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authorkib <kib@FreeBSD.org>2012-10-24 18:21:59 +0000
committerkib <kib@FreeBSD.org>2012-10-24 18:21:59 +0000
commit2a76567642712614056aeb2c90c97db6952205b3 (patch)
tree554a9c7b520cb733b297b2e6b5488211cade19f1 /sys/vm/vm_fault.c
parent09daf9f4d2e686773cb6b74346a6e3047377aea4 (diff)
downloadFreeBSD-src-2a76567642712614056aeb2c90c97db6952205b3.zip
FreeBSD-src-2a76567642712614056aeb2c90c97db6952205b3.tar.gz
Dirty the newly copied anonymous pages after the wired region is
forked. Otherwise, pagedaemon might reclaim the page without saving its content into the swap file, resulting in the valid content replaced by zeroes. Reported and tested by: pho Reviewed and comment update by: alc MFC after: 1 week
Diffstat (limited to 'sys/vm/vm_fault.c')
-rw-r--r--sys/vm/vm_fault.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index a3a90c6..ceee8f5 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -1287,9 +1287,11 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
access &= ~VM_PROT_WRITE;
/*
- * Loop through all of the pages in the entry's range, copying each
- * one from the source object (it should be there) to the destination
- * object.
+ * Loop through all of the pages in the entry's range, copying
+ * each one from the source object (it should be there) to the
+ * destination object. Note that copied pages are not wired
+ * and marked dirty to prevent reclamation without saving the
+ * content into the swap file on pageout.
*/
for (vaddr = dst_entry->start, dst_pindex = 0;
vaddr < dst_entry->end;
@@ -1332,6 +1334,7 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
pmap_copy_page(src_m, dst_m);
VM_OBJECT_UNLOCK(object);
dst_m->valid = VM_PAGE_BITS_ALL;
+ dst_m->dirty = VM_PAGE_BITS_ALL;
VM_OBJECT_UNLOCK(dst_object);
/*
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