netfilter: ipv4, defrag: switch hook PFs to nfproto

[~andy/linux] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 2bf9e110437c426e12587730545b370cbdd3bc69..1b7dc662bf9f229063cb3e7b97e8e4c22147b92b 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3486,6 +3486,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        if (unlikely(is_vm_hugetlb_page(vma)))
                return hugetlb_fault(mm, vma, address, flags);
 
+retry:
        pgd = pgd_offset(mm, address);
        pud = pud_alloc(mm, pgd, address);
        if (!pud)
@@ -3499,13 +3500,24 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                                          pmd, flags);
        } else {
                pmd_t orig_pmd = *pmd;
+               int ret;
+
                barrier();
                if (pmd_trans_huge(orig_pmd)) {
                        if (flags & FAULT_FLAG_WRITE &&
                            !pmd_write(orig_pmd) &&
-                           !pmd_trans_splitting(orig_pmd))
-                               return do_huge_pmd_wp_page(mm, vma, address,
-                                                          pmd, orig_pmd);
+                           !pmd_trans_splitting(orig_pmd)) {
+                               ret = do_huge_pmd_wp_page(mm, vma, address, pmd,
+                                                         orig_pmd);
+                               /*
+                                * If COW results in an oom, the huge pmd will
+                                * have been split, so retry the fault on the
+                                * pte for a smaller charge.
+                                */
+                               if (unlikely(ret & VM_FAULT_OOM))
+                                       goto retry;
+                               return ret;
+                       }
                        return 0;
                }
        }