| Message ID | 20180326041707.11246-1-mikey@neuling.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f0295e047fcf52ccb42561fb7de6942f5201b676 |
| Headers | show |
| Series | [v2] powerpc/eeh: Fix race with driver un/bind | expand |
On Mon, 2018-03-26 at 15:17 +1100, Michael Neuling wrote: > The current EEH callbacks can race with a driver unbind. This > can result in a backtraces like this: > > [ 7.573055] EEH: Frozen PHB#0-PE#1fc detected > [ 7.573063] EEH: PE location: S000009, PHB location: N/A > [ 7.573069] CPU: 2 PID: 2312 Comm: kworker/u258:3 Not tainted 4.15.6-openpower1 #2 > [ 7.573078] Workqueue: nvme-wq nvme_reset_work [nvme] > [ 7.573080] Call Trace: > [ 7.573088] [c000000ff12a3a30] [c0000000005f5000] dump_stack+0x9c/0xd0 > [ 7.573093] (unreliable) > [ 7.573106] [c000000ff12a3a70] [c00000000002385c] eeh_dev_check_failure+0x420/0x470 > [ 7.573111] [c000000ff12a3b10] [c00000000002394c] eeh_check_failure+0xa0/0xa4 > [ 7.573115] [c000000ff12a3b50] [c0080000088c2ff0] nvme_reset_work+0x138/0x1414 [nvme] > [ 7.573122] [c000000ff12a3cb0] [c000000000089c78] process_one_work+0x1ec/0x328 > [ 7.573132] [c000000ff12a3d40] [c00000000008a3b4] worker_thread+0x2e4/0x3a8 > [ 7.573140] [c000000ff12a3dc0] [c00000000008fed0] kthread+0x14c/0x154 > [ 7.573150] [c000000ff12a3e30] [c00000000000b594] ret_from_kernel_thread+0x5c/0xc8 > [ 7.573183] nvme nvme1: Removing after probe failure status: -19 > <snip> > cpu 0x23: Vector: 300 (Data Access) at [c000000ff50f3800] > pc: c0080000089a0eb0: nvme_error_detected+0x4c/0x90 [nvme] > lr: c000000000026564: eeh_report_error+0xe0/0x110 > sp: c000000ff50f3a80 > msr: 9000000000009033 > dar: 400 > dsisr: 40000000 > current = 0xc000000ff507c000 > paca = 0xc00000000fdc9d80 softe: 0 irq_happened: 0x01 > pid = 782, comm = eehd > Linux version 4.15.6-openpower1 (smc@smc-desktop) (gcc version 6.4.0 (Buildroot 2017.11.2-00008-g4b6188e)) #2 SM P Tue Feb 27 12:33:27 PST 2018 > enter ? for help > [c000000ff50f3af0] c000000000026564 eeh_report_error+0xe0/0x110 > [c000000ff50f3b30] c000000000025520 eeh_pe_dev_traverse+0xc0/0xdc > [c000000ff50f3bc0] c000000000026bd0 eeh_handle_normal_event+0x184/0x4c4 > [c000000ff50f3c70] c000000000026ff4 eeh_handle_event+0x30/0x288 > [c000000ff50f3d10] c00000000002758c eeh_event_handler+0x124/0x170 > [c000000ff50f3dc0] c00000000008fed0 kthread+0x14c/0x154 > [c000000ff50f3e30] c00000000000b594 ret_from_kernel_thread+0x5c/0xc8 > > The first part is an EEH (on boot), the second half is the resulting > crash. nvme probe starts the nvme_reset_work() worker thread. This > worker thread starts touching the device which see a device error > (EEH) and hence queues up an event in the powerpc EEH worker > thread. nvme_reset_work() then continues and runs > nvme_remove_dead_ctrl_work() which results in unbinding the driver > from the device and hence releases all resources. At the same time, > the EEH worker thread starts doing the EEH .error_detected() driver > callback, which no longer works since the resources have been freed. > > This fixes the problem in the same way the generic PCIe AER code (in > drivers/pci/pcie/aer/aerdrv_core.c) does. It makes the EEH code hold > the device_lock() while performing the driver EEH callbacks and > associated code. This ensures either the callbacks are no longer > register, or if they are registered the driver will not be removed > from underneath us. > > This has been broken forever. The EEH call backs were first introduced > in 2005 (in 77bd7415610) but it's not clear if a lock was needed back > then. > > Signed-off-by: Michael Neuling <mikey@neuling.org> > Cc: stable@vger.kernel.org Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > --- > v2: > Updates based on benh's comments: > - Change jump labels > - Clarify where lock is held in commit message > --- > arch/powerpc/kernel/eeh_driver.c | 68 +++++++++++++++++++++++++--------------- > 1 file changed, 42 insertions(+), 26 