From: David S. Miller <davem@davemloft.net>
Date: Mon, 15 Aug 2016 21:47:54 +0000 (-0700)
Subject: sparc64: Prepare to move to more saner user copy exception handling.
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=83a17d2661674d8c198adc0e183418f72aabab79;p=linux.git

sparc64: Prepare to move to more saner user copy exception handling.

The fixup helper function mechanism for handling user copy fault
handling is not %100 accurrate, and can never be made so.

We are going to transition the code to return the running return
return length, which is always kept track in one or more registers
of each of these routines.

In order to convert them one by one, we have to allow the existing
behavior to continue functioning.

Therefore make all the copy code that wants the fixup helper to be
used return negative one.

After all of the user copy routines have been converted, this logic
and the fixup helpers themselves can be removed completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index f8518df34b631..0244012435c84 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -198,8 +198,11 @@ copy_from_user(void *to, const void __user *from, unsigned long size)
 	check_object_size(to, size, false);
 
 	ret = ___copy_from_user(to, from, size);
-	if (unlikely(ret))
-		ret = copy_from_user_fixup(to, from, size);
+	if (unlikely(ret)) {
+		if ((long)ret < 0)
+			ret = copy_from_user_fixup(to, from, size);
+		return ret;
+	}
 
 	return ret;
 }
@@ -218,8 +221,11 @@ copy_to_user(void __user *to, const void *from, unsigned long size)
 	check_object_size(from, size, true);
 
 	ret = ___copy_to_user(to, from, size);
-	if (unlikely(ret))
-		ret = copy_to_user_fixup(to, from, size);
+	if (unlikely(ret)) {
+		if ((long)ret < 0)
+			ret = copy_to_user_fixup(to, from, size);
+		return ret;
+	}
 	return ret;
 }
 #define __copy_to_user copy_to_user
@@ -234,8 +240,11 @@ copy_in_user(void __user *to, void __user *from, unsigned long size)
 {
 	unsigned long ret = ___copy_in_user(to, from, size);
 
-	if (unlikely(ret))
-		ret = copy_in_user_fixup(to, from, size);
+	if (unlikely(ret)) {
+		if ((long)ret < 0)
+			ret = copy_in_user_fixup(to, from, size);
+		return ret;
+	}
 	return ret;
 }
 #define __copy_in_user copy_in_user
diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S
index 603d73654295d..5f17de6b5fc30 100644
--- a/arch/sparc/kernel/head_64.S
+++ b/arch/sparc/kernel/head_64.S
@@ -926,41 +926,40 @@ tlb_type:	.word	0	/* Must NOT end up in BSS */
 EXPORT_SYMBOL(tlb_type)
 	.section	".fixup",#alloc,#execinstr
 
-	.globl	__retl_efault, __ret_one, __retl_one
 ENTRY(__retl_efault)
 	retl
 	 mov	-EFAULT, %o0
 ENDPROC(__retl_efault)
 
-ENTRY(__retl_one)
+ENTRY(__retl_mone)
 	retl
-	 mov	1, %o0
-ENDPROC(__retl_one)
+	 mov	-1, %o0
+ENDPROC(__retl_mone)
 
-ENTRY(__retl_one_fp)
+ENTRY(__retl_mone_fp)
 	VISExitHalf
 	retl
 	 mov	1, %o0
-ENDPROC(__retl_one_fp)
+ENDPROC(__retl_mone_fp)
 
-ENTRY(__ret_one_asi)
+ENTRY(__ret_mone_asi)
 	wr	%g0, ASI_AIUS, %asi
 	ret
 	 restore %g0, 1, %o0
-ENDPROC(__ret_one_asi)
+ENDPROC(__ret_mone_asi)
 
-ENTRY(__retl_one_asi)
+ENTRY(__retl_mone_asi)
 	wr	%g0, ASI_AIUS, %asi
 	retl
 	 mov	1, %o0
-ENDPROC(__retl_one_asi)
+ENDPROC(__retl_mone_asi)
 
-ENTRY(__retl_one_asi_fp)
+ENTRY(__retl_mone_asi_fp)
 	wr	%g0, ASI_AIUS, %asi
 	VISExitHalf
 	retl
 	 mov	1, %o0
-ENDPROC(__retl_one_asi_fp)
+ENDPROC(__retl_mone_asi_fp)
 
