ARM: 9414/1: Fix build issue with LD_DEAD_CODE_DATA_ELIMINATION

There is a build issue with LD segmentation fault, while
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled, as bellow.

scripts/link-vmlinux.sh: line 49:  3796 Segmentation fault
 (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive
 ${objs} ${wl}--no-whole-archive ${wl}--start-group
 ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}

The error occurs in older versions of the GNU ld with version earlier
than 2.36. It makes most sense to have a minimum LD version as
a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION and eliminate
the impact of ".reloc  .text, R_ARM_NONE, ." when
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled.

Fixes: ed0f941 ("ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION")
Reported-by: Harith George <mail2hgg@gmail.com>
Tested-by: Harith George <mail2hgg@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
Link: https://lore.kernel.org/all/14e9aefb-88d1-4eee-8288-ef15d4a9b059@gmail.com/
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Author: Yuntao Liu

arch/arm/Kconfig

@@ -117,7 +117,7 @@ config ARM
 	select HAVE_KERNEL_XZ
 	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
 	select HAVE_KRETPROBES if HAVE_KPROBES
-	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD)
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
 	select HAVE_OPTPROBES if !THUMB2_KERNEL

arch/arm/kernel/entry-armv.S

@@ -29,6 +29,12 @@
 #include "entry-header.S"
 #include <asm/probes.h>
 
+#ifdef CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+#define RELOC_TEXT_NONE .reloc  .text, R_ARM_NONE, .
+#else
+#define RELOC_TEXT_NONE
+#endif
+
 /*
  * Interrupt handling.
  */
@@ -1065,7 +1071,7 @@ vector_addrexcptn:
 	.globl	vector_fiq
 
 	.section .vectors, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_swi		)
@@ -1079,7 +1085,7 @@ THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_swi		)
 
 #ifdef CONFIG_HARDEN_BRANCH_HISTORY
 	.section .vectors.bhb.loop8, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_bhb_loop8_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_loop8_swi	)
@@ -1092,7 +1098,7 @@ THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_bhb_loop8_swi	)
 	W(b)	vector_bhb_loop8_fiq
 
 	.section .vectors.bhb.bpiall, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_bhb_bpiall_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_bpiall_swi	)