diff options
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index ed1581b670d4..44f1e6366d04 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5585,6 +5585,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, struct page *page; struct hstate *h = hstate_vma(vma); unsigned long sz = huge_page_size(h); + bool adjust_reservation = false; unsigned long last_addr_mask; bool force_flush = false; @@ -5677,7 +5678,31 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, hugetlb_count_sub(pages_per_huge_page(h), mm); hugetlb_remove_rmap(page_folio(page)); + /* + * Restore the reservation for anonymous page, otherwise the + * backing page could be stolen by someone. + * If there we are freeing a surplus, do not set the restore + * reservation bit. + */ + if (!h->surplus_huge_pages && __vma_private_lock(vma) && + folio_test_anon(page_folio(page))) { + folio_set_hugetlb_restore_reserve(page_folio(page)); + /* Reservation to be adjusted after the spin lock */ + adjust_reservation = true; + } + spin_unlock(ptl); + + /* + * Adjust the reservation for the region that will have the + * reserve restored. Keep in mind that vma_needs_reservation() changes + * resv->adds_in_progress if it succeeds. If this is not done, + * do_exit() will not see it, and will keep the reservation + * forever. + */ + if (adjust_reservation && vma_needs_reservation(h, vma, address)) + vma_add_reservation(h, vma, address); + tlb_remove_page_size(tlb, page, huge_page_size(h)); /* * Bail out after unmapping reference page if supplied |