[RFC PATCH 2/4] arm: Prepare linker scripts for memory permissions

[Ilias Apalodimas]

Upcoming patches are switching the memory mappings to RW, RO, RW^X page
permissions after the U-Boot binary and its data are relocated. Add
annotations in the linker scripts to and mark text, data, rodata etc
sections and align them to a page boundary

Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
---
 Makefile                       | 15 +++++++++------
 arch/arm/cpu/armv8/u-boot.lds  | 32 +++++++++++++++++++-------------
 include/asm-generic/sections.h |  2 ++
 lib/efi_loader/efi_runtime.c   |  2 ++
 4 files changed, 32 insertions(+), 19 deletions(-)

diff --git a/Makefile b/Makefile
index 33bb86343c5b..8d7c062ec830 100644
--- a/Makefile
+++ b/Makefile
@@ -2176,13 +2176,16 @@ System.map:	u-boot
 # ARM relocations should all be R_ARM_RELATIVE (32-bit) or
 # R_AARCH64_RELATIVE (64-bit).
 checkarmreloc: u-boot
-	@RELOC="`$(CROSS_COMPILE)readelf -r -W $< | cut -d ' ' -f 4 | \
+	@RELOCS="`$(CROSS_COMPILE)readelf -r -W $< | cut -d ' ' -f 4 | \
 		grep R_A | sort -u`"; \
-	if test "$$RELOC" != "R_ARM_RELATIVE" -a \
-		 "$$RELOC" != "R_AARCH64_RELATIVE"; then \
-		echo "$< contains unexpected relocations: $$RELOC"; \
-		false; \
-	fi
+	for reloc in $$RELOCS; do \
+		if [ "$$reloc" != "R_ARM_RELATIVE" -a \
+		     "$$reloc" != "R_AARCH64_RELATIVE" -a \
+		"$$reloc" != "R_AARCH64_NONE" ]; then \
+			echo "$< contains unexpected relocations: $$reloc"; \
+			false; \
+		fi; \
+	done
 
 tools/version.h: include/version.h
 	$(Q)mkdir -p $(dir $@)
diff --git a/arch/arm/cpu/armv8/u-boot.lds b/arch/arm/cpu/armv8/u-boot.lds
index 857f44412e07..18e168e27135 100644
--- a/arch/arm/cpu/armv8/u-boot.lds
+++ b/arch/arm/cpu/armv8/u-boot.lds
@@ -22,7 +22,7 @@ SECTIONS
 
 	. = ALIGN(8);
 	__image_copy_start = ADDR(.text);
-	.text :
+	.text ALIGN(4096):
 	{
 		CPUDIR/start.o (.text*)
 	}
@@ -36,9 +36,12 @@ SECTIONS
                 __efi_runtime_stop = .;
 	}
 
-	.text_rest :
+	.text_rest ALIGN(4096) :
 	{
+		__text_start = .;
 		*(.text*)
+		. = ALIGN(4096);
+		__text_end = .;
 	}
 
 #ifdef CONFIG_ARMV8_PSCI
@@ -98,27 +101,30 @@ SECTIONS
 	}
 #endif
 
-	. = ALIGN(8);
-	.rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }
+	.rodata ALIGN(4096): {
+	    __start_rodata = .;
+	    *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*)))
+	    . = ALIGN(4096);
+	    __end_rodata = .;
+	}
 
-	. = ALIGN(8);
-	.data : {
+	.data ALIGN(4096) : {
+	    __start_data = .;
 		*(.data*)
+	    . = ALIGN(4096);
+	    __end_data = .;
 	}
 
-	. = ALIGN(8);
-
-	. = .;
-
 	. = ALIGN(8);
 	__u_boot_list : {
 		KEEP(*(SORT(__u_boot_list*)));
 	}
 
-	.efi_runtime_rel : {
+	.efi_runtime_rel ALIGN(4096) : {
                 __efi_runtime_rel_start = .;
 		*(.rel*.efi_runtime)
 		*(.rel*.efi_runtime.*)
+		. = ALIGN(4096);
                 __efi_runtime_rel_stop = .;
 	}
 
@@ -136,10 +142,10 @@ SECTIONS
 	/*
 	 * arch/arm/lib/crt0_64.S assumes __bss_start - __bss_end % 8 == 0
 	 */
-	.bss ALIGN(8) : {
+	.bss ALIGN(4096) : {
 		__bss_start = .;
 		*(.bss*)
-		. = ALIGN(8);
+		. = ALIGN(4096);
 		__bss_end = .;
 	}
 
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index b6bca53db10d..5626df796f33 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -23,6 +23,7 @@ extern char __kprobes_text_start[], __kprobes_text_end[];
 extern char __entry_text_start[], __entry_text_end[];
 extern char __initdata_begin[], __initdata_end[];
 extern char __start_rodata[], __end_rodata[];
+extern char __start_data[], __end_data[];
 extern char __efi_helloworld_begin[];
 extern char __efi_helloworld_end[];
 extern char __efi_var_file_begin[];
@@ -63,6 +64,7 @@ static inline int arch_is_kernel_data(unsigned long addr)
 
 /* Start of U-Boot text region */
 extern char __text_start[];
+extern char __text_end[];
 
 /* This marks the text region which must be relocated */
 extern char __image_copy_start[], __image_copy_end[];
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 35eb6a777665..c10a79301a92 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -742,6 +742,8 @@ void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
 		      rel->info, *p, rel->offset);
 
 		switch (rel->info & R_MASK) {
+		case 0:
+			break;
 		case R_RELATIVE:
 #ifdef IS_RELA
 		newaddr = rel->addend + offset - CONFIG_TEXT_BASE;
-- 
2.43.0