Jan Beulich
2010-Apr-12 13:56 UTC
[Xen-devel] [PATCH] linux/x86-64: kern_addr_valid() must not walk page tables mapping hypervisor space
Signed-off-by: Jan Beulich <jbeulich@novell.com> --- a/arch/x86_64/mm/init-xen.c +++ b/arch/x86_64/mm/init-xen.c @@ -1160,6 +1160,19 @@ int kern_addr_valid(unsigned long addr) if (above != 0 && above != -1UL) return 0; +#ifdef CONFIG_XEN + /* + * Don''t walk page tables for hypervisor addresses, but allow + * the M2P table to be accessed through e.g. /proc/kcore. + */ + if (addr >= (unsigned long)machine_to_phys_mapping && + addr < (unsigned long)(machine_to_phys_mapping + + (1UL << machine_to_phys_order))) + return 1; + if (addr >= HYPERVISOR_VIRT_START && addr < HYPERVISOR_VIRT_END) + return 0; +#endif + pgd = pgd_offset_k(addr); if (pgd_none(*pgd)) return 0; _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel