From 07b050f9290ee012a407a0f64151db902a1520f5 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Thu, 5 Jan 2023 22:28:36 +1100
Subject: [PATCH] powerpc/vmlinux.lds: Don't discard .rela* for relocatable
 builds

References: bsc#1194869
Patch-mainline: v6.2-rc3
Git-commit: 07b050f9290ee012a407a0f64151db902a1520f5

Relocatable kernels must not discard relocations, they need to be
processed at runtime. As such they are included for CONFIG_RELOCATABLE
builds in the powerpc linker script (line 340).

However they are also unconditionally discarded later in the
script (line 414). Previously that worked because the earlier inclusion
superseded the discard.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 137). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier, causing .rela* to
actually be discarded at link time, leading to build warnings and a
kernel that doesn't boot:

  ld: warning: discarding dynamic section .rela.init.rodata

Fix it by conditionally discarding .rela* only when CONFIG_RELOCATABLE
is disabled.

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20230105132349.384666-2-mpe@ellerman.id.au
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/kernel/vmlinux.lds.S | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index c5ea7d03d539..a4c6efadc90c 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -411,9 +411,12 @@ SECTIONS
 	DISCARDS
 	/DISCARD/ : {
 		*(*.EMB.apuinfo)
-		*(.glink .iplt .plt .rela* .comment)
+		*(.glink .iplt .plt .comment)
 		*(.gnu.version*)
 		*(.gnu.attributes)
 		*(.eh_frame)
+#ifndef CONFIG_RELOCATABLE
+		*(.rela*)
+#endif
 	}
 }
-- 
2.40.0