4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross <jgross@xxxxxxxx> commit 1ea34adb87c969b89dfd83f1905a79161e9ada26 upstream. When booted as Xen dom0 there won't be an EFI memmap allocated. Avoid issuing an error message in this case: [ 0.144079] efi: Failed to allocate new EFI memmap Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: linux-efi@xxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20170526113652.21339-2-matt@xxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/platform/efi/quirks.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -358,6 +358,9 @@ void __init efi_free_boot_services(void) free_bootmem_late(start, size); } + if (!num_entries) + return; + new_size = efi.memmap.desc_size * num_entries; new_phys = efi_memmap_alloc(num_entries); if (!new_phys) {