Thanks to Dave Hansen for pointing out problems related to the pfn check in the first version. I tried to fix it by adding a new arch_pfn_possible helper to arch/x86/mm/physaddr.h. Please note that I'm not quite sure about the name and the location(physaddr.h). Maybe we can keep the check directly in the valid_mmap_phys_addr_range. I will leave this to a discussion and fix it if required. Question: Do we need the CONFIG_PHYS_ADDR_T_64BIT ifdef? The boot_cpu_data.x86_phys_bits is set for all x86. So at this point it seems to me more like an "optimization" for x86_32 or something kept from historic reasons. I'm just curious and I of course may be missing something. Many thanks Frantisek Hrbata (2): x86: add arch_pfn_possible helper x86: add phys addr validity check for /dev/mem mmap arch/x86/include/asm/io.h | 4 ++++ arch/x86/mm/mmap.c | 12 ++++++++++++ arch/x86/mm/physaddr.h | 9 +++++++-- 3 files changed, 23 insertions(+), 2 deletions(-) -- 1.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>