Messages in this thread Patch in this message | | | From | Dave Young <> | Subject | [PATCH 4/5] efi x86: clear EFI_RUNTIME_SERVICES bit in case failures other than SetVirtualAddressMap | Date | Tue, 12 Aug 2014 14:10:21 +0800 |
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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 <dyoung@redhat.com> --- arch/x86/platform/efi/efi.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index eae91be..c42f49b 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(); @@ -882,8 +886,10 @@ static void __init __efi_enter_virtual_mode(void) void __init efi_enter_virtual_mode(void) { - if (efi_enabled(EFI_PARAVIRT)) + if (efi_enabled(EFI_PARAVIRT)) { + clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); return; + } if (efi_setup) kexec_enter_virtual_mode(); -- 1.8.3.1
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