>From c94d1a58392615ce4bf914ba79c1437117d3df57 Mon Sep 17 00:00:00 2001 From: Stefan Bader Date: Thu, 27 Jan 2011 10:03:14 -0500 Subject: [PATCH 2/2] xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn. commit cf04d120d9413de581437cf9a29f138ec1178f65 upstream In case the mfn_list does not have enough entries to fill a p2m page we do not want the entries from max_pfn up to the boundary to be filled with unknown values. Hence set them to INVALID_P2M_ENTRY. Signed-off-by: Konrad Rzeszutek Wilk [backported to 2.6.37] Signed-off-by: Stefan Bader --- arch/x86/xen/mmu.c | 18 ++++++------------ 1 files changed, 6 insertions(+), 12 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 468c9e2..198df8d 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -399,21 +399,15 @@ void __init xen_build_dynamic_phys_to_machine(void) * As long as the mfn_list has enough entries to completely * fill a p2m page, pointing into the array is ok. But if * not the entries beyond the last pfn will be undefined. - * And guessing that the 'what-ever-there-is' does not take it - * too kindly when changing it to invalid markers, a new page - * is allocated, initialized and filled with the valid part. */ if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) { unsigned long p2midx; - unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE); - p2m_init(p2m); - for (p2midx = 0; pfn + p2midx < max_pfn; p2midx++) { - p2m[p2midx] = mfn_list[pfn + p2midx]; - } - p2m_top[topidx][mididx] = p2m; - } else - p2m_top[topidx][mididx] = &mfn_list[pfn]; + p2midx = max_pfn % P2M_PER_PAGE; + for ( ; p2midx < P2M_PER_PAGE; p2midx++) + mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY; + } + p2m_top[topidx][mididx] = &mfn_list[pfn]; } } -- 1.7.0.4