From af313e5a4f56b248767d667c3c2436dda767df77 Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Wed, 30 Aug 2006 14:33:30 +0200
Subject: [S390] broken copy_in_user function.

The copy_in_user primitive does not work as advertised. If the source
and target area are available copy_in_user copies one byte too much.
If one of the memory areas is not available it does not copy as much
data as it can, but up to 257 bytes less.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/lib/uaccess.S   | 33 +++++++++++++++++----------------
 arch/s390/lib/uaccess64.S | 35 ++++++++++++++++++-----------------
 2 files changed, 35 insertions(+), 33 deletions(-)

diff --git a/arch/s390/lib/uaccess.S b/arch/s390/lib/uaccess.S
index 5d59e26..8372752 100644
--- a/arch/s390/lib/uaccess.S
+++ b/arch/s390/lib/uaccess.S
@@ -88,30 +88,31 @@ __copy_to_user_asm:
         .globl __copy_in_user_asm
 	# %r2 = from, %r3 = n, %r4 = to
 __copy_in_user_asm:
+	ahi	%r3,-1
+	jo	6f
 	sacf	256
-	bras	1,1f
-	mvc	0(1,%r4),0(%r2)
-0:	mvc	0(256,%r4),0(%r2)
-	la	%r2,256(%r2)
-	la	%r4,256(%r4)
-1:	ahi	%r3,-256
-	jnm	0b
-2:	ex	%r3,0(%r1)
-	sacf	0
-	slr	%r2,%r2
-	br	14
-3:	mvc	0(1,%r4),0(%r2)
+	bras	%r1,4f
+0:	ahi	%r3,257
+1:	mvc	0(1,%r4),0(%r2)
 	la	%r2,1(%r2)
 	la	%r4,1(%r4)
 	ahi	%r3,-1
+	jnz	1b
+2:	lr	%r2,%r3
+	br	%r14
+3:	mvc	0(256,%r4),0(%r2)
+	la	%r2,256(%r2)
+	la	%r4,256(%r4)
+4:	ahi	%r3,-256
 	jnm	3b
-4:	lr	%r2,%r3
+5:	ex	%r3,4(%r1)
 	sacf	0
+6:	slr	%r2,%r2
 	br	%r14
         .section __ex_table,"a"
-	.long	0b,3b
-	.long	2b,3b
-	.long	3b,4b
+	.long	1b,2b
+	.long	3b,0b
+	.long	5b,0b
         .previous
 
         .align 4
diff --git a/arch/s390/lib/uaccess64.S b/arch/s390/lib/uaccess64.S
index 19b41a3..1f755be 100644
--- a/arch/s390/lib/uaccess64.S
+++ b/arch/s390/lib/uaccess64.S
@@ -88,30 +88,31 @@ __copy_to_user_asm:
         .globl __copy_in_user_asm
 	# %r2 = from, %r3 = n, %r4 = to
 __copy_in_user_asm:
+	aghi	%r3,-1
+	jo	6f
 	sacf	256
-	bras	1,1f
-	mvc	0(1,%r4),0(%r2)
-0:	mvc	0(256,%r4),0(%r2)
-	la	%r2,256(%r2)
-	la	%r4,256(%r4)
-1:	aghi	%r3,-256
-	jnm	0b
-2:	ex	%r3,0(%r1)
-	sacf	0
-	slgr	%r2,%r2
-	br	14
-3:	mvc	0(1,%r4),0(%r2)
+	bras	%r1,4f
+0:	aghi	%r3,257
+1:	mvc	0(1,%r4),0(%r2)
 	la	%r2,1(%r2)
 	la	%r4,1(%r4)
 	aghi	%r3,-1
+	jnz	1b
+2:	lgr	%r2,%r3
+	br	%r14
+3:	mvc	0(256,%r4),0(%r2)
+	la	%r2,256(%r2)
+	la	%r4,256(%r4)
+4:	aghi	%r3,-256
 	jnm	3b
-4:	lgr	%r2,%r3
+5:	ex	%r3,4(%r1)
 	sacf	0
-	br	%r14
+6:	slgr	%r2,%r2
+	br	14
         .section __ex_table,"a"
-	.quad	0b,3b
-	.quad	2b,3b
-	.quad	3b,4b
+	.quad	1b,2b
+	.quad	3b,0b
+	.quad	5b,0b
         .previous
 
         .align 4
-- 
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