[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Dai]

We see the behavior when EEH e1000e adapter detects io permanent failure,
it will crash kernel with this stack:
EEH: Beginning: 'error_detected(permanent failure)'
EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
EEH: Finished:'error_detected(permanent failure)'
Oops: Exception in kernel mode, sig: 5 [#1]
NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
 LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
Call Trace:
[c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
[c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
[c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
[c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
[c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
[c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
[c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
[c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
[c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
[c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
[c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80

Basically the e1000e irqs haven't been freed at the time eeh is trying to 
remove the the e1000e device.
Need to make sure when e1000e_close is called to bring down the NIC,
if adapter error_state is pci_channel_io_perm_failure, it should also 
bring down the link and free irqs.

Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e4..cf618e1 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (!test_bit(__E1000_DOWN, &adapter->state) ||
+	    (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
-- 
1.7.1

[v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Dai]

We see the behavior when EEH e1000e adapter detects io permanent failure,
it will crash kernel with this stack:
EEH: Beginning: 'error_detected(permanent failure)'
EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
EEH: Finished:'error_detected(permanent failure)'
Oops: Exception in kernel mode, sig: 5 [#1]
NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
 LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
Call Trace:
[c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
[c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
[c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
[c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
[c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
[c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
[c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
[c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
[c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
[c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
[c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80

Basically the e1000e irqs haven't been freed at the time eeh is trying to 
remove the the e1000e device.
Need to make sure when e1000e_close is called to bring down the NIC,
if adapter error_state is pci_channel_io_perm_failure, it should also 
bring down the link and free irqs.

Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e4..cf618e1 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (!test_bit(__E1000_DOWN, &adapter->state) ||
+	    (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
-- 
1.7.1

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
>
> We see the behavior when EEH e1000e adapter detects io permanent failure,
> it will crash kernel with this stack:
> EEH: Beginning: 'error_detected(permanent failure)'
> EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> EEH: Finished:'error_detected(permanent failure)'
> Oops: Exception in kernel mode, sig: 5 [#1]
> NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
>  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> Call Trace:
> [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
>
> Basically the e1000e irqs haven't been freed at the time eeh is trying to
> remove the the e1000e device.
> Need to make sure when e1000e_close is called to bring down the NIC,
> if adapter error_state is pci_channel_io_perm_failure, it should also
> bring down the link and free irqs.
>
> Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e4..cf618e1 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
>
>         pm_runtime_get_sync(&pdev->dev);
>
> -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
>                 e1000e_down(adapter, true);
>                 e1000_free_irq(adapter);

It seems like the issue is the fact that e1000_io_error_detected is
calling e1000e_down without the e1000_free_irq() bit. Instead of doing
this couldn't you simply add the following to e1000_is_slot_reset in
the "result = PCI_ERS_RESULT_DISCONNECT" case:
    if (netif_running(netdev)
        e1000_free_irq(adapter);

Alternatively we could look at freeing and reallocating the IRQs in
the event of an error like we do for the e1000e_pm_freeze and
e1000e_pm_thaw cases. That might make more sense since we are dealing
with an error we might want to free and reallocate the IRQ resources
assigned to the device.

Thanks.

- Alex

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
>
> We see the behavior when EEH e1000e adapter detects io permanent failure,
> it will crash kernel with this stack:
> EEH: Beginning: 'error_detected(permanent failure)'
> EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> EEH: Finished:'error_detected(permanent failure)'
> Oops: Exception in kernel mode, sig: 5 [#1]
> NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
>  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> Call Trace:
> [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
>
> Basically the e1000e irqs haven't been freed at the time eeh is trying to
> remove the the e1000e device.
> Need to make sure when e1000e_close is called to bring down the NIC,
> if adapter error_state is pci_channel_io_perm_failure, it should also
> bring down the link and free irqs.
>
> Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e4..cf618e1 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
>
>         pm_runtime_get_sync(&pdev->dev);
>
> -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
>                 e1000e_down(adapter, true);
>                 e1000_free_irq(adapter);

It seems like the issue is the fact that e1000_io_error_detected is
calling e1000e_down without the e1000_free_irq() bit. Instead of doing
this couldn't you simply add the following to e1000_is_slot_reset in
the "result = PCI_ERS_RESULT_DISCONNECT" case:
    if (netif_running(netdev)
        e1000_free_irq(adapter);

Alternatively we could look at freeing and reallocating the IRQs in
the event of an error like we do for the e1000e_pm_freeze and
e1000e_pm_thaw cases. That might make more sense since we are dealing
with an error we might want to free and reallocate the IRQ resources
assigned to the device.

Thanks.

- Alex

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > it will crash kernel with this stack:
> > EEH: Beginning: 'error_detected(permanent failure)'
> > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > EEH: Finished:'error_detected(permanent failure)'
> > Oops: Exception in kernel mode, sig: 5 [#1]
> > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > Call Trace:
> > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> >
> > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > remove the the e1000e device.
> > Need to make sure when e1000e_close is called to bring down the NIC,
> > if adapter error_state is pci_channel_io_perm_failure, it should also
> > bring down the link and free irqs.
> >
> > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > ---
> >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> >  1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index d7d56e4..cf618e1 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> >
> >         pm_runtime_get_sync(&pdev->dev);
> >
> > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> >                 e1000e_down(adapter, true);
> >                 e1000_free_irq(adapter);
> 
> It seems like the issue is the fact that e1000_io_error_detected is
> calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> this couldn't you simply add the following to e1000_is_slot_reset in
> the "result = PCI_ERS_RESULT_DISCONNECT" case:
>     if (netif_running(netdev)
>         e1000_free_irq(adapter);
> 
> Alternatively we could look at freeing and reallocating the IRQs in
> the event of an error like we do for the e1000e_pm_freeze and
> e1000e_pm_thaw cases. That might make more sense since we are dealing
> with an error we might want to free and reallocate the IRQ resources
> assigned to the device.
> 
> Thanks.
> 
> - Alex

Thanks for the quick reply and comment!
Looked the e1000_io_slot_reset() routine:
        err = pci_enable_device_mem(pdev);
        if (err) {
                dev_err(&pdev->dev,
                        "Cannot re-enable PCI device after reset.\n");
                result = PCI_ERS_RESULT_DISCONNECT;
        } else {
I didn't see log message "Cannot re-enable PCI device after reset" at
the time of crash.

I can still apply the same logic in e1000_io_error_detected() routine:
    if (state == pci_channel_io_perm_failure) {
+       if (netif_running(netdev))
+           e1000_free_irq(adapter);
        return PCI_ERS_RESULT_DISCONNECT;
    }
Will test this once the test hardware is available again.

Thanks! - David

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > it will crash kernel with this stack:
> > EEH: Beginning: 'error_detected(permanent failure)'
> > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > EEH: Finished:'error_detected(permanent failure)'
> > Oops: Exception in kernel mode, sig: 5 [#1]
> > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > Call Trace:
> > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> >
> > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > remove the the e1000e device.
> > Need to make sure when e1000e_close is called to bring down the NIC,
> > if adapter error_state is pci_channel_io_perm_failure, it should also
> > bring down the link and free irqs.
> >
> > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > ---
> >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> >  1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index d7d56e4..cf618e1 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> >
> >         pm_runtime_get_sync(&pdev->dev);
> >
> > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> >                 e1000e_down(adapter, true);
> >                 e1000_free_irq(adapter);
> 
> It seems like the issue is the fact that e1000_io_error_detected is
> calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> this couldn't you simply add the following to e1000_is_slot_reset in
> the "result = PCI_ERS_RESULT_DISCONNECT" case:
>     if (netif_running(netdev)
>         e1000_free_irq(adapter);
> 
> Alternatively we could look at freeing and reallocating the IRQs in
> the event of an error like we do for the e1000e_pm_freeze and
> e1000e_pm_thaw cases. That might make more sense since we are dealing
> with an error we might want to free and reallocate the IRQ resources
> assigned to the device.
> 
> Thanks.
> 
> - Alex

Thanks for the quick reply and comment!
Looked the e1000_io_slot_reset() routine:
        err = pci_enable_device_mem(pdev);
        if (err) {
                dev_err(&pdev->dev,
                        "Cannot re-enable PCI device after reset.\n");
                result = PCI_ERS_RESULT_DISCONNECT;
        } else {
I didn't see log message "Cannot re-enable PCI device after reset" at
the time of crash.

I can still apply the same logic in e1000_io_error_detected() routine:
    if (state == pci_channel_io_perm_failure) {
+       if (netif_running(netdev))
+           e1000_free_irq(adapter);
        return PCI_ERS_RESULT_DISCONNECT;
    }
Will test this once the test hardware is available again.

Thanks! - David

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > it will crash kernel with this stack:
> > > EEH: Beginning: 'error_detected(permanent failure)'
> > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > EEH: Finished:'error_detected(permanent failure)'
> > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > Call Trace:
> > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > >
> > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > remove the the e1000e device.
> > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > bring down the link and free irqs.
> > >
> > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > ---
> > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > index d7d56e4..cf618e1 100644
> > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > >
> > >         pm_runtime_get_sync(&pdev->dev);
> > >
> > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > >                 e1000e_down(adapter, true);
> > >                 e1000_free_irq(adapter);
> >
> > It seems like the issue is the fact that e1000_io_error_detected is
> > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > this couldn't you simply add the following to e1000_is_slot_reset in
> > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> >     if (netif_running(netdev)
> >         e1000_free_irq(adapter);
> >
> > Alternatively we could look at freeing and reallocating the IRQs in
> > the event of an error like we do for the e1000e_pm_freeze and
> > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > with an error we might want to free and reallocate the IRQ resources
> > assigned to the device.
> >
> > Thanks.
> >
> > - Alex
>
> Thanks for the quick reply and comment!
> Looked the e1000_io_slot_reset() routine:
>         err = pci_enable_device_mem(pdev);
>         if (err) {
>                 dev_err(&pdev->dev,
>                         "Cannot re-enable PCI device after reset.\n");
>                 result = PCI_ERS_RESULT_DISCONNECT;
>         } else {
> I didn't see log message "Cannot re-enable PCI device after reset" at
> the time of crash.
>
> I can still apply the same logic in e1000_io_error_detected() routine:
>     if (state == pci_channel_io_perm_failure) {
> +       if (netif_running(netdev))
> +           e1000_free_irq(adapter);
>         return PCI_ERS_RESULT_DISCONNECT;
>     }
> Will test this once the test hardware is available again.

Are you sure this is the path you are hitting? Things aren't adding up.

I thought the issue was that the interface for the error handling was
calling e1000e_down() but not freeing the IRQs? In the path where you
are adding your code I don't see how the __E1000_DOWN would have been
set?

- Alex

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > it will crash kernel with this stack:
> > > EEH: Beginning: 'error_detected(permanent failure)'
> > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > EEH: Finished:'error_detected(permanent failure)'
> > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > Call Trace:
> > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > >
> > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > remove the the e1000e device.
> > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > bring down the link and free irqs.
> > >
> > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > ---
> > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > index d7d56e4..cf618e1 100644
> > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > >
> > >         pm_runtime_get_sync(&pdev->dev);
> > >
> > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > >                 e1000e_down(adapter, true);
> > >                 e1000_free_irq(adapter);
> >
> > It seems like the issue is the fact that e1000_io_error_detected is
> > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > this couldn't you simply add the following to e1000_is_slot_reset in
> > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> >     if (netif_running(netdev)
> >         e1000_free_irq(adapter);
> >
> > Alternatively we could look at freeing and reallocating the IRQs in
> > the event of an error like we do for the e1000e_pm_freeze and
> > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > with an error we might want to free and reallocate the IRQ resources
> > assigned to the device.
> >
> > Thanks.
> >
> > - Alex
>
> Thanks for the quick reply and comment!
> Looked the e1000_io_slot_reset() routine:
>         err = pci_enable_device_mem(pdev);
>         if (err) {
>                 dev_err(&pdev->dev,
>                         "Cannot re-enable PCI device after reset.\n");
>                 result = PCI_ERS_RESULT_DISCONNECT;
>         } else {
> I didn't see log message "Cannot re-enable PCI device after reset" at
> the time of crash.
>
> I can still apply the same logic in e1000_io_error_detected() routine:
>     if (state == pci_channel_io_perm_failure) {
> +       if (netif_running(netdev))
> +           e1000_free_irq(adapter);
>         return PCI_ERS_RESULT_DISCONNECT;
>     }
> Will test this once the test hardware is available again.

