[PATCH -next v5 2/8] arm64: extable: make uaaccess helper use extable type EX_TYPE_UACCESS_ERR_ZERO

[Tong Tiangen]

Currnetly, the extable type used by __arch_copy_from/to_user() is
EX_TYPE_FIXUP. In fact, It is more clearly to use meaningful
EX_TYPE_UACCESS_*.

Suggested-by: Mark Rutland <mark.rutland at arm.com>
Signed-off-by: Tong Tiangen <tongtiangen at huawei.com>
---
 arch/arm64/include/asm/asm-extable.h |  8 ++++++++
 arch/arm64/include/asm/asm-uaccess.h | 12 ++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/asm-extable.h
index 56ebe183e78b..9c94ac1f082c 100644
--- a/arch/arm64/include/asm/asm-extable.h
+++ b/arch/arm64/include/asm/asm-extable.h
@@ -28,6 +28,14 @@
 	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
 	.endm
 
+/*
+ * Create an exception table entry for uaccess `insn`, which will branch to `fixup`
+ * when an unhandled fault is taken.
+ * ex->data = ~0 means both reg_err and reg_zero is set to wzr(x31).
+ */
+	.macro          _asm_extable_uaccess, insn, fixup
+	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_UACCESS_ERR_ZERO, ~0)
+	.endm
 /*
  * Create an exception table entry for `insn` if `fixup` is provided. Otherwise
  * do nothing.
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
index 0557af834e03..75b211c98dea 100644
--- a/arch/arm64/include/asm/asm-uaccess.h
+++ b/arch/arm64/include/asm/asm-uaccess.h
@@ -61,7 +61,7 @@ alternative_else_nop_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable_uaccess	9999b, l
 
 /*
  * Generate the assembly for LDTR/STTR with exception table entries.
@@ -73,8 +73,8 @@ alternative_else_nop_endif
 8889:		ldtr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b, \l;
+		_asm_extable_uaccess	8889b, \l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -82,14 +82,14 @@ alternative_else_nop_endif
 8889:		sttr	\reg2, [\addr, #8];
 		add	\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
-		_asm_extable	8889b,\l;
+		_asm_extable_uaccess	8888b,\l;
+		_asm_extable_uaccess	8889b,\l;
 	.endm
 
 	.macro user_ldst l, inst, reg, addr, post_inc
 8888:		\inst		\reg, [\addr];
 		add		\addr, \addr, \post_inc;
 
-		_asm_extable	8888b,\l;
+		_asm_extable_uaccess	8888b, \l;
 	.endm
 #endif
-- 
2.25.1