linux/drivers/base/bus.c, branch v6.17

driver core: fix potential NULL pointer dereference in dev_uevent()

2025-04-15T15:04:35Z

If userspace reads "uevent" device attribute at the same time as another threads unbinds the device from its driver, change to dev->driver from a valid pointer to NULL may result in crash. Fix this by using READ_ONCE() when fetching the pointer, and take bus' drivers klist lock to make sure driver instance will not disappear while we access it. Use WRITE_ONCE() when setting the driver pointer to ensure there is no tearing. Signed-off-by: Dmitry Torokhov Reviewed-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20250311052417.1846985-3-dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman

drivers/base/bus.c: fix spelling of "subsystem"

2025-02-21T08:20:30Z

Fix spelling, "subystem" -> "subsystem" Signed-off-by: Bharadwaj Raju Link: https://lore.kernel.org/r/20250203220312.1052986-1-bharadwaj.raju777@gmail.com Signed-off-by: Greg Kroah-Hartman

driver core: Introduce device_iter_t for device iterating APIs

2025-01-10T14:26:12Z

There are several for_each APIs which has parameter with type below: int (*fn)(struct device *dev, void *data) They iterate over various device lists and call @fn() for each device with caller provided data @*data, and they usually need to modify @*data. Give the type an dedicated typedef with advantages shown below: typedef int (*device_iter_t)(struct device *dev, void *data) - Shorter API declarations and definitions - Prevent further for_each APIs from using bad parameter type So introduce device_iter_t and apply it to various existing APIs below: bus_for_each_dev() (class|driver)_for_each_device() device_for_each_child(_reverse|_reverse_from)(). Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman

driver core: Move true expression out of if condition in 3 device finding APIs

2025-01-10T14:26:12Z

For bus_find_device(), driver_find_device(), and device_find_child(), all of their function body have pattern below: { struct klist_iter i; struct device *dev; ... while ((dev = next_device(&i))) if (match(dev, data) && get_device(dev)) break; ... } The expression 'get_device(dev)' in the if condition always returns true since @dev != NULL. Move the expression to if body to make logic of these APIs more clearer. Reviewed-by: Fan Ni Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-3-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman

drivers/base: Introduce device_match_t for device finding APIs

2024-09-03T10:48:51Z

There are several drivers/base APIs for finding a specific device, and they currently use the following good type for the @match parameter: int (*match)(struct device *dev, const void *data) Since these operations do not modify the caller-provided @*data, this type is worthy of a dedicated typedef: typedef int (*device_match_t)(struct device *dev, const void *data) Advantages of using device_match_t: - Shorter API declarations and definitions - Prevent further APIs from using a bad type for @match So introduce device_match_t and apply it to the existing (bus|class|driver|auxiliary)_find_device() APIs. Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240813-dev_match_api-v3-1-6c6878a99b9f@quicinc.com Signed-off-by: Greg Kroah-Hartman

driver core: bus: Fix double free in driver API bus_register()

2024-07-31T12:55:49Z

For bus_register(), any error which happens after kset_register() will cause that @priv are freed twice, fixed by setting @priv with NULL after the first free. Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240727-bus_register_fix-v1-1-fed8dd0dba7a@quicinc.com Signed-off-by: Greg Kroah-Hartman

driver core: bus: Add simple error handling for buses_init()

2024-07-31T12:55:40Z

Add simple error handling for buses_init() since it is easy to do. Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240727-buses_init-v1-1-e863295a2c0e@quicinc.com Signed-off-by: Greg Kroah-Hartman

driver core: Remove unused parameter for virtual_device_parent()

2024-07-31T12:55:13Z

Function struct kobject *virtual_device_parent(struct device *dev) does not use its parameter @dev, and the kobject returned also has nothing deal with specific device, so remove the unused parameter. Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240725-virtual_kobj_fix-v1-1-36335cae4544@quicinc.com Signed-off-by: Greg Kroah-Hartman

driver core: bus: Return -EIO instead of 0 when show/store invalid bus attribute

2024-07-31T12:54:55Z

Return -EIO instead of 0 for below erroneous bus attribute operations: - read a bus attribute without show(). - write a bus attribute without store(). Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240724-bus_fix-v2-1-5adbafc698fb@quicinc.com Signed-off-by: Greg Kroah-Hartman

module: don't ignore sysfs_create_link() failures

2024-04-11T12:42:08Z

The sysfs_create_link() return code is marked as __must_check, but the module_add_driver() function tries hard to not care, by assigning the return code to a variable. When building with 'make W=1', gcc still warns because this variable is only assigned but not used: drivers/base/module.c: In function 'module_add_driver': drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable] Rework the code to properly unwind and return the error code to the caller. My reading of the original code was that it tries to not fail when the links already exist, so keep ignoring -EEXIST errors. Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/") See-also: 4a7fb6363f2d ("add __must_check to device management code") Signed-off-by: Arnd Bergmann Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman