kernel/linux.git/drivers/base/core.c, branch v6.18.21

driver core: generalize driver_override in struct device

2026-04-02T11:22:54+00:00

[ Upstream commit cb3d1049f4ea77d5ad93f17d8ac1f2ed4da70501 ] 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 Stable-dep-of: 2b38efc05bf7 ("driver core: platform: use generic driver_override infrastructure") Signed-off-by: Sasha Levin

driver core: fw_devlink: Don't warn about sync_state() pending

2025-10-17T07:47:40+00:00

Due to the wider deployment of the ->sync_state() support, for PM domains for example, we are receiving reports about the sync_state() pending message that is being logged in fw_devlink_dev_sync_state(). In particular as it's printed at the warning level, which is questionable. Even if it certainly is useful to know that the ->sync_state() condition could not be met, there may be nothing wrong with it. For example, a driver may be built as module and are still waiting to be initialized/probed. For this reason let's move to the info level for now. Reported-by: Geert Uytterhoeven Reported-by: Sebin Francis Reported-by: Diederik de Haas Reported-by: Jon Hunter Reviewed-by: Tomi Valkeinen Signed-off-by: Ulf Hansson Reviewed-by: Dhruva Gole Reviewed-by: Sebastian Reichel Reviewed-by: Kevin Hilman Acked-by: Saravana Kannan Reviewed-by: Sebin Francis Tested-by: Sebin Francis Signed-off-by: Greg Kroah-Hartman

Merge branches 'pm-core' and 'pm-runtime'

2025-10-07T10:20:36+00:00

Merge runtime PM framework updates and a core power management code fix for 6.18-rc1: - Make pm_runtime_put*() family of functions return 1 when the given device is already suspended which is consistent with the documentation (Brian Norris) - Add basic kunit tests for runtime PM API contracts and update return values in kerneldoc coments for the runtime PM API (Brian Norris, Dan Carpenter) - Add auto-cleanup macros for runtime PM "resume and get" and "get without resume" operations, use one of them in the PCI core and drop the existing "free" macro introduced for similar purpose, but somewhat cumbersome to use (Rafael Wysocki) - Make the core power management code avoid waiting on device links marked as SYNC_STATE_ONLY which is consistent with the handling of those device links elsewhere (Pin-yen Lin) * pm-core: PM: sleep: Do not wait on SYNC_STATE_ONLY device links * pm-runtime: PM: runtime: Fix error checking for kunit_device_register() PM: runtime: Introduce one more usage counter guard PM: runtime: Drop DEFINE_FREE() for pm_runtime_put() PCI/sysfs: Use runtime PM guard macro for auto-cleanup PM: runtime: Add auto-cleanup macros for "resume and get" operations PM: runtime: Update kerneldoc return codes PM: runtime: Make put{,_sync}() return 1 when already suspended PM: runtime: Add basic kunit tests for API contracts

PM: sleep: Do not wait on SYNC_STATE_ONLY device links

2025-09-27T12:10:51+00:00

Device links with DL_FLAG_SYNC_STATE_ONLY should not affect system suspend and resume, and functions like device_reorder_to_tail() and device_link_add() don't try to reorder the consumers with that flag. However, dpm_wait_for_consumers() and dpm_wait_for_suppliers() don't check thas flag before triggering dpm_wait(), leading to potential hang during suspend/resume. This can be reproduced on MT8186 Corsola Chromebook with devicetree like: usb-a-connector { compatible = "usb-a-connector"; port { usb_a_con: endpoint { remote-endpoint = <&usb_hs>; }; }; }; usb_host { compatible = "mediatek,mt8186-xhci", "mediatek,mtk-xhci"; port { usb_hs: endpoint { remote-endpoint = <&usb_a_con>; }; }; }; In this case, the two nodes form a cycle and a SYNC_STATE_ONLY devlink between usb_host (supplier) and usb-a-connector (consumer) is created. Address this by exporting device_link_flag_is_sync_state_only() and making dpm_wait_for_consumers() and dpm_wait_for_suppliers() use it when deciding if dpm_wait() should be called. Fixes: 05ef983e0d65a ("driver core: Add device link support for SYNC_STATE_ONLY flag") Signed-off-by: Pin-yen Lin Link: https://patch.msgid.link/20250926102320.4053167-1-treapking@chromium.org [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

driver core: Fix order of the kernel-doc parameters

2025-09-06T17:52:25+00:00

Fix the order of the kernel-doc parameters in device_find_child() and device_for_each_child*() functions to match the actual functions signature. No functional changes. Signed-off-by: Gil Fine Link: https://lore.kernel.org/r/20250831194930.2063390-1-gil.fine@linux.intel.com Signed-off-by: Greg Kroah-Hartman

