1 files changed, 10 insertions, 1 deletions

diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 133d558db452..ff90f049f8f6 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -54,6 +54,9 @@ void compat_exit_robust_list(struct task_struct *curr)
         compat_long_t futex_offset;
         int rc;
 
+        if (!futex_cmpxchg_enabled)
+                return;
+
         /*
          * Fetch the list head (which was registered earlier, via
          * sys_set_robust_list()):
@@ -115,6 +118,9 @@ asmlinkage long
 compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
                            compat_size_t len)
 {
+        if (!futex_cmpxchg_enabled)
+                return -ENOSYS;
+
         if (unlikely(len != sizeof(*head)))
                 return -EINVAL;
 
@@ -130,6 +136,9 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
         struct compat_robust_list_head __user *head;
         unsigned long ret;
 
+        if (!futex_cmpxchg_enabled)
+                return -ENOSYS;
+
         if (!pid)
                 head = current->compat_robust_list;
         else {
@@ -176,7 +185,7 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 
                 t = timespec_to_ktime(ts);
                 if (cmd == FUTEX_WAIT)
-                        t = ktime_add(ktime_get(), t);
+                        t = ktime_add_safe(ktime_get(), t);
                 tp = &t;
         }
         if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE)