| Message ID | 20170529020701.27765-1-gpiccoli@linux.vnet.ibm.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Date: Sun, 28 May 2017 23:07:01 -0300 > During PCI error recovery process, specifically on eeh_err_detected() > we might have a NULL netdev struct, hence a direct dereference will > lead to a kernel oops. This was observed with latest upstream kernel > (v4.12-rc2) on Chelsio adapter T422-CR in PowerPC machines. > > This patch checks for NULL pointer and avoids the crash, both in > eeh_err_detected() and eeh_resume(). Also, we avoid to trigger > a fatal error or to try disabling interrupts on FW during PCI > error recovery, because: (a) driver might not be able to accurately > access PCI regions in this case, and (b) trigger a fatal error > _during_ the recovery steps is a mistake that could prevent the > recovery path to complete successfully. > > Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com> > Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Applied, thanks.
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c index 38a5c6764bb5..b512149684fd 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c @@ -2771,6 +2771,9 @@ void t4_fatal_err(struct adapter *adap) { int port; + if (pci_channel_offline(adap->pdev)) + return; + /* Disable the SGE since ULDs are going to free resources that * could be exposed to the adapter. RDMA MWs for example... */ @@ -3882,9 +3885,10 @@ static pci_ers_result_t eeh_err_detected(struct pci_dev *pdev, spin_lock(&adap->stats_lock); for_each_port(adap, i) { struct net_device *dev = adap->port[i]; - - netif_device_detach(dev); - netif_carrier_off(dev); + if (dev) { + netif_device_detach(dev); + netif_carrier_off(dev); + } } spin_unlock(&adap->stats_lock); disable_interrupts(adap); @@ -3963,12 +3967,13 @@ static void eeh_resume(struct pci_dev *pdev) rtnl_lock(); for_each_port(adap, i) { struct net_device *dev = adap->port[i]; - - if (netif_running(dev)) { - link_start(dev); - cxgb_set_rxmode(dev); + if (dev) { + if (netif_running(dev)) { + link_start(dev); + cxgb_set_rxmode(dev); + } + netif_device_attach(dev); } - netif_device_attach(dev); } rtnl_unlock(); } diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c index aded42b96f6d..3a34aa629f7d 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c +++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c @@ -4557,8 +4557,13 @@ void t4_intr_enable(struct adapter *adapter) */ void t4_intr_disable(struct adapter *adapter) { - u32 whoami = t4_read_reg(adapter, PL_WHOAMI_A); - u32 pf = CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5 ? + u32 whoami, pf; + + if (pci_channel_offline(adapter->pdev)) + return; + + whoami = t4_read_reg(adapter, PL_WHOAMI_A); + pf = CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5 ? SOURCEPF_G(whoami) : T6_SOURCEPF_G(whoami); t4_write_reg(adapter, MYPF_REG(PL_PF_INT_ENABLE_A), 0);
During PCI error recovery process, specifically on eeh_err_detected() we might have a NULL netdev struct, hence a direct dereference will lead to a kernel oops. This was observed with latest upstream kernel (v4.12-rc2) on Chelsio adapter T422-CR in PowerPC machines. This patch checks for NULL pointer and avoids the crash, both in eeh_err_detected() and eeh_resume(). Also, we avoid to trigger a fatal error or to try disabling interrupts on FW during PCI error recovery, because: (a) driver might not be able to accurately access PCI regions in this case, and (b) trigger a fatal error _during_ the recovery steps is a mistake that could prevent the recovery path to complete successfully. Reported-by: Harsha Thyagaraja <hathyaga@in.ibm.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> --- drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 21 +++++++++++++-------- drivers/net/ethernet/chelsio/cxgb4/t4_hw.c | 9 +++++++-- 2 files changed, 20 insertions(+), 10 deletions(-)