[PATCH 1/3] nvmem: layouts: store owner from modules with nvmem_layout_driver_register()

From: Krzysztof Kozlowski
Date: Fri Mar 29 2024 - 12:14:04 EST


Modules registering driver with nvmem_layout_driver_register() might
forget to set .owner field. 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
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@xxxxxxxxxx>
---
drivers/nvmem/layouts.c | 6 ++++--
include/linux/nvmem-provider.h | 5 ++++-
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/nvmem/layouts.c b/drivers/nvmem/layouts.c
index 8b5e2de138eb..64dc7013a098 100644
--- a/drivers/nvmem/layouts.c
+++ b/drivers/nvmem/layouts.c
@@ -52,13 +52,15 @@ static const struct bus_type nvmem_layout_bus_type = {
.remove = nvmem_layout_bus_remove,
};

-int nvmem_layout_driver_register(struct nvmem_layout_driver *drv)
+int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,
+ struct module *owner)
{
drv->driver.bus = &nvmem_layout_bus_type;
+ drv->driver.owner = owner;

return driver_register(&drv->driver);
}
-EXPORT_SYMBOL_GPL(nvmem_layout_driver_register);
+EXPORT_SYMBOL_GPL(__nvmem_layout_driver_register);

void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv)
{
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index f0ba0e03218f..3ebeaa0ded00 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -199,7 +199,10 @@ int nvmem_add_one_cell(struct nvmem_device *nvmem,
int nvmem_layout_register(struct nvmem_layout *layout);
void nvmem_layout_unregister(struct nvmem_layout *layout);

-int nvmem_layout_driver_register(struct nvmem_layout_driver *drv);
+#define nvmem_layout_driver_register(drv) \
+ __nvmem_layout_driver_register(drv, THIS_MODULE)
+int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,
+ struct module *owner);
void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv);
#define module_nvmem_layout_driver(__nvmem_layout_driver) \
module_driver(__nvmem_layout_driver, nvmem_layout_driver_register, \

--
2.34.1