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authorGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>2017-05-28 23:07:01 -0300
committerDavid S. Miller <davem@davemloft.net>2017-05-30 12:15:59 -0400
commit025d0973a0ec2121c6fd0da59e8cc3829fbb221e (patch)
tree0482b55e4fa37f08f8b8b8e3f44449a23afd2c9c /drivers
parent468b0df61a5146e79f63380ad6c36228fd30619c (diff)
downloadlinux-actions-025d0973a0ec2121c6fd0da59e8cc3829fbb221e.tar.gz
cxgb4: avoid crash on PCI error recovery path
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> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c21
-rw-r--r--drivers/net/ethernet/chelsio/cxgb4/t4_hw.c9
2 files changed, 20 insertions, 10 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 38a5c6764bb50f..b512149684fda1 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 aded42b96f6d96..3a34aa629f7dd8 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);