linux-kernel - [RFC PATCH v1 20/23] LoongArch: Move some data definitions into the .data section

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Message-Id: <1687249112-2790-1-git-send-email-tangyouling@loongson.cn>
Date:   Tue, 20 Jun 2023 16:18:29 +0800
From:   Youling Tang <tangyouling@...ngson.cn>
To:     Josh Poimboeuf <jpoimboe@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Huacai Chen <chenhuacai@...nel.org>,
        madvenka@...ux.microsoft.com
Cc:     chenzhongjin@...wei.com, WANG Xuerui <kernel@...0n.name>,
        Xi Ruoyao <xry111@...111.site>, live-patching@...r.kernel.org,
        linux-kernel@...r.kernel.org, loongarch@...ts.linux.dev,
        tangyouling00@...il.com, youling.tang@...look.com,
        Jinyang He <hejinyang@...ngson.cn>
Subject: [RFC PATCH v1 20/23] LoongArch: Move some data definitions into the .data section

Make part of the data definition into the .data section, avoid objtool
to detect "unreachable instruction" warning.

At the same time, removing unreachable instruction flow operations
(b process_entry).

Co-developed-by: Jinyang He <hejinyang@...ngson.cn>
Signed-off-by: Jinyang He <hejinyang@...ngson.cn>
Signed-off-by: Youling Tang <tangyouling@...ngson.cn>
---
 arch/loongarch/kernel/genex.S           | 2 ++
 arch/loongarch/kernel/relocate_kernel.S | 7 +++----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/loongarch/kernel/genex.S b/arch/loongarch/kernel/genex.S
index 44ff1ff64260..883b718b5ffe 100644
--- a/arch/loongarch/kernel/genex.S
+++ b/arch/loongarch/kernel/genex.S
@@ -77,7 +77,9 @@ SYM_FUNC_END(except_vec_cex)
 	668:
 	RESTORE_ALL_AND_RET
 	SYM_FUNC_END(handle_\exception)
+	.pushsection	".data", "aw", %progbits
 	SYM_DATA(unwind_hint_\exception, .word 668b - 666b)
+	.popsection
 	.endm
 
 	BUILD_HANDLER ade ade badv
diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kernel/relocate_kernel.S
index d0123fa2b511..1ea3df967b46 100644
--- a/arch/loongarch/kernel/relocate_kernel.S
+++ b/arch/loongarch/kernel/relocate_kernel.S
@@ -75,7 +75,6 @@ copy_word:
 	LONG_ADDI	s5, s5, -1
 	beqz		s5, process_entry
 	b		copy_word
-	b		process_entry
 
 done:
 	ibar		0
@@ -112,6 +111,6 @@ SYM_CODE_END(kexec_smp_wait)
 
 relocate_new_kernel_end:
 
-SYM_DATA_START(relocate_new_kernel_size)
-	PTR		relocate_new_kernel_end - relocate_new_kernel
-SYM_DATA_END(relocate_new_kernel_size)
+.pushsection	".data", "aw", %progbits
+SYM_DATA(relocate_new_kernel_size, .long relocate_new_kernel_end - relocate_new_kernel)
+.popsection
-- 
2.39.2