From 3a63f70bf4c3a17f5d9c9bf3bc3288a23bdfefce Mon Sep 17 00:00:00 2001 From: Chao Fan Date: Wed, 23 Jan 2019 19:08:48 +0800 Subject: [PATCH] x86/boot: Early parse RSDP and save it in boot_params The RSDP is needed by KASLR so parse it early and save it in boot_params.acpi_rsdp_addr, before KASLR setup runs. RSDP is needed by other kernel facilities so have the parsing code built-in instead of a long "depends on" line in Kconfig. [ bp: - Trim commit message and comments - Add CONFIG_ACPI dependency in the Makefile - Move ->acpi_rsdp_addr assignment with the rest of boot_params massaging in extract_kernel(). ] Signed-off-by: Chao Fan Signed-off-by: Borislav Petkov Cc: bhe@redhat.com Cc: Cao jin 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: Masahiro Yamada Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner Cc: Tom Lendacky Cc: x86-ml Link: https://lkml.kernel.org/r/20190123110850.12433-6-fanc.fnst@cn.fujitsu.com --- arch/x86/boot/compressed/Makefile | 2 ++ arch/x86/boot/compressed/acpi.c | 19 +++++++++++++++++++ arch/x86/boot/compressed/misc.c | 3 +++ arch/x86/boot/compressed/misc.h | 7 +++++++ 4 files changed, 31 insertions(+) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index f0515ac8..6b84afd 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -84,6 +84,8 @@ ifdef CONFIG_X86_64 vmlinux-objs-y += $(obj)/pgtable_64.o endif +vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o + $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \ diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c index 66bda1b..b2b50ad 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -184,3 +184,22 @@ static acpi_physical_address bios_get_rsdp_addr(void) return 0; } + +/* Return RSDP address on success, otherwise 0. */ +acpi_physical_address get_rsdp_addr(void) +{ + acpi_physical_address pa; + + pa = get_acpi_rsdp(); + + if (!pa) + pa = boot_params->acpi_rsdp_addr; + + if (!pa) + pa = efi_get_rsdp_addr(); + + if (!pa) + pa = bios_get_rsdp_addr(); + + return pa; +} diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 8dd1d5c..c0d6c56 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -351,6 +351,9 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, /* Clear flags intended for solely in-kernel use. */ boot_params->hdr.loadflags &= ~KASLR_FLAG; + /* Save RSDP address for later use. */ + boot_params->acpi_rsdp_addr = get_rsdp_addr(); + sanitize_boot_params(boot_params); if (boot_params->screen_info.orig_video_mode == 7) { diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 764ad50..e1dd157 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -119,3 +119,10 @@ static inline void console_init(void) void set_sev_encryption_mask(void); #endif + +/* acpi.c */ +#ifdef CONFIG_ACPI +acpi_physical_address get_rsdp_addr(void); +#else +static inline acpi_physical_address get_rsdp_addr(void) { return 0; } +#endif -- 2.7.4