From 36f0c423552dacaca152324b8e9bda42a6d88865 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 19 Apr 2019 15:40:14 +0200 Subject: [PATCH] x86/boot: Disable RSDP parsing temporarily The original intention to move RDSP parsing very early, before KASLR does its ranges selection, was to accommodate movable memory regions machines (CONFIG_MEMORY_HOTREMOVE) to still be able to do memory hotplug. However, that broke kexec'ing a kernel on EFI machines because depending on where the EFI systab was mapped, on at least one machine it isn't present in the kexec mapping of the second kernel, leading to a triple fault in the early code. Fixing this properly requires significantly involved surgery and we cannot allow ourselves to do that, that close to the merge window. So disable the RSDP parsing code temporarily until it is fixed properly in the next release cycle. Signed-off-by: Borislav Petkov Cc: Ard Biesheuvel Cc: Baoquan He Cc: Chao Fan Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: indou.takao@jp.fujitsu.com Cc: Ingo Molnar Cc: Juergen Gross Cc: kasong@redhat.com Cc: Kees Cook Cc: "Kirill A. Shutemov" Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner Cc: Tom Lendacky Cc: x86-ml Link: https://lkml.kernel.org/r/20190419141952.GE10324@zn.tnic --- arch/x86/boot/compressed/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c0d6c56..5a237e8 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -352,7 +352,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, boot_params->hdr.loadflags &= ~KASLR_FLAG; /* Save RSDP address for later use. */ - boot_params->acpi_rsdp_addr = get_rsdp_addr(); + /* boot_params->acpi_rsdp_addr = get_rsdp_addr(); */ sanitize_boot_params(boot_params); -- 2.7.4