S390: Fix futex_atomic_cmpxchg_std inline assembly.

commit: d5b02b3ff1d9a2e1074f559c84ed378cfa6fc3c0 upstream

Add missing exception table entry so that the kernel can handle
proctection exceptions as well on the cs instruction. Currently only
specification exceptions are handled correctly.
The missing entry allows user space to crash the kernel.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
index 28c4500a58d0abb6556a0105f41ff9a0763e444b..d2ffbadb51a79e6ff803a3a55abc32be3c59df61 100644 (file)
--- a/arch/s390/lib/uaccess_std.c
+++ b/arch/s390/lib/uaccess_std.c
@@ -293,10 +293,10 @@ int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval)
 
        asm volatile(
                "   sacf 256\n"
-               "   cs   %1,%4,0(%5)\n"
-               "0: lr   %0,%1\n"
-               "1: sacf 0\n"
-               EX_TABLE(0b,1b)
+               "0: cs   %1,%4,0(%5)\n"
+               "1: lr   %0,%1\n"
+               "2: sacf 0\n"
+               EX_TABLE(0b,2b) EX_TABLE(1b,2b)
                : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
                : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
                : "cc", "memory" );