[v2,12/14] arm: efi: replace open coded constants with symbolic ones

Message ID 1486554947-3964-13-git-send-email-ard.biesheuvel@linaro.org
State New
Headers show
Series
  • arm64+ARM: efi: PE/COFF cleanup/hardening
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Commit Message

Ard Biesheuvel Feb. 8, 2017, 11:55 a.m.
Replace the various open coded constants in the EFI PE/COFF header with
definitions from pe.h, or expressions based on local symbols.

Note that this patch also changes the indentation to make room for the
symbolic constant names.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 arch/arm/boot/compressed/efi-header.S | 172 ++++++++++----------
 1 file changed, 89 insertions(+), 83 deletions(-)

-- 
2.7.4

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diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S
index 5873fc2b5f9a..7ff2b2f05e4c 100644
--- a/arch/arm/boot/compressed/efi-header.S
+++ b/arch/arm/boot/compressed/efi-header.S
@@ -1,5 +1,5 @@ 
 /*
- * Copyright (C) 2013-2015 Linaro Ltd
+ * Copyright (C) 2013-2017 Linaro Ltd
  * Authors: Roy Franz <roy.franz@linaro.org>
  *          Ard Biesheuvel <ard.biesheuvel@linaro.org>
  *
@@ -8,105 +8,111 @@ 
  * published by the Free Software Foundation.
  */
 
-		.macro	__nop
+#include <linux/pe.h>
+#include <linux/sizes.h>
+
+	.macro	__nop
 #ifdef CONFIG_EFI_STUB
-		@ This is almost but not quite a NOP, since it does clobber the
-		@ condition flags. But it is the best we can do for EFI, since
-		@ PE/COFF expects the magic string "MZ" at offset 0, while the
-		@ ARM/Linux boot protocol expects an executable instruction
-		@ there.
-		.inst	'M' | ('Z' << 8) | (0x1310 << 16)   @ tstne r0, #0x4d000
+	@ This is almost but not quite a NOP, since it does clobber the
+	@ condition flags. But it is the best we can do for EFI, since
+	@ PE/COFF expects the magic string "MZ" at offset 0, while the
+	@ ARM/Linux boot protocol expects an executable instruction
+	@ there.
+	.inst	MZ_MAGIC | (0x1310 << 16)		@ tstne r0, #0x4d000
 #else
-		mov	r0, r0
+	mov	r0, r0
 #endif
-		.endm
+	.endm
 
-		.macro	__EFI_HEADER
+	.macro	__EFI_HEADER
 #ifdef CONFIG_EFI_STUB
-		.set	start_offset, __efi_start - start
-		.org	start + 0x3c
-		@
-		@ The PE header can be anywhere in the file, but for
-		@ simplicity we keep it together with the MSDOS header
-		@ The offset to the PE/COFF header needs to be at offset
-		@ 0x3C in the MSDOS header.
-		@ The only 2 fields of the MSDOS header that are used are this
-		@ PE/COFF offset, and the "MZ" bytes at offset 0x0.
-		@
-		.long	pe_header - start	@ Offset to the PE header.
+	.set	start_offset, __efi_start - start
+	.org	start + 0x3c
+	@
+	@ The PE header can be anywhere in the file, but for
+	@ simplicity we keep it together with the MSDOS header
+	@ The offset to the PE/COFF header needs to be at offset
+	@ 0x3C in the MSDOS header.
+	@ The only 2 fields of the MSDOS header that are used are this
+	@ PE/COFF offset, and the "MZ" bytes at offset 0x0.
+	@
+	.long	pe_header - start		@ Offset to the PE header.
 
 pe_header:
-		.ascii	"PE\0\0"
+	.long	PE_MAGIC
 
 coff_header:
-		.short	0x01c2			@ ARM or Thumb
-		.short	1			@ nr_sections
-		.long	0 			@ TimeDateStamp
-		.long	0			@ PointerToSymbolTable
-		.long	0			@ NumberOfSymbols
-		.short	section_table - optional_header
-						@ SizeOfOptionalHeader
-		.short	0x306			@ Characteristics.
-						@ IMAGE_FILE_32BIT_MACHINE |
-						@ IMAGE_FILE_DEBUG_STRIPPED |
-						@ IMAGE_FILE_EXECUTABLE_IMAGE |
-						@ IMAGE_FILE_LINE_NUMS_STRIPPED
+	.short	IMAGE_FILE_MACHINE_THUMB		@ Machine
+	.short	section_count				@ NumberOfSections
+	.long	0 					@ TimeDateStamp
+	.long	0					@ PointerToSymbolTable
+	.long	0					@ NumberOfSymbols
+	.short	section_table - optional_header		@ SizeOfOptionalHeader
+	.short	IMAGE_FILE_32BIT_MACHINE | \
+		IMAGE_FILE_DEBUG_STRIPPED | \
+		IMAGE_FILE_EXECUTABLE_IMAGE | \
+		IMAGE_FILE_LINE_NUMS_STRIPPED		@ Characteristics
 
