svn commit: r336010 - in head/sys: amd64/amd64 i386/i386

[Konstantin Belousov]

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);