Thread (14 messages) 14 messages, 2 authors, 2019-10-02

Re: [PATCH v2 3/3] x86/boot: Introduce the kernel_info.setup_type_max

From: hpa@zytor.com
Date: 2019-07-12 16:00:03
Also in: lkml

On July 4, 2019 9:36:12 AM PDT, Daniel Kiper [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This field contains maximal allowed type for setup_data and
setup_indirect structs.

And finally bump setup_header version in arch/x86/boot/header.S.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Daniel Kiper <redacted>
Reviewed-by: Ross Philipson <redacted>
Reviewed-by: Eric Snowberg <eric.snowberg@oracle.com>
---
Documentation/x86/boot.rst             | 10 +++++++++-
arch/x86/boot/compressed/kernel_info.S |  4 ++++
arch/x86/boot/header.S                 |  2 +-
arch/x86/include/uapi/asm/bootparam.h  |  3 +++
4 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index 23d3726d54fc..63609fd0517f 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -73,7 +73,8 @@ 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 5.3) Added the kernel_info and setup_indirect.
+Protocol 2.15:	(Kernel 5.3) Added the kernel_info,
kernel_info.setup_type_max
+		and setup_indirect.
=============	============================================================

.. note::
@@ -980,6 +981,13 @@ Offset/size:	0x0004/4
This field contains the size of the kernel_info including
kernel_info.header.
It should be used by the boot loader to detect supported fields in the
kernel_info.

+============	==============
+Field name:	setup_type_max
+Offset/size:	0x0008/4
+============	==============
+
+  This field contains maximal allowed type for setup_data and
setup_indirect structs.
+

The Image Checksum
==================
diff --git a/arch/x86/boot/compressed/kernel_info.S
b/arch/x86/boot/compressed/kernel_info.S
index 3f1cb301b9ff..2f28aabf6558 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
@@ -9,4 +11,6 @@ kernel_info:
	.ascii	"InfO"
        /* Size. */
	.long	kernel_info_end - kernel_info
+        /* Maximal allowed type for setup_data and setup_indirect
structs. */
+	.long	SETUP_TYPE_MAX
kernel_info_end:
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index ec6a25a43148..893a456663ab 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -300,7 +300,7 @@ _start:
	# Part 2 of the header, from the old setup.S

		.ascii	"HdrS"		# header signature
-		.word	0x020d		# header version number (>= 0x0105)
+		.word	0x020f		# header version number (>= 0x0105)
					# or else old loadlin-1.5 will fail)
		.globl realmode_swtch
realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
diff --git a/arch/x86/include/uapi/asm/bootparam.h
b/arch/x86/include/uapi/asm/bootparam.h
index aaaa17fa6ad6..2ba870dae6f3 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -12,6 +12,9 @@
#define SETUP_JAILHOUSE			6
#define SETUP_INDIRECT			7

+/* max(SETUP_*) */
+#define SETUP_TYPE_MAX			SETUP_INDIRECT
+
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK	0x07FF
#define RAMDISK_PROMPT_FLAG		0x8000
Bump the version number and add setup_max before adding the indirect stuff. That will nicely double as at the very least a first-order validity check.

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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