Are you sure this is the path you are hitting? Things aren't adding up.

I thought the issue was that the interface for the error handling was
calling e1000e_down() but not freeing the IRQs? In the path where you
are adding your code I don't see how the __E1000_DOWN would have been
set?

- Alex

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > >
> > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > it will crash kernel with this stack:
> > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > EEH: Finished:'error_detected(permanent failure)'
> > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > Call Trace:
> > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > >
> > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > remove the the e1000e device.
> > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > bring down the link and free irqs.
> > > >
> > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > ---
> > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > >
> > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > index d7d56e4..cf618e1 100644
> > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > >
> > > >         pm_runtime_get_sync(&pdev->dev);
> > > >
> > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > >                 e1000e_down(adapter, true);
> > > >                 e1000_free_irq(adapter);
> > >
> > > It seems like the issue is the fact that e1000_io_error_detected is
> > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > >     if (netif_running(netdev)
> > >         e1000_free_irq(adapter);
> > >
> > > Alternatively we could look at freeing and reallocating the IRQs in
> > > the event of an error like we do for the e1000e_pm_freeze and
> > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > with an error we might want to free and reallocate the IRQ resources
> > > assigned to the device.
> > >
> > > Thanks.
> > >
> > > - Alex
> >
> > Thanks for the quick reply and comment!
> > Looked the e1000_io_slot_reset() routine:
> >         err = pci_enable_device_mem(pdev);
> >         if (err) {
> >                 dev_err(&pdev->dev,
> >                         "Cannot re-enable PCI device after reset.\n");
> >                 result = PCI_ERS_RESULT_DISCONNECT;
> >         } else {
> > I didn't see log message "Cannot re-enable PCI device after reset" at
> > the time of crash.
> >
> > I can still apply the same logic in e1000_io_error_detected() routine:
> >     if (state == pci_channel_io_perm_failure) {
> > +       if (netif_running(netdev))
> > +           e1000_free_irq(adapter);
> >         return PCI_ERS_RESULT_DISCONNECT;
> >     }
> > Will test this once the test hardware is available again.
> 
> Are you sure this is the path you are hitting? Things aren't adding up.
> 
> I thought the issue was that the interface for the error handling was
> calling e1000e_down() but not freeing the IRQs? In the path where you
> are adding your code I don't see how the __E1000_DOWN would have been
> set?
> 
> - Alex
We see the same stack every time the crash is triggered.

My understanding is not that the interface for the error handling was
calling e1000e_down() but not freeing IRQs.

In our case, on powerpc , if injecting eeh errors to reach preset
threshold value, it will be forced to be offline permanently.

In e1000e_close() to bring down link, the check: "if (!
test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
e1000_free_irq() are both not called. IRQs are not freed.

When e1000_remove() is called, it sees IRQs are not free, hence crash
the kernel.

This is the reason I have the original proposed patch to add an extra
check in e1000e_close().

For the 2nd change in e1000_io_error_detected() routine, I haven't
tested it yet.

Pardon me if causing any confusion, and Thanks for your time again! 

- David

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > >
> > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > it will crash kernel with this stack:
> > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > EEH: Finished:'error_detected(permanent failure)'
> > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > Call Trace:
> > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > >
> > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > remove the the e1000e device.
> > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > bring down the link and free irqs.
> > > >
> > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > ---
> > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > >
> > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > index d7d56e4..cf618e1 100644
> > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > >
> > > >         pm_runtime_get_sync(&pdev->dev);
> > > >
> > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > >                 e1000e_down(adapter, true);
> > > >                 e1000_free_irq(adapter);
> > >
> > > It seems like the issue is the fact that e1000_io_error_detected is
> > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > >     if (netif_running(netdev)
> > >         e1000_free_irq(adapter);
> > >
> > > Alternatively we could look at freeing and reallocating the IRQs in
> > > the event of an error like we do for the e1000e_pm_freeze and
> > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > with an error we might want to free and reallocate the IRQ resources
> > > assigned to the device.
> > >
> > > Thanks.
> > >
> > > - Alex
> >
> > Thanks for the quick reply and comment!
> > Looked the e1000_io_slot_reset() routine:
> >         err = pci_enable_device_mem(pdev);
> >         if (err) {
> >                 dev_err(&pdev->dev,
> >                         "Cannot re-enable PCI device after reset.\n");
> >                 result = PCI_ERS_RESULT_DISCONNECT;
> >         } else {
> > I didn't see log message "Cannot re-enable PCI device after reset" at
> > the time of crash.
> >
> > I can still apply the same logic in e1000_io_error_detected() routine:
> >     if (state == pci_channel_io_perm_failure) {
> > +       if (netif_running(netdev))
> > +           e1000_free_irq(adapter);
> >         return PCI_ERS_RESULT_DISCONNECT;
> >     }
> > Will test this once the test hardware is available again.
> 
> Are you sure this is the path you are hitting? Things aren't adding up.
> 
> I thought the issue was that the interface for the error handling was
> calling e1000e_down() but not freeing the IRQs? In the path where you
> are adding your code I don't see how the __E1000_DOWN would have been
> set?
> 
> - Alex
We see the same stack every time the crash is triggered.

My understanding is not that the interface for the error handling was
calling e1000e_down() but not freeing IRQs.

In our case, on powerpc , if injecting eeh errors to reach preset
threshold value, it will be forced to be offline permanently.

In e1000e_close() to bring down link, the check: "if (!
test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
e1000_free_irq() are both not called. IRQs are not freed.

When e1000_remove() is called, it sees IRQs are not free, hence crash
the kernel.

This is the reason I have the original proposed patch to add an extra
check in e1000e_close().

For the 2nd change in e1000_io_error_detected() routine, I haven't
tested it yet.

Pardon me if causing any confusion, and Thanks for your time again! 

- David

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 5:02 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> > On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> > > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > > >
> > > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > > it will crash kernel with this stack:
> > > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > > EEH: Finished:'error_detected(permanent failure)'
> > > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > > Call Trace:
> > > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > > >
> > > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > > remove the the e1000e device.
> > > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > > bring down the link and free irqs.
> > > > >
> > > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > > ---
> > > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > index d7d56e4..cf618e1 100644
> > > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > > >
> > > > >         pm_runtime_get_sync(&pdev->dev);
> > > > >
> > > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > > >                 e1000e_down(adapter, true);
> > > > >                 e1000_free_irq(adapter);
> > > >
> > > > It seems like the issue is the fact that e1000_io_error_detected is
> > > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > > >     if (netif_running(netdev)
> > > >         e1000_free_irq(adapter);
> > > >
> > > > Alternatively we could look at freeing and reallocating the IRQs in
> > > > the event of an error like we do for the e1000e_pm_freeze and
> > > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > > with an error we might want to free and reallocate the IRQ resources
> > > > assigned to the device.
> > > >
> > > > Thanks.
> > > >
> > > > - Alex
> > >
> > > Thanks for the quick reply and comment!
> > > Looked the e1000_io_slot_reset() routine:
> > >         err = pci_enable_device_mem(pdev);
> > >         if (err) {
> > >                 dev_err(&pdev->dev,
> > >                         "Cannot re-enable PCI device after reset.\n");
> > >                 result = PCI_ERS_RESULT_DISCONNECT;
> > >         } else {
> > > I didn't see log message "Cannot re-enable PCI device after reset" at
> > > the time of crash.
> > >
> > > I can still apply the same logic in e1000_io_error_detected() routine:
> > >     if (state == pci_channel_io_perm_failure) {
> > > +       if (netif_running(netdev))
> > > +           e1000_free_irq(adapter);
> > >         return PCI_ERS_RESULT_DISCONNECT;
> > >     }
> > > Will test this once the test hardware is available again.
> >
> > Are you sure this is the path you are hitting? Things aren't adding up.
> >
> > I thought the issue was that the interface for the error handling was
> > calling e1000e_down() but not freeing the IRQs? In the path where you
> > are adding your code I don't see how the __E1000_DOWN would have been
> > set?
> >
> > - Alex
> We see the same stack every time the crash is triggered.
>
> My understanding is not that the interface for the error handling was
> calling e1000e_down() but not freeing IRQs.

That is my understanding as well. However where you talked about
adding the code will end up being before we call e1000e_down() won't
it?

> In our case, on powerpc , if injecting eeh errors to reach preset
> threshold value, it will be forced to be offline permanently.
>
> In e1000e_close() to bring down link, the check: "if (!
> test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
> e1000_free_irq() are both not called. IRQs are not freed.

My concern is mainly that we don't want to mess up the ordering of
things or perform the same action multiple times, or do things
out-of-order.

> When e1000_remove() is called, it sees IRQs are not free, hence crash
> the kernel.
>
> This is the reason I have the original proposed patch to add an extra
> check in e1000e_close().

I get that, however the way you said you were going to change things
doesn't match up with that. You are freeing the IRQs without first
bringing down the interface.

> For the 2nd change in e1000_io_error_detected() routine, I haven't
> tested it yet.
>
> Pardon me if causing any confusion, and Thanks for your time again!
>
> - David

I need to take a look at a couple things. I am not sure why the
e1000e_close is even checking for the __E1000_DOWN bit. From what I
can tell the other drivers are just calling e1000_down() directly
without the check so I am not sure if something was added that makes
it so that we have to be careful about calling e1000_down more than
once or not. If not we could probably just pull that check and
simplify all of this.

Thanks.

- Alex

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[Alexander Duyck]

On Thu, Oct 3, 2019 at 5:02 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> > On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> > > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > > >
> > > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > > it will crash kernel with this stack:
> > > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > > EEH: Finished:'error_detected(permanent failure)'
> > > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > > Call Trace:
> > > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > > >
> > > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > > remove the the e1000e device.
> > > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > > bring down the link and free irqs.
> > > > >
> > > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > > ---
> > > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > index d7d56e4..cf618e1 100644
> > > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > > >
> > > > >         pm_runtime_get_sync(&pdev->dev);
> > > > >
> > > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > > >                 e1000e_down(adapter, true);
> > > > >                 e1000_free_irq(adapter);
> > > >
> > > > It seems like the issue is the fact that e1000_io_error_detected is
> > > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > > >     if (netif_running(netdev)
> > > >         e1000_free_irq(adapter);
> > > >
> > > > Alternatively we could look at freeing and reallocating the IRQs in
> > > > the event of an error like we do for the e1000e_pm_freeze and
> > > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > > with an error we might want to free and reallocate the IRQ resources
> > > > assigned to the device.
> > > >
> > > > Thanks.
> > > >
> > > > - Alex
> > >
> > > Thanks for the quick reply and comment!
> > > Looked the e1000_io_slot_reset() routine:
> > >         err = pci_enable_device_mem(pdev);
> > >         if (err) {
> > >                 dev_err(&pdev->dev,
> > >                         "Cannot re-enable PCI device after reset.\n");
> > >                 result = PCI_ERS_RESULT_DISCONNECT;
> > >         } else {
> > > I didn't see log message "Cannot re-enable PCI device after reset" at
> > > the time of crash.
> > >
> > > I can still apply the same logic in e1000_io_error_detected() routine:
> > >     if (state == pci_channel_io_perm_failure) {
> > > +       if (netif_running(netdev))
> > > +           e1000_free_irq(adapter);
> > >         return PCI_ERS_RESULT_DISCONNECT;
> > >     }
> > > Will test this once the test hardware is available again.
> >
> > Are you sure this is the path you are hitting? Things aren't adding up.
> >
> > I thought the issue was that the interface for the error handling was
> > calling e1000e_down() but not freeing the IRQs? In the path where you
> > are adding your code I don't see how the __E1000_DOWN would have been
> > set?
> >
> > - Alex
> We see the same stack every time the crash is triggered.
>
> My understanding is not that the interface for the error handling was
> calling e1000e_down() but not freeing IRQs.

