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2025-04-15driver core: fix potential NULL pointer dereference in dev_uevent()Dmitry Torokhov
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 <dmitry.torokhov@gmail.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20250311052417.1846985-3-dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-15driver core: introduce device_set_driver() helperDmitry Torokhov
In preparation to closing a race when reading driver pointer in dev_uevent() code, instead of setting device->driver pointer directly introduce device_set_driver() helper. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20250311052417.1846985-2-dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-15Revert "drivers: core: synchronize really_probe() and dev_uevent()"Dmitry Torokhov
This reverts commit c0a40097f0bc81deafc15f9195d1fb54595cd6d0. Probing a device can take arbitrary long time. In the field we observed that, for example, probing a bad micro-SD cards in an external USB card reader (or maybe cards were good but cables were flaky) sometimes takes longer than 2 minutes due to multiple retries at various levels of the stack. We can not block uevent_show() method for that long because udev is reading that attribute very often and that blocks udev and interferes with booting of the system. The change that introduced locking was concerned with dev_uevent() racing with unbinding the driver. However we can handle it without locking (which will be done in subsequent patch). There was also claim that synchronization with probe() is needed to properly load USB drivers, however this is a red herring: the change adding the lock was introduced in May of last year and USB loading and probing worked properly for many years before that. Revert the harmful locking. Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20250311052417.1846985-1-dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-28Merge tag 'pci-v6.15-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull pci updates from Bjorn Helgaas: "Enumeration: - Enable Configuration RRS SV, which makes device readiness visible, early instead of during child bus scanning (Bjorn Helgaas) - Log debug messages about reset methods being used (Bjorn Helgaas) - Avoid reset when it has been disabled via sysfs (Nishanth Aravamudan) - Add common pci-ep-bus.yaml schema for exporting several peripherals of a single PCI function via devicetree (Andrea della Porta) - Create DT nodes for PCI host bridges to enable loading device tree overlays to create platform devices for PCI devices that have several features that require multiple drivers (Herve Codina) Resource management: - Enlarge devres table[] to accommodate bridge windows, ROM, IOV BARs, etc., and validate BAR index in devres interfaces (Philipp Stanner) - Fix typo that repeatedly distributed resources to a bridge instead of iterating over subordinate bridges, which resulted in too little space to assign some BARs (Kai-Heng Feng) - Relax bridge window tail sizing for optional resources, e.g., IOV BARs, to avoid failures when removing and re-adding devices (Ilpo Järvinen) - Allow drivers to enable devices even if we haven't assigned optional IOV resources to them (Ilpo Järvinen) - Rework handling of optional resources (IOV BARs, ROMs) to reduce failures if we can't allocate them (Ilpo Järvinen) - Fix a NULL dereference in the SR-IOV VF creation error path (Shay Drory) - Fix s390 mmio_read/write syscalls, which didn't cause page faults in some cases, which broke vfio-pci lazy mapping on first access (Niklas Schnelle) - Add pdev->non_mappable_bars to replace CONFIG_VFIO_PCI_MMAP, which was disabled only for s390 (Niklas Schnelle) - Support mmap of PCI resources on s390 except for ISM devices (Niklas Schnelle) ASPM: - Delay pcie_link_state deallocation to avoid dangling pointers that cause invalid references during hot-unplug (Daniel Stodden) Power management: - Allow PCI bridges to go to D3Hot when suspending on all non-x86 systems (Manivannan Sadhasivam) Power control: - Create pwrctrl devices in pci_scan_device() to make it more symmetric with pci_pwrctrl_unregister() and make pwrctrl devices for PCI bridges possible (Manivannan Sadhasivam) - Unregister