From a21645e1dff35eaec69f2eb9c61adeafbb16c971 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Wed, 1 Apr 2009 13:49:35 +0100 Subject: [PATCH] x86: paging_log_dirty_op() should take care with invalid log_dirty.top Signed-off-by: Keir Fraser --- xen/arch/x86/mm/paging.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c index 2b898dd73b..0df7376c24 100644 --- a/xen/arch/x86/mm/paging.c +++ b/xen/arch/x86/mm/paging.c @@ -385,13 +385,14 @@ int paging_log_dirty_op(struct domain *d, struct xen_domctl_shadow_op *sc) } pages = 0; - l4 = map_domain_page(mfn_x(d->arch.paging.log_dirty.top)); + l4 = (mfn_valid(d->arch.paging.log_dirty.top) ? + map_domain_page(mfn_x(d->arch.paging.log_dirty.top)) : NULL); for ( i4 = 0; (pages < sc->pages) && (i4 < LOGDIRTY_NODE_ENTRIES); i4++ ) { - l3 = mfn_valid(l4[i4]) ? map_domain_page(mfn_x(l4[i4])) : NULL; + l3 = (l4 && mfn_valid(l4[i4])) ? map_domain_page(mfn_x(l4[i4])) : NULL; for ( i3 = 0; (pages < sc->pages) && (i3 < LOGDIRTY_NODE_ENTRIES); i3++ ) -- 2.30.2