From a5a750a98fe2812263546cc20badd32bab21ec52 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Thu, 14 Aug 2014 17:15:31 +0800 Subject: [PATCH] x86/efi: Clear EFI_RUNTIME_SERVICES if failing to enter virtual mode If enter virtual mode failed due to some reason other than the efi call the EFI_RUNTIME_SERVICES bit in efi.flags should be cleared thus users of efi runtime services can check the bit and handle the case instead of assume efi runtime is ok. Per Matt, if efi call SetVirtualAddressMap fails we will be not sure it's safe to make any assumptions about the state of the system. So kernel panics instead of clears EFI_RUNTIME_SERVICES bit. Signed-off-by: Dave Young Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 00f4cc5..d3096c0 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -724,6 +724,7 @@ static void __init kexec_enter_virtual_mode(void) */ if (!efi_is_native()) { efi_unmap_memmap(); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; } @@ -797,6 +798,7 @@ static void __init __efi_enter_virtual_mode(void) new_memmap = efi_map_regions(&count, &pg_shift); if (!new_memmap) { pr_err("Error reallocating memory, EFI runtime non-functional!\n"); + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; } @@ -804,8 +806,10 @@ static void __init __efi_enter_virtual_mode(void) BUG_ON(!efi.systab); - if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) + if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) { + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; + } efi_sync_low_kernel_mappings(); efi_dump_pagetable(); -- 2.7.4