Messages in this thread | | | Date | Sun, 13 Feb 2011 16:56:12 -0500 | From | Nikolaus Rath <> | Subject | Re: virt_to_page for userspace pointers |
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On 02/13/2011 03:37 PM, Brice Goglin wrote: > Le 13/02/2011 21:24, Nikolaus Rath a écrit : >> 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? >> > > If you don't lock the page, you have no guarantee that it won't get > swapped out or migrated while you look at the physical page.
That's fine, I know that if the page is there at all then it has been locked by a (different) kernel driver. Is there any way to find out what I want?
Thanks,
-Nikolaus
-- »Time flies like an arrow, fruit flies like a Banana.«
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