linux-mips
[Top] [All Lists]

RE: mips: Re-introduce copy_user_page

To: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>, Guenter Roeck <linux@roeck-us.net>, Ralf Baechle <ralf@linux-mips.org>
Subject: RE: mips: Re-introduce copy_user_page
From: "Wilcox, Matthew R" <matthew.r.wilcox@intel.com>
Date: Wed, 4 Feb 2015 16:25:08 +0000
Accept-language: en-CA, en-US
Cc: "linux-mips@linux-mips.org" <linux-mips@linux-mips.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Atsushi Nemoto <anemo@mba.ocn.ne.jp>
In-reply-to: <54D11608.2070408@imgtec.com>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <1422681807-28395-1-git-send-email-linux@roeck-us.net> <54D11608.2070408@imgtec.com>
Sender: linux-mips-bounce@linux-mips.org
Thread-index: AQHQP+Dc9wfYcGSMQU6+AGJBA2rhxpzfTD2w
Thread-topic: mips: Re-introduce copy_user_page
There is no 'struct page' for the source of this data.  We have a kernel 
address for it; that's all.

-----Original Message-----
From: Leonid Yegoshin [mailto:Leonid.Yegoshin@imgtec.com] 
Sent: Tuesday, February 03, 2015 10:40 AM
To: Guenter Roeck; Ralf Baechle
Cc: linux-mips@linux-mips.org; linux-kernel@vger.kernel.org; Atsushi Nemoto; 
Wilcox, Matthew R
Subject: Re: mips: Re-introduce copy_user_page

On 01/30/2015 09:23 PM, Guenter Roeck wrote:
> Commit bcd022801ee5 ("MIPS: Fix COW D-cache aliasing on fork") replaced
> the inline function copy_user_page for mips with an external reference,
> but neglected to introduce the actual non-inline function. Restore it.
>
> Fixes: bcd022801ee5 ("MIPS: Fix COW D-cache aliasing on fork")
> Fixes: 4927b7d77c00 ("dax,ext2: replace the XIP page fault handler with the 
> DAX page fault handler")
> Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>

Why do you use copy_user_page?
It doesn't work properly in HIGHMEM environment and it is excluded from 
MIPS because of that, I believe.

You should use copy_user_highpage() for user pages.

- Leonid.


<Prev in Thread] Current Thread [Next in Thread>