Re: [PATCH] [BUGFIX] rmap: remove anon_vma check in page_address_in_vma()

[Rik van Riel]

On 04/22/2010 10:08 PM, Naoya Horiguchi wrote:
> Currently page_address_in_vma() compares vma->anon_vma and page_anon_vma(page)
> for parameter check, but in 2.6.34 a vma can have multiple anon_vmas with
> anon_vma_chain, so current check does not work. (For anonymous page shared by
> multiple processes, some verified (page,vma) pairs return -EFAULT wrongly.)
>
> We can go to checking all anon_vmas in the "same_vma" chain, but it needs
> to meet lock requirement. Instead, we can remove anon_vma check safely
> because page_address_in_vma() assumes that page and vma are already checked
> to belong to the identical process.
>
> Signed-off-by: Naoya Horiguchi<n-horiguchi@xxxxxxxxxxxxx>
> Cc: Andrew Morton<akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Rik van Riel<riel@xxxxxxxxxx>
> Cc: Andi Kleen<andi@xxxxxxxxxxxxxx>

Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
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