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authorNeil Horman <nhorman@tuxdriver.com>2014-03-10 06:55:55 -0400
committerDavid S. Miller <davem@davemloft.net>2014-03-11 16:13:55 -0400
commitd25f06ea466ea521b563b76661180b4e44714ae6 (patch)
treef06790e3eca6293469b8ae8fb4cb74e2287dd31d /drivers/net/vmxnet3
parentdd38743b4cc2f86be250eaf156cf113ba3dd531a (diff)
downloadop-kernel-dev-d25f06ea466ea521b563b76661180b4e44714ae6.zip
op-kernel-dev-d25f06ea466ea521b563b76661180b4e44714ae6.tar.gz
vmxnet3: fix netpoll race condition
vmxnet3's netpoll driver is incorrectly coded. It directly calls vmxnet3_do_poll, which is the driver internal napi poll routine. As the netpoll controller method doesn't block real napi polls in any way, there is a potential for race conditions in which the netpoll controller method and the napi poll method run concurrently. The result is data corruption causing panics such as this one recently observed: PID: 1371 TASK: ffff88023762caa0 CPU: 1 COMMAND: "rs:main Q:Reg" #0 [ffff88023abd5780] machine_kexec at ffffffff81038f3b #1 [ffff88023abd57e0] crash_kexec at ffffffff810c5d92 #2 [ffff88023abd58b0] oops_end at ffffffff8152b570 #3 [ffff88023abd58e0] die at ffffffff81010e0b #4 [ffff88023abd5910] do_trap at ffffffff8152add4 #5 [ffff88023abd5970] do_invalid_op at ffffffff8100cf95 #6 [ffff88023abd5a10] invalid_op at ffffffff8100bf9b [exception RIP: vmxnet3_rq_rx_complete+1968] RIP: ffffffffa00f1e80 RSP: ffff88023abd5ac8 RFLAGS: 00010086 RAX: 0000000000000000 RBX: ffff88023b5dcee0 RCX: 00000000000000c0 RDX: 0000000000000000 RSI: 00000000000005f2 RDI: ffff88023b5dcee0 RBP: ffff88023abd5b48 R8: 0000000000000000 R9: ffff88023a3b6048 R10: 0000000000000000 R11: 0000000000000002 R12: ffff8802398d4cd8 R13: ffff88023af35140 R14: ffff88023b60c890 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff88023abd5b50] vmxnet3_do_poll at ffffffffa00f204a [vmxnet3] #8 [ffff88023abd5b80] vmxnet3_netpoll at ffffffffa00f209c [vmxnet3] #9 [ffff88023abd5ba0] netpoll_poll_dev at ffffffff81472bb7 The fix is to do as other drivers do, and have the poll controller call the top half interrupt handler, which schedules a napi poll properly to recieve frames Tested by myself, successfully. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Shreyas Bhatewara <sbhatewara@vmware.com> CC: "VMware, Inc." <pv-drivers@vmware.com> CC: "David S. Miller" <davem@davemloft.net> CC: stable@vger.kernel.org Reviewed-by: Shreyas N Bhatewara <sbhatewara@vmware.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/vmxnet3')
-rw-r--r--drivers/net/vmxnet3/vmxnet3_drv.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 3be786f..b7daa02 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -1761,12 +1761,18 @@ static void
vmxnet3_netpoll(struct net_device *netdev)
{
struct vmxnet3_adapter *adapter = netdev_priv(netdev);
+ int i;
- if (adapter->intr.mask_mode == VMXNET3_IMM_ACTIVE)
- vmxnet3_disable_all_intrs(adapter);
-
- vmxnet3_do_poll(adapter, adapter->rx_queue[0].rx_ring[0].size);
- vmxnet3_enable_all_intrs(adapter);
+ switch (adapter->intr.type) {
+ case VMXNET3_IT_MSIX:
+ for (i = 0; i < adapter->num_rx_queues; i++)
+ vmxnet3_msix_rx(0, &adapter->rx_queue[i]);
+ break;
+ case VMXNET3_IT_MSI:
+ default:
+ vmxnet3_intr(0, adapter->netdev);
+ break;
+ }
}
#endif /* CONFIG_NET_POLL_CONTROLLER */
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