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amap_splitref: assert that origref->ar_amap is initialized 

by caller beforehand.
This commit is contained in:
yamt 2006-04-21 14:04:45 +00:00
parent 0f4aad0236
commit 93127a7b4c
1 changed files with 11 additions and 9 deletions
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20
sys/uvm/uvm_amap.c
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@ -1,4 +1,4 @@
/* $NetBSD: uvm_amap.c,v 1.72 2006/02/15 14:06:45 yamt Exp $ */
/* $NetBSD: uvm_amap.c,v 1.73 2006/04/21 14:04:45 yamt Exp $ */
/*
*
@ -42,7 +42,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_amap.c,v 1.72 2006/02/15 14:06:45 yamt Exp $");
__KERNEL_RCSID(0, "$NetBSD: uvm_amap.c,v 1.73 2006/04/21 14:04:45 yamt Exp $");
#include "opt_uvmhist.h"
@ -1035,33 +1035,35 @@ void
amap_splitref(struct vm_aref *origref, struct vm_aref *splitref, vaddr_t offset)
{
int leftslots;
struct vm_amap *amap;
KASSERT(splitref->ar_amap == origref->ar_amap);
AMAP_B2SLOT(leftslots, offset);
if (leftslots == 0)
panic("amap_splitref: split at zero offset");
amap_lock(origref->ar_amap);
amap = origref->ar_amap;
amap_lock(amap);
/*
* now: amap is locked and we have a valid am_mapped array.
*/
if (origref->ar_amap->am_nslot - origref->ar_pageoff - leftslots <= 0)
if (amap->am_nslot - origref->ar_pageoff - leftslots <= 0)
panic("amap_splitref: map size check failed");
#ifdef UVM_AMAP_PPREF
/*
* establish ppref before we add a duplicate reference to the amap
*/
if (origref->ar_amap->am_ppref == NULL)
amap_pp_establish(origref->ar_amap, origref->ar_pageoff);
if (amap->am_ppref == NULL)
amap_pp_establish(amap, origref->ar_pageoff);
#endif
splitref->ar_amap = origref->ar_amap;
splitref->ar_amap->am_ref++; /* not a share reference */
amap->am_ref++; /* not a share reference */
splitref->ar_pageoff = origref->ar_pageoff + leftslots;
amap_unlock(origref->ar_amap);
amap_unlock(amap);
}
#ifdef UVM_AMAP_PPREF