mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry

mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry

When the pagetable is walked in the implementation of /proc/<pid>/pagemap,
pmd_soft_dirty() is used for both the PMD huge page map and the PMD
migration entries.  That is wrong, pmd_swp_soft_dirty() should be used
for the PMD migration entries instead because the different page table
entry flag is used.

As a result, /proc/pid/pagemap may report incorrect soft dirty information
for PMD migration entries.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path")
Signed-off-by: "Huang, Ying" <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Naoya Horiguchi <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: "Jérôme Glisse" <[email protected]>
Cc: Daniel Colascione <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>