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From: Nikolaus Rath <Nikolaus@rath.org>
To: Brice Goglin <Brice.Goglin@ens-lyon.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: virt_to_page for userspace pointers
Date: Sun, 13 Feb 2011 15:24:55 -0500	[thread overview]
Message-ID: <4D583E17.80606@rath.org> (raw)
In-Reply-To: <4D4DC2D6.8030905@ens-lyon.org>

On 02/05/2011 04:36 PM, Brice Goglin wrote:
>> Is there an equivalent function to virt_to_page (and virt_to_phys) that
>> works with userspace pointers? Or do I have to manually walk through the
>> page tables? In the later case, are there any examples of this kind of
>> search that I could use as a basis?
>>   
> 
> You probably want get_user_pages() (or get_user_pages_fast()).

Thanks for the pointer, that already helped a lot!

I would, however, prefer a more primitive function that just gives me
the struct page without locking it. And if the page is swapped out, I'd
rather get a NULL pointer than having a page frame allocated.  Is there
anything like that?

Thanks,

   -Nikolaus

-- 
 »Time flies like an arrow, fruit flies like a Banana.«

  PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6  02CF A9AD B7F8 AE4E 425C

  reply	other threads:[~2011-02-13 20:30 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-03 20:50 Reversing a memory mapping? Nikolaus Rath
2011-02-05 21:04 ` virt_to_page for userspace pointers (was: Reversing a memory mapping?) Nikolaus Rath
2011-02-05 21:36   ` virt_to_page for userspace pointers Brice Goglin
2011-02-13 20:24     ` Nikolaus Rath [this message]
2011-02-13 20:37       ` Brice Goglin
2011-02-13 21:56         ` Nikolaus Rath
2011-02-13 22:06           ` Alan Cox
2011-02-13 22:11             ` Nikolaus Rath
2011-02-14 22:46       ` Nikolaus Rath
2011-07-26 12:03         ` Alexey Skidanov

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