[PATCH v10 3/6] arm64: add uaccess to machine check safe

[Tong Tiangen]

If user process access memory fails due to hardware memory error, only the
relevant processes are affected, so it is more reasonable to kill the user
process and isolate the corrupt page than to panic the kernel.

Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
---
 arch/arm64/lib/copy_from_user.S | 10 +++++-----
 arch/arm64/lib/copy_to_user.S   | 10 +++++-----
 arch/arm64/mm/extable.c         |  8 ++++----
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 34e317907524..1bf676e9201d 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -25,7 +25,7 @@
 	.endm
 
 	.macro strb1 reg, ptr, val
-	strb \reg, [\ptr], \val
+	USER(9998f, strb \reg, [\ptr], \val)
 	.endm
 
 	.macro ldrh1 reg, ptr, val
@@ -33,7 +33,7 @@
 	.endm
 
 	.macro strh1 reg, ptr, val
-	strh \reg, [\ptr], \val
+	USER(9998f, strh \reg, [\ptr], \val)
 	.endm
 
 	.macro ldr1 reg, ptr, val
@@ -41,7 +41,7 @@
 	.endm
 
 	.macro str1 reg, ptr, val
-	str \reg, [\ptr], \val
+	USER(9998f, str \reg, [\ptr], \val)
 	.endm
 
 	.macro ldp1 reg1, reg2, ptr, val
@@ -49,7 +49,7 @@
 	.endm
 
 	.macro stp1 reg1, reg2, ptr, val
-	stp \reg1, \reg2, [\ptr], \val
+	USER(9998f, stp \reg1, \reg2, [\ptr], \val)
 	.endm
 
 end	.req	x5
@@ -66,7 +66,7 @@ SYM_FUNC_START(__arch_copy_from_user)
 	b.ne	9998f
 	// Before being absolutely sure we couldn't copy anything, try harder
 USER(9998f, ldtrb tmp1w, [srcin])
-	strb	tmp1w, [dst], #1
+USER(9998f, strb	tmp1w, [dst], #1)
 9998:	sub	x0, end, dst			// bytes not copied
 	ret
 SYM_FUNC_END(__arch_copy_from_user)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 802231772608..cc031bd87455 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -20,7 +20,7 @@
  *	x0 - bytes not copied
  */
 	.macro ldrb1 reg, ptr, val
-	ldrb  \reg, [\ptr], \val
+	USER(9998f, ldrb  \reg, [\ptr], \val)
 	.endm
 
 	.macro strb1 reg, ptr, val
@@ -28,7 +28,7 @@
 	.endm
 
 	.macro ldrh1 reg, ptr, val
-	ldrh  \reg, [\ptr], \val
+	USER(9998f, ldrh  \reg, [\ptr], \val)
 	.endm
 
 	.macro strh1 reg, ptr, val
@@ -36,7 +36,7 @@
 	.endm
 
 	.macro ldr1 reg, ptr, val
-	ldr \reg, [\ptr], \val
+	USER(9998f, ldr \reg, [\ptr], \val)
 	.endm
 
 	.macro str1 reg, ptr, val
@@ -44,7 +44,7 @@
 	.endm
 
 	.macro ldp1 reg1, reg2, ptr, val
-	ldp \reg1, \reg2, [\ptr], \val
+	USER(9998f, ldp \reg1, \reg2, [\ptr], \val)
 	.endm
 
 	.macro stp1 reg1, reg2, ptr, val
@@ -64,7 +64,7 @@ SYM_FUNC_START(__arch_copy_to_user)
 9997:	cmp	dst, dstin
 	b.ne	9998f
 	// Before being absolutely sure we couldn't copy anything, try harder
-	ldrb	tmp1w, [srcin]
+USER(9998f, ldrb	tmp1w, [srcin])
 USER(9998f, sttrb tmp1w, [dst])
 	add	dst, dst, #1
 9998:	sub	x0, end, dst			// bytes not copied
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index 478e639f8680..28ec35e3d210 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -85,10 +85,10 @@ bool fixup_exception_mc(struct pt_regs *regs)
 	if (!ex)
 		return false;
 
-	/*
-	 * This is not complete, More Machine check safe extable type can
-	 * be processed here.
-	 */
+	switch (ex->type) {
+	case EX_TYPE_UACCESS_ERR_ZERO:
+		return ex_handler_uaccess_err_zero(ex, regs);
+	}
 
 	return false;
 }
-- 
2.25.1