arm64: copy_form/to_user support machine check safe

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GB28
CVE: NA

-------------------------------

Add copy_{to, from}_user() to machine check safe.

If copy fail due to hardware memory error, only the relevant processes are
affected, so killing the user process and isolate the user page with
hardware memory errors is a more reasonable choice than kernel panic.
Signed-off-by: NTong Tiangen <tongtiangen@huawei.com>

arch/arm64/include/asm/asm-uaccess.h

@@ -70,6 +70,9 @@ alternative_else_nop_endif
 
 		_asm_extable	8888b,\l;
 		_asm_extable	8889b,\l;
+
+		_asm_mc_extable	8888b,\l;
+		_asm_mc_extable	8889b,\l;
 	.endm
 
 	.macro user_stp l, reg1, reg2, addr, post_inc
@@ -86,5 +89,7 @@ alternative_else_nop_endif
 		add		\addr, \addr, \post_inc;
 
 		_asm_extable	8888b,\l;
+
+		_asm_mc_extable	8888b,\l;
 	.endm
 #endif

arch/arm64/include/asm/assembler.h

@@ -162,8 +162,12 @@ alternative_endif
 
 #define USER(l, x...)				\
 9999:	x;					\
-	_asm_extable	9999b, l
+	_asm_extable	9999b, l;		\
+	_asm_mc_extable	9999b, l
 
+#define USER_MC(l, x...)			\
+9999:	x;					\
+	_asm_mc_extable	9999b, l
 /*
  * Register aliases.
  */

arch/arm64/lib/copy_from_user.S

@@ -25,7 +25,7 @@
 	.endm
 
 	.macro strb1 reg, ptr, val
-	strb \reg, [\ptr], \val
+	USER_MC(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_MC(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_MC(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_MC(9998f, stp \reg1, \reg2, [\ptr], \val)
 	.endm
 
 end	.req	x5

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_MC(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_MC(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_MC(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_MC(9998f, ldp \reg1, \reg2, [\ptr], \val)
 	.endm
 
 	.macro stp1 reg1, reg2, ptr, val
@@ -67,7 +67,7 @@ EXPORT_SYMBOL(__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_MC(9998f, ldrb tmp1w, [srcin])
 USER(9998f, sttrb tmp1w, [dst])
 	add	dst, dst, #1
 9998:	sub	x0, end, dst			// bytes not copied