That is my understanding as well. However where you talked about
adding the code will end up being before we call e1000e_down() won't
it?

> In our case, on powerpc , if injecting eeh errors to reach preset
> threshold value, it will be forced to be offline permanently.
>
> In e1000e_close() to bring down link, the check: "if (!
> test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
> e1000_free_irq() are both not called. IRQs are not freed.

My concern is mainly that we don't want to mess up the ordering of
things or perform the same action multiple times, or do things
out-of-order.

> When e1000_remove() is called, it sees IRQs are not free, hence crash
> the kernel.
>
> This is the reason I have the original proposed patch to add an extra
> check in e1000e_close().

I get that, however the way you said you were going to change things
doesn't match up with that. You are freeing the IRQs without first
bringing down the interface.

> For the 2nd change in e1000_io_error_detected() routine, I haven't
> tested it yet.
>
> Pardon me if causing any confusion, and Thanks for your time again!
>
> - David

I need to take a look at a couple things. I am not sure why the
e1000e_close is even checking for the __E1000_DOWN bit. From what I
can tell the other drivers are just calling e1000_down() directly
without the check so I am not sure if something was added that makes
it so that we have to be careful about calling e1000_down more than
once or not. If not we could probably just pull that check and
simplify all of this.

Thanks.

- Alex

[Intel-wired-lan] [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Fri, 2019-10-04 at 07:35 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 5:02 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> > > On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > > >
> > > > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > > > >
> > > > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > > > it will crash kernel with this stack:
> > > > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > > > EEH: Finished:'error_detected(permanent failure)'
> > > > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > > > Call Trace:
> > > > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > > > >
> > > > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > > > remove the the e1000e device.
> > > > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > > > bring down the link and free irqs.
> > > > > >
> > > > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > > > ---
> > > > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > index d7d56e4..cf618e1 100644
> > > > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > > > >
> > > > > >         pm_runtime_get_sync(&pdev->dev);
> > > > > >
> > > > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > > > >                 e1000e_down(adapter, true);
> > > > > >                 e1000_free_irq(adapter);
> > > > >
> > > > > It seems like the issue is the fact that e1000_io_error_detected is
> > > > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > > > >     if (netif_running(netdev)
> > > > >         e1000_free_irq(adapter);
> > > > >
> > > > > Alternatively we could look at freeing and reallocating the IRQs in
> > > > > the event of an error like we do for the e1000e_pm_freeze and
> > > > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > > > with an error we might want to free and reallocate the IRQ resources
> > > > > assigned to the device.
> > > > >
> > > > > Thanks.
> > > > >
> > > > > - Alex
> > > >
> > > > Thanks for the quick reply and comment!
> > > > Looked the e1000_io_slot_reset() routine:
> > > >         err = pci_enable_device_mem(pdev);
> > > >         if (err) {
> > > >                 dev_err(&pdev->dev,
> > > >                         "Cannot re-enable PCI device after reset.\n");
> > > >                 result = PCI_ERS_RESULT_DISCONNECT;
> > > >         } else {
> > > > I didn't see log message "Cannot re-enable PCI device after reset" at
> > > > the time of crash.
> > > >
> > > > I can still apply the same logic in e1000_io_error_detected() routine:
> > > >     if (state == pci_channel_io_perm_failure) {
> > > > +       if (netif_running(netdev))
> > > > +           e1000_free_irq(adapter);
> > > >         return PCI_ERS_RESULT_DISCONNECT;
> > > >     }
> > > > Will test this once the test hardware is available again.
> > >
> > > Are you sure this is the path you are hitting? Things aren't adding up.
> > >
> > > I thought the issue was that the interface for the error handling was
> > > calling e1000e_down() but not freeing the IRQs? In the path where you
> > > are adding your code I don't see how the __E1000_DOWN would have been
> > > set?
> > >
> > > - Alex
> > We see the same stack every time the crash is triggered.
> >
> > My understanding is not that the interface for the error handling was
> > calling e1000e_down() but not freeing IRQs.
> 
> That is my understanding as well. However where you talked about
> adding the code will end up being before we call e1000e_down() won't
> it?
> 
Agree. It's possible.
> > In our case, on powerpc , if injecting eeh errors to reach preset
> > threshold value, it will be forced to be offline permanently.
> >
> > In e1000e_close() to bring down link, the check: "if (!
> > test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
> > e1000_free_irq() are both not called. IRQs are not freed.
> 
> My concern is mainly that we don't want to mess up the ordering of
> things or perform the same action multiple times, or do things
> out-of-order.
> 
> > When e1000_remove() is called, it sees IRQs are not free, hence crash
> > the kernel.
> >
> > This is the reason I have the original proposed patch to add an extra
> > check in e1000e_close().
> 
> I get that, however the way you said you were going to change things
> doesn't match up with that. You are freeing the IRQs without first
> bringing down the interface.
> 
> > For the 2nd change in e1000_io_error_detected() routine, I haven't
> > tested it yet.
> >
> > Pardon me if causing any confusion, and Thanks for your time again!
> >
> > - David
> 
> I need to take a look at a couple things. I am not sure why the
> e1000e_close is even checking for the __E1000_DOWN bit. From what I
> can tell the other drivers are just calling e1000_down() directly
> without the check so I am not sure if something was added that makes
> it so that we have to be careful about calling e1000_down more than
> once or not. If not we could probably just pull that check and
> simplify all of this.
> 
> Thanks.
> 
> - Alex
I noticed this earlier like e1000 doesn't have the __E1000_DOWN bit
check in e1000_close(), but e1000e has this bit check in e1000e_close().
If we can pull this check w/o side effect, that will simplify all of
this.

Thanks! - David

Re: [v1] e1000e: EEH on e1000e adapter detects io perm failure can trigger crash

[David Z. Dai]

On Fri, 2019-10-04 at 07:35 -0700, Alexander Duyck wrote:
> On Thu, Oct 3, 2019 at 5:02 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote:
> > > On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > > >
> > > > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote:
> > > > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <zdai@linux.vnet.ibm.com> wrote:
> > > > > >
> > > > > > We see the behavior when EEH e1000e adapter detects io permanent failure,
> > > > > > it will crash kernel with this stack:
> > > > > > EEH: Beginning: 'error_detected(permanent failure)'
> > > > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking e1000e->error_detected(permanent failure)
> > > > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect'
> > > > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking e1000e->error_detected(permanent failure)
> > > > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect'
> > > > > > EEH: Finished:'error_detected(permanent failure)'
> > > > > > Oops: Exception in kernel mode, sig: 5 [#1]
> > > > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280
> > > > > >  LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280
> > > > > > Call Trace:
> > > > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 (unreliable)
> > > > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180
> > > > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e]
> > > > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120
> > > > > > [c0000004f491bb30] [c00000000088da6c] device_release_driver_internal+0x2bc/0x3f0
> > > > > > [c0000004f491bb80] [c00000000076f5a8] pci_stop_and_remove_bus_device+0xb8/0x110
> > > > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130
> > > > > > [c0000004f491bc50] [c00000000004ad34] eeh_handle_normal_event+0x1d4/0x660
> > > > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0
> > > > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0
> > > > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80
> > > > > >
> > > > > > Basically the e1000e irqs haven't been freed at the time eeh is trying to
> > > > > > remove the the e1000e device.
> > > > > > Need to make sure when e1000e_close is called to bring down the NIC,
> > > > > > if adapter error_state is pci_channel_io_perm_failure, it should also
> > > > > > bring down the link and free irqs.
> > > > > >
> > > > > > Reported-by: Morumuri Srivalli  <smorumu1@in.ibm.com>
> > > > > > Signed-off-by: David Dai <zdai@linux.vnet.ibm.com>
> > > > > > ---
> > > > > >  drivers/net/ethernet/intel/e1000e/netdev.c |    3 ++-
> > > > > >  1 files changed, 2 insertions(+), 1 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > index d7d56e4..cf618e1 100644
> > > > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev)
> > > > > >
> > > > > >         pm_runtime_get_sync(&pdev->dev);
> > > > > >
> > > > > > -       if (!test_bit(__E1000_DOWN, &adapter->state)) {
> > > > > > +       if (!test_bit(__E1000_DOWN, &adapter->state) ||
> > > > > > +           (adapter->pdev->error_state == pci_channel_io_perm_failure)) {
> > > > > >                 e1000e_down(adapter, true);
> > > > > >                 e1000_free_irq(adapter);
> > > > >
> > > > > It seems like the issue is the fact that e1000_io_error_detected is
> > > > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing
> > > > > this couldn't you simply add the following to e1000_is_slot_reset in
> > > > > the "result = PCI_ERS_RESULT_DISCONNECT" case:
> > > > >     if (netif_running(netdev)
> > > > >         e1000_free_irq(adapter);
> > > > >
> > > > > Alternatively we could look at freeing and reallocating the IRQs in
> > > > > the event of an error like we do for the e1000e_pm_freeze and
> > > > > e1000e_pm_thaw cases. That might make more sense since we are dealing
> > > > > with an error we might want to free and reallocate the IRQ resources
> > > > > assigned to the device.
> > > > >
> > > > > Thanks.
> > > > >
> > > > > - Alex
> > > >
> > > > Thanks for the quick reply and comment!
> > > > Looked the e1000_io_slot_reset() routine:
> > > >         err = pci_enable_device_mem(pdev);
> > > >         if (err) {
> > > >                 dev_err(&pdev->dev,
> > > >                         "Cannot re-enable PCI device after reset.\n");
> > > >                 result = PCI_ERS_RESULT_DISCONNECT;
> > > >         } else {
> > > > I didn't see log message "Cannot re-enable PCI device after reset" at
> > > > the time of crash.
> > > >
> > > > I can still apply the same logic in e1000_io_error_detected() routine:
> > > >     if (state == pci_channel_io_perm_failure) {
> > > > +       if (netif_running(netdev))
> > > > +           e1000_free_irq(adapter);
> > > >         return PCI_ERS_RESULT_DISCONNECT;
> > > >     }
> > > > Will test this once the test hardware is available again.
> > >
> > > Are you sure this is the path you are hitting? Things aren't adding up.
> > >
> > > I thought the issue was that the interface for the error handling was
> > > calling e1000e_down() but not freeing the IRQs? In the path where you
> > > are adding your code I don't see how the __E1000_DOWN would have been
> > > set?
> > >
> > > - Alex
> > We see the same stack every time the crash is triggered.
> >
> > My understanding is not that the interface for the error handling was
> > calling e1000e_down() but not freeing IRQs.
> 
> That is my understanding as well. However where you talked about
> adding the code will end up being before we call e1000e_down() won't
> it?
> 
Agree. It's possible.
> > In our case, on powerpc , if injecting eeh errors to reach preset
> > threshold value, it will be forced to be offline permanently.
> >
> > In e1000e_close() to bring down link, the check: "if (!
> > test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and
> > e1000_free_irq() are both not called. IRQs are not freed.
> 
> My concern is mainly that we don't want to mess up the ordering of
> things or perform the same action multiple times, or do things
> out-of-order.
> 
> > When e1000_remove() is called, it sees IRQs are not free, hence crash
> > the kernel.
> >
> > This is the reason I have the original proposed patch to add an extra
> > check in e1000e_close().
> 
> I get that, however the way you said you were going to change things
> doesn't match up with that. You are freeing the IRQs without first
> bringing down the interface.
> 
> > For the 2nd change in e1000_io_error_detected() routine, I haven't
> > tested it yet.
> >
> > Pardon me if causing any confusion, and Thanks for your time again!
> >
> > - David
> 
> I need to take a look at a couple things. I am not sure why the
> e1000e_close is even checking for the __E1000_DOWN bit. From what I
> can tell the other drivers are just calling e1000_down() directly
> without the check so I am not sure if something was added that makes
> it so that we have to be careful about calling e1000_down more than
> once or not. If not we could probably just pull that check and
> simplify all of this.
> 
> Thanks.
> 
> - Alex
I noticed this earlier like e1000 doesn't have the __E1000_DOWN bit
check in e1000_close(), but e1000e has this bit check in e1000e_close().
If we can pull this check w/o side effect, that will simplify all of
this.