deletions(-) > > diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c > index 0c0b66fc5b..295ba83384 100644 > --- a/arch/powerpc/kernel/eeh_driver.c > +++ b/arch/powerpc/kernel/eeh_driver.c > @@ -207,18 +207,18 @@ static void *eeh_report_error(void *data, void *userdata) > > if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) > return NULL; > + > + device_lock(&dev->dev); > dev->error_state = pci_channel_io_frozen; > > driver = eeh_pcid_get(dev); > - if (!driver) return NULL; > + if (!driver) goto out_no_dev; > > eeh_disable_irq(dev); > > if (!driver->err_handler || > - !driver->err_handler->error_detected) { > - eeh_pcid_put(dev); > - return NULL; > - } > + !driver->err_handler->error_detected) > + goto out; > > rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); > > @@ -227,8 +227,12 @@ static void *eeh_report_error(void *data, void *userdata) > if (*res == PCI_ERS_RESULT_NONE) *res = rc; > > edev->in_error = true; > - eeh_pcid_put(dev); > pci_uevent_ers(dev, PCI_ERS_RESULT_NONE); > + > +out: > + eeh_pcid_put(dev); > +out_no_dev: > + device_unlock(&dev->dev); > return NULL; > } > > @@ -251,15 +255,14 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata) > if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) > return NULL; > > + device_lock(&dev->dev); > driver = eeh_pcid_get(dev); > - if (!driver) return NULL; > + if (!driver) goto out_no_dev; > > if (!driver->err_handler || > !driver->err_handler->mmio_enabled || > - (edev->mode & EEH_DEV_NO_HANDLER)) { > - eeh_pcid_put(dev); > - return NULL; > - } > + (edev->mode & EEH_DEV_NO_HANDLER)) > + goto out; > > rc = driver->err_handler->mmio_enabled(dev); > > @@ -267,7 +270,10 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata) > if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; > if (*res == PCI_ERS_RESULT_NONE) *res = rc; > > +out: > eeh_pcid_put(dev); > +out_no_dev: > + device_unlock(&dev->dev); > return NULL; > } > > @@ -290,20 +296,20 @@ static void *eeh_report_reset(void *data, void *userdata) > > if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) > return NULL; > + > + device_lock(&dev->dev); > dev->error_state = pci_channel_io_normal; > > driver = eeh_pcid_get(dev); > - if (!driver) return NULL; > + if (!driver) goto out_no_dev; > > eeh_enable_irq(dev); > > if (!driver->err_handler || > !driver->err_handler->slot_reset || > (edev->mode & EEH_DEV_NO_HANDLER) || > - (!edev->in_error)) { > - eeh_pcid_put(dev); > - return NULL; > - } > + (!edev->in_error)) > + goto out; > > rc = driver->err_handler->slot_reset(dev); > if ((*res == PCI_ERS_RESULT_NONE) || > @@ -311,7 +317,10 @@ static void *eeh_report_reset(void *data, void *userdata) > if (*res == PCI_ERS_RESULT_DISCONNECT && > rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; > > +out: > eeh_pcid_put(dev); > +out_no_dev: > + device_unlock(&dev->dev); > return NULL; > } > > @@ -362,10 +371,12 @@ static void *eeh_report_resume(void *data, void *userdata) > > if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) > return NULL; > + > + device_lock(&dev->dev); > dev->error_state = pci_channel_io_normal; > > driver = eeh_pcid_get(dev); > - if (!driver) return NULL; > + if (!driver) goto out_no_dev; > > was_in_error = edev->in_error; > edev->in_error = false; > @@ -375,18 +386,20 @@ static void *eeh_report_resume(void *data, void *userdata) > !driver->err_handler->resume || > (edev->mode & EEH_DEV_NO_HANDLER) || !was_in_error) { > edev->mode &= ~EEH_DEV_NO_HANDLER; > - eeh_pcid_put(dev); > - return NULL; > + goto out; > } > > driver->err_handler->resume(dev); > > - eeh_pcid_put(dev); > pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED); > +out: > + eeh_pcid_put(dev); > #ifdef CONFIG_PCI_IOV > if (eeh_ops->notify_resume && eeh_dev_to_pdn(edev)) > eeh_ops->notify_resume(eeh_dev_to_pdn(edev)); > #endif > +out_no_dev: > + device_unlock(&dev->dev); > return NULL; > } > > @@ -406,23 +419,26 @@ static void *eeh_report_failure(void *data, void *userdata) > > if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) > return NULL; > + > + device_lock(&dev->dev); > dev->error_state = pci_channel_io_perm_failure; > > driver = eeh_pcid_get(dev); > - if (!driver) return NULL; > + if (!driver) goto out_no_dev; > > eeh_disable_irq(dev); > > if (!driver->err_handler || > - !driver->err_handler->error_detected) { > - eeh_pcid_put(dev); > - return NULL; > - } > + !driver->err_handler->error_detected) > + goto out; > > driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); > > - eeh_pcid_put(dev); > pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT); > +out: > + eeh_pcid_put(dev); > +out_no_dev: > + device_unlock(&dev->dev); > return NULL; > } >
On Mon, 2018-03-26 at 04:17:07 UTC, Michael Neuling wrote: > The current EEH callbacks can race with a driver unbind. This > can result in a backtraces like this: > > [ 7.573055] EEH: Frozen PHB#0-PE#1fc detected > [ 7.573063] EEH: PE location: S000009, PHB location: N/A > [ 7.573069] CPU: 2 PID: 2312 Comm: kworker/u258:3 Not tainted 4.15.6-openpower1 #2 > [ 7.573078] Workqueue: nvme-wq nvme_reset_work [nvme] > [ 7.573080] Call Trace: > [ 7.573088] [c000000ff12a3a30] [c0000000005f5000] dump_stack+0x9c/0xd0 > [ 7.573093] (unreliable) > [ 7.573106] [c000000ff12a3a70] [c00000000002385c] eeh_dev_check_failure+0x420/0x470 > [ 7.573111] [c000000ff12a3b10] [c00000000002394c] eeh_check_failure+0xa0/0xa4 > [ 7.573115] [c000000ff12a3b50] [c0080000088c2ff0] nvme_reset_work+0x138/0x1414 [nvme] > [ 7.573122] [c000000ff12a3cb0] [c000000000089c78] process_one_work+0x1ec/0x328 > [ 7.573132] [c000000ff12a3d40] [c00000000008a3b4] worker_thread+0x2e4/0x3a8 > [ 7.573140] [c000000ff12a3dc0] [c00000000008fed0] kthread+0x14c/0x154 > [ 7.573150] [c000000ff12a3e30] [c00000000000b594] ret_from_kernel_thread+0x5c/0xc8 > [ 7.573183] nvme nvme1: Removing after probe failure status: -19 > <snip> > cpu 0x23: Vector: 300 (Data Access) at [c000000ff50f3800] > pc: c0080000089a0eb0: nvme_error_detected+0x4c/0x90 [nvme] > lr: c000000000026564: eeh_report_error+0xe0/0x110 > sp: c000000ff50f3a80 > msr: 9000000000009033 > dar: 400 > dsisr: 40000000 > current = 0xc000000ff507c000 > paca = 0xc00000000fdc9d80 softe: 0 irq_happened: 0x01 > pid = 782, comm = eehd > Linux version 4.15.6-openpower1 (smc@smc-desktop) (gcc version 6.4.0 (Buildroot 2017.11.2-00008-g4b6188e)) #2 SM P Tue Feb 27 12:33:27 PST 2018 > enter ? for help > [c000000ff50f3af0] c000000000026564 eeh_report_error+0xe0/0x110 > [c000000ff50f3b30] c000000000025520 eeh_pe_dev_traverse+0xc0/0xdc > [c000000ff50f3bc0] c000000000026bd0 eeh_handle_normal_event+0x184/0x4c4 > [c000000ff50f3c70] c000000000026ff4 eeh_handle_event+0x30/0x288 > [c000000ff50f3d10] c00000000002758c eeh_event_handler+0x124/0x170 > [c000000ff50f3dc0] c00000000008fed0 kthread+0x14c/0x154 > [c000000ff50f3e30] c00000000000b594 ret_from_kernel_thread+0x5c/0xc8 > > The first part is an EEH (on boot), the second half is the resulting > crash. nvme probe starts the nvme_reset_work() worker thread. This > worker thread starts touching the device which see a device error > (EEH) and hence queues up an event in the powerpc EEH worker > thread. nvme_reset_work() then continues and runs > nvme_remove_dead_ctrl_work() which results in unbinding the driver > from the device and hence releases all resources. At the same time, > the EEH worker thread starts doing the EEH .error_detected() driver > callback, which no longer works since the resources have been freed. > > This fixes the problem in the same way the generic PCIe AER code (in > drivers/pci/pcie/aer/aerdrv_core.c) does. It makes the EEH code hold > the device_lock() while performing the driver EEH callbacks and > associated code. This ensures either the callbacks are no longer > register, or if they are registered the driver will not be removed > from underneath us. > > This has been broken forever. The EEH call backs were first introduced > in 2005 (in 77bd7415610) but it's not clear if a lock was needed back > then. > > Signed-off-by: Michael Neuling <mikey@neuling.org> > Cc: stable@vger.kernel.org > Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/f0295e047fcf52ccb42561fb7de694 cheers
