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authorKonstantin Baydarov <kbaidarov@ru.mvista.com>2008-04-29 01:01:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 08:06:14 -0700
commit5956dce1485efe3816febc24aa52490dcb2be837 (patch)
tree292231b7783baaf980a65eacb199a0384446f566 /drivers/char/ipmi/ipmi_msghandler.c
parentbda4c30aa6f7dc1483f39ea1dfe37bcab8a96207 (diff)
downloadvexpress-lsk-5956dce1485efe3816febc24aa52490dcb2be837.tar.gz
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>
Diffstat (limited to 'drivers/char/ipmi/ipmi_msghandler.c')
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c30
1 files changed, 24 insertions, 6 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 9f0075ca34b..8b71f5638b6 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -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);
}