[PATCH v2 3/3] riscv: separate .data and .text sections of EFI binaries

[Heinrich Schuchardt]

EFI binaries should not contain sections that are both writable and
executable. Separate the RX .text section from the RW .data section

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v2:
	split patches
---
 arch/riscv/lib/crt0_riscv_efi.S    | 37 ++++++++++++++++++++++--------
 arch/riscv/lib/elf_riscv32_efi.lds | 22 ++++++++++++------
 arch/riscv/lib/elf_riscv64_efi.lds | 22 ++++++++++++------
 3 files changed, 58 insertions(+), 23 deletions(-)

diff --git a/arch/riscv/lib/crt0_riscv_efi.S b/arch/riscv/lib/crt0_riscv_efi.S
index ffe18fa387b..46b08552371 100644
--- a/arch/riscv/lib/crt0_riscv_efi.S
+++ b/arch/riscv/lib/crt0_riscv_efi.S
@@ -53,7 +53,7 @@ pe_header:
 	.long	IMAGE_NT_SIGNATURE		/* 'PE' */
 coff_header:
 	.short	PE_MACHINE			/* RISC-V 64/32-bit */
-	.short	2				/* nr_sections */
+	.short	3				/* nr_sections */
 	.long	0				/* TimeDateStamp */
 	.long	0				/* PointerToSymbolTable */
 	.long	0				/* NumberOfSymbols */
@@ -144,16 +144,35 @@ section_table:
 	.byte	0
 	.byte	0
 	.byte	0			/* end of 0 padding of section name */
-	.long	_edata - _start		/* VirtualSize */
+	.long	_etext - _start		/* VirtualSize */
 	.long	_start - ImageBase	/* VirtualAddress */
-	.long	_edata - _start		/* SizeOfRawData */
+	.long	_etext - _start		/* SizeOfRawData */
 	.long	_start - ImageBase	/* PointerToRawData */
-
-	.long	0		/* PointerToRelocations (0 for executables) */
-	.long	0		/* PointerToLineNumbers (0 for executables) */
-	.short	0		/* NumberOfRelocations  (0 for executables) */
-	.short	0		/* NumberOfLineNumbers  (0 for executables) */
-	.long	0xe0500020	/* Characteristics (section flags) */
+	.long	0			/* PointerToRelocations (0 for executables) */
+	.long	0			/* PointerToLineNumbers (0 for executables) */
+	.short	0			/* NumberOfRelocations  (0 for executables) */
+	.short	0			/* NumberOfLineNumbers  (0 for executables) */
+	/* Characteristics (section flags) */
+	.long	(IMAGE_SCN_MEM_READ | \
+		 IMAGE_SCN_MEM_EXECUTE | \
+		 IMAGE_SCN_CNT_CODE)
+
+	.ascii	".data"
+	.byte	0
+	.byte	0
+	.byte	0			/* end of 0 padding of section name */
+	.long	_edata - _data		/* VirtualSize */
+	.long	_data - ImageBase	/* VirtualAddress */
+	.long	_edata - _data		/* SizeOfRawData */
+	.long	_data - ImageBase	/* PointerToRawData */
+	.long	0			/* PointerToRelocations */
+	.long	0			/* PointerToLineNumbers */
+	.short	0			/* NumberOfRelocations */
+	.short	0			/* NumberOfLineNumbers */
+	/* Characteristics (section flags) */
+	.long	(IMAGE_SCN_MEM_WRITE | \
+		 IMAGE_SCN_MEM_READ | \
+		 IMAGE_SCN_CNT_INITIALIZED_DATA)
 
 	.align		12
 _start:
diff --git a/arch/riscv/lib/elf_riscv32_efi.lds b/arch/riscv/lib/elf_riscv32_efi.lds
index 940a5816b82..7b9bd7b7f15 100644
--- a/arch/riscv/lib/elf_riscv32_efi.lds
+++ b/arch/riscv/lib/elf_riscv32_efi.lds
@@ -7,6 +7,12 @@
 
 OUTPUT_FORMAT("elf32-littleriscv", "elf32-littleriscv", "elf32-littleriscv")
 OUTPUT_ARCH(riscv)
+
+PHDRS
+{
+	data PT_LOAD FLAGS(3); /* SHF_WRITE | SHF_ALLOC */
+}
+
 ENTRY(_start)
 SECTIONS
 {
@@ -18,11 +24,17 @@ SECTIONS
 		*(.gnu.linkonce.t.*)
 		*(.srodata)
 		*(.rodata*)
+		. = ALIGN(16);
+		*(.dynamic);
 		. = ALIGN(512);
 	}
+	.rela.dyn : { *(.rela.dyn) }
+	.rela.plt : { *(.rela.plt) }
+	.rela.got : { *(.rela.got) }
+	.rela.data : { *(.rela.data) *(.rela.data*) }
 	_etext = .;
 	_text_size = . - _text;
-	.dynamic  : { *(.dynamic) }
+	. = ALIGN(4096);
 	.data : {
 		_data = .;
 		*(.sdata)
@@ -47,12 +59,8 @@ SECTIONS
 		. = ALIGN(512);
 		_bss_end = .;
 		_edata = .;
-	}
-	.rela.dyn : { *(.rela.dyn) }
-	.rela.plt : { *(.rela.plt) }
-	.rela.got : { *(.rela.got) }
-	.rela.data : { *(.rela.data) *(.rela.data*) }
-	_data_size = . - _etext;
+	} :data
+	_data_size = _edata - _data;
 
 	. = ALIGN(4096);
 	.dynsym   : { *(.dynsym) }
diff --git a/arch/riscv/lib/elf_riscv64_efi.lds b/arch/riscv/lib/elf_riscv64_efi.lds
index be9f0ac6022..d0b4f3d1d64 100644
--- a/arch/riscv/lib/elf_riscv64_efi.lds
+++ b/arch/riscv/lib/elf_riscv64_efi.lds
@@ -7,6 +7,12 @@
 
 OUTPUT_FORMAT("elf64-littleriscv", "elf64-littleriscv", "elf64-littleriscv")
 OUTPUT_ARCH(riscv)
+
+PHDRS
+{
+	data PT_LOAD FLAGS(3); /* SHF_WRITE | SHF_ALLOC */
+}
+
 ENTRY(_start)
 SECTIONS
 {
@@ -18,11 +24,17 @@ SECTIONS
 		*(.gnu.linkonce.t.*)
 		*(.srodata)
 		*(.rodata*)
+		. = ALIGN(16);
+		*(.dynamic);
 		. = ALIGN(512);
 	}
+	.rela.dyn : { *(.rela.dyn) }
+	.rela.plt : { *(.rela.plt) }
+	.rela.got : { *(.rela.got) }
+	.rela.data : { *(.rela.data) *(.rela.data*) }
 	_etext = .;
 	_text_size = . - _text;
-	.dynamic  : { *(.dynamic) }
+	. = ALIGN(4096);
 	.data : {
 		_data = .;
 		*(.sdata)
@@ -47,12 +59,8 @@ SECTIONS
 		. = ALIGN(512);
 		_bss_end = .;
 		_edata = .;
-	}
-	.rela.dyn : { *(.rela.dyn) }
-	.rela.plt : { *(.rela.plt) }
-	.rela.got : { *(.rela.got) }
-	.rela.data : { *(.rela.data) *(.rela.data*) }
-	_data_size = . - _etext;
+	} :data
+	_data_size = _edata - _data;
 
 	. = ALIGN(4096);
 	.dynsym   : { *(.dynsym) }
-- 
2.43.0