From 61cca2fab7ecba18f9b9680cd736ef5fa82ad3b1 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 15 Sep 2011 08:52:40 +0100 Subject: [PATCH] xen/i386: follow-up to "replace order-based range checking of M2P table by linear one" The numbers obtained from the hypervisor really can't ever lead to an overflow here, only the original calculation going through the order of the range could have. This avoids the (as Jeremy points outs) somewhat ugly NULL-based calculation here. Signed-off-by: Jan Beulich Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/mmu.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 24abc1f..a3872f7 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1721,10 +1721,8 @@ void __init xen_setup_machphys_mapping(void) machine_to_phys_nr = MACH2PHYS_NR_ENTRIES; } #ifdef CONFIG_X86_32 - if ((machine_to_phys_mapping + machine_to_phys_nr) - < machine_to_phys_mapping) - machine_to_phys_nr = (unsigned long *)NULL - - machine_to_phys_mapping; + WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1)) + < machine_to_phys_mapping); #endif } -- 2.7.4