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Date:   Fri, 8 Apr 2022 21:17:46 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     x86-ml <x86@kernel.org>
Cc:     Ard Biesheuvel <ardb@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] x86/boot: Add an efi.h header for the decompressor
Message-ID: <YlCKWhMJEMUgJmjF@zn.tnic>
MIME-Version: 1.0
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Hi,

this is something that has been bothering me for a while: kernel proper
namespace leaking into the decompressor and causing all kinds of ugly
conflicts between definitions and us having to do preprocessor hacks to
fix the build.

We recently started putting shared functionality into

arch/x86/include/asm/shared/

The other thing to do is to copy linux/ namespace symbols into a
separate decompressor header and then block any further includes of
headers from there. Future needs would simply copy the required bits
like I did below.

And this below is converting the efi side of things. It goes ontop of
the x86/sev branch which adds two more linux/efi.h includes and which
triggered me to finally productize this.

I'll queue it soon if there are no objections.

Thx.

---
From: Borislav Petkov <bp@suse.de>

Copy the needed symbols only and remove the kernel proper includes.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/boot/compressed/acpi.c       |   3 +-
 arch/x86/boot/compressed/efi.c        |   2 -
 arch/x86/boot/compressed/efi.h        | 126 ++++++++++++++++++++++++++
 arch/x86/boot/compressed/kaslr.c      |   3 +-
 arch/x86/boot/compressed/misc.h       |   3 +-
 arch/x86/boot/compressed/pgtable_64.c |   3 +-
 6 files changed, 131 insertions(+), 9 deletions(-)
 create mode 100644 arch/x86/boot/compressed/efi.h

diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index 64b172dabd5c..9caf89063e77 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -3,10 +3,9 @@
 #include "misc.h"
 #include "error.h"
 #include "../string.h"
+#include "efi.h"
 
 #include <linux/numa.h>
-#include <linux/efi.h>
-#include <asm/efi.h>
 
 /*
  * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0'
diff --git a/arch/x86/boot/compressed/efi.c b/arch/x86/boot/compressed/efi.c
index 09fa3b5d70b8..6edd034b0b30 100644
--- a/arch/x86/boot/compressed/efi.c
+++ b/arch/x86/boot/compressed/efi.c
@@ -6,8 +6,6 @@
  */
 