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 0c0b66fc5b..295ba83384 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -207,18 +207,18 @@ static void *eeh_report_error(void *data, void *userdata) if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) return NULL; + + device_lock(&dev->dev); dev->error_state = pci_channel_io_frozen; driver = eeh_pcid_get(dev); - if (!driver) return NULL; + if (!driver) goto out_no_dev; eeh_disable_irq(dev); if (!driver->err_handler || - !driver->err_handler->error_detected) { - eeh_pcid_put(dev); - return NULL; - } + !driver->err_handler->error_detected) + goto out; rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); @@ -227,8 +227,12 @@ static void *eeh_report_error(void *data, void *userdata) if (*res == PCI_ERS_RESULT_NONE) *res = rc; edev->in_error = true; - eeh_pcid_put(dev); pci_uevent_ers(dev, PCI_ERS_RESULT_NONE); + +out: + eeh_pcid_put(dev); +out_no_dev: + device_unlock(&dev->dev); return NULL; } @@ -251,15 +255,14 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata) if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) return NULL; + device_lock(&dev->dev); driver = eeh_pcid_get(dev); - if (!driver) return NULL; + if (!driver) goto out_no_dev; if (!driver->err_handler || !driver->err_handler->mmio_enabled || - (edev->mode & EEH_DEV_NO_HANDLER)) { - eeh_pcid_put(dev); - return NULL; - } + (edev->mode & EEH_DEV_NO_HANDLER)) + goto out; rc = driver->err_handler->mmio_enabled(dev); @@ -267,7 +270,10 @@ static void *eeh_report_mmio_enabled(void *data, void *userdata) if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; if (*res == PCI_ERS_RESULT_NONE) *res = rc; +out: eeh_pcid_put(dev); +out_no_dev: + device_unlock(&dev->dev); return NULL; } @@ -290,20 +296,20 @@ static void *eeh_report_reset(void *data, void *userdata) if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) return NULL; + + device_lock(&dev->dev); dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); - if (!driver) return NULL; + if (!driver) goto out_no_dev; eeh_enable_irq(dev); if (!driver->err_handler || !driver->err_handler->slot_reset || (edev->mode & EEH_DEV_NO_HANDLER) || - (!edev->in_error)) { - eeh_pcid_put(dev); - return NULL; - } + (!edev->in_error)) + goto out; rc = driver->err_handler->slot_reset(dev); if ((*res == PCI_ERS_RESULT_NONE) || @@ -311,7 +317,10 @@ static void *eeh_report_reset(void *data, void *userdata) if (*res == PCI_ERS_RESULT_DISCONNECT && rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; +out: eeh_pcid_put(dev); +out_no_dev: + device_unlock(&dev->dev); return NULL; } @@ -362,10 +371,12 @@ static void *eeh_report_resume(void *data, void *userdata) if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) return NULL; + + device_lock(&dev->dev); dev->error_state = pci_channel_io_normal; driver = eeh_pcid_get(dev); - if (!driver) return NULL; + if (!driver) goto out_no_dev; was_in_error = edev->in_error; edev->in_error = false; @@ -375,18 +386,20 @@ static void *eeh_report_resume(void *data, void *userdata) !driver->err_handler->resume || (edev->mode & EEH_DEV_NO_HANDLER) || !was_in_error) { edev->mode &= ~EEH_DEV_NO_HANDLER; - eeh_pcid_put(dev); - return NULL; + goto out; } driver->err_handler->resume(dev); - eeh_pcid_put(dev); pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED); +out: + eeh_pcid_put(dev); #ifdef CONFIG_PCI_IOV if (eeh_ops->notify_resume && eeh_dev_to_pdn(edev)) eeh_ops->notify_resume(eeh_dev_to_pdn(edev)); #endif +out_no_dev: + device_unlock(&dev->dev); return NULL; } @@ -406,23 +419,26 @@ static void *eeh_report_failure(void *data, void *userdata) if (!dev || eeh_dev_removed(edev) || eeh_pe_passed(edev->pe)) return NULL; + + device_lock(&dev->dev); dev->error_state = pci_channel_io_perm_failure; driver = eeh_pcid_get(dev); - if (!driver) return NULL; + if (!driver) goto out_no_dev; eeh_disable_irq(dev); if (!driver->err_handler || - !driver->err_handler->error_detected) { - eeh_pcid_put(dev); - return NULL; - } + !driver->err_handler->error_detected) + goto out; driver->err_handler->error_detected(dev, pci_channel_io_perm_failure); - eeh_pcid_put(dev); pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT); +out: + eeh_pcid_put(dev); +out_no_dev: + device_unlock(&dev->dev); return NULL; }
