This is a note to let you know that I have just added a patch titled

    ipmi: move timer init to before irq is setup

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt33.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 475f3be3c566ea156482676efab229ffdbf445ae Mon Sep 17 00:00:00 2001
From: Jan Stancek <[email protected]>
Date: Tue, 8 Dec 2015 13:57:51 -0500
Subject: ipmi: move timer init to before irq is setup

commit 27f972d3e00b50639deb4cc1392afaeb08d3cecc upstream.

We encountered a panic on boot in ipmi_si on a dell per320 due to an
uninitialized timer as follows.

static int smi_start_processing(void       *send_info,
                                ipmi_smi_t intf)
{
        /* Try to claim any interrupts. */
        if (new_smi->irq_setup)
                new_smi->irq_setup(new_smi);

 --> IRQ arrives here and irq handler tries to modify uninitialized timer

    which triggers BUG_ON(!timer->function) in __mod_timer().

 Call Trace:
   <IRQ>
   [<ffffffffa0532617>] start_new_msg+0x47/0x80 [ipmi_si]
   [<ffffffffa053269e>] start_check_enables+0x4e/0x60 [ipmi_si]
   [<ffffffffa0532bd8>] smi_event_handler+0x1e8/0x640 [ipmi_si]
   [<ffffffff810f5584>] ? __rcu_process_callbacks+0x54/0x350
   [<ffffffffa053327c>] si_irq_handler+0x3c/0x60 [ipmi_si]
   [<ffffffff810efaf0>] handle_IRQ_event+0x60/0x170
   [<ffffffff810f245e>] handle_edge_irq+0xde/0x180
   [<ffffffff8100fc59>] handle_irq+0x49/0xa0
   [<ffffffff8154643c>] do_IRQ+0x6c/0xf0
   [<ffffffff8100ba53>] ret_from_intr+0x0/0x11

        /* Set up the timer that drives the interface. */
        setup_timer(&new_smi->si_timer, smi_timeout, (long)new_smi);

The following patch fixes the problem.

To: [email protected]
To: Corey Minyard <[email protected]>
CC: [email protected]

Signed-off-by: Jan Stancek <[email protected]>
Signed-off-by: Tony Camuso <[email protected]>
Signed-off-by: Corey Minyard <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 drivers/char/ipmi/ipmi_si_intf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 15e4a60..90344a5 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -1141,15 +1141,15 @@ static int smi_start_processing(void       *send_info,

        new_smi->intf = intf;

-       /* Try to claim any interrupts. */
-       if (new_smi->irq_setup)
-               new_smi->irq_setup(new_smi);
-
        /* Set up the timer that drives the interface. */
        setup_timer(&new_smi->si_timer, smi_timeout, (long)new_smi);
        new_smi->last_timeout_jiffies = jiffies;
        mod_timer(&new_smi->si_timer, jiffies + SI_TIMEOUT_JIFFIES);

+       /* Try to claim any interrupts. */
+       if (new_smi->irq_setup)
+               new_smi->irq_setup(new_smi);
+
        /*
         * Check if the user forcefully enabled the daemon.
         */
--
1.9.1

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