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Date: Thu, 30 Aug 2001 01:26:04 +0200
From: Ralf Baechle <ralf@uni-koblenz.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Brian Gerst <bgerst@didntduck.org>, Harald Barth <haba@pdc.kth.se>,
        linux-kernel@vger.kernel.org
Subject: Re: Size of pointers in sys_call_table?
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In-Reply-To: <E15blYK-0006Fb-00@the-village.bc.nu>; from alan@lxorguk.ukuu.org.uk on Tue, Aug 28, 2001 at 05:17:24PM +0100
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On Tue, Aug 28, 2001 at 05:17:24PM +0100, Alan Cox wrote:

> > The layout of the sys_call_table is totally architecture dependant.  The
> > question to ask here is why do you need to use it?  Modifying it to hook
> > into syscalls is frowned upon.
> 
> And potentially unsafe (think about caching, and non atomic writes on
> some platforms)

Breakage practically guaranteed on MIPS systems where additional information
beyond the pointer is associated with a syscall entry point.  Breakage also
guaranteed on ccNUMA systems that run per-node copies of the kernel.

  Ralf