| Message ID | 11864888.O9o76ZdvQC@kreacher (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | hwmon: acpi_power_meter: Use acpi_bus_get_acpi_device() | expand |
On Tue, Oct 12, 2021 at 07:30:40PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael@kernel.org> > > In read_domain_devices(), acpi_bus_get_device() is called to obtain > the ACPI device object attached to the given ACPI handle and > subsequently that object is passed to get_device() for reference > counting, but there is a window between the acpi_bus_get_device() > and get_device() calls in which the ACPI device object in question > may go away. > > To address this issue, make read_domain_devices() use > acpi_bus_get_acpi_device() to reference count and return the given > ACPI device object in one go and export that function to modules. > > While at it, also make read_domain_devices() and > remove_domain_devices() use acpi_dev_put() instead of calling > put_device() directly on the ACPI device objects returned by > acpi_bus_get_acpi_device(). Good catch! Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Rafael J. Wysocki <rafael@kernel.org> > --- > drivers/acpi/scan.c | 1 + > drivers/hwmon/acpi_power_meter.c | 13 +++++-------- > 2 files changed, 6 insertions(+), 8 deletions(-) > > Index: linux-pm/drivers/hwmon/acpi_power_meter.c > =================================================================== > --- linux-pm.orig/drivers/hwmon/acpi_power_meter.c > +++ linux-pm/drivers/hwmon/acpi_power_meter.c > @@ -535,7 +535,7 @@ static void remove_domain_devices(struct > > sysfs_remove_link(resource->holders_dir, > kobject_name(&obj->dev.kobj)); > - put_device(&obj->dev); > + acpi_dev_put(obj); > } > > kfree(resource->domain_devices); > @@ -597,18 +597,15 @@ static int read_domain_devices(struct ac > continue; > > /* Create a symlink to domain objects */ > - resource->domain_devices[i] = NULL; > - if (acpi_bus_get_device(element->reference.handle, > - &resource->domain_devices[i])) > + obj = acpi_bus_get_acpi_device(element->reference.handle); > + resource->domain_devices[i] = obj; > + if (!obj) > continue; > > - obj = resource->domain_devices[i]; > - get_device(&obj->dev); > - > res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj, > kobject_name(&obj->dev.kobj)); > if (res) { > - put_device(&obj->dev); > + acpi_dev_put(obj); > resource->domain_devices[i] = NULL; > } > } > Index: linux-pm/drivers/acpi/scan.c > =================================================================== > --- linux-pm.orig/drivers/acpi/scan.c > +++ linux-pm/drivers/acpi/scan.c > @@ -608,6 +608,7 @@ struct acpi_device *acpi_bus_get_acpi_de > { > return handle_to_device(handle, get_acpi_device); > } > +EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device); > > static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) > { > > >
Index: linux-pm/drivers/hwmon/acpi_power_meter.c =================================================================== --- linux-pm.orig/drivers/hwmon/acpi_power_meter.c +++ linux-pm/drivers/hwmon/acpi_power_meter.c @@ -535,7 +535,7 @@ static void remove_domain_devices(struct sysfs_remove_link(resource->holders_dir, kobject_name(&obj->dev.kobj)); - put_device(&obj->dev); + acpi_dev_put(obj); } kfree(resource->domain_devices); @@ -597,18 +597,15 @@ static int read_domain_devices(struct ac continue; /* Create a symlink to domain objects */ - resource->domain_devices[i] = NULL; - if (acpi_bus_get_device(element->reference.handle, - &resource->domain_devices[i])) + obj = acpi_bus_get_acpi_device(element->reference.handle); + resource->domain_devices[i] = obj; + if (!obj) continue; - obj = resource->domain_devices[i]; - get_device(&obj->dev); - res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj, kobject_name(&obj->dev.kobj)); if (res) { - put_device(&obj->dev); + acpi_dev_put(obj); resource->domain_devices[i] = NULL; } } Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -608,6 +608,7 @@ struct acpi_device *acpi_bus_get_acpi_de { return handle_to_device(handle, get_acpi_device); } +EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device); static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) {