[tip: x86/boot] x86/boot: Introduce kernel_info.setup_type_max

From: tip-bot2 for Daniel Kiper
Date: Tue Nov 12 2019 - 12:54:22 EST


The following commit has been merged into the x86/boot branch of tip:

Commit-ID: 00cd1c154d565c62ad5e065bf3530f68bdf59490
Gitweb: https://git.kernel.org/tip/00cd1c154d565c62ad5e065bf3530f68bdf59490
Author: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
AuthorDate: Tue, 12 Nov 2019 14:46:39 +01:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Tue, 12 Nov 2019 16:16:54 +01:00

x86/boot: Introduce kernel_info.setup_type_max

This field contains maximal allowed type for setup_data.

Do not bump setup_header version in arch/x86/boot/header.S because it
will be followed by additional changes coming into the Linux/x86 boot
protocol.

Suggested-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Reviewed-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
Reviewed-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: ard.biesheuvel@xxxxxxxxxx
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: dave.hansen@xxxxxxxxxxxxxxx
Cc: eric.snowberg@xxxxxxxxxx
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: kanth.ghatraju@xxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: linux-efi <linux-efi@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: rdunlap@xxxxxxxxxxxxx
Cc: ross.philipson@xxxxxxxxxx
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20191112134640.16035-3-daniel.kiper@xxxxxxxxxx
---
Documentation/x86/boot.rst | 9 ++++++++-
arch/x86/boot/compressed/kernel_info.S | 5 +++++
arch/x86/include/uapi/asm/bootparam.h | 3 +++
3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index c60fafd..6cdd767 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -73,7 +73,7 @@ Protocol 2.14: BURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c188
(x86/boot: Add ACPI RSDP address to setup_header)
DO NOT USE!!! ASSUME SAME AS 2.13.

-Protocol 2.15: (Kernel 5.5) Added the kernel_info.
+Protocol 2.15: (Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.
============= ============================================================

.. note::
@@ -981,6 +981,13 @@ Offset/size: 0x0008/4
This field contains the size of the kernel_info including kernel_info.header
and kernel_info.kernel_info_var_len_data.

+============ ==============
+Field name: setup_type_max
+Offset/size: 0x000c/4
+============ ==============
+
+ This field contains maximal allowed type for setup_data.
+

The Image Checksum
==================
diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S
index 8ea6f6e..018dacb 100644
--- a/arch/x86/boot/compressed/kernel_info.S
+++ b/arch/x86/boot/compressed/kernel_info.S
@@ -1,5 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */

+#include <asm/bootparam.h>
+
.section ".rodata.kernel_info", "a"

.global kernel_info
@@ -12,6 +14,9 @@ kernel_info:
/* Size total. */
.long kernel_info_end - kernel_info

+ /* Maximal allowed type for setup_data. */
+ .long SETUP_TYPE_MAX
+
kernel_info_var_len_data:
/* Empty for time being... */
kernel_info_end:
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index a1ebcd7..dbb4112 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -11,6 +11,9 @@
#define SETUP_APPLE_PROPERTIES 5
#define SETUP_JAILHOUSE 6

+/* max(SETUP_*) */
+#define SETUP_TYPE_MAX SETUP_JAILHOUSE
+
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000