From: Neil Horman Date: Mon, 10 Mar 2014 10:55:55 +0000 (-0400) Subject: vmxnet3: fix netpoll race condition X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d25f06ea466e;p=linux-beck.git 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 CC: Shreyas Bhatewara CC: "VMware, Inc." CC: "David S. Miller" CC: stable@vger.kernel.org Reviewed-by: Shreyas N Bhatewara Signed-off-by: David S. Miller --- diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 3be786faaaec..b7daa02ff026 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 */