lwn.git/include/linux/device, branch master

Merge tag 'driver-core-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

2026-04-14T02:03:11+00:00

Pull driver core updates from Danilo Krummrich: "debugfs: - Fix NULL pointer dereference in debugfs_create_str() - Fix misplaced EXPORT_SYMBOL_GPL for debugfs_create_str() - Fix soundwire debugfs NULL pointer dereference from uninitialized firmware_file device property: - Make fwnode flags modifications thread safe; widen the field to unsigned long and use set_bit() / clear_bit() based accessors - Document how to check for the property presence devres: - Separate struct devres_node from its "subclasses" (struct devres, struct devres_group); give struct devres_node its own release and free callbacks for per-type dispatch - Introduce struct devres_action for devres actions, avoiding the ARCH_DMA_MINALIGN alignment overhead of struct devres - Export struct devres_node and its init/add/remove/dbginfo primitives for use by Rust Devres - Fix missing node debug info in devm_krealloc() - Use guard(spinlock_irqsave) where applicable; consolidate unlock paths in devres_release_group() driver_override: - Convert PCI, WMI, vdpa, s390/cio, s390/ap, and fsl-mc to the generic driver_override infrastructure, replacing per-bus driver_override strings, sysfs attributes, and match logic; fixes a potential UAF from unsynchronized access to driver_override in bus match() callbacks - Simplify __device_set_driver_override() logic kernfs: - Send IN_DELETE_SELF and IN_IGNORED inotify events on kernfs file and directory removal - Add corresponding selftests for memcg platform: - Allow attaching software nodes when creating platform devices via a new 'swnode' field in struct platform_device_info - Add kerneldoc for struct platform_device_info software node: - Move software node initialization from postcore_initcall() to driver_init(), making it available early in the boot process - Move kernel_kobj initialization (ksysfs_init) earlier to support the above - Remove software_node_exit(); dead code in a built-in unit SoC: - Introduce of_machine_read_compatible() and of_machine_read_model() OF helpers and export soc_attr_read_machine() to replace direct accesses to of_root from SoC drivers; also enables CONFIG_COMPILE_TEST coverage for these drivers sysfs: - Constify attribute group array pointers to 'const struct attribute_group *const *' in sysfs functions, device_add_groups() / device_remove_groups(), and struct class Rust: - Devres: - Embed struct devres_node directly in Devres instead of going through devm_add_action(), avoiding the extra allocation and the unnecessary ARCH_DMA_MINALIGN alignment - I/O: - Turn IoCapable from a marker trait into a functional trait carrying the raw I/O accessor implementation (io_read / io_write), providing working defaults for the per-type Io methods - Add RelaxedMmio wrapper type, making relaxed accessors usable in code generic over the Io trait - Remove overloaded per-type Io methods and per-backend macros from Mmio and PCI ConfigSpace - I/O (Register): - Add IoLoc trait and generic read/write/update methods to the Io trait, making I/O operations parameterizable by typed locations - Add register! macro for defining hardware register types with typed bitfield accessors backed by Bounded values; supports direct, relative, and array register addressing - Add write_reg() / try_write_reg() and LocatedRegister trait - Update PCI sample driver to demonstrate the register! macro Example: ``` register! { /// UART control register. CTRL(u32) @ 0x18 { /// Receiver enable. 19:19 rx_enable => bool; /// Parity configuration. 14:13 parity ?=> Parity; } /// FIFO watermark and counter register. WATER(u32) @ 0x2c { /// Number of datawords in the receive FIFO. 26:24 rx_count; /// RX interrupt threshold. 17:16 rx_water; } } impl WATER { fn rx_above_watermark(&self) -> bool { self.rx_count() > self.rx_water() } } fn init(bar: &pci::Bar) { let water = WATER::zeroed() .with_const_rx_water::<1>(); // > 3 would not compile bar.write_reg(water); let ctrl = CTRL::zeroed() .with_parity(Parity::Even) .with_rx_enable(true); bar.write_reg(ctrl); } fn handle_rx(bar: &pci::Bar) { if bar.read(WATER).rx_above_watermark() { // drain the FIFO } } fn set_parity(bar: &pci::Bar, parity: Parity) { bar.update(CTRL, |r| r.with_parity(parity)); } ``` - IRQ: - Move 'static bounds from where clauses to trait declarations for IRQ handler traits - Misc: - Enable the generic_arg_infer Rust feature - Extend Bounded with shift operations, single-bit bool conversion, and const get() Misc: - Make deferred_probe_timeout default a Kconfig option - Drop auxiliary_dev_pm_ops; the PM core falls back to driver PM callbacks when no bus type PM ops are set - Add conditional guard support for device_lock() - Add ksysfs.c to the DRIVER CORE MAINTAINERS entry - Fix kernel-doc warnings in base.h - Fix stale reference to memory_block_add_nid() in documentation" * tag 'driver-core-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (67 commits) bus: fsl-mc: use generic driver_override infrastructure s390/ap: use generic driver_override infrastructure s390/cio: use generic driver_override infrastructure vdpa: use generic driver_override infrastructure platform/wmi: use generic driver_override infrastructure PCI: use generic driver_override infrastructure driver core: make software nodes available earlier software node: remove software_node_exit() kernel: ksysfs: initialize kernel_kobj earlier MAINTAINERS: add ksysfs.c to the DRIVER CORE entry drivers/base/memory: fix stale reference to memory_block_add_nid() device property: Document how to check for the property presence soundwire: debugfs: initialize firmware_file to empty string debugfs: fix placement of EXPORT_SYMBOL_GPL for debugfs_create_str() debugfs: check for NULL pointer in debugfs_create_str() driver core: Make deferred_probe_timeout default a Kconfig option driver core: simplify __device_set_driver_override() clearing logic driver core: auxiliary bus: Drop auxiliary_dev_pm_ops device property: Make modifications of fwnode "flags" thread safe rust: devres: embed struct devres_node directly ...

kernfs: pass struct ns_common instead of const void * for namespace tags

2026-04-09T12:36:52+00:00

kernfs has historically used const void * to pass around namespace tags used for directory-level namespace filtering. The only current user of this is sysfs network namespace tagging where struct net pointers are cast to void *. Replace all const void * namespace parameters with const struct ns_common * throughout the kernfs, sysfs, and kobject namespace layers. This includes the kobj_ns_type_operations callbacks, kobject_namespace(), and all sysfs/kernfs APIs that accept or return namespace tags. Passing struct ns_common is needed because various codepaths require access to the underlying namespace. A struct ns_common can always be converted back to the concrete namespace type (e.g., struct net) via container_of() or to_ns_common() in the reverse direction. This is a preparatory change for switching to ns_id-based directory iteration to prevent a KASLR pointer leak through the current use of raw namespace pointers as hash seeds and comparison keys. Signed-off-by: Christian Brauner

Merge tag 'v7.0-rc5' into driver-core-next

2026-03-22T22:13:33+00:00

We need the driver-core fixes in here as well to build on top of. Signed-off-by: Danilo Krummrich

driver core: generalize driver_override in struct device

2026-03-17T19:30:23+00:00

Currently, there are 12 busses (including platform and PCI) that duplicate the driver_override logic for their individual devices. All of them seem to be prone to the bug described in [1]. While this could be solved for every bus individually using a separate lock, solving this in the driver-core generically results in less (and cleaner) changes overall. Thus, move driver_override to struct device, provide corresponding accessors for busses and handle locking with a separate lock internally. In particular, add device_set_driver_override(), device_has_driver_override(), device_match_driver_override() and generalize the sysfs store() and show() callbacks via a driver_override feature flag in struct bus_type. Until all busses have migrated, keep driver_set_override() in place. Note that we can't use the device lock for the reasons described in [2]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220789 [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [2] Tested-by: Gui-Dong Han Co-developed-by: Gui-Dong Han Signed-off-by: Gui-Dong Han Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260303115720.48783-2-dakr@kernel.org [ Use dev->bus instead of sp->bus for consistency; fix commit message to refer to the struct bus_type's driver_override feature flag. - Danilo ] Signed-off-by: Danilo Krummrich

driver core: make struct class groups members constant arrays

2026-03-13T09:21:31+00:00

Constify the groups arrays, allowing to assign constant arrays. Signed-off-by: Heiner Kallweit Link: https://patch.msgid.link/7ff56b07-09ca-4948-b98f-5bd37ceef21e@gmail.com Signed-off-by: Greg Kroah-Hartman

Revert "driver core: enforce device_lock for driver_match_device()"

2026-03-03T12:12:42+00:00

This reverts commit dc23806a7c47 ("driver core: enforce device_lock for driver_match_device()") and commit 289b14592cef ("driver core: fix inverted "locked" suffix of driver_match_device()"). While technically correct, there is a major downside to this approach: When a device is already present in the system and a driver is registered on the same bus, we iterate over all devices registered on this bus to see if one of them matches. If we come across an already bound one where the corresponding driver crashed while holding the device lock (e.g. in probe()) we can't make any progress anymore. However, drivers are typically the least tested code in the kernel and hence it is a case that is likely to happen regularly. Besides hurting developer ergonomics, it potentially decreases chances of shutting things down cleanly and obtaining logs in production environments as well [1]. This came up in the context of a firewire bug, which only in combination with the reverted commit, caused the machine to hang [2]. Additionally, it was observed in [3]. Thus, revert commit dc23806a7c47 ("driver core: enforce device_lock for driver_match_device()") and add a brief note clarifying that an implementer of struct bus_type must not expect match() to be called with the device lock held. Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Link: https://lore.kernel.org/all/67f655bb-4d81-4609-b008-68d200255dd2@davidgow.net/ [2] Link: https://lore.kernel.org/lkml/CALbr=LZ4v7N=tO1vgOsyj9AS+XuNbn6kG-QcF+PacdMjSo0iyw@mail.gmail.com/ [3] Reported-by: Linus Torvalds Closes: https://lore.kernel.org/driver-core/CAHk-=wgJ_L1C=HjcYJotg_zrZEmiLFJaoic+PWthjuQrutrfJw@mail.gmail.com/ Reviewed-by: Gui-Dong Han Acked-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260302002545.19389-1-dakr@kernel.org [ Add additional Link: reference. - Danilo ] Signed-off-by: Danilo Krummrich

Merge tag 'v6.19-rc7' into driver-core-next

2026-01-26T12:23:52+00:00

We need the driver-core fixes in here as well to build on top of. Signed-off-by: Danilo Krummrich

driver-core: move devres_for_each_res() to base.h

2026-01-22T16:13:36+00:00

devres_for_each_res() is only used by .../firmware_loader/main.c, which already includes base.h. The usage of devres_for_each_res() by code outside of driver-core is questionable, hence move it to base.h. Acked-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260119162920.77189-1-dakr@kernel.org Signed-off-by: Danilo Krummrich

rust: driver: drop device private data post unbind

2026-01-16T00:17:29+00:00

Currently, the driver's device private data is allocated and initialized from driver core code called from bus abstractions after the driver's probe() callback returned the corresponding initializer. Similarly, the driver's device private data is dropped within the remove() callback of bus abstractions after calling the remove() callback of the corresponding driver. However, commit 6f61a2637abe ("rust: device: introduce Device::drvdata()") introduced an accessor for the driver's device private data for a Device, i.e. a device that is currently bound to a driver. Obviously, this is in conflict with dropping the driver's device private data in remove(), since a device can not be considered to be fully unbound after remove() has finished: We also have to consider registrations guarded by devres - such as IRQ or class device registrations - which are torn down after remove() in devres_release_all(). Thus, it can happen that, for instance, a class device or IRQ callback still calls Device::drvdata(), which then runs concurrently to remove() (which sets dev->driver_data to NULL and drops the driver's device private data), before devres_release_all() started to tear down the corresponding registration. This is because devres guarded registrations can, as expected, access the corresponding Device that defines their scope. In C it simply is the driver's responsibility to ensure that its device private data is freed after e.g. an IRQ registration is unregistered. Typically, C drivers achieve this by allocating their device private data with e.g. devm_kzalloc() before doing anything else, i.e. before e.g. registering an IRQ with devm_request_threaded_irq(), relying on the reverse order cleanup of devres. Technically, we could do something similar in Rust. However, the resulting code would be pretty messy: In Rust we have to differentiate between allocated but uninitialized memory and initialized memory in the type system. Thus, we would need to somehow keep track of whether the driver's device private data object has been initialized (i.e. probe() was successful and returned a valid initializer for this memory) and conditionally call the destructor of the corresponding object when it is freed. This is because we'd need to allocate and register the memory of the driver's device private data *before* it is initialized by the initializer returned by the driver's probe() callback, because the driver could already register devres guarded registrations within probe() outside of the driver's device private data initializer. Luckily there is a much simpler solution: Instead of dropping the driver's device private data at the end of remove(), we just drop it after the device has been fully unbound, i.e. after all devres callbacks have been processed. For this, we introduce a new post_unbind() callback private to the driver-core, i.e. the callback is neither exposed to drivers, nor to bus abstractions. This way, the driver-core code can simply continue to conditionally allocate the memory for the driver's device private data when the driver's initializer is returned from probe() - no change needed - and drop it when the driver-core code receives the post_unbind() callback. Closes: https://lore.kernel.org/all/DEZMS6Y4A7XE.XE7EUBT5SJFJ@kernel.org/ Fixes: 6f61a2637abe ("rust: device: introduce Device::drvdata()") Acked-by: Alice Ryhl Acked-by: Greg Kroah-Hartman Acked-by: Igor Korotin Link: https://patch.msgid.link/20260107103511.570525-7-dakr@kernel.org [ Remove #ifdef CONFIG_RUST, rename post_unbind() to post_unbind_rust(). - Danilo] Signed-off-by: Danilo Krummrich

driver core: make bus_find_device_by_acpi_dev() stub prototype aligned

2026-01-10T00:03:53+00:00

Currently the bus_find_device_by_acpi_dev() stub for !CONFIG_ACPI case takes a const void * parameter instead of const struct acpi_device *. As long as it's a pointer, we may named it as we want to with the help of a forward declaration. Hence move the declaration out of the ifdeffery and use the same prototype in both cases. This adds a bit of an additional type checking at a compilation time. Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20251229144325.1252197-1-andriy.shevchenko@linux.intel.com [ Fix minor typo in the commit message. - Danilo ] Signed-off-by: Danilo Krummrich