Commit 3ae7f509 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'driver-core-6.15-rc4' of... 

Merge tag 'driver-core-6.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core fixes to resolve a number of reported
  problems. Included in here are:

   - driver core sync fix revert to resolve a much reported problem,
     hopefully this is finally resolved

   - MAINTAINERS file update, documenting that the driver-core tree is
     now under a "shared" maintainership model, thanks to Rafael and
     Danilo for offering to do this!

   - auxbus documentation and MAINTAINERS file update

   - MAINTAINERS file update for Rust PCI code

   - firmware rust binding fixup

   - software node link fix

  All of these have been in linux-next for over a week with no reported
  issues"

* tag 'driver-core-6.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  drivers/base/memory: Avoid overhead from for_each_present_section_nr()
  software node: Prevent link creation failure from causing kobj reference count imbalance
  device property: Add a note to the fwnode.h
  drivers/base: Add myself as auxiliary bus reviewer
  drivers/base: Extend documentation with preferred way to use auxbus
  driver core: fix potential NULL pointer dereference in dev_uevent()
  driver core: introduce device_set_driver() helper
  Revert "drivers: core: synchronize really_probe() and dev_uevent()"
  MAINTAINERS: update the location of the driver-core git tree
  rust: firmware: Use `ffi::c_char` type in `FwFunc`
  MAINTAINERS: pci: add entry for Rust PCI code
parents 882cd652 b9792abb

MAINTAINERS

+14 −3
Original line number Diff line number Diff line
@@ -3873,8 +3873,9 @@ AUXILIARY BUS DRIVER 
M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>

R:	Dave Ertman <david.m.ertman@intel.com>

R:	Ira Weiny <ira.weiny@intel.com>

R:	Leon Romanovsky <leon@kernel.org>

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git

F:	Documentation/driver-api/auxiliary_bus.rst

F:	drivers/base/auxiliary.c

F:	include/linux/auxiliary_bus.h
@@ -7233,7 +7234,7 @@ M: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
M:	"Rafael J. Wysocki" <rafael@kernel.org>

M:	Danilo Krummrich <dakr@kernel.org>

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git

F:	Documentation/core-api/kobject.rst

F:	drivers/base/

F:	fs/debugfs/
@@ -13118,7 +13119,7 @@ KERNFS 
M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>

M:	Tejun Heo <tj@kernel.org>

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git

F:	fs/kernfs/

F:	include/linux/kernfs.h








@@ -18750,6 +18751,16 @@ F:	include/asm-generic/pci*







F:	include/linux/of_pci.h









F:	include/linux/pci*









F:	include/uapi/linux/pci*

















PCI SUBSYSTEM [RUST]









M:	Danilo Krummrich <dakr@kernel.org>









R:	Bjorn Helgaas <bhelgaas@google.com>









R:	Krzysztof Wilczyński <kwilczynski@kernel.org>









L:	linux-pci@vger.kernel.org









S:	Maintained









C:	irc://irc.oftc.net/linux-pci









T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git









F:	rust/helpers/pci.c









F:	rust/kernel/pci.rs









F:	samples/rust/rust_driver_pci.rs

































drivers/base/auxiliary.c



+10
−0






























Original line number
Diff line number
Diff line







@@ -156,6 +156,16 @@







 *		},









 *		.ops = my_custom_ops,









 *	};









 *









 * Please note that such custom ops approach is valid, but it is hard to implement









 * it right without global locks per-device to protect from auxiliary_drv removal









 * during call to that ops. In addition, this implementation lacks proper module









 * dependency, which causes to load/unload races between auxiliary parent and devices









 * modules.









 *









 * The most easiest way to provide these ops reliably without needing to









 * have a lock is to EXPORT_SYMBOL*() them and rely on already existing









 * modules infrastructure for validity and correct dependencies chains.









