2019-07-04 16:38:05

by Daniel Kiper

[permalink] [raw]
Subject: [PATCH v2 3/3] x86/boot: Introduce the kernel_info.setup_type_max

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 <[email protected]>
Signed-off-by: Daniel Kiper <[email protected]>
Reviewed-by: Ross Philipson <[email protected]>
Reviewed-by: Eric Snowberg <[email protected]>
---
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
--
2.11.0


2019-07-12 16:02:17

by H. Peter Anvin

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

On July 4, 2019 9:36:12 AM PDT, Daniel Kiper <[email protected]> wrote:
>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 <[email protected]>
>Signed-off-by: Daniel Kiper <[email protected]>
>Reviewed-by: Ross Philipson <[email protected]>
>Reviewed-by: Eric Snowberg <[email protected]>
>---
> 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.

--
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