hugetlb: follow_hugetlb_page() for write access

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.

[[email protected]: build fix]
Signed-off-by: Adam Litke <[email protected]>
Reviewed-by: Ken Chen <[email protected]>
Cc: David Gibson <[email protected]>
Cc: William Lee Irwin III <[email protected]>
Cc: Badari Pulavarty <[email protected]>
Signed-off-by: Erez Zadok <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions