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From: Nathan Chancellor <nathan@kernel.org>
Date: Wed, 07 Feb 2024 17:14:58 -0700
Subject: [PATCH 06/11] s390/boot: vmlinux.lds.S: Handle '.rela' sections
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Message-Id: <20240207-s390-lld-and-orphan-warn-v1-6-8a665b3346ab@kernel.org>
References: <20240207-s390-lld-and-orphan-warn-v1-0-8a665b3346ab@kernel.org>
In-Reply-To: <20240207-s390-lld-and-orphan-warn-v1-0-8a665b3346ab@kernel.org>
To: hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com
Cc: borntraeger@linux.ibm.com, svens@linux.ibm.com, maskray@google.com, 
 ndesaulniers@google.com, linux-s390@vger.kernel.org, 
 linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, 
 Nathan Chancellor <nathan@kernel.org>

When building with CONFIG_LD_ORPHAN_WARN after selecting
CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several warnings from
arch/s390/boot/head.o due to the unhandled presence of '.rela' sections:

  s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'
  s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn'

These sections are unneeded for the decompressor and they are not
emitted in the binary currently. In a manner similar to other
architectures, coalesce the sections into '.rela.dyn' and ensure it is
zero sized, which is a safe/tested approach versus full discard.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/s390/boot/vmlinux.lds.S | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/s390/boot/vmlinux.lds.S b/arch/s390/boot/vmlinux.lds.S
index 2f0bc05664ed..ff8c62d84f98 100644
--- a/arch/s390/boot/vmlinux.lds.S
+++ b/arch/s390/boot/vmlinux.lds.S
@@ -137,6 +137,10 @@ SECTIONS
 		*(.igot .igot.plt)
 	}
 	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
+	.rela.dyn : {
+		*(.rela.*) *(.rela_*)
+	}
+	ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
 
 	/* Sections to be discarded */
 	/DISCARD/ : {

-- 
2.43.0