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Date: Mon, 20 Nov 2000 12:33:00 -0700
From: Michal Jaegermann <michal@harddata.com>
To: linux-kernel@vger.kernel.org
Cc: akenning@dog.topology.org
Subject: Re: easy-to-fix bug in /dev/null driver
Message-ID: <20001120123300.A19251@mail.harddata.com>
In-Reply-To: <20001120160638.A14325@dog.topology.org> <20001121005304.A15760@dog.topology.org>
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In-Reply-To: <20001121005304.A15760@dog.topology.org>; from Alan Kennington on Tue, Nov 21, 2000 at 12:53:04AM +1030
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On Tue, Nov 21, 2000 at 12:53:04AM +1030, Alan Kennington wrote:
> 
> I still think that write_null() should be rewritten as:
> 
> ===================================================
> static ssize_t write_null(struct file * file, const char * buf,
>                           size_t count, loff_t *ppos)
> {
>         return (count <= 2147483647) ? count : 2147483647;
> }
> =================================================== 
> 
> This would fix the problem without introducing any new errors.
> (Unless someone change the definitions of ssize_t and size_t!!)

Someone already did.  Or, more precisely, there are platforms where
values used in 'return' above are bogus.

Shifting 1 up by sizeof(ssize_t) * 8 - 1 and subtracting one from
the result, in order to derive the maximal allowable value, might work.
I do not think that we have anything with non-8 bit bytes yet.

  Michal
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