Thanks! - David

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

This patch is meant to address possible race conditions that can exist
between network configuration and power management. A similar issue was
fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
netif_device_detach").

In addition it consolidates the code so that the PCI error handling code
will essentially perform the power management freeze on the device prior to
attempting a reset, and will thaw the device afterwards if that is what it
is planning to do. Otherwise when we call close on the interface it should
see it is detached and not attempt to call the logic to down the interface
and free the IRQs again.

From what I can tell the check that was adding the check for __E1000_DOWN
in e1000e_close was added when runtime power management was added. However
it should not be relevant for us as we perform a call to
pm_runtime_get_sync before we call e1000_down/free_irq so it should always
be back up before we call into this anyway.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---

I'm putting this out as an RFC for now. I haven't had a chance to do much
testing yet, but I have verified no build issues, and the driver appears
to load, link, and pass traffic without problems.

This should address issues seen with either double freeing or never freeing
IRQs that have been seen on this and similar drivers in the past.

I'll submit this formally after testing it over the weekend assuming there
are no issues.

 drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e42a6aa..182a2c8f12d8 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (netif_device_present(netdev)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
 		/* Link status message must follow this format */
-		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
+		pr_info("%s NIC Link is Down\n", netdev->name);
 	}
 
 	napi_disable(&adapter->napi);
@@ -6299,6 +6299,7 @@ static int e1000e_pm_freeze(struct device *dev)
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
+	rtnl_lock();
 	netif_device_detach(netdev);
 
 	if (netif_running(netdev)) {
@@ -6313,6 +6314,8 @@ static int e1000e_pm_freeze(struct device *dev)
 		e1000e_down(adapter, false);
 		e1000_free_irq(adapter);
 	}
+	rtnl_unlock();
+
 	e1000e_reset_interrupt_capability(adapter);
 
 	/* Allow time for pending master requests to run */
@@ -6626,27 +6629,30 @@ static int __e1000_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_thaw(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	int rc = 0;
 
 	e1000e_set_interrupt_capability(adapter);
-	if (netif_running(netdev)) {
-		u32 err = e1000_request_irq(adapter);
 
-		if (err)
-			return err;
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		rc = e1000_request_irq(adapter);
+		if (rc)
+			goto err_irq;
 
 		e1000e_up(adapter);
 	}
 
 	netif_device_attach(netdev);
-
-	return 0;
+	rtnl_unlock();
+err_irq:
+	return rc;
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -6821,13 +6827,11 @@ static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
-	netif_device_detach(netdev);
+	e1000e_pm_freeze(&pdev->dev);
 
 	if (state == pci_channel_io_perm_failure)
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	if (netif_running(netdev))
-		e1000e_down(adapter, true);
 	pci_disable_device(pdev);
 
 	/* Request a slot slot reset. */
@@ -6893,10 +6897,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
 
 	e1000_init_manageability_pt(adapter);
 
-	if (netif_running(netdev))
-		e1000e_up(adapter);
-
-	netif_device_attach(netdev);
+	e1000e_pm_thaw(&pdev->dev);
 
 	/* If the controller has AMT, do not set DRV_LOAD until the interface
 	 * is up.  For all other cases, let the f/w know that the h/w is now

[RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

This patch is meant to address possible race conditions that can exist
between network configuration and power management. A similar issue was
fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
netif_device_detach").

In addition it consolidates the code so that the PCI error handling code
will essentially perform the power management freeze on the device prior to
attempting a reset, and will thaw the device afterwards if that is what it
is planning to do. Otherwise when we call close on the interface it should
see it is detached and not attempt to call the logic to down the interface
and free the IRQs again.

>From what I can tell the check that was adding the check for __E1000_DOWN
in e1000e_close was added when runtime power management was added. However
it should not be relevant for us as we perform a call to
pm_runtime_get_sync before we call e1000_down/free_irq so it should always
be back up before we call into this anyway.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---

I'm putting this out as an RFC for now. I haven't had a chance to do much
testing yet, but I have verified no build issues, and the driver appears
to load, link, and pass traffic without problems.

This should address issues seen with either double freeing or never freeing
IRQs that have been seen on this and similar drivers in the past.

I'll submit this formally after testing it over the weekend assuming there
are no issues.

 drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e42a6aa..182a2c8f12d8 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (netif_device_present(netdev)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
 		/* Link status message must follow this format */
-		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
+		pr_info("%s NIC Link is Down\n", netdev->name);
 	}
 
 	napi_disable(&adapter->napi);
@@ -6299,6 +6299,7 @@ static int e1000e_pm_freeze(struct device *dev)
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
+	rtnl_lock();
 	netif_device_detach(netdev);
 
 	if (netif_running(netdev)) {
@@ -6313,6 +6314,8 @@ static int e1000e_pm_freeze(struct device *dev)
 		e1000e_down(adapter, false);
 		e1000_free_irq(adapter);
 	}
+	rtnl_unlock();
+
 	e1000e_reset_interrupt_capability(adapter);
 
 	/* Allow time for pending master requests to run */
@@ -6626,27 +6629,30 @@ static int __e1000_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_thaw(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	int rc = 0;
 
 	e1000e_set_interrupt_capability(adapter);
-	if (netif_running(netdev)) {
-		u32 err = e1000_request_irq(adapter);
 
-		if (err)
-			return err;
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		rc = e1000_request_irq(adapter);
+		if (rc)
+			goto err_irq;
 
 		e1000e_up(adapter);
 	}
 
 	netif_device_attach(netdev);
-
-	return 0;
+	rtnl_unlock();
+err_irq:
+	return rc;
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -6821,13 +6827,11 @@ static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 
-	netif_device_detach(netdev);
+	e1000e_pm_freeze(&pdev->dev);
 
 	if (state == pci_channel_io_perm_failure)
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	if (netif_running(netdev))
-		e1000e_down(adapter, true);
 	pci_disable_device(pdev);
 
 	/* Request a slot slot reset. */
@@ -6893,10 +6897,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
 
 	e1000_init_manageability_pt(adapter);
 
-	if (netif_running(netdev))
-		e1000e_up(adapter);
-
-	netif_device_attach(netdev);
+	e1000e_pm_thaw(&pdev->dev);
 
 	/* If the controller has AMT, do not set DRV_LOAD until the interface
 	 * is up.  For all other cases, let the f/w know that the h/w is now

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
> >From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
> 
> I'm putting this out as an RFC for now. I haven't had a chance to do much
> testing yet, but I have verified no build issues, and the driver appears
> to load, link, and pass traffic without problems.
> 
> This should address issues seen with either double freeing or never freeing
> IRQs that have been seen on this and similar drivers in the past.
> 
> I'll submit this formally after testing it over the weekend assuming there
> are no issues.
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
>  1 file changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..182a2c8f12d8 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
>  	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
>  		e1000e_down(adapter, true);
>  		e1000_free_irq(adapter);
> 
>  		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
>  	}
> 
>  	napi_disable(&adapter->napi);
> @@ -6299,6 +6299,7 @@ static int e1000e_pm_freeze(struct device *dev)
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> 
> +	rtnl_lock();
>  	netif_device_detach(netdev);
> 
>  	if (netif_running(netdev)) {
> @@ -6313,6 +6314,8 @@ static int e1000e_pm_freeze(struct device *dev)
>  		e1000e_down(adapter, false);
>  		e1000_free_irq(adapter);
>  	}
> +	rtnl_unlock();
> +
>  	e1000e_reset_interrupt_capability(adapter);
> 
>  	/* Allow time for pending master requests to run */
> @@ -6626,27 +6629,30 @@ static int __e1000_resume(struct pci_dev *pdev)
>  	return 0;
>  }
> 
> -#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_thaw(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
>  	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
>  		e1000e_up(adapter);
>  	}
> 
>  	netif_device_attach(netdev);
> -
> -	return 0;
> +	rtnl_unlock();
> +err_irq:
> +	return rc;
>  }
> 
> +#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_suspend(struct device *dev)
>  {
>  	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6821,13 +6827,11 @@ static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
>  	struct net_device *netdev = pci_get_drvdata(pdev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> 
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
>  	if (state == pci_channel_io_perm_failure)
>  		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
>  	pci_disable_device(pdev);
> 
>  	/* Request a slot slot reset. */
> @@ -6893,10 +6897,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
>  	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
>  	/* If the controller has AMT, do not set DRV_LOAD until the interface
>  	 * is up.  For all other cases, let the f/w know that the h/w is now
In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
deadlock.
from:
+       rtnl_unlock();
+err_irq:

to:
+err_irq:
+       rtnl_unlock();

I will find hardware to test this patch next week. Will update the test
result later.

Thanks! - David

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
> >From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
> 
> I'm putting this out as an RFC for now. I haven't had a chance to do much
> testing yet, but I have verified no build issues, and the driver appears
> to load, link, and pass traffic without problems.
> 
> This should address issues seen with either double freeing or never freeing
> IRQs that have been seen on this and similar drivers in the past.
> 
> I'll submit this formally after testing it over the weekend assuming there
> are no issues.
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
>  1 file changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..182a2c8f12d8 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
>  	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
>  		e1000e_down(adapter, true);
>  		e1000_free_irq(adapter);
> 
>  		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
>  	}
> 
>  	napi_disable(&adapter->napi);
> @@ -6299,6 +6299,7 @@ static int e1000e_pm_freeze(struct device *dev)
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> 
> +	rtnl_lock();
>  	netif_device_detach(netdev);
> 
>  	if (netif_running(netdev)) {
> @@ -6313,6 +6314,8 @@ static int e1000e_pm_freeze(struct device *dev)
>  		e1000e_down(adapter, false);
>  		e1000_free_irq(adapter);
>  	}
> +	rtnl_unlock();
> +
>  	e1000e_reset_interrupt_capability(adapter);
> 
>  	/* Allow time for pending master requests to run */
> @@ -6626,27 +6629,30 @@ static int __e1000_resume(struct pci_dev *pdev)
>  	return 0;
>  }
> 
> -#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_thaw(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
>  	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
>  		e1000e_up(adapter);
>  	}
> 
>  	netif_device_attach(netdev);
> -
> -	return 0;
> +	rtnl_unlock();
> +err_irq:
> +	return rc;
>  }
> 
> +#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_suspend(struct device *dev)
>  {
>  	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6821,13 +6827,11 @@ static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
>  	struct net_device *netdev = pci_get_drvdata(pdev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> 
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
>  	if (state == pci_channel_io_perm_failure)
>  		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
>  	pci_disable_device(pdev);
> 
>  	/* Request a slot slot reset. */
> @@ -6893,10 +6897,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
>  	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
>  	/* If the controller has AMT, do not set DRV_LOAD until the interface
>  	 * is up.  For all other cases, let the f/w know that the h/w is now
In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
deadlock.
from:
+       rtnl_unlock();
+err_irq:

to:
+err_irq:
+       rtnl_unlock();

I will find hardware to test this patch next week. Will update the test
result later.

