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Commit 82802f96 authored by Hidehiro Kawai's avatar Hidehiro Kawai Committed by Corey Minyard
Browse files

ipmi: Don't flush messages in sender() in run-to-completion mode 



When flushing queued messages in run-to-completion mode,
smi_event_handler() is recursively called.

flush_messages()
 smi_event_handler()
  handle_transaction_done()
   deliver_recv_msg()
    ipmi_smi_msg_received()
     smi_recv_tasklet()
      sender()
       flush_messages()
        smi_event_handler()
         ...

The depth of the recursive call depends on the number of queued
messages, so it can cause a stack overflow if many messages have
been queued.

To solve this problem, this patch removes flush_messages()
from sender()@ipmi_si_intf.c.  Instead, add flush_messages() to
caller side of sender() if needed.  Additionally, to implement this,
add new handler flush_messages to struct ipmi_smi_handlers.

Signed-off-by: default avatarHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>

Fixed up a comment and some spacing issues.

Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
parent e45361d7

drivers/char/ipmi/ipmi_msghandler.c

+3 −0
Original line number Diff line number Diff line
@@ -4295,6 +4295,9 @@ 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);

}

drivers/char/ipmi/ipmi_si_intf.c

+5 −5
Original line number Diff line number Diff line
@@ -924,8 +924,9 @@ static void check_start_timer_thread(struct smi_info *smi_info) 
	}

}



static void flush_messages(struct smi_info *smi_info)

static void flush_messages(void *send_info)

{

	struct smi_info *smi_info = send_info;

	enum si_sm_result result;



	/*
@@ -949,12 +950,10 @@ static void sender(void *send_info, 


	if (smi_info->run_to_completion) {

		/*

		 * If we are running to completion, start it and run

		 * transactions until everything is clear.

		 * If we are running to completion, start it.  Upper

		 * layer will call flush_messages to clear it out.

		 */

		smi_info->waiting_msg = msg;



		flush_messages(smi_info);

		return;

	}
@@ -1260,6 +1259,7 @@ static const struct ipmi_smi_handlers handlers = { 
	.set_need_watch		= set_need_watch,

	.set_maintenance_mode   = set_maintenance_mode,

	.set_run_to_completion  = set_run_to_completion,

	.flush_messages		= flush_messages,

	.poll			= poll,

};

include/linux/ipmi_smi.h

+5 −0
Original line number Diff line number Diff line
@@ -115,6 +115,11 @@ struct ipmi_smi_handlers { 
	   implement it. */

	void (*set_need_watch)(void *send_info, bool enable);



	/*

	 * Called when flushing all pending messages.

	 */

	void (*flush_messages)(void *send_info);



	/* Called when the interface should go into "run to

	   completion" mode.  If this call sets the value to true, the

	   interface should make sure that all messages are flushed