From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- drivers/char/ipmi/ipmi_msghandler.c | 46 +++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 9 deletions(-) (limited to 'drivers/char/ipmi/ipmi_msghandler.c') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index bf75f6361..e3536da05 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/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); } -- cgit v1.2.3-54-g00ecf