Thanks! - David

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Fri, Oct 4, 2019 at 7:18 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > This patch is meant to address possible race conditions that can exist
> > between network configuration and power management. A similar issue was
> > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > netif_device_detach").
> >
> > In addition it consolidates the code so that the PCI error handling code
> > will essentially perform the power management freeze on the device prior to
> > attempting a reset, and will thaw the device afterwards if that is what it
> > is planning to do. Otherwise when we call close on the interface it should
> > see it is detached and not attempt to call the logic to down the interface
> > and free the IRQs again.
> >
> > >From what I can tell the check that was adding the check for __E1000_DOWN
> > in e1000e_close was added when runtime power management was added. However
> > it should not be relevant for us as we perform a call to
> > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > be back up before we call into this anyway.
> >
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > ---
> >
> > I'm putting this out as an RFC for now. I haven't had a chance to do much
> > testing yet, but I have verified no build issues, and the driver appears
> > to load, link, and pass traffic without problems.
> >
> > This should address issues seen with either double freeing or never freeing
> > IRQs that have been seen on this and similar drivers in the past.
> >
> > I'll submit this formally after testing it over the weekend assuming there
> > are no issues.
> >
> >  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
> >  1 file changed, 17 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index d7d56e42a6aa..182a2c8f12d8 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c

<snip>

> >
> > -#ifdef CONFIG_PM_SLEEP
> >  static int e1000e_pm_thaw(struct device *dev)
> >  {
> >       struct net_device *netdev = dev_get_drvdata(dev);
> >       struct e1000_adapter *adapter = netdev_priv(netdev);
> > +     int rc = 0;
> >
> >       e1000e_set_interrupt_capability(adapter);
> > -     if (netif_running(netdev)) {
> > -             u32 err = e1000_request_irq(adapter);
> >
> > -             if (err)
> > -                     return err;
> > +     rtnl_lock();
> > +     if (netif_running(netdev)) {
> > +             rc = e1000_request_irq(adapter);
> > +             if (rc)
> > +                     goto err_irq;
> >
> >               e1000e_up(adapter);
> >       }
> >
> >       netif_device_attach(netdev);
> > -
> > -     return 0;
> > +     rtnl_unlock();
> > +err_irq:
> > +     return rc;
> >  }
> >
> In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
> deadlock.
> from:
> +       rtnl_unlock();
> +err_irq:
>
> to:
> +err_irq:
> +       rtnl_unlock();
>
> I will find hardware to test this patch next week. Will update the test
> result later.
>
> Thanks! - David

Thanks for spotting that. I will update my copy of the patch for when
I submit the final revision.

I'll probably wait to submit it for acceptance until you have had a
chance to verify that it resolves the issue you were seeing.

Thanks.

- Alex

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Fri, Oct 4, 2019 at 7:18 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > This patch is meant to address possible race conditions that can exist
> > between network configuration and power management. A similar issue was
> > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > netif_device_detach").
> >
> > In addition it consolidates the code so that the PCI error handling code
> > will essentially perform the power management freeze on the device prior to
> > attempting a reset, and will thaw the device afterwards if that is what it
> > is planning to do. Otherwise when we call close on the interface it should
> > see it is detached and not attempt to call the logic to down the interface
> > and free the IRQs again.
> >
> > >From what I can tell the check that was adding the check for __E1000_DOWN
> > in e1000e_close was added when runtime power management was added. However
> > it should not be relevant for us as we perform a call to
> > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > be back up before we call into this anyway.
> >
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > ---
> >
> > I'm putting this out as an RFC for now. I haven't had a chance to do much
> > testing yet, but I have verified no build issues, and the driver appears
> > to load, link, and pass traffic without problems.
> >
> > This should address issues seen with either double freeing or never freeing
> > IRQs that have been seen on this and similar drivers in the past.
> >
> > I'll submit this formally after testing it over the weekend assuming there
> > are no issues.
> >
> >  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
> >  1 file changed, 17 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index d7d56e42a6aa..182a2c8f12d8 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c

<snip>

> >
> > -#ifdef CONFIG_PM_SLEEP
> >  static int e1000e_pm_thaw(struct device *dev)
> >  {
> >       struct net_device *netdev = dev_get_drvdata(dev);
> >       struct e1000_adapter *adapter = netdev_priv(netdev);
> > +     int rc = 0;
> >
> >       e1000e_set_interrupt_capability(adapter);
> > -     if (netif_running(netdev)) {
> > -             u32 err = e1000_request_irq(adapter);
> >
> > -             if (err)
> > -                     return err;
> > +     rtnl_lock();
> > +     if (netif_running(netdev)) {
> > +             rc = e1000_request_irq(adapter);
> > +             if (rc)
> > +                     goto err_irq;
> >
> >               e1000e_up(adapter);
> >       }
> >
> >       netif_device_attach(netdev);
> > -
> > -     return 0;
> > +     rtnl_unlock();
> > +err_irq:
> > +     return rc;
> >  }
> >
> In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
> deadlock.
> from:
> +       rtnl_unlock();
> +err_irq:
>
> to:
> +err_irq:
> +       rtnl_unlock();
>
> I will find hardware to test this patch next week. Will update the test
> result later.
>
> Thanks! - David

Thanks for spotting that. I will update my copy of the patch for when
I submit the final revision.

I'll probably wait to submit it for acceptance until you have had a
chance to verify that it resolves the issue you were seeing.

Thanks.

- Alex

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Sat, 2019-10-05 at 10:22 -0700, Alexander Duyck wrote:
> On Fri, Oct 4, 2019 at 7:18 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> > > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > >
> > > This patch is meant to address possible race conditions that can exist
> > > between network configuration and power management. A similar issue was
> > > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > > netif_device_detach").
> > >
> > > In addition it consolidates the code so that the PCI error handling code
> > > will essentially perform the power management freeze on the device prior to
> > > attempting a reset, and will thaw the device afterwards if that is what it
> > > is planning to do. Otherwise when we call close on the interface it should
> > > see it is detached and not attempt to call the logic to down the interface
> > > and free the IRQs again.
> > >
> > > >From what I can tell the check that was adding the check for __E1000_DOWN
> > > in e1000e_close was added when runtime power management was added. However
> > > it should not be relevant for us as we perform a call to
> > > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > > be back up before we call into this anyway.
> > >
> > > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > > ---
> > >
> > > I'm putting this out as an RFC for now. I haven't had a chance to do much
> > > testing yet, but I have verified no build issues, and the driver appears
> > > to load, link, and pass traffic without problems.
> > >
> > > This should address issues seen with either double freeing or never freeing
> > > IRQs that have been seen on this and similar drivers in the past.
> > >
> > > I'll submit this formally after testing it over the weekend assuming there
> > > are no issues.
> > >
> > >  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
> > >  1 file changed, 17 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > index d7d56e42a6aa..182a2c8f12d8 100644
> > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> 
> <snip>
> 
> > >
> > > -#ifdef CONFIG_PM_SLEEP
> > >  static int e1000e_pm_thaw(struct device *dev)
> > >  {
> > >       struct net_device *netdev = dev_get_drvdata(dev);
> > >       struct e1000_adapter *adapter = netdev_priv(netdev);
> > > +     int rc = 0;
> > >
> > >       e1000e_set_interrupt_capability(adapter);
> > > -     if (netif_running(netdev)) {
> > > -             u32 err = e1000_request_irq(adapter);
> > >
> > > -             if (err)
> > > -                     return err;
> > > +     rtnl_lock();
> > > +     if (netif_running(netdev)) {
> > > +             rc = e1000_request_irq(adapter);
> > > +             if (rc)
> > > +                     goto err_irq;
> > >
> > >               e1000e_up(adapter);
> > >       }
> > >
> > >       netif_device_attach(netdev);
> > > -
> > > -     return 0;
> > > +     rtnl_unlock();
> > > +err_irq:
> > > +     return rc;
> > >  }
> > >
> > In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
> > deadlock.
> > from:
> > +       rtnl_unlock();
> > +err_irq:
> >
> > to:
> > +err_irq:
> > +       rtnl_unlock();
> >
> > I will find hardware to test this patch next week. Will update the test
> > result later.
> >
> > Thanks! - David
> 
> Thanks for spotting that. I will update my copy of the patch for when
> I submit the final revision.
> 
> I'll probably wait to submit it for acceptance until you have had a
> chance to verify that it resolves the issue you were seeing.
> 
> Thanks.
> 
> - Alex
We have tested on one of the test box.
With this patch, it doesn't crash kernel anymore, which is good!

However we see this warning message from the log file for irq number 0:
[10206.317270] Trying to free already-free IRQ 0

With this stack:
[10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
[10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
[10206.317347] Call Trace:
[10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
+0x304/0x370 (unreliable)
[10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
[10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
+0x98/0xc0 [e1000e]
[10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
+0xb8/0x100 [e1000e]
[10206.317372] [c00000008b92baa0] [d000000007458b6c]
e1000_io_error_detected+0x34/0x70 [e1000e]
[10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
+0xc8/0x190
[10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
+0x9c/0x170
[10206.317379] [c00000008b92bbb0] [c000000000040d84]
eeh_handle_normal_event+0xe4/0x580
[10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
+0x30/0x340
[10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
+0x140/0x200
[10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
[10206.317389] [c00000008b92be30] [c00000000000b560]
ret_from_kernel_thread+0x5c/0x7c

Thanks! - David

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Sat, 2019-10-05 at 10:22 -0700, Alexander Duyck wrote:
> On Fri, Oct 4, 2019 at 7:18 PM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> > On Fri, 2019-10-04 at 16:36 -0700, Alexander Duyck wrote:
> > > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > >
> > > This patch is meant to address possible race conditions that can exist
> > > between network configuration and power management. A similar issue was
> > > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > > netif_device_detach").
> > >
> > > In addition it consolidates the code so that the PCI error handling code
> > > will essentially perform the power management freeze on the device prior to
> > > attempting a reset, and will thaw the device afterwards if that is what it
> > > is planning to do. Otherwise when we call close on the interface it should
> > > see it is detached and not attempt to call the logic to down the interface
> > > and free the IRQs again.
> > >
> > > >From what I can tell the check that was adding the check for __E1000_DOWN
> > > in e1000e_close was added when runtime power management was added. However
> > > it should not be relevant for us as we perform a call to
> > > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > > be back up before we call into this anyway.
> > >
> > > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > > ---
> > >
> > > I'm putting this out as an RFC for now. I haven't had a chance to do much
> > > testing yet, but I have verified no build issues, and the driver appears
> > > to load, link, and pass traffic without problems.
> > >
> > > This should address issues seen with either double freeing or never freeing
> > > IRQs that have been seen on this and similar drivers in the past.
> > >
> > > I'll submit this formally after testing it over the weekend assuming there
> > > are no issues.
> > >
> > >  drivers/net/ethernet/intel/e1000e/netdev.c |   33 ++++++++++++++--------------
> > >  1 file changed, 17 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > index d7d56e42a6aa..182a2c8f12d8 100644
> > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> 
> <snip>
> 
> > >
> > > -#ifdef CONFIG_PM_SLEEP
> > >  static int e1000e_pm_thaw(struct device *dev)
> > >  {
> > >       struct net_device *netdev = dev_get_drvdata(dev);
> > >       struct e1000_adapter *adapter = netdev_priv(netdev);
> > > +     int rc = 0;
> > >
> > >       e1000e_set_interrupt_capability(adapter);
> > > -     if (netif_running(netdev)) {
> > > -             u32 err = e1000_request_irq(adapter);
> > >
> > > -             if (err)
> > > -                     return err;
> > > +     rtnl_lock();
> > > +     if (netif_running(netdev)) {
> > > +             rc = e1000_request_irq(adapter);
> > > +             if (rc)
> > > +                     goto err_irq;
> > >
> > >               e1000e_up(adapter);
> > >       }
> > >
> > >       netif_device_attach(netdev);
> > > -
> > > -     return 0;
> > > +     rtnl_unlock();
> > > +err_irq:
> > > +     return rc;
> > >  }
> > >
> > In e1000e_pm_thaw(), these 2 lines need to switch order to avoid
> > deadlock.
> > from:
> > +       rtnl_unlock();
> > +err_irq:
> >
> > to:
> > +err_irq:
> > +       rtnl_unlock();
> >
> > I will find hardware to test this patch next week. Will update the test
> > result later.
> >
> > Thanks! - David
> 
> Thanks for spotting that. I will update my copy of the patch for when
> I submit the final revision.
> 
> I'll probably wait to submit it for acceptance until you have had a
> chance to verify that it resolves the issue you were seeing.
> 
> Thanks.
> 
> - Alex
We have tested on one of the test box.
With this patch, it doesn't crash kernel anymore, which is good!