 optional_header:
-		.short	0x10b			@ PE32 format
-		.byte	0x02			@ MajorLinkerVersion
-		.byte	0x14			@ MinorLinkerVersion
-		.long	_end - __efi_start	@ SizeOfCode
-		.long	0			@ SizeOfInitializedData
-		.long	0			@ SizeOfUninitializedData
-		.long	efi_stub_entry - start	@ AddressOfEntryPoint
-		.long	start_offset		@ BaseOfCode
-		.long	0			@ data
+	.short	PE_OPT_MAGIC_PE32			@ PE32 format
+	.byte	0x02					@ MajorLinkerVersion
+	.byte	0x14					@ MinorLinkerVersion
+	.long	_end - __efi_start			@ SizeOfCode
+	.long	0					@ SizeOfInitializedData
+	.long	0					@ SizeOfUninitializedData
+	.long	efi_stub_entry - start			@ AddressOfEntryPoint
+	.long	start_offset				@ BaseOfCode
+	.long	0					@ BaseOfData
 
 extra_header_fields:
-		.long	0			@ ImageBase
-		.long	0x200			@ SectionAlignment
-		.long	0x200			@ FileAlignment
-		.short	0			@ MajorOperatingSystemVersion
-		.short	0			@ MinorOperatingSystemVersion
-		.short	0			@ MajorImageVersion
-		.short	0			@ MinorImageVersion
-		.short	0			@ MajorSubsystemVersion
-		.short	0			@ MinorSubsystemVersion
-		.long	0			@ Win32VersionValue
+	.long	0					@ ImageBase
+	.long	SZ_512					@ SectionAlignment
+	.long	SZ_512					@ FileAlignment
+	.short	0					@ MajorOsVersion
+	.short	0					@ MinorOsVersion
+	.short	0					@ MajorImageVersion
+	.short	0					@ MinorImageVersion
+	.short	0					@ MajorSubsystemVersion
+	.short	0					@ MinorSubsystemVersion
+	.long	0					@ Win32VersionValue
 
-		.long	_end - start		@ SizeOfImage
-		.long	start_offset		@ SizeOfHeaders
-		.long	0			@ CheckSum
-		.short	0xa			@ Subsystem (EFI application)
-		.short	0			@ DllCharacteristics
-		.long	0			@ SizeOfStackReserve
-		.long	0			@ SizeOfStackCommit
-		.long	0			@ SizeOfHeapReserve
-		.long	0			@ SizeOfHeapCommit
-		.long	0			@ LoaderFlags
-		.long	0x6			@ NumberOfRvaAndSizes
+	.long	_end - start				@ SizeOfImage
+	.long	start_offset				@ SizeOfHeaders
+	.long	0					@ CheckSum
+	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION		@ Subsystem
+	.short	0					@ DllCharacteristics
+	.long	0					@ SizeOfStackReserve
+	.long	0					@ SizeOfStackCommit
+	.long	0					@ SizeOfHeapReserve
+	.long	0					@ SizeOfHeapCommit
+	.long	0					@ LoaderFlags
+	.long	(section_table - .) / 8			@ NumberOfRvaAndSizes
 
-		.quad	0			@ ExportTable
-		.quad	0			@ ImportTable
-		.quad	0			@ ResourceTable
-		.quad	0			@ ExceptionTable
-		.quad	0			@ CertificationTable
-		.quad	0			@ BaseRelocationTable
+	.quad	0					@ ExportTable
+	.quad	0					@ ImportTable
+	.quad	0					@ ResourceTable
+	.quad	0					@ ExceptionTable
+	.quad	0					@ CertificationTable
+	.quad	0					@ BaseRelocationTable
 
 section_table:
-		.ascii	".text\0\0\0"
-		.long	_end - __efi_start	@ VirtualSize
-		.long	__efi_start		@ VirtualAddress
-		.long	_edata - __efi_start	@ SizeOfRawData
-		.long	__efi_start		@ PointerToRawData
-		.long	0			@ PointerToRelocations
-		.long	0			@ PointerToLineNumbers
-		.short	0			@ NumberOfRelocations
-		.short	0			@ NumberOfLineNumbers
-		.long	0xe0000020		@ Characteristics
+	.ascii	".text\0\0\0"
+	.long	_end - __efi_start			@ VirtualSize
+	.long	__efi_start				@ VirtualAddress
+	.long	_edata - __efi_start			@ SizeOfRawData
+	.long	__efi_start				@ PointerToRawData
+	.long	0					@ PointerToRelocations
+	.long	0					@ PointerToLineNumbers
+	.short	0					@ NumberOfRelocations
+	.short	0					@ NumberOfLineNumbers
+	.long	IMAGE_SCN_CNT_CODE | \
+		IMAGE_SCN_MEM_READ | \
+		IMAGE_SCN_MEM_WRITE | \
+		IMAGE_SCN_MEM_EXECUTE			@ Characteristics
+
+	.set	section_count, (. - section_table) / 40
 
-		.align	9
+	.align	9
 __efi_start:
 #endif
-		.endm
+	.endm