From f1434c2e8e57aa9f75ea8d20612396524df8cd96 Mon Sep 17 00:00:00 2001 From: Malcolm Crossley Date: Wed, 25 Apr 2012 12:35:56 +0200 Subject: [PATCH] x86-64: Fix memory hotplug epfn upper limit test for updating the compat M2P table The epfn is being compared to (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) without a 2 bit shift, resulting in the epfn being compared to the size of the RDWR_COMPAT_MPT table in bytes instead of the maximum page frame number that the RDWR_COMPAT_MPT table can map. Signed-off-by: Malcolm Crossley Committed-by: Jan Beulich --- xen/arch/x86/x86_64/mm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c index 6a71c2860e..635a499d65 100644 --- a/xen/arch/x86/x86_64/mm.c +++ b/xen/arch/x86/x86_64/mm.c @@ -454,7 +454,7 @@ static int setup_compat_m2p_table(struct mem_hotadd_info *info) if ((smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2)) ) return 0; - if (epfn > (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START)) + if ( epfn > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) ) epfn = (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2; emap = ( (epfn + ((1UL << (L2_PAGETABLE_SHIFT - 2)) - 1 )) & -- 2.30.2