linux-kernel - [PATCH 6/7] LoongArch: vmlinux.lds.S: Remove `.fixup` section

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Date:   Mon, 10 Oct 2022 17:34:36 +0800
From:   Youling Tang <tangyouling@...ngson.cn>
To:     Huacai Chen <chenhuacai@...nel.org>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Michal Marek <michal.lkml@...kovi.net>
Cc:     WANG Xuerui <kernel@...0n.name>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Alexei Starovoitov <ast@...nel.org>, loongarch@...ts.linux.dev,
        linux-kernel@...r.kernel.org, linux-kbuild@...r.kernel.org,
        bpf@...r.kernel.org
Subject: [PATCH 6/7] LoongArch: vmlinux.lds.S: Remove `.fixup` section

After using the `.L_xxx` lable instead of `.fixup`, we no longer place
anything into a `.fixup` section, so we no longer need to place those
sections into the `.text` section in the main kernel Image.

Remove the use of `.fixup`.

Signed-off-by: Youling Tang <tangyouling@...ngson.cn>
---

Using `irp` allows you to easily define multiple lables, provide
convenience for implementing __{copy, clear}_user_fast in the future.

 arch/loongarch/kernel/vmlinux.lds.S |  1 -
 arch/loongarch/lib/clear_user.S     | 14 +++++---------
 arch/loongarch/lib/copy_user.S      | 16 ++++++----------
 3 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S
index efecda0c2361..d382c88f47b2 100644
--- a/arch/loongarch/kernel/vmlinux.lds.S
+++ b/arch/loongarch/kernel/vmlinux.lds.S
@@ -48,7 +48,6 @@ SECTIONS
 		KPROBES_TEXT
 		IRQENTRY_TEXT
 		SOFTIRQENTRY_TEXT
-		*(.fixup)
 		*(.gnu.warning)
 	} :text = 0
 	. = ALIGN(PECOFF_SEGMENT_ALIGN);
diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S
index 7a066d6a41b8..167823b21def 100644
--- a/arch/loongarch/lib/clear_user.S
+++ b/arch/loongarch/lib/clear_user.S
@@ -9,15 +9,11 @@
 #include <asm/export.h>
 #include <asm/regdef.h>
 
-.macro fixup_ex from, to, offset, fix
-.if \fix
-	.section .fixup, "ax"
-\to:	addi.d	a0, a1, \offset
+.irp to, 0
+.L_fixup_handle_\to\():
+	addi.d	a0, a1, (\to) * (-8)
 	jr	ra
-	.previous
-.endif
-	_asm_extable \from\()b, \to\()b
-.endm
+.endr
 
 /*
  * unsigned long __clear_user(void *addr, size_t size)
@@ -36,7 +32,7 @@ SYM_FUNC_START(__clear_user)
 2:	move	a0, a1
 	jr	ra
 
-	fixup_ex 1, 3, 0, 1
+	_asm_extable 1, .L_fixup_handle_0
 SYM_FUNC_END(__clear_user)
 
 EXPORT_SYMBOL(__clear_user)
diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S
index f8ace04586c2..5d7bfa8d53d2 100644
--- a/arch/loongarch/lib/copy_user.S
+++ b/arch/loongarch/lib/copy_user.S
@@ -9,15 +9,11 @@
 #include <asm/export.h>
 #include <asm/regdef.h>
 
-.macro fixup_ex from, to, offset, fix
-.if \fix
-	.section .fixup, "ax"
-\to:	addi.d	a0, a2, \offset
+.irp to, 0
+.L_fixup_handle_\to\():
+	addi.d	a0, a2, (\to) * (-8)
 	jr	ra
-	.previous
-.endif
-	_asm_extable \from\()b, \to\()b
-.endm
+.endr
 
 /*
  * unsigned long __copy_user(void *to, const void *from, size_t n)
@@ -39,8 +35,8 @@ SYM_FUNC_START(__copy_user)
 3:	move	a0, a2
 	jr	ra
 
-	fixup_ex 1, 4, 0, 1
-	fixup_ex 2, 4, 0, 0
+	_asm_extable 1, .L_fixup_handle_0
+	_asm_extable 2, .L_fixup_handle_0
 SYM_FUNC_END(__copy_user)
 
 EXPORT_SYMBOL(__copy_user)
-- 
2.36.1