 ENTRY(__retl_o1)
 	retl
diff --git a/arch/sparc/lib/GENcopy_from_user.S b/arch/sparc/lib/GENcopy_from_user.S
index b7d0bd6b14063..5bce682022465 100644
--- a/arch/sparc/lib/GENcopy_from_user.S
+++ b/arch/sparc/lib/GENcopy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/GENcopy_to_user.S b/arch/sparc/lib/GENcopy_to_user.S
index 780550e1afc74..f663ce3ee8d99 100644
--- a/arch/sparc/lib/GENcopy_to_user.S
+++ b/arch/sparc/lib/GENcopy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NG2copy_from_user.S b/arch/sparc/lib/NG2copy_from_user.S
index d5242b8c4f949..4d47fa5519d4f 100644
--- a/arch/sparc/lib/NG2copy_from_user.S
+++ b/arch/sparc/lib/NG2copy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi;\
+	.word 98b, __retl_mone_asi;\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi_fp;\
+	.word 98b, __retl_mone_asi_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NG2copy_to_user.S b/arch/sparc/lib/NG2copy_to_user.S
index 4e962d993b10c..2078d752709a7 100644
--- a/arch/sparc/lib/NG2copy_to_user.S
+++ b/arch/sparc/lib/NG2copy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi;\
+	.word 98b, __retl_mone_asi;\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi_fp;\
+	.word 98b, __retl_mone_asi_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NG4copy_from_user.S b/arch/sparc/lib/NG4copy_from_user.S
index 2e8ee7ad07a9c..f9746e7cf25ee 100644
--- a/arch/sparc/lib/NG4copy_from_user.S
+++ b/arch/sparc/lib/NG4copy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi;\
+	.word 98b, __retl_mone_asi;\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi_fp;\
+	.word 98b, __retl_mone_asi_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NG4copy_to_user.S b/arch/sparc/lib/NG4copy_to_user.S
index be0bf4590df89..5fa44349addee 100644
--- a/arch/sparc/lib/NG4copy_to_user.S
+++ b/arch/sparc/lib/NG4copy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi;\
+	.word 98b, __retl_mone_asi;\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_asi_fp;\
+	.word 98b, __retl_mone_asi_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NGcopy_from_user.S b/arch/sparc/lib/NGcopy_from_user.S
index 5d1e4d1ac21ed..e61694c444af8 100644
--- a/arch/sparc/lib/NGcopy_from_user.S
+++ b/arch/sparc/lib/NGcopy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __ret_one_asi;\
+	.word 98b, __ret_mone_asi;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/NGcopy_to_user.S b/arch/sparc/lib/NGcopy_to_user.S
index ff630dcb273c9..2d6b33d3998f0 100644
--- a/arch/sparc/lib/NGcopy_to_user.S
+++ b/arch/sparc/lib/NGcopy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __ret_one_asi;\
+	.word 98b, __ret_mone_asi;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/U1copy_from_user.S b/arch/sparc/lib/U1copy_from_user.S
index ecc5692fa2b49..1ad59fbac7a75 100644
--- a/arch/sparc/lib/U1copy_from_user.S
+++ b/arch/sparc/lib/U1copy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_fp;\
+	.word 98b, __retl_mone_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/U1copy_to_user.S b/arch/sparc/lib/U1copy_to_user.S
index 9eea392e44d47..adcc3a5101850 100644
--- a/arch/sparc/lib/U1copy_to_user.S
+++ b/arch/sparc/lib/U1copy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_fp;\
+	.word 98b, __retl_mone_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/U3copy_from_user.S b/arch/sparc/lib/U3copy_from_user.S
index 88ad73d86fe44..1046e2b083fec 100644
--- a/arch/sparc/lib/U3copy_from_user.S
+++ b/arch/sparc/lib/U3copy_from_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_fp;\
+	.word 98b, __retl_mone_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/U3copy_to_user.S b/arch/sparc/lib/U3copy_to_user.S
index 845139d755372..032b0c5419b0c 100644
--- a/arch/sparc/lib/U3copy_to_user.S
+++ b/arch/sparc/lib/U3copy_to_user.S
@@ -7,7 +7,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;
 
@@ -15,7 +15,7 @@
 98:	x;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one_fp;\
+	.word 98b, __retl_mone_fp;\
 	.text;			\
 	.align 4;
 
diff --git a/arch/sparc/lib/copy_in_user.S b/arch/sparc/lib/copy_in_user.S
index 482de093bdaeb..86e6663dd4e09 100644
--- a/arch/sparc/lib/copy_in_user.S
+++ b/arch/sparc/lib/copy_in_user.S
@@ -13,7 +13,7 @@
 98:	x,y;			\
 	.section __ex_table,"a";\
 	.align 4;		\
-	.word 98b, __retl_one;	\
+	.word 98b, __retl_mone;	\
 	.text;			\
 	.align 4;