Since gup-fast doesn't have the vma reference, teach it to detect such huge pfnmaps by checking the special bit for pmd/pud too, just like ptes. Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> --- mm/gup.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index d19884e097fd..a49f67a512ee 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -3038,6 +3038,9 @@ static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr, if (!pmd_access_permitted(orig, flags & FOLL_WRITE)) return 0; + if (pmd_special(orig)) + return 0; + if (pmd_devmap(orig)) { if (unlikely(flags & FOLL_LONGTERM)) return 0; @@ -3082,6 +3085,9 @@ static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr, if (!pud_access_permitted(orig, flags & FOLL_WRITE)) return 0; + if (pud_special(orig)) + return 0; + if (pud_devmap(orig)) { if (unlikely(flags & FOLL_LONGTERM)) return 0; -- 2.45.0