pwrctrl devices in pci_destroy_dev() so DOE, ASPM, etc. can still access devices after pci_stop_dev() (Manivannan Sadhasivam) - If there's a pwrctrl device for a PCI device, skip scanning it because the pwrctrl core will rescan the bus after the device is powered on (Manivannan Sadhasivam) - Add a pwrctrl driver for PCI slots based on voltage regulators described via devicetree (Manivannan Sadhasivam) Bandwidth control: - Add set_pcie_speed.sh to TEST_PROGS to fix issue when executing the set_pcie_cooling_state.sh test case (Yi Lai) - Avoid a NULL pointer dereference when we run out of bus numbers to assign for a bridge secondary bus (Lukas Wunner) Hotplug: - Drop superfluous pci_hotplug_slot_list, try_module_get() calls, and NULL pointer checks (Lukas Wunner) - Drop shpchp module init/exit logging, replace shpchp dbg() with ctrl_dbg(), and remove unused dbg(), err(), info(), warn() wrappers (Ilpo Järvinen) - Drop 'shpchp_debug' module parameter in favor of standard dynamic debugging (Ilpo Järvinen) - Drop unused cpcihp .get_power(), .set_power() function pointers (Guilherme Giacomo Simoes) - Disable hotplug interrupts in portdrv only when pciehp is not enabled to avoid issuing two hotplug commands too close together (Feng Tang) - Skip pciehp 'device replaced' check if the device has been removed to address a deadlock when resuming after a device was removed during system sleep (Lukas Wunner) - Don't enable pciehp hotplug interupt when resuming in poll mode (Ilpo Järvinen) Virtualization: - Fix bugs in 'pci=config_acs=' kernel command line parameter (Tushar Dave) DOE: - Expose supported DOE features via sysfs (Alistair Francis) - Allow DOE support to be enabled even if CXL isn't enabled (Alistair Francis) Endpoint framework: - Convert PCI device data so pci-epf-test works correctly on big-endian endpoint systems (Niklas Cassel) - Add BAR_RESIZABLE type to endpoint framework and add DWC core support for EPF drivers to set BAR_RESIZABLE type and size (Niklas Cassel) - Fix pci-epf-test double free that causes an oops if the host reboots and PERST# deassertion restarts endpoint BAR allocation (Christian Bruel) - Fix endpoint BAR testing so tests can skip disabled BARs instead of reporting them as failures (Niklas Cassel) - Widen endpoint test BAR size variable to accommodate BARs larger than INT_MAX (Niklas Cassel) - Remove unused tools 'pci' build target left over after moving tests to tools/testing/selftests/pci_endpoint (Jianfeng Liu) Altera PCIe controller driver: - Add DT binding and driver support for Agilex family (P-Tile, F-Tile, R-Tile) (Matthew Gerlach and D M, Sharath Kumar) AMD MDB PCIe controller driver: - Add DT binding and driver for AMD MDB (Multimedia DMA Bridge) (Thippeswamy Havalige) Broadcom STB PCIe controller driver: - Add BCM2712 MSI-X DT binding and interrupt controller drivers and add softdep on irq_bcm2712_mip driver to ensure that it is loaded first (Stanimir Varbanov) - Expand inbound window map to 64GB so it can accommodate BCM2712 (Stanimir Varbanov) - Add BCM2712 support and DT updates (Stanimir Varbanov) - Apply link speed restriction before bringing link up, not after (Jim Quinlan) - Update Max Link Speed in Link Capabilities via the internal writable register, not the read-only config register (Jim Quinlan) - Handle regulator_bulk_get() error to avoid panic when we call regulator_bulk_free() later (Jim Quinlan) - Disable regulators only when removing the bus immediately below a Root Port because we don't support regulators deeper in the hierarchy (Jim Quinlan) - Make const read-only arrays static (Colin Ian King) Cadence PCIe endpoint driver: - Correct MSG TLP generation so endpoints can generate INTx messages (Hans Zhang) Freescale i.MX6 PCIe controller driver: - Identify the second controller on i.MX8MQ based on devicetree 'linux,pci-domain' instead of DBI 'reg' address (Richard Zhu) - Remove imx_pcie_cpu_addr_fixup() since dwc core can now derive the ATU input address (using parent_bus_offset) from devicetree (Frank Li) Freescale Layerscape PCIe controller driver: - Drop deprecated 'num-ib-windows' and 'num-ob-windows' and unnecessary 'status' from example (Krzysztof Kozlowski) - Correct the syscon_regmap_lookup_by_phandle_args("fsl,pcie-scfg") arg_count