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Re: Kernel/User Memory Access and Original Sin

To: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Subject: Re: Kernel/User Memory Access and Original Sin
From: "Kevin D. Kissell" <kevink@mips.com>
Date: Mon, 28 Feb 2000 14:56:04 +0100
Cc: "Linux/MIPS fnet" <linux-mips@fnet.fr>, "Linux/MIPS algor" <linux-porters@algor.co.uk>, "Linux SGI" <linux@cthulhu.engr.sgi.com>
>__access_ok has one purpose. To verify the address range given is entirely
>sensible to feed to __copy_*_user. If you have to do handling the complex
>way (eg if your cpu design requires it) then __access_ok can just return 1
>and the __copy_*_user - inline or out of line - can do all the work.


Thanks.  I think I have localized the hole in the signal handling that
would have defeated these mechanisms, though another related
failure that was also solved by the sledgehammer __access_ok
remains mysterious.  I'll apply the more localized fix and repeat the 
crashme experiments...

            Kevin K.


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