Commit af313e5a authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent dc709bd1

arch/s390/lib/uaccess.S

+17 −16
Original line number Diff line number Diff line
@@ -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

arch/s390/lib/uaccess64.S

+18 −17
Original line number Diff line number Diff line
@@ -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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