Module Name: src
Committed By: ad
Date: Fri May 22 19:02:59 UTC 2020
Modified Files:
src/sys/uvm: uvm_aobj.c
Log Message:
uao_get(): handle PGO_OVERWRITE.
To generate a diff of this commit:
cvs rdiff -u -r1.143 -r1.144 src/sys/uvm/uvm_aobj.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/uvm/uvm_aobj.c
diff -u src/sys/uvm/uvm_aobj.c:1.143 src/sys/uvm/uvm_aobj.c:1.144
--- src/sys/uvm/uvm_aobj.c:1.143 Wed May 20 12:47:36 2020
+++ src/sys/uvm/uvm_aobj.c Fri May 22 19:02:59 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_aobj.c,v 1.143 2020/05/20 12:47:36 hannken Exp $ */
+/* $NetBSD: uvm_aobj.c,v 1.144 2020/05/22 19:02:59 ad Exp $ */
/*
* Copyright (c) 1998 Chuck Silvers, Charles D. Cranor and
@@ -38,7 +38,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.143 2020/05/20 12:47:36 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.144 2020/05/22 19:02:59 ad Exp $");
#ifdef _KERNEL_OPT
#include "opt_uvmhist.h"
@@ -804,6 +804,7 @@ uao_get(struct uvm_object *uobj, voff_t
struct vm_page *ptmp = NULL; /* Quell compiler warning */
int lcv, gotpages, maxpages, swslot = -1, pageidx = -1; /* XXX: gcc */
UVMHIST_FUNC("uao_get"); UVMHIST_CALLED(pdhist);
+ bool overwrite = ((flags & PGO_OVERWRITE) != 0);
UVMHIST_LOG(pdhist, "aobj=%#jx offset=%jd, flags=%jd",
(uintptr_t)uobj, offset, flags,0);
@@ -921,7 +922,8 @@ uao_get(struct uvm_object *uobj, voff_t
pageidx = current_offset >> PAGE_SHIFT;
swslot = uao_find_swslot(uobj, pageidx);
ptmp = uao_pagealloc(uobj, current_offset,
- swslot == 0 ? UVM_PGA_ZERO : 0);
+ swslot != 0 || overwrite ? 0 :
+ UVM_PGA_ZERO);
/* out of RAM? */
if (ptmp == NULL) {
@@ -1036,9 +1038,15 @@ uao_get(struct uvm_object *uobj, voff_t
/*
* note that we will allow the page being writably-mapped
- * (!PG_RDONLY) regardless of access_type.
+ * (!PG_RDONLY) regardless of access_type. if overwrite,
+ * the page can be modified through an unmanaged mapping
+ * so mark it dirty up front.
*/
- uvm_pagemarkdirty(ptmp, UVM_PAGE_STATUS_UNKNOWN);
+ if (overwrite) {
+ uvm_pagemarkdirty(ptmp, UVM_PAGE_STATUS_DIRTY);
+ } else {
+ uvm_pagemarkdirty(ptmp, UVM_PAGE_STATUS_UNKNOWN);
+ }
/*
* we got the page! clear the fake flag (indicates valid
