s390: get rid of zeroing, switch to RAW_COPY_USER

[folded a fix from Martin]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 23 insertions, 45 deletions

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index f481fcde067b..1e5bb2b86c42 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -26,7 +26,7 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
 	tmp1 = -4096UL;
 	asm volatile(
 		"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
-		"9: jz    7f\n"
+		"6: jz    4f\n"
 		"1: algr  %0,%3\n"
 		"   slgr  %1,%3\n"
 		"   slgr  %2,%3\n"
@@ -35,23 +35,13 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
 		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
 		"   slgr  %4,%1\n"
 		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   4f\n"
+		"   jnh   5f\n"
 		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
-		"10:slgr  %0,%4\n"
-		"   algr  %2,%4\n"
-		"4: lghi  %4,-1\n"
-		"   algr  %4,%0\n"	/* copy remaining size, subtract 1 */
-		"   bras  %3,6f\n"	/* memset loop */
-		"   xc    0(1,%2),0(%2)\n"
-		"5: xc    0(256,%2),0(%2)\n"
-		"   la    %2,256(%2)\n"
-		"6: aghi  %4,-256\n"
-		"   jnm   5b\n"
-		"   ex    %4,0(%3)\n"
-		"   j     8f\n"
-		"7: slgr  %0,%0\n"
-		"8:\n"
-		EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
+		"7: slgr  %0,%4\n"
+		"   j     5f\n"
+		"4: slgr  %0,%0\n"
+		"5:\n"
+		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
 		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
 		: "d" (reg0) : "cc", "memory");
 	return size;
@@ -67,49 +57,38 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
 	asm volatile(
 		"   sacf  0\n"
 		"0: mvcp  0(%0,%2),0(%1),%3\n"
-		"10:jz    8f\n"
+		"7: jz    5f\n"
 		"1: algr  %0,%3\n"
 		"   la    %1,256(%1)\n"
 		"   la    %2,256(%2)\n"
 		"2: mvcp  0(%0,%2),0(%1),%3\n"
-		"11:jnz   1b\n"
-		"   j     8f\n"
+		"8: jnz   1b\n"
+		"   j     5f\n"
 		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
 		"   lghi  %3,-4096\n"
 		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
 		"   slgr  %4,%1\n"
 		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   5f\n"
+		"   jnh   6f\n"
 		"4: mvcp  0(%4,%2),0(%1),%3\n"
-		"12:slgr  %0,%4\n"
-		"   algr  %2,%4\n"
-		"5: lghi  %4,-1\n"
-		"   algr  %4,%0\n"	/* copy remaining size, subtract 1 */
-		"   bras  %3,7f\n"	/* memset loop */
-		"   xc    0(1,%2),0(%2)\n"
-		"6: xc    0(256,%2),0(%2)\n"
-		"   la    %2,256(%2)\n"
-		"7: aghi  %4,-256\n"
-		"   jnm   6b\n"
-		"   ex    %4,0(%3)\n"
-		"   j     9f\n"
-		"8: slgr  %0,%0\n"
-		"9: sacf  768\n"
-		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
-		EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
+		"9: slgr  %0,%4\n"
+		"   j     6f\n"
+		"5: slgr  %0,%0\n"
+		"6: sacf  768\n"
+		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
 		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
 		: : "cc", "memory");
 	return size;
 }
 
-unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
+unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	check_object_size(to, n, false);
 	if (static_branch_likely(&have_mvcos))
 		return copy_from_user_mvcos(to, from, n);
 	return copy_from_user_mvcp(to, from, n);
 }
-EXPORT_SYMBOL(__copy_from_user);
+EXPORT_SYMBOL(raw_copy_from_user);
 
 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
 					       unsigned long size)
@@ -176,14 +155,13 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
 	return size;
 }
 
-unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
+unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	check_object_size(from, n, true);
 	if (static_branch_likely(&have_mvcos))
 		return copy_to_user_mvcos(to, from, n);
 	return copy_to_user_mvcs(to, from, n);
 }
-EXPORT_SYMBOL(__copy_to_user);
+EXPORT_SYMBOL(raw_copy_to_user);
 
 static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
 					       unsigned long size)
@@ -240,13 +218,13 @@ static inline unsigned long copy_in_user_mvc(void __user *to, const void __user
 	return size;
 }
 
-unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
+unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
 	if (static_branch_likely(&have_mvcos))
 		return copy_in_user_mvcos(to, from, n);
 	return copy_in_user_mvc(to, from, n);
 }
-EXPORT_SYMBOL(__copy_in_user);
+EXPORT_SYMBOL(raw_copy_in_user);
 
 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
 {