Commit-ID:  3a63f70bf4c3a17f5d9c9bf3bc3288a23bdfefce
Gitweb:     https://git.kernel.org/tip/3a63f70bf4c3a17f5d9c9bf3bc3288a23bdfefce
Author:     Chao Fan <fanc.f...@cn.fujitsu.com>
AuthorDate: Wed, 23 Jan 2019 19:08:48 +0800
Committer:  Borislav Petkov <b...@suse.de>
CommitDate: Fri, 1 Feb 2019 11:52:55 +0100

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 <fanc.f...@cn.fujitsu.com>
Signed-off-by: Borislav Petkov <b...@suse.de>
Cc: b...@redhat.com
Cc: Cao jin <caoj.f...@cn.fujitsu.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: indou.ta...@jp.fujitsu.com
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Juergen Gross <jgr...@suse.com>
Cc: kas...@redhat.com
Cc: Kees Cook <keesc...@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Masahiro Yamada <yamada.masah...@socionext.com>
Cc: msys.miz...@gmail.com
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: x86-ml <x...@kernel.org>
Link: https://lkml.kernel.org/r/20190123110850.12433-6-fanc.f...@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 f0515ac895a4..6b84afdd7538 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 66bda1b5cf94..b2b50ad5299a 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 8dd1d5ccae58..c0d6c560df69 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 764ad50c0119..e1dd15769cf3 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

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