From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: linux-kernel@vger.kernel.org
Subject: [S390] broken copy_in_user function.
Date: Wed, 30 Aug 2006 14:37:38 +0200 [thread overview]
Message-ID: <20060830123738.GA21193@skybase> (raw)
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
[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 -urpN linux-2.6/arch/s390/lib/uaccess64.S linux-2.6-patched/arch/s390/lib/uaccess64.S
--- linux-2.6/arch/s390/lib/uaccess64.S 2006-06-18 03:49:35.000000000 +0200
+++ linux-2.6-patched/arch/s390/lib/uaccess64.S 2006-08-30 14:24:31.000000000 +0200
@@ -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
diff -urpN linux-2.6/arch/s390/lib/uaccess.S linux-2.6-patched/arch/s390/lib/uaccess.S
--- linux-2.6/arch/s390/lib/uaccess.S 2006-06-18 03:49:35.000000000 +0200
+++ linux-2.6-patched/arch/s390/lib/uaccess.S 2006-08-30 14:24:31.000000000 +0200
@@ -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
reply other threads:[~2006-08-30 12:37 UTC|newest]
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