Author: kib
Date: Thu Jul  5 17:28:06 2018
New Revision: 336010
URL: https://svnweb.freebsd.org/changeset/base/336010

Log:
  Extend r335969 to superpages.
  
  It is possible that a fictitious unmanaged userspace mapping of
  superpage is created on x86, e.g. by pmap_object_init_pt(), with the
  physical address outside the vm_page_array[] coverage.
  
  Noted and reviewed by:        alc
  Sponsored by: The FreeBSD Foundation
  MFC after:    1 week
  Differential revision:        https://reviews.freebsd.org/D16085

Modified:
  head/sys/amd64/amd64/pmap.c
  head/sys/i386/i386/pmap.c

Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c Thu Jul  5 17:26:44 2018        (r336009)
+++ head/sys/amd64/amd64/pmap.c Thu Jul  5 17:28:06 2018        (r336010)
@@ -2308,7 +2308,6 @@ retry:
                                    PG_PS_FRAME) | (va & PDRMASK), &pa))
                                        goto retry;
                                m = PHYS_TO_VM_PAGE(pa);
-                               vm_page_hold(m);
                        }
                } else {
                        pte = *pmap_pde_to_pte(pdep, va);
@@ -2318,10 +2317,10 @@ retry:
                                    &pa))
                                        goto retry;
                                m = PHYS_TO_VM_PAGE(pa);
-                               if (m != NULL)
-                                       vm_page_hold(m);
                        }
                }
+               if (m != NULL)
+                       vm_page_hold(m);
        }
        PA_UNLOCK_COND(pa);
        PMAP_UNLOCK(pmap);

Modified: head/sys/i386/i386/pmap.c
==============================================================================
--- head/sys/i386/i386/pmap.c   Thu Jul  5 17:26:44 2018        (r336009)
+++ head/sys/i386/i386/pmap.c   Thu Jul  5 17:28:06 2018        (r336010)
@@ -1673,7 +1673,6 @@ retry:
                                    PG_PS_FRAME) | (va & PDRMASK), &pa))
                                        goto retry;
                                m = PHYS_TO_VM_PAGE(pa);
-                               vm_page_hold(m);
                        }
                } else {
                        pte = pmap_pte_ufast(pmap, va, pde);
@@ -1683,10 +1682,10 @@ retry:
                                    &pa))
                                        goto retry;
                                m = PHYS_TO_VM_PAGE(pa);
-                               if (m != NULL)
-                                       vm_page_hold(m);
                        }
                }
+               if (m != NULL)
+                       vm_page_hold(m);
        }
        PA_UNLOCK_COND(pa);
        PMAP_UNLOCK(pmap);
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