However we see this warning message from the log file for irq number 0:
[10206.317270] Trying to free already-free IRQ 0

With this stack:
[10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
[10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
[10206.317347] Call Trace:
[10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
+0x304/0x370 (unreliable)
[10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
[10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
+0x98/0xc0 [e1000e]
[10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
+0xb8/0x100 [e1000e]
[10206.317372] [c00000008b92baa0] [d000000007458b6c]
e1000_io_error_detected+0x34/0x70 [e1000e]
[10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
+0xc8/0x190
[10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
+0x9c/0x170
[10206.317379] [c00000008b92bbb0] [c000000000040d84]
eeh_handle_normal_event+0xe4/0x580
[10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
+0x30/0x340
[10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
+0x140/0x200
[10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
[10206.317389] [c00000008b92be30] [c00000000000b560]
ret_from_kernel_thread+0x5c/0x7c

Thanks! - David

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>

<snip>

> We have tested on one of the test box.
> With this patch, it doesn't crash kernel anymore, which is good!
>
> However we see this warning message from the log file for irq number 0:
> [10206.317270] Trying to free already-free IRQ 0
>
> With this stack:
> [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> [10206.317347] Call Trace:
> [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> +0x304/0x370 (unreliable)
> [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> +0x98/0xc0 [e1000e]
> [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> +0xb8/0x100 [e1000e]
> [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> e1000_io_error_detected+0x34/0x70 [e1000e]
> [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> +0xc8/0x190
> [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> +0x9c/0x170
> [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> eeh_handle_normal_event+0xe4/0x580
> [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> +0x30/0x340
> [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> +0x140/0x200
> [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> [10206.317389] [c00000008b92be30] [c00000000000b560]
> ret_from_kernel_thread+0x5c/0x7c
>
> Thanks! - David

Hmm. I wonder if it is possibly calling the report
e1000_io_error_detected multiple times. If so then the secondary calls
to e1000_pm_freeze would cause issues.

I will add a check so that we only down the interface and free the
IRQs if the interface is in the present and running state.

I'll submit an update patch shortly.

Thanks.

- Alex

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>

<snip>

> We have tested on one of the test box.
> With this patch, it doesn't crash kernel anymore, which is good!
>
> However we see this warning message from the log file for irq number 0:
> [10206.317270] Trying to free already-free IRQ 0
>
> With this stack:
> [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> [10206.317347] Call Trace:
> [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> +0x304/0x370 (unreliable)
> [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> +0x98/0xc0 [e1000e]
> [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> +0xb8/0x100 [e1000e]
> [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> e1000_io_error_detected+0x34/0x70 [e1000e]
> [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> +0xc8/0x190
> [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> +0x9c/0x170
> [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> eeh_handle_normal_event+0xe4/0x580
> [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> +0x30/0x340
> [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> +0x140/0x200
> [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> [10206.317389] [c00000008b92be30] [c00000000000b560]
> ret_from_kernel_thread+0x5c/0x7c
>
> Thanks! - David

Hmm. I wonder if it is possibly calling the report
e1000_io_error_detected multiple times. If so then the secondary calls
to e1000_pm_freeze would cause issues.

I will add a check so that we only down the interface and free the
IRQs if the interface is in the present and running state.

I'll submit an update patch shortly.

Thanks.

- Alex

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Mon, 2019-10-07 at 10:02 -0700, Alexander Duyck wrote:
> On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> 
> <snip>
> 
> > We have tested on one of the test box.
> > With this patch, it doesn't crash kernel anymore, which is good!
> >
> > However we see this warning message from the log file for irq number 0:
> > [10206.317270] Trying to free already-free IRQ 0
> >
> > With this stack:
> > [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> > [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> > [10206.317347] Call Trace:
> > [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> > +0x304/0x370 (unreliable)
> > [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> > [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> > +0x98/0xc0 [e1000e]
> > [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> > +0xb8/0x100 [e1000e]
> > [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> > e1000_io_error_detected+0x34/0x70 [e1000e]
> > [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> > +0xc8/0x190
> > [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> > +0x9c/0x170
> > [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> > eeh_handle_normal_event+0xe4/0x580
> > [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> > +0x30/0x340
> > [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> > +0x140/0x200
> > [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> > [10206.317389] [c00000008b92be30] [c00000000000b560]
> > ret_from_kernel_thread+0x5c/0x7c
> >
> > Thanks! - David
> 
> Hmm. I wonder if it is possibly calling the report
> e1000_io_error_detected multiple times. If so then the secondary calls
> to e1000_pm_freeze would cause issues.
> 
> I will add a check so that we only down the interface and free the
> IRQs if the interface is in the present and running state.
> 
> I'll submit an update patch shortly.
> 
> Thanks.
> 
> - Alex
It only complains about IRQ number 0 in the log.
Could you please let me know the actual place where you will add the
check?
I can retest it again.

Thanks! - David

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Mon, 2019-10-07 at 10:02 -0700, Alexander Duyck wrote:
> On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> >
> 
> <snip>
> 
> > We have tested on one of the test box.
> > With this patch, it doesn't crash kernel anymore, which is good!
> >
> > However we see this warning message from the log file for irq number 0:
> > [10206.317270] Trying to free already-free IRQ 0
> >
> > With this stack:
> > [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> > [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> > [10206.317347] Call Trace:
> > [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> > +0x304/0x370 (unreliable)
> > [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> > [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> > +0x98/0xc0 [e1000e]
> > [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> > +0xb8/0x100 [e1000e]
> > [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> > e1000_io_error_detected+0x34/0x70 [e1000e]
> > [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> > +0xc8/0x190
> > [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> > +0x9c/0x170
> > [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> > eeh_handle_normal_event+0xe4/0x580
> > [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> > +0x30/0x340
> > [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> > +0x140/0x200
> > [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> > [10206.317389] [c00000008b92be30] [c00000000000b560]
> > ret_from_kernel_thread+0x5c/0x7c
> >
> > Thanks! - David
> 
> Hmm. I wonder if it is possibly calling the report
> e1000_io_error_detected multiple times. If so then the secondary calls
> to e1000_pm_freeze would cause issues.
> 
> I will add a check so that we only down the interface and free the
> IRQs if the interface is in the present and running state.
> 
> I'll submit an update patch shortly.
> 
> Thanks.
> 
> - Alex
It only complains about IRQ number 0 in the log.
Could you please let me know the actual place where you will add the
check?
I can retest it again.

Thanks! - David

[Intel-wired-lan] [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Mon, Oct 7, 2019 at 10:12 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Mon, 2019-10-07 at 10:02 -0700, Alexander Duyck wrote:
> > On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> >
> > <snip>
> >
> > > We have tested on one of the test box.
> > > With this patch, it doesn't crash kernel anymore, which is good!
> > >
> > > However we see this warning message from the log file for irq number 0:
> > > [10206.317270] Trying to free already-free IRQ 0
> > >
> > > With this stack:
> > > [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> > > [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> > > [10206.317347] Call Trace:
> > > [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> > > +0x304/0x370 (unreliable)
> > > [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> > > [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> > > +0x98/0xc0 [e1000e]
> > > [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> > > +0xb8/0x100 [e1000e]
> > > [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> > > e1000_io_error_detected+0x34/0x70 [e1000e]
> > > [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> > > +0xc8/0x190
> > > [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> > > +0x9c/0x170
> > > [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> > > eeh_handle_normal_event+0xe4/0x580
> > > [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> > > +0x30/0x340
> > > [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> > > +0x140/0x200
> > > [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> > > [10206.317389] [c00000008b92be30] [c00000000000b560]
> > > ret_from_kernel_thread+0x5c/0x7c
> > >
> > > Thanks! - David
> >
> > Hmm. I wonder if it is possibly calling the report
> > e1000_io_error_detected multiple times. If so then the secondary calls
> > to e1000_pm_freeze would cause issues.
> >
> > I will add a check so that we only down the interface and free the
> > IRQs if the interface is in the present and running state.
> >
> > I'll submit an update patch shortly.
> >
> > Thanks.
> >
> > - Alex
> It only complains about IRQ number 0 in the log.

I suspect that is because the IRQ is already freed. So there are no
other interrupts enabled and it thinks it is running in legacy IRQ
mode.

> Could you please let me know the actual place where you will add the
> check?
> I can retest it again.
>
> Thanks! - David

So I will need to add another variable called "present" to
e1000_pm_freeze, I will assign netif_device_present() to it after
taking the rtnl_lock and before I detach the interface, and will test
for it and netif_running() before calling the logic that calls
e1000_down and e1000_free_irq.

- Alex

Re: [RFC PATCH] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

On Mon, Oct 7, 2019 at 10:12 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
>
> On Mon, 2019-10-07 at 10:02 -0700, Alexander Duyck wrote:
> > On Mon, Oct 7, 2019 at 8:51 AM David Z. Dai <zdai@linux.vnet.ibm.com> wrote:
> > >
> >
> > <snip>
> >
> > > We have tested on one of the test box.
> > > With this patch, it doesn't crash kernel anymore, which is good!
> > >
> > > However we see this warning message from the log file for irq number 0:
> > > [10206.317270] Trying to free already-free IRQ 0
> > >
> > > With this stack:
> > > [10206.317344] NIP [c00000000018cbf8] __free_irq+0x308/0x370
> > > [10206.317346] LR [c00000000018cbf4] __free_irq+0x304/0x370
> > > [10206.317347] Call Trace:
> > > [10206.317348] [c00000008b92b970] [c00000000018cbf4] __free_irq
> > > +0x304/0x370 (unreliable)
> > > [10206.317351] [c00000008b92ba00] [c00000000018cd84] free_irq+0x84/0xf0
> > > [10206.317358] [c00000008b92ba30] [d000000007449e60] e1000_free_irq
> > > +0x98/0xc0 [e1000e]
> > > [10206.317365] [c00000008b92ba60] [d000000007458a70] e1000e_pm_freeze
> > > +0xb8/0x100 [e1000e]
> > > [10206.317372] [c00000008b92baa0] [d000000007458b6c]
> > > e1000_io_error_detected+0x34/0x70 [e1000e]
> > > [10206.317375] [c00000008b92bad0] [c000000000040358] eeh_report_failure
> > > +0xc8/0x190
> > > [10206.317377] [c00000008b92bb20] [c00000000003eb2c] eeh_pe_dev_traverse
> > > +0x9c/0x170
> > > [10206.317379] [c00000008b92bbb0] [c000000000040d84]
> > > eeh_handle_normal_event+0xe4/0x580
> > > [10206.317382] [c00000008b92bc60] [c000000000041330] eeh_handle_event
> > > +0x30/0x340
> > > [10206.317384] [c00000008b92bd10] [c000000000041780] eeh_event_handler
> > > +0x140/0x200
> > > [10206.317386] [c00000008b92bdc0] [c0000000001397c8] kthread+0x1a8/0x1b0
> > > [10206.317389] [c00000008b92be30] [c00000000000b560]
> > > ret_from_kernel_thread+0x5c/0x7c
> > >
> > > Thanks! - David
> >
> > Hmm. I wonder if it is possibly calling the report
> > e1000_io_error_detected multiple times. If so then the secondary calls
> > to e1000_pm_freeze would cause issues.
> >
> > I will add a check so that we only down the interface and free the
> > IRQs if the interface is in the present and running state.
> >
> > I'll submit an update patch shortly.
> >
> > Thanks.
> >
> > - Alex
> It only complains about IRQ number 0 in the log.

