linux-kernel - [PATCH -next v6 06/10] arm64: extable: cleanup redundant extable type EX_TYPE

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Date:   Tue, 21 Jun 2022 07:26:34 +0000
From:   Tong Tiangen <tongtiangen@...wei.com>
To:     Mark Rutland <mark.rutland@....com>,
        James Morse <james.morse@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Robin Murphy <robin.murphy@....com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>, <x86@...nel.org>,
        "H . Peter Anvin" <hpa@...or.com>
CC:     <linuxppc-dev@...ts.ozlabs.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
        Kefeng Wang <wangkefeng.wang@...wei.com>,
        Xie XiuQi <xiexiuqi@...wei.com>,
        Guohanjun <guohanjun@...wei.com>,
        Tong Tiangen <tongtiangen@...wei.com>
Subject: [PATCH -next v6 06/10] arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP

Currently, extable type EX_TYPE_FIXUP is no place to use, We can safely
remove it.

Suggested-by: Mark Rutland <mark.rutland@....com>
Signed-off-by: Tong Tiangen <tongtiangen@...wei.com>
Acked-by: Mark Rutland <mark.rutland@....com>
---
 arch/arm64/include/asm/asm-extable.h | 23 ++++-------------------
 arch/arm64/mm/extable.c              |  9 ---------
 2 files changed, 4 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index b97213d292ce..980d1dd8e1a3 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -6,11 +6,10 @@
 #include <asm/gpr-num.h>
 
 #define EX_TYPE_NONE			0
-#define EX_TYPE_FIXUP			1
-#define EX_TYPE_BPF			2
-#define EX_TYPE_UACCESS_ERR_ZERO	3
-#define EX_TYPE_KACCESS_ERR_ZERO	4
-#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	5
+#define EX_TYPE_BPF			1
+#define EX_TYPE_UACCESS_ERR_ZERO	2
+#define EX_TYPE_KACCESS_ERR_ZERO	3
+#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD	4
 
 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */
 #define EX_DATA_REG_ERR_SHIFT	0
@@ -35,9 +34,6 @@
 	.short		(data);				\
 	.popsection;
 
-#define _ASM_EXTABLE(insn, fixup)	\
-	__ASM_EXTABLE_RAW(insn, fixup, EX_TYPE_FIXUP, 0)
-
 #define EX_DATA_REG(reg, gpr)	\
 	(.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT)
 
@@ -55,14 +51,6 @@
 #define _ASM_EXTABLE_UACCESS(insn, fixup)				\
 	_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr)
 
-/*
- * Create an exception table entry for `insn`, which will branch to `fixup`
- * when an unhandled fault is taken.
- */
-	.macro		_asm_extable, insn, fixup
-	_ASM_EXTABLE(\insn, \fixup)
-	.endm
-
 /*
  * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
  * when an unhandled fault is taken.
@@ -94,9 +82,6 @@
 	".short		(" data ")\n"			\
 	".popsection\n"
 
-#define _ASM_EXTABLE(insn, fixup) \
-	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
-
 #define EX_DATA_REG(reg, gpr)						\
 	"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
 
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 056591e5ca80..228d681a8715 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -16,13 +16,6 @@ get_ex_fixup(const struct exception_table_entry *ex)
 	return ((unsigned long)&ex->fixup + ex->fixup);
 }
 
-static bool ex_handler_fixup(const struct exception_table_entry *ex,
-			     struct pt_regs *regs)
-{
-	regs->pc = get_ex_fixup(ex);
-	return true;
-}
-
 static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
 					struct pt_regs *regs)
 {
@@ -72,8 +65,6 @@ bool fixup_exception(struct pt_regs *regs)
 		return false;
 
 	switch (ex->type) {
-	case EX_TYPE_FIXUP:
-		return ex_handler_fixup(ex, regs);
 	case EX_TYPE_BPF:
 		return ex_handler_bpf(ex, regs);
 	case EX_TYPE_UACCESS_ERR_ZERO:
-- 
2.25.1