mm/hmm: fix hmm_range_fault()'s handling of swapped out pages

hmm_range_fault() may return NULL pages because some of the pfns are equal
to HMM_PFN_NONE. This happens randomly under memory pressure. The reason
is during the swapped out page pte path, hmm_vma_handle_pte() doesn't
update the fault variable from cpu_flags, so it failed to call
hmm_vam_do_fault() to swap the page in.

The fix is to call hmm_pte_need_fault() to update fault variable.

Fixes: 74eee180b935 ("mm/hmm/mirror: device page fault handler")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Philip Yang <[email protected]>
Reviewed-by: "Jérôme Glisse" <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

0 files changed, 0 insertions, 0 deletions