bernd@petrovitsch.priv.at
LUGA : http://www.luga.at
prev parent reply other threads:[~2013-05-18 15:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-17 21:33 [PATCH v2] nfsd: avoid undefined signed overflow Jim Rees
2013-05-17 21:40 ` Bruce Fields
2013-05-17 22:30 ` Jim Rees
2013-05-18 11:04 ` Bernd Petrovitsch
2013-05-18 14:58 ` Jim Rees
2013-05-18 15:49 ` Bernd Petrovitsch [this message]
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