[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>
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 @@
.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 @@
.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
- jnm 3b
-4: lgr %r2,%r3
- sacf 0
+ 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
+5: ex %r3,4(%r1)
+ sacf 0
+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