[PATCH] hugetlb: follow_hugetlb_page for write access

Ken Chen kenchen at google.com
Fri Nov 9 07:43:20 EST 2007


On Nov 7, 2007 11:51 AM, Adam Litke <agl at us.ibm.com> wrote:
> When calling get_user_pages(), a write flag is passed in by the caller to
> indicate if write access is required on the faulted-in pages.  Currently,
> follow_hugetlb_page() ignores this flag and always faults pages for
> read-only access.  This can cause data corruption because a device driver
> that calls get_user_pages() with write set will not expect COW faults to
> occur on the returned pages.
>
> This patch passes the write flag down to follow_hugetlb_page() and makes
> sure hugetlb_fault() is called with the right write_access parameter.
>
> Signed-off-by: Adam Litke <agl at us.ibm.com>

Adam, this looks good.

Reviewed-by: Ken Chen <kenchen at google.com>



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