 #include "misc.h"
-#include <linux/efi.h>
-#include <asm/efi.h>
 
 /**
  * efi_get_type - Given a pointer to boot_params, determine the type of EFI environment.
diff --git a/arch/x86/boot/compressed/efi.h b/arch/x86/boot/compressed/efi.h
new file mode 100644
index 000000000000..7db2f41b54cd
--- /dev/null
+++ b/arch/x86/boot/compressed/efi.h
@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_EFI_H
+#define BOOT_COMPRESSED_EFI_H
+
+#if defined(_LINUX_EFI_H) || defined(_ASM_X86_EFI_H)
+#error Please do not include kernel proper namespace headers
+#endif
+
+typedef guid_t efi_guid_t __aligned(__alignof__(u32));
+
+#define EFI_GUID(a, b, c, d...) (efi_guid_t){ {					\
+	(a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff,	\
+	(b) & 0xff, ((b) >> 8) & 0xff,						\
+	(c) & 0xff, ((c) >> 8) & 0xff, d } }
+
+#define ACPI_TABLE_GUID				EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3,  0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
+#define ACPI_20_TABLE_GUID			EFI_GUID(0x8868e871, 0xe4f1, 0x11d3,  0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81)
+#define EFI_CC_BLOB_GUID			EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42)
+
+#define EFI32_LOADER_SIGNATURE	"EL32"
+#define EFI64_LOADER_SIGNATURE	"EL64"
+
+/*
+ * Generic EFI table header
+ */
+typedef	struct {
+	u64 signature;
+	u32 revision;
+	u32 headersize;
+	u32 crc32;
+	u32 reserved;
+} efi_table_hdr_t;
+
+#define EFI_CONVENTIONAL_MEMORY		 7
+
+#define EFI_MEMORY_MORE_RELIABLE \
+				((u64)0x0000000000010000ULL)	/* higher reliability */
+#define EFI_MEMORY_SP		((u64)0x0000000000040000ULL)	/* soft reserved */
+
+#define EFI_PAGE_SHIFT		12
+
+typedef struct {
+	u32 type;
+	u32 pad;
+	u64 phys_addr;
+	u64 virt_addr;
+	u64 num_pages;
+	u64 attribute;
+} efi_memory_desc_t;
+
+#define efi_early_memdesc_ptr(map, desc_size, n)			\
+	(efi_memory_desc_t *)((void *)(map) + ((n) * (desc_size)))
+
+typedef struct {
+	efi_guid_t guid;
+	u64 table;
+} efi_config_table_64_t;
+
+typedef struct {
+	efi_guid_t guid;
+	u32 table;
+} efi_config_table_32_t;
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u64 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 __pad1;
+	u64 con_in_handle;
+	u64 con_in;
+	u64 con_out_handle;
+	u64 con_out;
+	u64 stderr_handle;
+	u64 stderr;
+	u64 runtime;
+	u64 boottime;
+	u32 nr_tables;
+	u32 __pad2;
+	u64 tables;
+} efi_system_table_64_t;
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u32 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 con_in_handle;
+	u32 con_in;
+	u32 con_out_handle;
+	u32 con_out;
+	u32 stderr_handle;
+	u32 stderr;
+	u32 runtime;
+	u32 boottime;
+	u32 nr_tables;
+	u32 tables;
+} efi_system_table_32_t;
+
+/* kexec external ABI */
+struct efi_setup_data {
+	u64 fw_vendor;
+	u64 __unused;
+	u64 tables;
+	u64 smbios;
+	u64 reserved[8];
+};
+
+static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right)
+{
+	return memcmp(&left, &right, sizeof (efi_guid_t));
+}
+
+#ifdef CONFIG_EFI
+bool __pure __efi_soft_reserve_enabled(void);
+
+static inline bool __pure efi_soft_reserve_enabled(void)
+{
+	return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE)
+		&& __efi_soft_reserve_enabled();
+}
+#else
+static inline bool efi_soft_reserve_enabled(void)
+{
+	return false;
+}
+#endif /* CONFIG_EFI */
+#endif /* BOOT_COMPRESSED_EFI_H */
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 411b268bc0a2..4a3f223973f4 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -22,15 +22,14 @@
 #include "misc.h"
 #include "error.h"
 #include "../string.h"
+#include "efi.h"
 
 #include <generated/compile.h>
 #include <linux/module.h>
 #include <linux/uts.h>
 #include <linux/utsname.h>
 #include <linux/ctype.h>
-#include <linux/efi.h>
 #include <generated/utsrelease.h>
-#include <asm/efi.h>
 
 #define _SETUP
 #include <asm/setup.h>	/* For COMMAND_LINE_SIZE */
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 75d284ec763f..4ca2857ea041 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -23,7 +23,6 @@
 #include <linux/screen_info.h>
 #include <linux/elf.h>
 #include <linux/io.h>
-#include <linux/efi.h>
 #include <asm/page.h>
 #include <asm/boot.h>
 #include <asm/bootparam.h>
@@ -35,6 +34,8 @@
 #define BOOT_BOOT_H
 #include "../ctype.h"
 
+#include "efi.h"
+
 #ifdef CONFIG_X86_64
 #define memptr long
 #else
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index a1733319a22a..2ac12ff4111b 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -1,11 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "misc.h"
-#include <linux/efi.h>
 #include <asm/e820/types.h>
 #include <asm/processor.h>
-#include <asm/efi.h>
 #include "pgtable.h"
 #include "../string.h"
+#include "efi.h"
 
 #define BIOS_START_MIN		0x20000U	/* 128K, less than this is insane */
 #define BIOS_START_MAX		0x9f000U	/* 640K, absolute maximum */
-- 
2.35.1


-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette