ixgbevf: fix softirq-safe to unsafe splat on internal mbx_lock
The lockdep splat below identifies a case where irq safe to unsafe
lock order is detected. Resolved by making mbx_lock bh.
======================================================
[ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]
3.6.0-rc5jk-net-next+ #119 Not tainted
------------------------------------------------------
ip/2608 [HC0[0]:SC0[2]:HE1:SE0] is trying to acquire:
(&(&adapter->mbx_lock)->rlock){+.+...}, at: [<ffffffffa008114e>] ixgbevf_set_rx_mode+0x36/0xd2 [ixgbevf]
and this task is already holding:
(_xmit_ETHER){+.....}, at: [<ffffffff814097c8>] dev_set_rx_mode+0x1e/0x33
which would create a new lock dependency:
(_xmit_ETHER){+.....} -> (&(&adapter->mbx_lock)->rlock){+.+...}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(&(&mc->mca_lock)->rlock){+.-...}
... which became SOFTIRQ-irq-safe at:
[<ffffffff81092ee5>] __lock_acquire+0x2f2/0xdf3
[<ffffffff81093b11>] lock_acquire+0x12b/0x158
[<ffffffff814bdbcd>] _raw_spin_lock_bh+0x4a/0x7d
[<ffffffffa011a740>] mld_ifc_timer_expire+0x1b2/0x282 [ipv6]
[<ffffffff81054580>] run_timer_softirq+0x2a2/0x3ee
[<ffffffff8104cc42>] __do_softirq+0x161/0x2b9
[<ffffffff814c6a7c>] call_softirq+0x1c/0x30
[<ffffffff81011bc7>] do_softirq+0x4b/0xa3
[<ffffffff8104c8d5>] irq_exit+0x53/0xd7
[<ffffffff814c734d>] do_IRQ+0x9d/0xb4
[<ffffffff814be56f>] ret_from_intr+0x0/0x1a
[<ffffffff813de21c>] cpuidle_enter+0x12/0x14
[<ffffffff813de235>] cpuidle_enter_state+0x17/0x3f
[<ffffffff813deb6c>] cpuidle_idle_call+0x140/0x21c
[<ffffffff8101764c>] cpu_idle+0x79/0xcd
[<ffffffff814a59f5>] rest_init+0x149/0x150
[<ffffffff81ca2cbc>] start_kernel+0x37c/0x389
[<ffffffff81ca22dd>] x86_64_start_reservations+0xb8/0xbd
[<ffffffff81ca23e3>] x86_64_start_kernel+0x101/0x110
to a SOFTIRQ-irq-unsafe lock:
(&(&adapter->mbx_lock)->rlock){+.+...}
... which became SOFTIRQ-irq-unsafe at:
... [<ffffffff81092f59>] __lock_acquire+0x366/0xdf3
[<ffffffff81093b11>] lock_acquire+0x12b/0x158
[<ffffffff814bd862>] _raw_spin_lock+0x45/0x7a
[<ffffffffa0080fde>] ixgbevf_negotiate_api+0x3d/0x6d [ixgbevf]
[<ffffffffa008404b>] ixgbevf_open+0x6c/0x43e [ixgbevf]
[<ffffffff8140b2c1>] __dev_open+0xa0/0xe6
[<ffffffff814099b6>] __dev_change_flags+0xbe/0x142
[<ffffffff8140b1eb>] dev_change_flags+0x21/0x57
[<ffffffff8141a523>] do_setlink+0x2e2/0x7f4
[<ffffffff8141ad8c>] rtnl_newlink+0x277/0x4bb
[<ffffffff81419c08>] rtnetlink_rcv_msg+0x236/0x253
[<ffffffff8142f92d>] netlink_rcv_skb+0x43/0x94
[<ffffffff814199cb>] rtnetlink_rcv+0x26/0x2d
[<ffffffff8142f6dc>] netlink_unicast+0xee/0x174
[<ffffffff8142ff12>] netlink_sendmsg+0x26a/0x288
[<ffffffff813f5a0d>] __sock_sendmsg_nosec+0x58/0x61
[<ffffffff813f7d57>] __sock_sendmsg+0x3d/0x48
[<ffffffff813f7ed9>] sock_sendmsg+0x6e/0x87
[<ffffffff813f93d4>] __sys_sendmsg+0x206/0x288
[<ffffffff813f95ce>] sys_sendmsg+0x42/0x60
[<ffffffff814c57a9>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Chain exists of:
&(&mc->mca_lock)->rlock --> _xmit_ETHER --> &(&adapter->mbx_lock)->rlock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(&adapter->mbx_lock)->rlock);
local_irq_disable();
lock(&(&mc->mca_lock)->rlock);
lock(_xmit_ETHER);
<Interrupt>
lock(&(&mc->mca_lock)->rlock);
*** DEADLOCK ***
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
1 file changed