The current EEH callbacks can race with a driver unbind. This can result in a backtraces like this: [ 7.573055] EEH: Frozen PHB#0-PE#1fc detected [ 7.573063] EEH: PE location: S000009, PHB location: N/A [ 7.573069] CPU: 2 PID: 2312 Comm: kworker/u258:3 Not tainted 4.15.6-openpower1 #2 [ 7.573078] Workqueue: nvme-wq nvme_reset_work [nvme] [ 7.573080] Call Trace: [ 7.573088] [c000000ff12a3a30] [c0000000005f5000] dump_stack+0x9c/0xd0 [ 7.573093] (unreliable) [ 7.573106] [c000000ff12a3a70] [c00000000002385c] eeh_dev_check_failure+0x420/0x470 [ 7.573111] [c000000ff12a3b10] [c00000000002394c] eeh_check_failure+0xa0/0xa4 [ 7.573115] [c000000ff12a3b50] [c0080000088c2ff0] nvme_reset_work+0x138/0x1414 [nvme] [ 7.573122] [c000000ff12a3cb0] [c000000000089c78] process_one_work+0x1ec/0x328 [ 7.573132] [c000000ff12a3d40] [c00000000008a3b4] worker_thread+0x2e4/0x3a8 [ 7.573140] [c000000ff12a3dc0] [c00000000008fed0] kthread+0x14c/0x154 [ 7.573150] [c000000ff12a3e30] [c00000000000b594] ret_from_kernel_thread+0x5c/0xc8 [ 7.573183] nvme nvme1: Removing after probe failure status: -19 <snip> cpu 0x23: Vector: 300 (Data Access) at [c000000ff50f3800] pc: c0080000089a0eb0: nvme_error_detected+0x4c/0x90 [nvme] lr: c000000000026564: eeh_report_error+0xe0/0x110 sp: c000000ff50f3a80 msr: 9000000000009033 dar: 400 dsisr: 40000000 current = 0xc000000ff507c000 paca = 0xc00000000fdc9d80 softe: 0 irq_happened: 0x01 pid = 782, comm = eehd Linux version 4.15.6-openpower1 (smc@smc-desktop) (gcc version 6.4.0 (Buildroot 2017.11.2-00008-g4b6188e)) #2 SM P Tue Feb 27 12:33:27 PST 2018 enter ? for help [c000000ff50f3af0] c000000000026564 eeh_report_error+0xe0/0x110 [c000000ff50f3b30] c000000000025520 eeh_pe_dev_traverse+0xc0/0xdc [c000000ff50f3bc0] c000000000026bd0 eeh_handle_normal_event+0x184/0x4c4 [c000000ff50f3c70] c000000000026ff4 eeh_handle_event+0x30/0x288 [c000000ff50f3d10] c00000000002758c eeh_event_handler+0x124/0x170 [c000000ff50f3dc0] c00000000008fed0 kthread+0x14c/0x154 [c000000ff50f3e30] c00000000000b594 ret_from_kernel_thread+0x5c/0xc8 The first part is an EEH (on boot), the second half is the resulting crash. nvme probe starts the nvme_reset_work() worker thread. This worker thread starts touching the device which see a device error (EEH) and hence queues up an event in the powerpc EEH worker thread. nvme_reset_work() then continues and runs nvme_remove_dead_ctrl_work() which results in unbinding the driver from the device and hence releases all resources. At the same time, the EEH worker thread starts doing the EEH .error_detected() driver callback, which no longer works since the resources have been freed. This fixes the problem in the same way the generic PCIe AER code (in drivers/pci/pcie/aer/aerdrv_core.c) does. It makes the EEH code hold the device_lock() while performing the driver EEH callbacks and associated code. This ensures either the callbacks are no longer register, or if they are registered the driver will not be removed from underneath us. This has been broken forever. The EEH call backs were first introduced in 2005 (in 77bd7415610) but it's not clear if a lock was needed back then. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: stable@vger.kernel.org --- v2: Updates based on benh's comments: - Change jump labels - Clarify where lock is held in commit message --- arch/powerpc/kernel/eeh_driver.c | 68 +++++++++++++++++++++++++--------------- 1 file changed, 42 insertions(+), 26 deletions(-)