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ipmi: move message error checking to avoid deadlock 

V1->V2: in handle_one_rcv_msg, if data_size > 2, set requeue to zero and
        goto out instead of calling ipmi_free_msg.
        Kosuke Tatsukawa <tatsu@ab.jp.nec.com>

In the source stack trace below, function set_need_watch tries to
take out the same si_lock that was taken earlier by ipmi_thread.

ipmi_thread() [drivers/char/ipmi/ipmi_si_intf.c:995]
 smi_event_handler() [drivers/char/ipmi/ipmi_si_intf.c:765]
  handle_transaction_done() [drivers/char/ipmi/ipmi_si_intf.c:555]
   deliver_recv_msg() [drivers/char/ipmi/ipmi_si_intf.c:283]
    ipmi_smi_msg_received() [drivers/char/ipmi/ipmi_msghandler.c:4503]
     intf_err_seq() [drivers/char/ipmi/ipmi_msghandler.c:1149]
      smi_remove_watch() [drivers/char/ipmi/ipmi_msghandler.c:999]
       set_need_watch() [drivers/char/ipmi/ipmi_si_intf.c:1066]

Upstream commit e1891cffd4 adds code to
ipmi_smi_msg_received() to call smi_remove_watch() via intf_err_seq()
and this seems to be causing the deadlock.

commit e1891cffd4
Author: Corey Minyard <cminyard@mvista.com>
Date:   Wed Oct 24 15:17:04 2018 -0500
    ipmi: Make the smi watcher be disabled immediately when not needed

The fix is to put all messages in the queue and move the message
checking code out of ipmi_smi_msg_received and into handle_one_recv_msg,
which processes the message checking after ipmi_thread releases its
locks.

Additionally,Kosuke Tatsukawa <tatsu@ab.jp.nec.com> reported that
handle_new_recv_msgs calls ipmi_free_msg when handle_one_rcv_msg returns
zero, so that the call to ipmi_free_msg in handle_one_rcv_msg introduced
another panic when "ipmitool sensor list" was run in a loop. He
submitted this part of the patch.

+free_msg:
+               requeue = 0;
+               goto out;

Reported by: Osamu Samukawa <osa-samukawa@tg.jp.nec.com>
Characterized by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Fixes: e1891cffd4 ("ipmi: Make the smi watcher be disabled immediately when not needed")
Cc: stable@vger.kernel.org # 5.1
Signed-off-by: Corey Minyard <cminyard@mvista.com>
This commit is contained in:
Tony Camuso 2019-08-22 08:24:53 -04:00 committed by Corey Minyard
parent c4436c9149
commit 383035211c
1 changed files with 57 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
drivers/char/ipmi/ipmi_msghandler.c
View File

@ -4218,7 +4218,53 @@ static int handle_one_recv_msg(struct ipmi_smi *intf,
int chan;
ipmi_debug_msg("Recv:", msg->rsp, msg->rsp_size);
if (msg->rsp_size < 2) {
if ((msg->data_size >= 2)
&& (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
&& (msg->data[1] == IPMI_SEND_MSG_CMD)
&& (msg->user_data == NULL)) {
if (intf->in_shutdown)
goto free_msg;
/*
* This is the local response to a command send, start
* the timer for these. The user_data will not be
* NULL if this is a response send, and we will let
* response sends just go through.
*/
/*
* Check for errors, if we get certain errors (ones
* that mean basically we can try again later), we
* ignore them and start the timer. Otherwise we
* report the error immediately.
*/
if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
&& (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
&& (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
&& (msg->rsp[2] != IPMI_BUS_ERR)
&& (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
int ch = msg->rsp[3] & 0xf;
struct ipmi_channel *chans;
/* Got an error sending the message, handle it. */
chans = READ_ONCE(intf->channel_list)->c;
if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
|| (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
ipmi_inc_stat(intf, sent_lan_command_errs);
else
ipmi_inc_stat(intf, sent_ipmb_command_errs);
intf_err_seq(intf, msg->msgid, msg->rsp[2]);
} else
/* The message was sent, start the timer. */
intf_start_seq_timer(intf, msg->msgid);
free_msg:
requeue = 0;
goto out;
} else if (msg->rsp_size < 2) {
/* Message is too small to be correct. */
dev_warn(intf->si_dev,
"BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
@ -4475,62 +4521,16 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf,
unsigned long flags = 0; /* keep us warning-free. */
int run_to_completion = intf->run_to_completion;
if ((msg->data_size >= 2)
&& (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
&& (msg->data[1] == IPMI_SEND_MSG_CMD)
&& (msg->user_data == NULL)) {
if (intf->in_shutdown)
goto free_msg;
/*
* This is the local response to a command send, start
* the timer for these. The user_data will not be
* NULL if this is a response send, and we will let
* response sends just go through.
*/
/*
* Check for errors, if we get certain errors (ones
* that mean basically we can try again later), we
* ignore them and start the timer. Otherwise we
* report the error immediately.
*/
if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
&& (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
&& (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
&& (msg->rsp[2] != IPMI_BUS_ERR)
&& (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
int ch = msg->rsp[3] & 0xf;
struct ipmi_channel *chans;
/* Got an error sending the message, handle it. */
chans = READ_ONCE(intf->channel_list)->c;
if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
|| (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
ipmi_inc_stat(intf, sent_lan_command_errs);
else
ipmi_inc_stat(intf, sent_ipmb_command_errs);
intf_err_seq(intf, msg->msgid, msg->rsp[2]);
} else
/* The message was sent, start the timer. */
intf_start_seq_timer(intf, msg->msgid);
free_msg:
ipmi_free_smi_msg(msg);
} else {
/*
* To preserve message order, we keep a queue and deliver from
* a tasklet.
*/
if (!run_to_completion)
spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
flags);
}
/*
* To preserve message order, we keep a queue and deliver from
* a tasklet.
*/
if (!run_to_completion)
spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
if (!run_to_completion)
spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
flags);
if (!run_to_completion)
spin_lock_irqsave(&intf->xmit_msgs_lock, flags);