x86/efi: Do not export efi runtime map in case old map

For ioremapped efi memory aka old_map the virt addresses are not persistant
across kexec reboot. kexec-tools will read the runtime maps from sysfs then
pass them to 2nd kernel and assuming kexec efi boot is ok. This will cause
kexec boot failure.

To address this issue do not export runtime maps in case efi old_map so
userspace can use no efi boot instead.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 3781dd39e8bd55a03b8acd779113f40c151442b4..4d36932ca4f2d3ca06503682daec1071bd225286 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -919,6 +919,9 @@ static void __init save_runtime_map(void)
        void *tmp, *p, *q = NULL;
        int count = 0;
 
+       if (efi_enabled(EFI_OLD_MEMMAP))
+               return;
+
        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
                md = p;