I suspect that is because the IRQ is already freed. So there are no
other interrupts enabled and it thinks it is running in legacy IRQ
mode.

> Could you please let me know the actual place where you will add the
> check?
> I can retest it again.
>
> Thanks! - David

So I will need to add another variable called "present" to
e1000_pm_freeze, I will assign netif_device_present() to it after
taking the rtnl_lock and before I detach the interface, and will test
for it and netif_running() before calling the logic that calls
e1000_down and e1000_free_irq.

- Alex

[Intel-wired-lan] [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

This patch is meant to address possible race conditions that can exist
between network configuration and power management. A similar issue was
fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
netif_device_detach").

In addition it consolidates the code so that the PCI error handling code
will essentially perform the power management freeze on the device prior to
attempting a reset, and will thaw the device afterwards if that is what it
is planning to do. Otherwise when we call close on the interface it should
see it is detached and not attempt to call the logic to down the interface
and free the IRQs again.

From what I can tell the check that was adding the check for __E1000_DOWN
in e1000e_close was added when runtime power management was added. However
it should not be relevant for us as we perform a call to
pm_runtime_get_sync before we call e1000_down/free_irq so it should always
be back up before we call into this anyway.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---

RFC v2: Dropped some unused variables
	Added logic to check for device present before removing to pm_freeze
	Fixed misplaced err_irq to before rtnl_unlock()

 drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e42a6aa..8b4e589aca36 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (netif_device_present(netdev)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
 		/* Link status message must follow this format */
-		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
+		pr_info("%s NIC Link is Down\n", netdev->name);
 	}
 
 	napi_disable(&adapter->napi);
@@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	bool present;
 
+	rtnl_lock();
+
+	present = netif_device_present(netdev);
 	netif_device_detach(netdev);
 
-	if (netif_running(netdev)) {
+	if (present && netif_running(netdev)) {
 		int count = E1000_CHECK_RESET_COUNT;
 
 		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
@@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
 		e1000e_down(adapter, false);
 		e1000_free_irq(adapter);
 	}
+	rtnl_unlock();
+
 	e1000e_reset_interrupt_capability(adapter);
 
 	/* Allow time for pending master requests to run */
@@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_thaw(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	int rc = 0;
 
 	e1000e_set_interrupt_capability(adapter);
-	if (netif_running(netdev)) {
-		u32 err = e1000_request_irq(adapter);
 
-		if (err)
-			return err;
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		rc = e1000_request_irq(adapter);
+		if (rc)
+			goto err_irq;
 
 		e1000e_up(adapter);
 	}
 
 	netif_device_attach(netdev);
+err_irq:
+	rtnl_unlock();
 
-	return 0;
+	return rc;
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
 static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
 						pci_channel_state_t state)
 {
-	struct net_device *netdev = pci_get_drvdata(pdev);
-	struct e1000_adapter *adapter = netdev_priv(netdev);
-
-	netif_device_detach(netdev);
+	e1000e_pm_freeze(&pdev->dev);
 
 	if (state == pci_channel_io_perm_failure)
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	if (netif_running(netdev))
-		e1000e_down(adapter, true);
 	pci_disable_device(pdev);
 
 	/* Request a slot slot reset. */
@@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
 
 	e1000_init_manageability_pt(adapter);
 
-	if (netif_running(netdev))
-		e1000e_up(adapter);
-
-	netif_device_attach(netdev);
+	e1000e_pm_thaw(&pdev->dev);
 
 	/* If the controller has AMT, do not set DRV_LOAD until the interface
 	 * is up.  For all other cases, let the f/w know that the h/w is now

[RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Alexander Duyck]

From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

This patch is meant to address possible race conditions that can exist
between network configuration and power management. A similar issue was
fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
netif_device_detach").

In addition it consolidates the code so that the PCI error handling code
will essentially perform the power management freeze on the device prior to
attempting a reset, and will thaw the device afterwards if that is what it
is planning to do. Otherwise when we call close on the interface it should
see it is detached and not attempt to call the logic to down the interface
and free the IRQs again.

>From what I can tell the check that was adding the check for __E1000_DOWN
in e1000e_close was added when runtime power management was added. However
it should not be relevant for us as we perform a call to
pm_runtime_get_sync before we call e1000_down/free_irq so it should always
be back up before we call into this anyway.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---

RFC v2: Dropped some unused variables
	Added logic to check for device present before removing to pm_freeze
	Fixed misplaced err_irq to before rtnl_unlock()

 drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index d7d56e42a6aa..8b4e589aca36 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
 
 	pm_runtime_get_sync(&pdev->dev);
 
-	if (!test_bit(__E1000_DOWN, &adapter->state)) {
+	if (netif_device_present(netdev)) {
 		e1000e_down(adapter, true);
 		e1000_free_irq(adapter);
 
 		/* Link status message must follow this format */
-		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
+		pr_info("%s NIC Link is Down\n", netdev->name);
 	}
 
 	napi_disable(&adapter->napi);
@@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	bool present;
 
+	rtnl_lock();
+
+	present = netif_device_present(netdev);
 	netif_device_detach(netdev);
 
-	if (netif_running(netdev)) {
+	if (present && netif_running(netdev)) {
 		int count = E1000_CHECK_RESET_COUNT;
 
 		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
@@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
 		e1000e_down(adapter, false);
 		e1000_free_irq(adapter);
 	}
+	rtnl_unlock();
+
 	e1000e_reset_interrupt_capability(adapter);
 
 	/* Allow time for pending master requests to run */
@@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_thaw(struct device *dev)
 {
 	struct net_device *netdev = dev_get_drvdata(dev);
 	struct e1000_adapter *adapter = netdev_priv(netdev);
+	int rc = 0;
 
 	e1000e_set_interrupt_capability(adapter);
-	if (netif_running(netdev)) {
-		u32 err = e1000_request_irq(adapter);
 
-		if (err)
-			return err;
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		rc = e1000_request_irq(adapter);
+		if (rc)
+			goto err_irq;
 
 		e1000e_up(adapter);
 	}
 
 	netif_device_attach(netdev);
+err_irq:
+	rtnl_unlock();
 
-	return 0;
+	return rc;
 }
 
+#ifdef CONFIG_PM_SLEEP
 static int e1000e_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
 static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
 						pci_channel_state_t state)
 {
-	struct net_device *netdev = pci_get_drvdata(pdev);
-	struct e1000_adapter *adapter = netdev_priv(netdev);
-
-	netif_device_detach(netdev);
+	e1000e_pm_freeze(&pdev->dev);
 
 	if (state == pci_channel_io_perm_failure)
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	if (netif_running(netdev))
-		e1000e_down(adapter, true);
 	pci_disable_device(pdev);
 
 	/* Request a slot slot reset. */
@@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
 
 	e1000_init_manageability_pt(adapter);
 
-	if (netif_running(netdev))
-		e1000e_up(adapter);
-
-	netif_device_attach(netdev);
+	e1000e_pm_thaw(&pdev->dev);
 
 	/* If the controller has AMT, do not set DRV_LOAD until the interface
 	 * is up.  For all other cases, let the f/w know that the h/w is now

[Intel-wired-lan] [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Mon, 2019-10-07 at 10:27 -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
> >From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
> 
> RFC v2: Dropped some unused variables
> 	Added logic to check for device present before removing to pm_freeze
> 	Fixed misplaced err_irq to before rtnl_unlock()
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
>  1 file changed, 21 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..8b4e589aca36 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
>  	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
>  		e1000e_down(adapter, true);
>  		e1000_free_irq(adapter);
> 
>  		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
>  	}
> 
>  	napi_disable(&adapter->napi);
> @@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	bool present;
> 
> +	rtnl_lock();
> +
> +	present = netif_device_present(netdev);
>  	netif_device_detach(netdev);
> 
> -	if (netif_running(netdev)) {
> +	if (present && netif_running(netdev)) {
>  		int count = E1000_CHECK_RESET_COUNT;
> 
>  		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
> @@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
>  		e1000e_down(adapter, false);
>  		e1000_free_irq(adapter);
>  	}
> +	rtnl_unlock();
> +
>  	e1000e_reset_interrupt_capability(adapter);
> 
>  	/* Allow time for pending master requests to run */
> @@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
>  	return 0;
>  }
> 
> -#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_thaw(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
>  	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
>  		e1000e_up(adapter);
>  	}
> 
>  	netif_device_attach(netdev);
> +err_irq:
> +	rtnl_unlock();
> 
> -	return 0;
> +	return rc;
>  }
> 
> +#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_suspend(struct device *dev)
>  {
>  	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
>  static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
>  						pci_channel_state_t state)
>  {
> -	struct net_device *netdev = pci_get_drvdata(pdev);
> -	struct e1000_adapter *adapter = netdev_priv(netdev);
> -
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
>  	if (state == pci_channel_io_perm_failure)
>  		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
>  	pci_disable_device(pdev);
> 
>  	/* Request a slot slot reset. */
> @@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
>  	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
>  	/* If the controller has AMT, do not set DRV_LOAD until the interface
>  	 * is up.  For all other cases, let the f/w know that the h/w is now
> 
Tested this v2 version patch. There is no more crash, which is good.
And It also eliminates the double free warning message.
This patch is good to go.

Thanks! - David

Re: [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[David Z. Dai]

On Mon, 2019-10-07 at 10:27 -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
> >From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
> 
> RFC v2: Dropped some unused variables
> 	Added logic to check for device present before removing to pm_freeze
> 	Fixed misplaced err_irq to before rtnl_unlock()
> 
>  drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
>  1 file changed, 21 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..8b4e589aca36 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
>  	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
>  		e1000e_down(adapter, true);
>  		e1000_free_irq(adapter);
> 
>  		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
>  	}
> 
>  	napi_disable(&adapter->napi);
> @@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	bool present;
> 
> +	rtnl_lock();
> +
> +	present = netif_device_present(netdev);
>  	netif_device_detach(netdev);
> 
> -	if (netif_running(netdev)) {
> +	if (present && netif_running(netdev)) {
>  		int count = E1000_CHECK_RESET_COUNT;
> 
>  		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
> @@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
>  		e1000e_down(adapter, false);
>  		e1000_free_irq(adapter);
>  	}
> +	rtnl_unlock();
> +
>  	e1000e_reset_interrupt_capability(adapter);
> 
>  	/* Allow time for pending master requests to run */
> @@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
>  	return 0;
>  }
> 
> -#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_thaw(struct device *dev)
>  {
>  	struct net_device *netdev = dev_get_drvdata(dev);
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
>  	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
>  		e1000e_up(adapter);
>  	}
> 
>  	netif_device_attach(netdev);
> +err_irq:
> +	rtnl_unlock();
> 
> -	return 0;
> +	return rc;
>  }
> 
> +#ifdef CONFIG_PM_SLEEP
>  static int e1000e_pm_suspend(struct device *dev)
>  {
>  	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
>  static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
>  						pci_channel_state_t state)
>  {
> -	struct net_device *netdev = pci_get_drvdata(pdev);
> -	struct e1000_adapter *adapter = netdev_priv(netdev);
> -
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
>  	if (state == pci_channel_io_perm_failure)
>  		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
>  	pci_disable_device(pdev);
> 
>  	/* Request a slot slot reset. */
> @@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
>  	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
>  	/* If the controller has AMT, do not set DRV_LOAD until the interface
>  	 * is up.  For all other cases, let the f/w know that the h/w is now
> 
Tested this v2 version patch. There is no more crash, which is good.
And It also eliminates the double free warning message.
This patch is good to go.

Thanks! - David

[Intel-wired-lan] [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Kai-Heng Feng]

Hi Greg,

> On Oct 8, 2019, at 01:27, Alexander Duyck <alexander.duyck@gmail.com> wrote:
> 
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
>> From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>

Please merge this commit, a7023819404ac9bd2bb311a4fafd38515cfa71ec to stable v5.14.

