1 files changed, 5 insertions, 0 deletions

diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index d1c3ed9943e5..af73b8dfde28 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -763,6 +763,9 @@ get_wchan (struct task_struct *p)
         unsigned long ip;
         int count = 0;
 
+        if (!p || p == current || p->state == TASK_RUNNING)
+                return 0;
+
         /*
          * Note: p may not be a blocked task (it could be current or
          * another process running on some other CPU.  Rather than
@@ -773,6 +776,8 @@ get_wchan (struct task_struct *p)
          */
         unw_init_from_blocked_task(&info, p);
         do {
+                if (p->state == TASK_RUNNING)
+                        return 0;
                 if (unw_unwind(&info) < 0)
                         return 0;
                 unw_get_ip(&info, &ip);