Module Name: src
Committed By: christos
Date: Fri Jul 18 12:36:57 UTC 2014
Modified Files:
src/sys/sys: mman.h
src/sys/uvm: uvm_map.c
Log Message:
Add MAP_INHERIT_ZERO
To generate a diff of this commit:
cvs rdiff -u -r1.46 -r1.47 src/sys/sys/mman.h
cvs rdiff -u -r1.329 -r1.330 src/sys/uvm/uvm_map.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/sys/mman.h
diff -u src/sys/sys/mman.h:1.46 src/sys/sys/mman.h:1.47
--- src/sys/sys/mman.h:1.46 Mon Jun 30 17:46:33 2014
+++ src/sys/sys/mman.h Fri Jul 18 08:36:57 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: mman.h,v 1.46 2014/06/30 21:46:33 matt Exp $ */
+/* $NetBSD: mman.h,v 1.47 2014/07/18 12:36:57 christos Exp $ */
/*-
* Copyright (c) 1982, 1986, 1993
@@ -161,6 +161,7 @@ typedef __off_t off_t; /* file offset
#define MAP_INHERIT_NONE 2 /* absent from child */
#define MAP_INHERIT_DONATE_COPY 3 /* copy and delete -- not
implemented in UVM */
+#define MAP_INHERIT_ZERO 4 /* zero in child */
#define MAP_INHERIT_DEFAULT MAP_INHERIT_COPY
#endif
Index: src/sys/uvm/uvm_map.c
diff -u src/sys/uvm/uvm_map.c:1.329 src/sys/uvm/uvm_map.c:1.330
--- src/sys/uvm/uvm_map.c:1.329 Fri Jul 18 08:19:09 2014
+++ src/sys/uvm/uvm_map.c Fri Jul 18 08:36:57 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_map.c,v 1.329 2014/07/18 12:19:09 christos Exp $ */
+/* $NetBSD: uvm_map.c,v 1.330 2014/07/18 12:36:57 christos Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.329 2014/07/18 12:19:09 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.330 2014/07/18 12:36:57 christos Exp $");
#include "opt_ddb.h"
#include "opt_uvmhist.h"
@@ -3097,6 +3097,7 @@ uvm_map_inherit(struct vm_map *map, vadd
case MAP_INHERIT_NONE:
case MAP_INHERIT_COPY:
case MAP_INHERIT_SHARE:
+ case MAP_INHERIT_ZERO:
break;
default:
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
@@ -4346,6 +4347,35 @@ uvm_mapent_forkcopy(struct vm_map *new_m
}
/*
+ * zero the mapping: the new entry will be zero initialized
+ */
+static void
+uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map,
+ struct vm_map_entry *old_entry)
+{
+ struct vm_map_entry *new_entry;
+
+ new_entry = uvm_mapent_clone(new_map, old_entry, 0);
+
+ new_entry->etype |=
+ (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
+
+ if (new_entry->aref.ar_amap) {
+ uvm_map_unreference_amap(new_entry, 0);
+ new_entry->aref.ar_pageoff = 0;
+ new_entry->aref.ar_amap = NULL;
+ }
+
+ if (UVM_ET_ISOBJ(new_entry)) {
+ if (new_entry->object.uvm_obj->pgops->pgo_detach)
+ new_entry->object.uvm_obj->pgops->pgo_detach(
+ new_entry->object.uvm_obj);
+ new_entry->object.uvm_obj = NULL;
+ new_entry->etype &= ~UVM_ET_OBJ;
+ }
+}
+
+/*
* F O R K - m a i n e n t r y p o i n t
*/
/*
@@ -4405,6 +4435,9 @@ uvmspace_fork(struct vmspace *vm1)
uvm_mapent_forkcopy(new_map, old_map, old_entry);
break;
+ case MAP_INHERIT_ZERO:
+ uvm_mapent_forkzero(new_map, old_map, old_entry);
+ break;
default:
KASSERT(0);
break;
