On Wed, Mar 27, 2024 at 01:40:54PM +0100, Krzysztof Kozlowski wrote:
Modules registering driver with register_virtio_driver() might forget to set .owner field. i2c-virtio.c for example has it missing. The field is used by some of other kernel parts for reference counting (try_module_get()), so it is expected that drivers will set it.
Solve the problem by moving this task away from the drivers to the core amba bus code, just like we did for platform_driver in commit 9447057eaff8 ("platform_device: use a macro instead of platform_driver_register").
Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org
This makes sense. So this will be:
Fixes: 3cfc88380413 ("i2c: virtio: add a virtio i2c frontend driver") Cc: "Jie Deng" jie.deng@intel.com
and I think I will pick this patch for this cycle to fix the bug. The cleanups can go in the next cycle.
Documentation/driver-api/virtio/writing_virtio_drivers.rst | 1 - drivers/virtio/virtio.c | 6 ++++-- include/linux/virtio.h | 7 +++++-- 3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/Documentation/driver-api/virtio/writing_virtio_drivers.rst b/Documentation/driver-api/virtio/writing_virtio_drivers.rst index e14c58796d25..e5de6f5d061a 100644 --- a/Documentation/driver-api/virtio/writing_virtio_drivers.rst +++ b/Documentation/driver-api/virtio/writing_virtio_drivers.rst @@ -97,7 +97,6 @@ like this::
static struct virtio_driver virtio_dummy_driver = { .driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index f173587893cb..9510c551dce8 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -362,14 +362,16 @@ static const struct bus_type virtio_bus = { .remove = virtio_dev_remove, };
-int register_virtio_driver(struct virtio_driver *driver) +int __register_virtio_driver(struct virtio_driver *driver, struct module *owner) { /* Catch this early. */ BUG_ON(driver->feature_table_size && !driver->feature_table); driver->driver.bus = &virtio_bus;
- driver->driver.owner = owner;
- return driver_register(&driver->driver);
} -EXPORT_SYMBOL_GPL(register_virtio_driver); +EXPORT_SYMBOL_GPL(__register_virtio_driver);
void unregister_virtio_driver(struct virtio_driver *driver) { diff --git a/include/linux/virtio.h b/include/linux/virtio.h index b0201747a263..26c4325aa373 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -170,7 +170,7 @@ size_t virtio_max_dma_size(const struct virtio_device *vdev);
/**
- struct virtio_driver - operations for a virtio I/O driver
- @driver: underlying device driver (populate name and owner).
- @driver: underlying device driver (populate name).
- @id_table: the ids serviced by this driver.
- @feature_table: an array of feature numbers supported by this driver.
- @feature_table_size: number of entries in the feature table array.
@@ -208,7 +208,10 @@ static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) return container_of(drv, struct virtio_driver, driver); }
-int register_virtio_driver(struct virtio_driver *drv); +/* use a macro to avoid include chaining to get THIS_MODULE */ +#define register_virtio_driver(drv) \
- __register_virtio_driver(drv, THIS_MODULE)
+int __register_virtio_driver(struct virtio_driver *drv, struct module *owner); void unregister_virtio_driver(struct virtio_driver *drv);
/* module_virtio_driver() - Helper macro for drivers that don't do
-- 2.34.1