From 3ea86495aef2f6de26b7cb1599ba350dd6a0c521 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Mon, 23 Jul 2018 10:57:30 +0900
Subject: [PATCH] efi/arm: preserve early mapping of UEFI memory map longer for
BGRT
The BGRT code validates the contents of the table against the UEFI
memory map, and so it expects it to be mapped when the code runs.
On ARM, this is currently not the case, since we tear down the early
mapping after efi_init() completes, and only create the permanent
mapping in arm_enable_runtime_services(), which executes as an early
initcall, but still leaves a window where the UEFI memory map is not
mapped.
So move the call to efi_memmap_unmap() from efi_init() to
arm_enable_runtime_services().
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: fold in EFI_MEMMAP attribute check from Ard]
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
drivers/firmware/efi/arm-init.c | 1 -
drivers/firmware/efi/arm-runtime.c | 4 +++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index b5214c143feed..388a929baf95d 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -259,7 +259,6 @@ void __init efi_init(void)
reserve_regions();
efi_esrt_init();
- efi_memmap_unmap();
memblock_reserve(params.mmap & PAGE_MASK,
PAGE_ALIGN(params.mmap_size +
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 5889cbea60b84..4712445c32130 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -110,11 +110,13 @@ static int __init arm_enable_runtime_services(void)
{
u64 mapsize;
- if (!efi_enabled(EFI_BOOT)) {
+ if (!efi_enabled(EFI_BOOT) || !efi_enabled(EFI_MEMMAP)) {
pr_info("EFI services will not be available.\n");
return 0;
}
+ efi_memmap_unmap();
+
if (efi_runtime_disabled()) {
pr_info("EFI runtime services will be disabled.\n");
return 0;
--
2.30.2