# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1253002418 -3600
# Node ID 582970a2d2dcd1d041ab29237ea8f8a2e31b8989
# Parent 973f4bbf472331a59a9f3ae716bfb72347767f46
PoD: Check p2m assumption in debug builds
The PoD code assumes that if:
* A page is in a domain's p2m table
* And it's owned by the domain
* And it's not a xenheap page
then:
* It's on the domain's page list.
This patch adds a check for this assumption when debug=y.
Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
---
xen/arch/x86/mm/p2m.c | 30 ++++++++++++++++++++++++++++++
1 files changed, 30 insertions(+)
diff -r 973f4bbf4723 -r 582970a2d2dc xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c Tue Sep 15 09:13:01 2009 +0100
+++ b/xen/arch/x86/mm/p2m.c Tue Sep 15 09:13:38 2009 +0100
@@ -1530,6 +1530,36 @@ int set_p2m_entry(struct domain *d, unsi
9 : 0;
else
order = 0;
+
+#ifndef NDEBUG
+ /* PoD code assumes that a page owned by the domain, not from the
xenheap, and in the p2m
+ * is on the domain page list. Verify this assumption. */
+ if ( mfn_valid(mfn)
+ && p2m_is_ram(p2mt)
+ && page_get_owner(mfn_to_page(mfn))==d
+ && ( (mfn_to_page(mfn)->count_info & PGC_xen_heap) == 0 ) )
+ {
+ struct page_info *p, *q;
+
+ p = mfn_to_page(mfn);
+
+ spin_lock(&d->page_alloc_lock);
+
+ /* Walk the domain page list and make sure this page is on it... */
+ for ( q = page_list_first(&d->page_list) ; q; q =
page_list_next(q, &d->page_list) )
+ if ( q == p )
+ break;
+ if ( !q )
+ {
+ printk("%s: mfn %lx owned by d%d, not xen_heap, but not on
domain page_list!\n",
+ __func__, mfn_x(mfn), d->domain_id);
+ BUG();
+ }
+
+ spin_unlock(&d->page_alloc_lock);
+ }
+#endif
+
rc = d->arch.p2m->set_entry(d, gfn, mfn, order, p2mt);
gfn += 1ul << order;
if ( mfn_x(mfn) != INVALID_MFN )
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