driver core: get_dev_from_fwnode(): document potential race

2025-09-06T17:52:21+00:00

Commit 9a4681a485ee ("driver core: Export get_dev_from_fwnode()") made get_dev_from_fwnode() publicly available, but didn't document the guarantees a caller must uphold: get_dev_from_fwnode() obtains a reference count from the device pointer stored in a struct fwnode_handle. While having its own reference count, struct fwnode_handle does not keep a reference count of the device it has a pointer to. Consequently, a caller must guarantee that it is impossible that the last device reference is dropped and the device is released concurrently while calling get_dev_from_fwnode(), otherwise this is a potential UAF and hence a bug. Thus, document this potential race condition for get_dev_from_fwnode(). Cc: Ulf Hansson Cc: Saravana Kannan Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20250829205911.33142-1-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

2025-07-29T19:15:39+00:00

Pull driver core updates from Danilo Krummrich: "debugfs: - Remove unneeded debugfs_file_{get,put}() instances - Remove last remnants of debugfs_real_fops() - Allow storing non-const void * in struct debugfs_inode_info::aux sysfs: - Switch back to attribute_group::bin_attrs (treewide) - Switch back to bin_attribute::read()/write() (treewide) - Constify internal references to 'struct bin_attribute' Support cache-ids for device-tree systems: - Add arch hook arch_compact_of_hwid() - Use arch_compact_of_hwid() to compact MPIDR values on arm64 Rust: - Device: - Introduce CoreInternal device context (for bus internal methods) - Provide generic drvdata accessors for bus devices - Provide Driver::unbind() callbacks - Use the infrastructure above for auxiliary, PCI and platform - Implement Device::as_bound() - Rename Device::as_ref() to Device::from_raw() (treewide) - Implement fwnode and device property abstractions - Implement example usage in the Rust platform sample driver - Devres: - Remove the inner reference count (Arc) and use pin-init instead - Replace Devres::new_foreign_owned() with devres::register() - Require T to be Send in Devres - Initialize the data kept inside a Devres last - Provide an accessor for the Devres associated Device - Device ID: - Add support for ACPI device IDs and driver match tables - Split up generic device ID infrastructure - Use generic device ID infrastructure in net::phy - DMA: - Implement the dma::Device trait - Add DMA mask accessors to dma::Device - Implement dma::Device for PCI and platform devices - Use DMA masks from the DMA sample module - I/O: - Implement abstraction for resource regions (struct resource) - Implement resource-based ioremap() abstractions - Provide platform device accessors for I/O (remap) requests - Misc: - Support fallible PinInit types in Revocable - Implement Wrapper for Opaque - Merge pin-init blanket dependencies (for Devres) Misc: - Fix OF node leak in auxiliary_device_create() - Use util macros in device property iterators - Improve kobject sample code - Add device_link_test() for testing device link flags - Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits - Hint to prefer container_of_const() over container_of()" * tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits) rust: io: fix broken intra-doc links to `platform::Device` rust: io: fix broken intra-doc link to missing `flags` module rust: io: mem: enable IoRequest doc-tests rust: platform: add resource accessors rust: io: mem: add a generic iomem abstraction rust: io: add resource abstraction rust: samples: dma: set DMA mask rust: platform: implement the `dma::Device` trait rust: pci: implement the `dma::Device` trait rust: dma: add DMA addressing capabilities rust: dma: implement `dma::Device` trait rust: net::phy Change module_phy_driver macro to use module_device_table macro rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id rust: device_id: split out index support into a separate trait device: rust: rename Device::as_ref() to Device::from_raw() arm64: cacheinfo: Provide helper to compress MPIDR value into u32 cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id cacheinfo: Set cache 'id' based on DT data container_of: Document container_of() is not to be used in new code driver core: auxiliary bus: fix OF node leak ...

driver core: Export get_dev_from_fwnode()

2025-07-09T11:29:37+00:00

It has turned out get_dev_from_fwnode() is useful at a few other places outside of the driver core, as in gpiolib.c for example. Therefore let's make it available as a common helper function. Suggested-by: Saravana Kannan Cc: Greg Kroah-Hartman Tested-by: Hiago De Franco # Colibri iMX8X Tested-by: Tomi Valkeinen # TI AM62A,Xilinx ZynqMP ZCU106 Acked-by: Greg Kroah-Hartman Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20250701114733.636510-18-ulf.hansson@linaro.org

driver core: Add device_link_test() for testing device link flags

2025-06-17T08:57:56+00:00

To avoid coding mistakes like the one fixed by commit 3860cbe23963 ("PM: sleep: Fix bit masking operation"), introduce device_link_test() for testing device link flags and use it where applicable. No intentional functional impact. Signed-off-by: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/2793309.mvXUDI8C0e@rjwysocki.net Signed-off-by: Greg Kroah-Hartman

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

2025-04-15T15:04:35+00:00

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