Jan Beulich
2011-Aug-17 07:49 UTC
[Xen-devel] [PATCH] linux-2.6.18/i386: follow-up to c/s 1101
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 <jbeulich@novell.com> --- a/arch/i386/mach-xen/setup.c +++ b/arch/i386/mach-xen/setup.c @@ -110,10 +110,8 @@ void __init pre_setup_arch_hook(void) machine_to_phys_nr = mapping.max_mfn + 1; } else machine_to_phys_nr = MACH2PHYS_NR_ENTRIES; - 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); if (!xen_feature(XENFEAT_auto_translated_physmap)) phys_to_machine_mapping _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel