futex: Sanitize cmpxchg_futex_value_locked API

[linux-flexiantxendom0.git] / arch / ia64 / include / asm / futex.h

diff --git a/arch/ia64/include/asm/futex.h b/arch/ia64/include/asm/futex.h
index c7f0f06..b072840 100644 (file)
--- a/arch/ia64/include/asm/futex.h
+++ b/arch/ia64/include/asm/futex.h
@@ -100,23 +100,26 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+                             int oldval, int newval)
 {
        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
                return -EFAULT;
 
        {
-               register unsigned long r8 __asm ("r8");
+               register unsigned long r8 __asm ("r8") = 0;
+               unsigned long prev;
                __asm__ __volatile__(
                        "       mf;;                                    \n"
                        "       mov ar.ccv=%3;;                         \n"
                        "[1:]   cmpxchg4.acq %0=[%1],%2,ar.ccv          \n"
                        "       .xdata4 \"__ex_table\", 1b-., 2f-.      \n"
                        "[2:]"
-                       : "=r" (r8)
+                       : "=r" (prev)
                        : "r" (uaddr), "r" (newval),
                          "rO" ((long) (unsigned) oldval)
                        : "memory");
+               *uval = prev;
                return r8;
        }
 }