diff mbox series

[RFC,3/4] arm64/boot: Populate vmlinux ELF program headers

Message ID 20241218150316.1583806-9-ardb+git@google.com
State New
Headers show
Series efi/zboot: Encapsulate ELF image for arm64 | expand

Commit Message

Ard Biesheuvel Dec. 18, 2024, 3:03 p.m. UTC 
From: Ard Biesheuvel <ardb@kernel.org>

In order to be able to use the ELF vmlinux image as the [zboot
compressed] boot image, populate the program headers explicitly to
describe text+rodata+inittext as R-X and initdata+data+bss as RW-.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/kernel/vmlinux.lds.S | 33 +++++++++++++-------
 1 file changed, 22 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index f84c71f04d9e..33d9c683e434 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -59,6 +59,7 @@ 
 
 #define RO_EXCEPTION_TABLE_ALIGN	4
 #define RUNTIME_DISCARD_EXIT
+#define LOAD_OFFSET			KIMAGE_VADDR
 
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/cache.h>
@@ -70,7 +71,9 @@ 
 #include "image.h"
 
 OUTPUT_ARCH(aarch64)
-ENTRY(_text)
+ENTRY(elf_entry)
+
+elf_entry = ABSOLUTE(primary_entry - KIMAGE_VADDR);
 
 jiffies = jiffies_64;
 
@@ -150,6 +153,11 @@  PECOFF_FILE_ALIGNMENT = 0x200;
 #define PECOFF_EDATA_PADDING
 #endif
 
+PHDRS {
+	text PT_LOAD FLAGS(5);          /* R_X */
+	data PT_LOAD FLAGS(6);          /* RW_ */
+}
+
 SECTIONS
 {
 	/*
@@ -166,10 +174,10 @@  SECTIONS
 
 	. = KIMAGE_VADDR;
 
-	.head.text : {
+	.head.text : AT (0x0) {
 		_text = .;
 		HEAD_TEXT
-	}
+	} :text
 	.text : ALIGN(SEGMENT_ALIGN) {	/* Real text segment		*/
 		_stext = .;		/* Text and read-only data	*/
 			IRQENTRY_TEXT
@@ -248,10 +256,6 @@  SECTIONS
 	__inittext_end = .;
 	__initdata_begin = .;
 
-	init_idmap_pg_dir = .;
-	. += INIT_IDMAP_DIR_SIZE;
-	init_idmap_pg_end = .;
-
 	.init.data : {
 		INIT_DATA
 		INIT_SETUP(16)
@@ -259,13 +263,18 @@  SECTIONS
 		CON_INITCALL
 		INIT_RAM_FS
 		*(.init.altinstructions .init.bss)	/* from the EFI stub */
-	}
+	} :data
 	.exit.data : {
 		EXIT_DATA
 	}
 
 	RUNTIME_CONST_VARIABLES
 
+	. = ALIGN(PAGE_SIZE);
+	init_idmap_pg_dir = .;
+	. += INIT_IDMAP_DIR_SIZE;
+	init_idmap_pg_end = .;
+
 	PERCPU_SECTION(L1_CACHE_BYTES)
 	HYPERVISOR_PERCPU_SECTION
 
@@ -325,10 +334,12 @@  SECTIONS
 	init_pg_end = .;
 	/* end of zero-init region */
 
-	. += SZ_4K;		/* stack for the early C runtime */
-	early_init_stack = .;
+	.early_init_stack : {
+		. += SZ_4K;		/* stack for the early C runtime */
+		early_init_stack = .;
 
-	. = ALIGN(SEGMENT_ALIGN);
+		. = ALIGN(SEGMENT_ALIGN);
+	}
 	__pecoff_data_size = ABSOLUTE(. - __initdata_begin);
 	_end = .;