These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / char / ipmi / ipmi_msghandler.c

diff --git a/kernel/drivers/char/ipmi/ipmi_msghandler.c b/kernel/drivers/char/ipmi/ipmi_msghandler.c
index bf75f63..e3536da 100644 (file)
--- a/kernel/drivers/char/ipmi/ipmi_msghandler.c
+++ b/kernel/drivers/char/ipmi/ipmi_msghandler.c
@@ -342,7 +342,7 @@ struct ipmi_smi {
         * an umpreemptible region to use this.  You must fetch the
         * value into a local variable and make sure it is not NULL.
         */
-       struct ipmi_smi_handlers *handlers;
+       const struct ipmi_smi_handlers *handlers;
        void                     *send_info;
 
 #ifdef CONFIG_PROC_FS
@@ -744,7 +744,13 @@ static void deliver_response(struct ipmi_recv_msg *msg)
                        ipmi_inc_stat(intf, unhandled_local_responses);
                }
                ipmi_free_recv_msg(msg);
-       } else {
+       } else if (!oops_in_progress) {
+               /*
+                * If we are running in the panic context, calling the
+                * receive handler doesn't much meaning and has a deadlock
+                * risk.  At this moment, simply skip it in that case.
+                */
+
                ipmi_user_t user = msg->user;
                user->handler->ipmi_recv_hndl(msg, user->handler_data);
        }
@@ -1015,7 +1021,7 @@ int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
 {
        int           rv = 0;
        ipmi_smi_t    intf;
-       struct ipmi_smi_handlers *handlers;
+       const struct ipmi_smi_handlers *handlers;
 
        mutex_lock(&ipmi_interfaces_mutex);
        list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
@@ -1501,7 +1507,7 @@ static struct ipmi_smi_msg *smi_add_send_msg(ipmi_smi_t intf,
 }
 
 
-static void smi_send(ipmi_smi_t intf, struct ipmi_smi_handlers *handlers,
+static void smi_send(ipmi_smi_t intf, const struct ipmi_smi_handlers *handlers,
                     struct ipmi_smi_msg *smi_msg, int priority)
 {
        int run_to_completion = intf->run_to_completion;
@@ -2747,7 +2753,7 @@ void ipmi_poll_interface(ipmi_user_t user)
 }
 EXPORT_SYMBOL(ipmi_poll_interface);
 
-int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
+int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
                      void                     *send_info,
                      struct ipmi_device_id    *device_id,
                      struct device            *si_dev,
@@ -3959,6 +3965,10 @@ free_msg:
 
        if (!run_to_completion)
                spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
+       /*
+        * We can get an asynchronous event or receive message in addition
+        * to commands we send.
+        */
        if (msg == intf->curr_msg)
                intf->curr_msg = NULL;
        if (!run_to_completion)
@@ -4015,7 +4025,7 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
                              unsigned int *waiting_msgs)
 {
        struct ipmi_recv_msg     *msg;
-       struct ipmi_smi_handlers *handlers;
+       const struct ipmi_smi_handlers *handlers;
 
        if (intf->in_shutdown)
                return;
@@ -4082,7 +4092,7 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
                                ipmi_inc_stat(intf,
                                              retransmitted_ipmb_commands);
 
-                       smi_send(intf, intf->handlers, smi_msg, 0);
+                       smi_send(intf, handlers, smi_msg, 0);
                } else
                        ipmi_free_smi_msg(smi_msg);
 
@@ -4291,6 +4301,9 @@ static void ipmi_panic_request_and_wait(ipmi_smi_t           intf,
                            0, 1); /* Don't retry, and don't wait. */
        if (rv)
                atomic_sub(2, &panic_done_count);
+       else if (intf->handlers->flush_messages)
+               intf->handlers->flush_messages(intf->send_info);
+
        while (atomic_read(&panic_done_count) != 0)
                ipmi_poll(intf);
 }
@@ -4364,9 +4377,7 @@ static void send_panic_events(char *str)
                        /* Interface is not ready. */
                        continue;
 
-               intf->run_to_completion = 1;
                /* Send the event announcing the panic. */
-               intf->handlers->set_run_to_completion(intf->send_info, 1);
                ipmi_panic_request_and_wait(intf, &addr, &msg);
        }
 
@@ -4506,6 +4517,23 @@ static int panic_event(struct notifier_block *this,
                        /* Interface is not ready. */
                        continue;
 
+               /*
+                * If we were interrupted while locking xmit_msgs_lock or
+                * waiting_rcv_msgs_lock, the corresponding list may be
+                * corrupted.  In this case, drop items on the list for
+                * the safety.
+                */
+               if (!spin_trylock(&intf->xmit_msgs_lock)) {
+                       INIT_LIST_HEAD(&intf->xmit_msgs);
+                       INIT_LIST_HEAD(&intf->hp_xmit_msgs);
+               } else
+                       spin_unlock(&intf->xmit_msgs_lock);
+
+               if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
+                       INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
+               else
+                       spin_unlock(&intf->waiting_rcv_msgs_lock);
+
                intf->run_to_completion = 1;
                intf->handlers->set_run_to_completion(intf->send_info, 1);
        }