1 files changed, 16 insertions, 0 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index af42ef8900a6..b1b796dad3f1 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -260,12 +260,20 @@ static void expunge_all(struct msg_queue *msq, int res)
         while (tmp != &msq->q_receivers) {
                 struct msg_receiver *msr;
 
+                /*
+                 * Make sure that the wakeup doesnt preempt
+                 * this CPU prematurely. (on PREEMPT_RT)
+                 */
+                preempt_disable_rt();
+
                 msr = list_entry(tmp, struct msg_receiver, r_list);
                 tmp = tmp->next;
                 msr->r_msg = NULL;
                 wake_up_process(msr->r_tsk);
                 smp_mb();
                 msr->r_msg = ERR_PTR(res);
+
+                preempt_enable_rt();
         }
 }
 
@@ -612,6 +620,12 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
                     !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
                                                msr->r_msgtype, msr->r_mode)) {
 
+                        /*
+                         * Make sure that the wakeup doesnt preempt
+                         * this CPU prematurely. (on PREEMPT_RT)
+                         */
+                        preempt_disable_rt();
+
                         list_del(&msr->r_list);
                         if (msr->r_maxsize < msg->m_ts) {
                                 msr->r_msg = NULL;
@@ -625,9 +639,11 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
                                 wake_up_process(msr->r_tsk);
                                 smp_mb();
                                 msr->r_msg = msg;
+                                preempt_enable_rt();
 
                                 return 1;
                         }
+                        preempt_enable_rt();
                 }
         }
         return 0;