From: Arnd Bergmann <arnd@arndb.de>
To: Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: Re: [PATCH] sparc: copy_from_user() should not return -EFAULT
Date: Tue, 5 Jan 2010 18:55:58 +0100
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Cc: Arjan van de Ven <arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>,
       David Miller <davem@davemloft.net>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       Chris Zankel <chris@zankel.net>
References: <20100104154345.GA5671@osiris.boeblingen.de.ibm.com> <20100105053117.6a7c3377@infradead.org> <20100105152215.GD5480@osiris.boeblingen.de.ibm.com>
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On Tuesday 05 January 2010, Heiko Carstens wrote:
> Subject: [PATCH] sparc: copy_from_user() should not return -EFAULT
> 
> From: Heiko Carstens <heiko.carstens@de.ibm.com>
> 
> Callers of copy_from_user() expect it to return the number of bytes
> it could not copy. In no case it is supposed to return -EFAULT.
> 
> In case of a detected buffer overflow just return the requested
> length. In addition one could think of a memset that would clear
> the size of the target object.
> 
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

The xtensa clear_user function seems to have a similar issue,
it should return size on failure, not -EFAULT.

	Arnd
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