`modprobe -r e1000e` triggers a null pointer dereference [1] after the the following two patches are applied to v5.4.y:
d635e7c4b34e6a630c7a1e8f1a8fd52c3e3ceea7 e1000e: Revert "e1000e: Make watchdog use delayed work"
21c6137939723ed6f5e4aec7882cdfc247304c27 e1000e: Drop unnecessary __E1000_DOWN bit twiddling

[1] https://bugs.launchpad.net/bugs/1864303

Kai-Heng

> ---
> 
> RFC v2: Dropped some unused variables
> 	Added logic to check for device present before removing to pm_freeze
> 	Fixed misplaced err_irq to before rtnl_unlock()
> 
> drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
> 1 file changed, 21 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..8b4e589aca36 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
> 	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
> 		e1000e_down(adapter, true);
> 		e1000_free_irq(adapter);
> 
> 		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
> 	}
> 
> 	napi_disable(&adapter->napi);
> @@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
> {
> 	struct net_device *netdev = dev_get_drvdata(dev);
> 	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	bool present;
> 
> +	rtnl_lock();
> +
> +	present = netif_device_present(netdev);
> 	netif_device_detach(netdev);
> 
> -	if (netif_running(netdev)) {
> +	if (present && netif_running(netdev)) {
> 		int count = E1000_CHECK_RESET_COUNT;
> 
> 		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
> @@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
> 		e1000e_down(adapter, false);
> 		e1000_free_irq(adapter);
> 	}
> +	rtnl_unlock();
> +
> 	e1000e_reset_interrupt_capability(adapter);
> 
> 	/* Allow time for pending master requests to run */
> @@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
> 	return 0;
> }
> 
> -#ifdef CONFIG_PM_SLEEP
> static int e1000e_pm_thaw(struct device *dev)
> {
> 	struct net_device *netdev = dev_get_drvdata(dev);
> 	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
> 	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
> 		e1000e_up(adapter);
> 	}
> 
> 	netif_device_attach(netdev);
> +err_irq:
> +	rtnl_unlock();
> 
> -	return 0;
> +	return rc;
> }
> 
> +#ifdef CONFIG_PM_SLEEP
> static int e1000e_pm_suspend(struct device *dev)
> {
> 	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
> static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
> 						pci_channel_state_t state)
> {
> -	struct net_device *netdev = pci_get_drvdata(pdev);
> -	struct e1000_adapter *adapter = netdev_priv(netdev);
> -
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
> 	if (state == pci_channel_io_perm_failure)
> 		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
> 	pci_disable_device(pdev);
> 
> 	/* Request a slot slot reset. */
> @@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
> 	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
> 	/* If the controller has AMT, do not set DRV_LOAD until the interface
> 	 * is up.  For all other cases, let the f/w know that the h/w is now
> 

Re: [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Kai-Heng Feng]

Hi Greg,

> On Oct 8, 2019, at 01:27, Alexander Duyck <alexander.duyck@gmail.com> wrote:
> 
> From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> This patch is meant to address possible race conditions that can exist
> between network configuration and power management. A similar issue was
> fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> netif_device_detach").
> 
> In addition it consolidates the code so that the PCI error handling code
> will essentially perform the power management freeze on the device prior to
> attempting a reset, and will thaw the device afterwards if that is what it
> is planning to do. Otherwise when we call close on the interface it should
> see it is detached and not attempt to call the logic to down the interface
> and free the IRQs again.
> 
>> From what I can tell the check that was adding the check for __E1000_DOWN
> in e1000e_close was added when runtime power management was added. However
> it should not be relevant for us as we perform a call to
> pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> be back up before we call into this anyway.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>

Please merge this commit, a7023819404ac9bd2bb311a4fafd38515cfa71ec to stable v5.14.

`modprobe -r e1000e` triggers a null pointer dereference [1] after the the following two patches are applied to v5.4.y:
d635e7c4b34e6a630c7a1e8f1a8fd52c3e3ceea7 e1000e: Revert "e1000e: Make watchdog use delayed work"
21c6137939723ed6f5e4aec7882cdfc247304c27 e1000e: Drop unnecessary __E1000_DOWN bit twiddling

[1] https://bugs.launchpad.net/bugs/1864303

Kai-Heng

> ---
> 
> RFC v2: Dropped some unused variables
> 	Added logic to check for device present before removing to pm_freeze
> 	Fixed misplaced err_irq to before rtnl_unlock()
> 
> drivers/net/ethernet/intel/e1000e/netdev.c |   40 +++++++++++++++-------------
> 1 file changed, 21 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index d7d56e42a6aa..8b4e589aca36 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -4715,12 +4715,12 @@ int e1000e_close(struct net_device *netdev)
> 
> 	pm_runtime_get_sync(&pdev->dev);
> 
> -	if (!test_bit(__E1000_DOWN, &adapter->state)) {
> +	if (netif_device_present(netdev)) {
> 		e1000e_down(adapter, true);
> 		e1000_free_irq(adapter);
> 
> 		/* Link status message must follow this format */
> -		pr_info("%s NIC Link is Down\n", adapter->netdev->name);
> +		pr_info("%s NIC Link is Down\n", netdev->name);
> 	}
> 
> 	napi_disable(&adapter->napi);
> @@ -6298,10 +6298,14 @@ static int e1000e_pm_freeze(struct device *dev)
> {
> 	struct net_device *netdev = dev_get_drvdata(dev);
> 	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	bool present;
> 
> +	rtnl_lock();
> +
> +	present = netif_device_present(netdev);
> 	netif_device_detach(netdev);
> 
> -	if (netif_running(netdev)) {
> +	if (present && netif_running(netdev)) {
> 		int count = E1000_CHECK_RESET_COUNT;
> 
> 		while (test_bit(__E1000_RESETTING, &adapter->state) && count--)
> @@ -6313,6 +6317,8 @@ static int e1000e_pm_freeze(struct device *dev)
> 		e1000e_down(adapter, false);
> 		e1000_free_irq(adapter);
> 	}
> +	rtnl_unlock();
> +
> 	e1000e_reset_interrupt_capability(adapter);
> 
> 	/* Allow time for pending master requests to run */
> @@ -6626,27 +6632,31 @@ static int __e1000_resume(struct pci_dev *pdev)
> 	return 0;
> }
> 
> -#ifdef CONFIG_PM_SLEEP
> static int e1000e_pm_thaw(struct device *dev)
> {
> 	struct net_device *netdev = dev_get_drvdata(dev);
> 	struct e1000_adapter *adapter = netdev_priv(netdev);
> +	int rc = 0;
> 
> 	e1000e_set_interrupt_capability(adapter);
> -	if (netif_running(netdev)) {
> -		u32 err = e1000_request_irq(adapter);
> 
> -		if (err)
> -			return err;
> +	rtnl_lock();
> +	if (netif_running(netdev)) {
> +		rc = e1000_request_irq(adapter);
> +		if (rc)
> +			goto err_irq;
> 
> 		e1000e_up(adapter);
> 	}
> 
> 	netif_device_attach(netdev);
> +err_irq:
> +	rtnl_unlock();
> 
> -	return 0;
> +	return rc;
> }
> 
> +#ifdef CONFIG_PM_SLEEP
> static int e1000e_pm_suspend(struct device *dev)
> {
> 	struct pci_dev *pdev = to_pci_dev(dev);
> @@ -6818,16 +6828,11 @@ static void e1000_netpoll(struct net_device *netdev)
> static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
> 						pci_channel_state_t state)
> {
> -	struct net_device *netdev = pci_get_drvdata(pdev);
> -	struct e1000_adapter *adapter = netdev_priv(netdev);
> -
> -	netif_device_detach(netdev);
> +	e1000e_pm_freeze(&pdev->dev);
> 
> 	if (state == pci_channel_io_perm_failure)
> 		return PCI_ERS_RESULT_DISCONNECT;
> 
> -	if (netif_running(netdev))
> -		e1000e_down(adapter, true);
> 	pci_disable_device(pdev);
> 
> 	/* Request a slot slot reset. */
> @@ -6893,10 +6898,7 @@ static void e1000_io_resume(struct pci_dev *pdev)
> 
> 	e1000_init_manageability_pt(adapter);
> 
> -	if (netif_running(netdev))
> -		e1000e_up(adapter);
> -
> -	netif_device_attach(netdev);
> +	e1000e_pm_thaw(&pdev->dev);
> 
> 	/* If the controller has AMT, do not set DRV_LOAD until the interface
> 	 * is up.  For all other cases, let the f/w know that the h/w is now
> 

[Intel-wired-lan] [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Greg Kroah-Hartman]

On Tue, Feb 25, 2020 at 05:42:26PM +0800, Kai-Heng Feng wrote:
> Hi Greg,
> 
> > On Oct 8, 2019, at 01:27, Alexander Duyck <alexander.duyck@gmail.com> wrote:
> > 
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > 
> > This patch is meant to address possible race conditions that can exist
> > between network configuration and power management. A similar issue was
> > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > netif_device_detach").
> > 
> > In addition it consolidates the code so that the PCI error handling code
> > will essentially perform the power management freeze on the device prior to
> > attempting a reset, and will thaw the device afterwards if that is what it
> > is planning to do. Otherwise when we call close on the interface it should
> > see it is detached and not attempt to call the logic to down the interface
> > and free the IRQs again.
> > 
> >> From what I can tell the check that was adding the check for __E1000_DOWN
> > in e1000e_close was added when runtime power management was added. However
> > it should not be relevant for us as we perform a call to
> > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > be back up before we call into this anyway.
> > 
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> Please merge this commit, a7023819404ac9bd2bb311a4fafd38515cfa71ec to stable v5.14.
> 
> `modprobe -r e1000e` triggers a null pointer dereference [1] after the the following two patches are applied to v5.4.y:
> d635e7c4b34e6a630c7a1e8f1a8fd52c3e3ceea7 e1000e: Revert "e1000e: Make watchdog use delayed work"
> 21c6137939723ed6f5e4aec7882cdfc247304c27 e1000e: Drop unnecessary __E1000_DOWN bit twiddling

Now queued up, thanks.

greg k-h

Re: [RFC PATCH v2] e1000e: Use rtnl_lock to prevent race conditions between net and pci/pm

[Greg Kroah-Hartman]

On Tue, Feb 25, 2020 at 05:42:26PM +0800, Kai-Heng Feng wrote:
> Hi Greg,
> 
> > On Oct 8, 2019, at 01:27, Alexander Duyck <alexander.duyck@gmail.com> wrote:
> > 
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > 
> > This patch is meant to address possible race conditions that can exist
> > between network configuration and power management. A similar issue was
> > fixed for igb in commit 9474933caf21 ("igb: close/suspend race in
> > netif_device_detach").
> > 
> > In addition it consolidates the code so that the PCI error handling code
> > will essentially perform the power management freeze on the device prior to
> > attempting a reset, and will thaw the device afterwards if that is what it
> > is planning to do. Otherwise when we call close on the interface it should
> > see it is detached and not attempt to call the logic to down the interface
> > and free the IRQs again.
> > 
> >> From what I can tell the check that was adding the check for __E1000_DOWN
> > in e1000e_close was added when runtime power management was added. However
> > it should not be relevant for us as we perform a call to
> > pm_runtime_get_sync before we call e1000_down/free_irq so it should always
> > be back up before we call into this anyway.
> > 
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> 
> Please merge this commit, a7023819404ac9bd2bb311a4fafd38515cfa71ec to stable v5.14.
> 
> `modprobe -r e1000e` triggers a null pointer dereference [1] after the the following two patches are applied to v5.4.y:
> d635e7c4b34e6a630c7a1e8f1a8fd52c3e3ceea7 e1000e: Revert "e1000e: Make watchdog use delayed work"
> 21c6137939723ed6f5e4aec7882cdfc247304c27 e1000e: Drop unnecessary __E1000_DOWN bit twiddling

Now queued up, thanks.

greg k-h