 */



















static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
































drivers/base/base.h



+17
−0






























Original line number
Diff line number
Diff line







@@ -73,6 +73,7 @@ static inline void subsys_put(struct subsys_private *sp)







		kset_put(&sp->subsys);









}



















struct subsys_private *bus_to_subsys(const struct bus_type *bus);









struct subsys_private *class_to_subsys(const struct class *class);



















struct driver_private {








@@ -180,6 +181,22 @@ int driver_add_groups(const struct device_driver *drv, const struct attribute_gr







void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups);









void device_driver_detach(struct device *dev);



















static inline void device_set_driver(struct device *dev, const struct device_driver *drv)









{









	/*









	 * Majority (all?) read accesses to dev->driver happens either









	 * while holding device lock or in bus/driver code that is only









	 * invoked when the device is bound to a driver and there is no









	 * concern of the pointer being changed while it is being read.









	 * However when reading device's uevent file we read driver pointer









	 * without taking device lock (so we do not block there for









	 * arbitrary amount of time). We use WRITE_ONCE() here to prevent









	 * tearing so that READ_ONCE() can safely be used in uevent code.









	 */









	// FIXME - this cast should not be needed "soon"









	WRITE_ONCE(dev->driver, (struct device_driver *)drv);









}



















int devres_release_all(struct device *dev);









void device_block_probing(void);









void device_unblock_probing(void);
































drivers/base/bus.c



+1
−1






























Original line number
Diff line number
Diff line







@@ -57,7 +57,7 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,







 * NULL.  A call to subsys_put() must be done when finished with the pointer in









 * order for it to be properly freed.









 */









static struct subsys_private *bus_to_subsys(const struct bus_type *bus)









struct subsys_private *bus_to_subsys(const struct bus_type *bus)









{









	struct subsys_private *sp = NULL;









	struct kobject *kobj;
































drivers/base/core.c



+32
−6






























Original line number
Diff line number
Diff line







@@ -2624,6 +2624,35 @@ static const char *dev_uevent_name(const struct kobject *kobj)







	return NULL;









}



















/*









 * Try filling "DRIVER=<name>" uevent variable for a device. Because this









 * function may race with binding and unbinding the device from a driver,









 * we need to be careful. Binding is generally safe, at worst we miss the









 * fact that the device is already bound to a driver (but the driver









 * information that is delivered through uevents is best-effort, it may









 * become obsolete as soon as it is generated anyways). Unbinding is more









 * risky as driver pointer is transitioning to NULL, so READ_ONCE() should









 * be used to make sure we are dealing with the same pointer, and to









 * ensure that driver structure is not going to disappear from under us









 * we take bus' drivers klist lock. The assumption that only registered









 * driver can be bound to a device, and to unregister a driver bus code









 * will take the same lock.









 */









static void dev_driver_uevent(const struct device *dev, struct kobj_uevent_env *env)









{









	struct subsys_private *sp = bus_to_subsys(dev->bus);



















	if (sp) {









		scoped_guard(spinlock, &sp->klist_drivers.k_lock) {









			struct device_driver *drv = READ_ONCE(dev->driver);









			if (drv)









				add_uevent_var(env, "DRIVER=%s", drv->name);









		}



















		subsys_put(sp);









	}









}



















static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)









{









	const struct device *dev = kobj_to_dev(kobj);








@@ -2655,8 +2684,8 @@ static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)







	if (dev->type && dev->type->name)









		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);



















	if (dev->driver)









		add_uevent_var(env, "DRIVER=%s", dev->driver->name);









	/* Add "DRIVER=%s" variable if the device is bound to a driver */









	dev_driver_uevent(dev, env);



















	/* Add common DT information about the device */









	of_device_uevent(dev, env);








@@ -2726,11 +2755,8 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,







	if (!env)









		return -ENOMEM;



















	/* Synchronize with really_probe() */









	device_lock(dev);









	/* let the kset specific function add its keys */









	retval = kset->uevent_ops->uevent(&dev->kobj, env);









	device_unlock(dev);









	if (retval)









		goto out;


















@@ -3700,7 +3726,7 @@ int device_add(struct device *dev)







	device_pm_remove(dev);









	dpm_sysfs_remove(dev);









 DPMError:









	dev->driver = NULL;









	device_set_driver(dev, NULL);









	bus_remove_device(dev);









 BusError:









	device_remove_attrs(dev);