OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ipmi: don't grab locks in run-to-completion mode 

This patch prevents deadlocks in IPMI panic handler caused by msg_lock
in smi_info structure and waiting_msgs_lock in ipmi_smi structure.

[cminyard@mvista.com: remove unnecessary memory barriers]
Signed-off-by: Konstantin Baydarov <kbaidarov@ru.mvista.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Konstantin Baydarov 2008-04-29 01:01:03 -07:00 committed by Linus Torvalds
parent bda4c30aa6
commit 5956dce148
2 changed files with 28 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/char/ipmi/ipmi_msghandler.c
View File

@ -351,8 +351,16 @@ struct ipmi_smi
/* Invalid data in an event. */
unsigned int invalid_events;
/* Events that were received with the proper format. */
unsigned int events;
/*
* run_to_completion duplicate of smb_info, smi_info
* and ipmi_serial_info structures. Used to decrease numbers of
* parameters passed by "low" level IPMI code.
*/
int run_to_completion;
};
#define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
@ -3451,8 +3459,9 @@ static int handle_new_recv_msg(ipmi_smi_t intf,
void ipmi_smi_msg_received(ipmi_smi_t intf,
struct ipmi_smi_msg *msg)
{
unsigned long flags;
unsigned long flags = 0; /* keep us warning-free. */
int rv;
int run_to_completion;
if ((msg->data_size >= 2)
@ -3501,21 +3510,28 @@ void ipmi_smi_msg_received(ipmi_smi_t intf,
/* To preserve message order, if the list is not empty, we
tack this message onto the end of the list. */
spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
run_to_completion = intf->run_to_completion;
if (!run_to_completion)
spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
if (!list_empty(&intf->waiting_msgs)) {
list_add_tail(&msg->link, &intf->waiting_msgs);
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
goto out;
}
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
rv = handle_new_recv_msg(intf, msg);
if (rv > 0) {
/* Could not handle the message now, just add it to a
list to handle later. */
spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
run_to_completion = intf->run_to_completion;
if (!run_to_completion)
spin_lock_irqsave(&intf->waiting_msgs_lock, flags);
list_add_tail(&msg->link, &intf->waiting_msgs);
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->waiting_msgs_lock, flags);
} else if (rv == 0) {
ipmi_free_smi_msg(msg);
}
@ -3884,6 +3900,7 @@ 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);
i_ipmi_request(NULL,
@ -4059,6 +4076,7 @@ static int panic_event(struct notifier_block *this,
/* Interface is not ready. */
continue;
intf->run_to_completion = 1;
intf->handlers->set_run_to_completion(intf->send_info, 1);
}

6
drivers/char/ipmi/ipmi_si_intf.c
View File

@ -289,7 +289,8 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
/* No need to save flags, we aleady have interrupts off and we
already hold the SMI lock. */
spin_lock(&(smi_info->msg_lock));
if (!smi_info->run_to_completion)
spin_lock(&(smi_info->msg_lock));
/* Pick the high priority queue first. */
if (!list_empty(&(smi_info->hp_xmit_msgs))) {
@ -329,7 +330,8 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info)
rv = SI_SM_CALL_WITHOUT_DELAY;
}
out:
spin_unlock(&(smi_info->msg_lock));
if (!smi_info->run_to_completion)
spin_unlock(&(smi_info->msg_lock));
return rv;
}