Commit fbabd829 authored by Dan Williams's avatar Dan Williams

acpi, nfit: fix module unload vs workqueue shutdown race

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: default avatarLinda Knippers <linda.knippers@hpe.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 8b06b884
......@@ -2604,6 +2604,7 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
return rc;
}
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);
if (acpi_desc->cancel || acpi_desc->init_complete) {
mutex_unlock(&acpi_desc->init_mutex);
if (acpi_desc->init_complete)
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));
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;
}
......
......@@ -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,
......
......@@ -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;
......
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