1 files changed, 16 insertions, 0 deletions

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 319148bd4b05..2f25a363068c 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -269,6 +269,22 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
         efi_scratch.use_pgd = true;
 
         /*
+         * Certain firmware versions are way too sentimential and still believe
+         * they are exclusive and unquestionable owners of the first physical page,
+         * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
+         * (but then write-access it later during SetVirtualAddressMap()).
+         *
+         * Create a 1:1 mapping for this page, to avoid triple faults during early
+         * boot with such firmware. We are free to hand this page to the BIOS,
+         * as trim_bios_range() will reserve the first page and isolate it away
+         * from memory allocators anyway.
+         */
+        if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) {
+                pr_err("Failed to create 1:1 mapping for the first page!\n");
+                return 1;
+        }
+
+        /*
          * When making calls to the firmware everything needs to be 1:1
          * mapped and addressable with 32-bit pointers. Map the kernel
          * text and allocate a new stack because we can't rely on the