linux-kernel - Re: copy_*

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Message-ID: <4EA3E926.80203@zytor.com>
Date:	Sun, 23 Oct 2011 12:15:02 +0200
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Xin Tong <xerox.time.tech@...il.com>
CC:	Américo Wang <xiyou.wangcong@...il.com>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: copy_*_user

On 10/23/2011 11:23 AM, Xin Tong wrote:
> I found that __copy_from_user_ll(void *to, const void __user *from,
> unsigned long n) eventually calls some asm which use mov and rep on
> the passed-in to & from pointers. This is in kernel mode and to & from
> are virtual addresses ? are not the kernel accessing physical RAM
> directly ( without pagetable ) ?

No.  What gave you that idea?

	-hpa

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