From: Rusty Russell <rusty@rustcorp.com.au>
To: David Howells <dhowells@redhat.com>
Cc: akpm@linux-foundation.org, mm-commits@vger.kernel.org,
linux-arch@vger.kernel.org, randy.dunlap@oracle.com
Subject: Re: + expose-range-checking-functions-from-arch-specific.patch added to -mm tree
Date: Wed, 11 Apr 2007 12:19:10 +1000 [thread overview]
Message-ID: <1176257950.26372.50.camel@localhost.localdomain> (raw)
In-Reply-To: <6632.1176200270@redhat.com>
On Tue, 2007-04-10 at 11:17 +0100, David Howells wrote:
> akpm@linux-foundation.org wrote:
>
> > + * @limit: the first invalid value
>
> If this is the case, ...
>
> > + *
> > + * Like val + len > limit, except with overflow checking.
> > + */
> > +static inline bool val_outside(unsigned long val, unsigned long len,
> > + unsigned long limit)
> > +
> > +{
> > + return val + len > limit || val + len < val;
>
> ... then shouldn't that be "val + len >= limit"?
You're the second one to ask this. I'm pretty sure it's still right
(and it's what the old code used to do).
Consider the case where limit is 0xC0000000, val is 0xBFFFFFFF and len
is 1.
Hope that helps,
Rusty.
next prev parent reply other threads:[~2007-04-11 2:19 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-06 21:27 + expose-range-checking-functions-from-arch-specific.patch added to -mm tree akpm
2007-04-10 10:17 ` David Howells
2007-04-11 2:19 ` Rusty Russell [this message]
2007-04-11 2:48 ` Andrew Morton
2007-04-11 10:49 ` David Howells
2007-04-11 18:24 ` Andrew Morton
2007-04-11 23:28 ` Rusty Russell
2007-04-12 16:05 ` + expose-range-checking-functions-from-arch-specific.patchadded " Luck, Tony
2007-04-13 0:08 ` Rusty Russell
2007-04-11 23:41 ` + expose-range-checking-functions-from-arch-specific.patch added " Rusty Russell
2007-04-12 10:47 ` David Howells
2007-04-12 14:51 ` Randy Dunlap
2007-04-12 7:42 ` Geert Uytterhoeven
2007-04-11 13:17 ` Rusty Russell
2007-04-11 17:03 ` David Howells
2007-04-11 18:31 ` Andrew Morton
2007-04-11 19:17 ` David Howells
2007-04-11 22:52 ` Rusty Russell
2007-04-12 10:49 ` David Howells
2007-04-11 10:47 ` David Howells
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