Buggy UEFI firmware implementations may try to access the EFI_BOOT_SERVICES_* memory regions even after those regions have been surrendered to the kernel (after calling ExitBootServices() on the firmware). If such regions are not mapped, a page fault will be generated. Fix that up. We are sure that we will not have false positives as those memory regions are reserved and the kernel cannot use them. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> --- arch/x86/mm/fault.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index a241946..f084912 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -14,6 +14,7 @@ #include <linux/hugetlb.h> /* hstate_index_to_shift */ #include <linux/prefetch.h> /* prefetchw */ #include <linux/context_tracking.h> /* exception_enter(), ... */ +#include <linux/efi.h> /* fixup for buggy UEFI firmware*/ #include <asm/traps.h> /* dotraplinkage, ... */ #include <asm/pgalloc.h> /* pgd_*(), ... */ @@ -702,6 +703,13 @@ no_context(struct pt_regs *regs, unsigned long error_code, return; /* + * Try to fixup faults caused by illegal access to BOOT_SERVICES_* + * regions by UEFI firmware. + */ + if (efi_boot_services_fixup(address)) + return; + + /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice: */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
