On 04/18/2017 02:06 PM, Dan Williams wrote: > The workqueue may still be running when the devres callbacks start > firing to deallocate an acpi_nfit_desc instance. Stop and flush the > workqueue before letting any other devres de-allocations proceed. > > Reported-by: Linda Knippers <linda.knippers@xxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> > --- > > I was able to produce a reliable nfit_test crash failure by running the > tests on hardware *and* disabling all debug messages. That last detail > may be why I have been seeing much less frequent failures. With this > change, in addition to the previous fix [1], I was again able to > complete a successful run. It seems a bit better because I can sometimes get a test to complete but then I'll get a panic when I try again. The footprints are the same as before, sometimes when unloading the module but sometimes in a kfree or related function. I'd be interested in your .config file and exactly how you're building your bare metal kernel. -- ljk > > [1]: https://patchwork.kernel.org/patch/9681861/ > > drivers/acpi/nfit/core.c | 76 +++++++++++++++++++++++--------------- > drivers/acpi/nfit/nfit.h | 1 + > tools/testing/nvdimm/test/nfit.c | 4 ++ > 3 files changed, 51 insertions(+), 30 deletions(-) > > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > index 69c6cc77130c..261eea1d2906 100644 > --- a/drivers/acpi/nfit/core.c > +++ b/drivers/acpi/nfit/core.c > @@ -2604,7 +2604,8 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc) > return rc; > } > > - queue_work(nfit_wq, &acpi_desc->work); > + if (!acpi_desc->cancel) > + queue_work(nfit_wq, &acpi_desc->work); > return 0; > } > > @@ -2650,32 +2651,11 @@ static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc) > return 0; > } > > -static void acpi_nfit_destruct(void *data) > +static void acpi_nfit_unregister(void *data) > { > struct acpi_nfit_desc *acpi_desc = data; > - struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus); > > - /* > - * Destruct under acpi_desc_lock so that nfit_handle_mce does not > - * race teardown > - */ > - mutex_lock(&acpi_desc_lock); > - acpi_desc->cancel = 1; > - /* > - * Bounce the nvdimm bus lock to make sure any in-flight > - * acpi_nfit_ars_rescan() submissions have had a chance to > - * either submit or see ->cancel set. > - */ > - device_lock(bus_dev); > - device_unlock(bus_dev); > - > - flush_workqueue(nfit_wq); > - if (acpi_desc->scrub_count_state) > - sysfs_put(acpi_desc->scrub_count_state); > nvdimm_bus_unregister(acpi_desc->nvdimm_bus); > - acpi_desc->nvdimm_bus = NULL; > - list_del(&acpi_desc->list); > - mutex_unlock(&acpi_desc_lock); > } > > int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz) > @@ -2693,7 +2673,7 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz) > if (!acpi_desc->nvdimm_bus) > return -ENOMEM; > > - rc = devm_add_action_or_reset(dev, acpi_nfit_destruct, > + rc = devm_add_action_or_reset(dev, acpi_nfit_unregister, > acpi_desc); > if (rc) > return rc; > @@ -2787,9 +2767,10 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc) > > /* bounce the init_mutex to make init_complete valid */ > mutex_lock(&acpi_desc->init_mutex); > - mutex_unlock(&acpi_desc->init_mutex); > - if (acpi_desc->init_complete) > + if (acpi_desc->cancel || acpi_desc->init_complete) { > + mutex_unlock(&acpi_desc->init_mutex); > return 0; > + } > > /* > * Scrub work could take 10s of seconds, userspace may give up so we > @@ -2798,6 +2779,7 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc) > INIT_WORK_ONSTACK(&flush.work, flush_probe); > COMPLETION_INITIALIZER_ONSTACK(flush.cmp); > queue_work(nfit_wq, &flush.work); > + mutex_unlock(&acpi_desc->init_mutex); > > rc = wait_for_completion_interruptible(&flush.cmp); > cancel_work_sync(&flush.work); > @@ -2834,10 +2816,12 @@ int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc) > if (work_busy(&acpi_desc->work)) > return -EBUSY; > > - if (acpi_desc->cancel) > + mutex_lock(&acpi_desc->init_mutex); > + if (acpi_desc->cancel) { > + mutex_unlock(&acpi_desc->init_mutex); > return 0; > + } > > - mutex_lock(&acpi_desc->init_mutex); > list_for_each_entry(nfit_spa, &acpi_desc->spas, list) { > struct acpi_nfit_system_address *spa = nfit_spa->spa; > > @@ -2886,6 +2870,35 @@ static void acpi_nfit_put_table(void *table) > acpi_put_table(table); > } > > +void acpi_nfit_shutdown(void *data) > +{ > + struct acpi_nfit_desc *acpi_desc = data; > + struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus); > + > + /* > + * Destruct under acpi_desc_lock so that nfit_handle_mce does not > + * race teardown > + */ > + mutex_lock(&acpi_desc_lock); > + list_del(&acpi_desc->list); > + mutex_unlock(&acpi_desc_lock); > + > + mutex_lock(&acpi_desc->init_mutex); > + acpi_desc->cancel = 1; > + mutex_unlock(&acpi_desc->init_mutex); > + > + /* > + * Bounce the nvdimm bus lock to make sure any in-flight > + * acpi_nfit_ars_rescan() submissions have had a chance to > + * either submit or see ->cancel set. > + */ > + device_lock(bus_dev); > + device_unlock(bus_dev); > + > + flush_workqueue(nfit_wq); > +} > +EXPORT_SYMBOL_GPL(acpi_nfit_shutdown); > + > static int acpi_nfit_add(struct acpi_device *adev) > { > struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL }; > @@ -2933,12 +2946,15 @@ static int acpi_nfit_add(struct acpi_device *adev) > rc = acpi_nfit_init(acpi_desc, (void *) tbl > + sizeof(struct acpi_table_nfit), > sz - sizeof(struct acpi_table_nfit)); > - return rc; > + > + if (rc) > + return rc; > + return devm_add_action_or_reset(dev, acpi_nfit_shutdown, acpi_desc); > } > > static int acpi_nfit_remove(struct acpi_device *adev) > { > - /* see acpi_nfit_destruct */ > + /* see acpi_nfit_unregister */ > return 0; > } > > diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h > index fac098bfa585..58fb7d68e04a 100644 > --- a/drivers/acpi/nfit/nfit.h > +++ b/drivers/acpi/nfit/nfit.h > @@ -239,6 +239,7 @@ static inline struct acpi_nfit_desc *to_acpi_desc( > > const u8 *to_nfit_uuid(enum nfit_uuids id); > int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *nfit, acpi_size sz); > +void acpi_nfit_shutdown(void *data); > void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event); > void __acpi_nvdimm_notify(struct device *dev, u32 event); > int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, > diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c > index d7fb1b894128..c2187178fb13 100644 > --- a/tools/testing/nvdimm/test/nfit.c > +++ b/tools/testing/nvdimm/test/nfit.c > @@ -1851,6 +1851,10 @@ static int nfit_test_probe(struct platform_device *pdev) > if (rc) > return rc; > > + rc = devm_add_action_or_reset(&pdev->dev, acpi_nfit_shutdown, acpi_desc); > + if (rc) > + return rc; > + > if (nfit_test->setup != nfit_test0_setup) > return 0; > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
