futex: Sanitize cmpxchg_futex_value_locked API

[linux-flexiantxendom0.git] / arch / s390 / lib / uaccess_std.c

diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
index a6c4f7e..1d6643c 100644 (file)
--- a/arch/s390/lib/uaccess_std.c
+++ b/arch/s390/lib/uaccess_std.c
@@ -287,19 +287,21 @@ int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old)
        return ret;
 }
 
-int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval)
+int futex_atomic_cmpxchg_std(int *uval, int __user *uaddr,
+                            int oldval, int newval)
 {
        int ret;
 
        asm volatile(
                "   sacf 256\n"
                "0: cs   %1,%4,0(%5)\n"
-               "1: lr   %0,%1\n"
+               "1: la   %0,0\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" );
+       *uval = oldval;
        return ret;
 }