From 1297667083d5442aafe3e337b9413bf02b114edb Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Mon, 19 Sep 2016 13:09:09 +0100 Subject: [PATCH] x86/efi: Only map RAM into EFI page tables if in mixed-mode Waiman reported that booting with CONFIG_EFI_MIXED enabled on his multi-terabyte HP machine results in boot crashes, because the EFI region mapping functions loop forever while trying to map those regions describing RAM. While this patch doesn't fix the underlying hang, there's really no reason to map EFI_CONVENTIONAL_MEMORY regions into the EFI page tables when mixed-mode is not in use at runtime. Reported-by: Waiman Long Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Linus Torvalds CC: Theodore Ts'o Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Scott J Norton Cc: Douglas Hatch Cc: # v4.6+ Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 677e29e29473..8dd3784eb075 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -245,7 +245,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) * text and allocate a new stack because we can't rely on the * stack pointer being < 4GB. */ - if (!IS_ENABLED(CONFIG_EFI_MIXED)) + if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native()) return 0; /* -- 2.20.1