[src/trunk]: src/sys/dev/pci/ixgbe Fix race about writing adapter->link_activ...

[knakahara <knakahara%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f8ce5aeaa864
branches:  trunk
changeset: 321519:f8ce5aeaa864
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Tue Mar 20 09:46:25 2018 +0000

description:
Fix race about writing adapter->link_active for ixg(4).

adapter->link_active is updated by ixgbe_update_link_status() only.
The function is called from the following four functions.
    - ixgbe_media_status()
    - ixgbe_local_timer1()
    - ixgbe_stop()
    - ixgbe_handle_link()

The functions other than ixgbe_handle_link() call ixgbe_update_link_status()
with holding IXGBE_CORE_LOCK, however ixgbe_handle_link() calls it without
holding IXGBE_CORE_LOCK. That can cause race. So, add IXGBE_CORE_LOCK to
ixgbe_handle_link().

Tested by msaitoh@n.o and me.

diffstat:

 sys/dev/pci/ixgbe/ixgbe.c |  8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diffs (34 lines):

diff -r 901bdb7cc985 -r f8ce5aeaa864 sys/dev/pci/ixgbe/ixgbe.c
--- a/sys/dev/pci/ixgbe/ixgbe.c Mon Mar 19 17:29:08 2018 +0000
+++ b/sys/dev/pci/ixgbe/ixgbe.c Tue Mar 20 09:46:25 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: ixgbe.c,v 1.135 2018/03/15 06:48:51 msaitoh Exp $ */
+/* $NetBSD: ixgbe.c,v 1.136 2018/03/20 09:46:25 knakahara Exp $ */
 
 /******************************************************************************
 
@@ -4486,6 +4486,8 @@
        device_t        dev = adapter->dev;
        struct ixgbe_hw *hw = &adapter->hw;
 
+       KASSERT(mutex_owned(&adapter->core_mtx));
+
        if (adapter->link_up) {
                if (adapter->link_active == FALSE) {
                        if (adapter->link_speed == IXGBE_LINK_SPEED_10GB_FULL){
@@ -6338,11 +6340,15 @@
        struct adapter  *adapter = context;
        struct ixgbe_hw *hw = &adapter->hw;
 
+       IXGBE_CORE_LOCK(adapter);
+
        ixgbe_check_link(hw, &adapter->link_speed, &adapter->link_up, 0);
        ixgbe_update_link_status(adapter);
 
        /* Re-enable link interrupts */
        IXGBE_WRITE_REG(hw, IXGBE_EIMS, IXGBE_EIMS_LSC);
+
+       IXGBE_CORE_UNLOCK(adapter);
 } /* ixgbe_handle_link */
 
 /************************************************************************