to fix probe failure on LS1043A (Ioana Ciornei) HiSilicon STB PCIe controller driver: - Call phy_exit() to clean up if histb_pcie_probe() fails (Christophe JAILLET) Intel Gateway PCIe controller driver: - Remove intel_pcie_cpu_addr() since dwc core can now derive the ATU input address (using parent_bus_offset) from devicetree (Frank Li) Intel VMD host bridge driver: - Convert vmd_dev.cfg_lock from spinlock_t to raw_spinlock_t so pci_ops.read() will never sleep, even on PREEMPT_RT where spinlock_t becomes a sleepable lock, to avoid calling a sleeping function from invalid context (Ryo Takakura) MediaTek PCIe Gen3 controller driver: - Remove leftover mac_reset assert for Airoha EN7581 SoC (Lorenzo Bianconi) - Add EN7581 PBUS controller 'mediatek,pbus-csr' DT property and program host bridge memory aperture to this syscon node (Lorenzo Bianconi) Qualcomm PCIe controller driver: - Add qcom,pcie-ipq5332 binding (Varadarajan Narayanan) - Add qcom i.MX8QM and i.MX8QXP/DXP optional DMA interrupt (Alexander Stein) - Add optional dma-coherent DT property for Qualcomm SA8775P (Dmitry Baryshkov) - Make DT iommu property required for SA8775P and prohibited for SDX55 (Dmitry Baryshkov) - Add DT IOMMU and DMA-related properties for Qualcomm SM8450 (Dmitry Baryshkov) - Add endpoint DT properties for SAR2130P and enable endpoint mode in driver (Dmitry Baryshkov) - Describe endpoint BAR0 and BAR2 as 64-bit only and BAR1 and BAR3 as RESERVED (Manivannan Sadhasivam) Rockchip DesignWare PCIe controller driver: - Describe rk3568 and rk3588 BARs as Resizable, not Fixed (Niklas Cassel) Synopsys DesignWare PCIe controller driver: - Add debugfs-based Silicon Debug, Error Injection, Statistical Counter support for DWC (Shradha Todi) - Add debugfs property to expose LTSSM status of DWC PCIe link (Hans Zhang) - Add Rockchip support for DWC debugfs features (Niklas Cassel) - Add dw_pcie_parent_bus_offset() to look up the parent bus address of a specified 'reg' property and return the offset from the CPU physical address (Frank Li) - Use dw_pcie_parent_bus_offset() to derive CPU -> ATU addr offset via 'reg[config]' for host controllers and 'reg[addr_space]' for endpoint controllers (Frank Li) - Apply struct dw_pcie.parent_bus_offset in ATU users to remove use of .cpu_addr_fixup() when programming ATU (Frank Li) TI J721E PCIe driver: - Correct the 'link down' interrupt bit for J784S4 (Siddharth Vadapalli) TI Keystone PCIe controller driver: - Describe AM65x BARs 2 and 5 as Resizable (not Fixed) and reduce alignment requirement from 1MB to 64KB (Niklas Cassel) Xilinx Versal CPM PCIe controller driver: - Free IRQ domain in probe error path to avoid leaking it (Thippeswamy Havalige) - Add DT .compatible "xlnx,versal-cpm5nc-host" and driver support for Versal Net CPM5NC Root Port controller (Thippeswamy Havalige) - Add driver support for CPM5_HOST1 (Thippeswamy Havalige) Miscellaneous: - Convert fsl,mpc83xx-pcie binding to YAML (J. Neuschäfer) - Use for_each_available_child_of_node_scoped() to simplify apple, kirin, mediatek, mt7621, tegra drivers (Zhang Zekun)" * tag 'pci-v6.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (197 commits) PCI: layerscape: Fix arg_count to syscon_regmap_lookup_by_phandle_args() PCI: j721e: Fix the value of .linkdown_irq_regfield for J784S4 misc: pci_endpoint_test: Add support for PCITEST_IRQ_TYPE_AUTO PCI: endpoint: pci-epf-test: Expose supported IRQ types in CAPS register PCI: dw-rockchip: Endpoint mode cannot raise INTx interrupts PCI: endpoint: Add intx_capable to epc_features struct dt-bindings: PCI: Add common schema for devices accessible through PCI BARs PCI: intel-gw: Remove intel_pcie_cpu_addr() PCI: imx6: Remove imx_pcie_cpu_addr_fixup() PCI: dwc: Use parent_bus_offset to remove need for .cpu_addr_fixup() PCI: dwc: ep: Ensure proper iteration over outbound map windows PCI: dwc: ep: Use devicetree 'reg[addr_space]' to derive CPU -> ATU addr offset PCI: dwc: ep: Consolidate devicetree handling in dw_pcie_ep_get_resources() PCI: dwc: ep: Call epc_create() early in dw_pcie_ep_init() PCI: dwc: Use devicetree 'reg[config]' to derive CPU -> ATU addr offset PCI: dwc: Add dw_pcie_parent_bus_offset() checking and debug PCI: dwc: Add dw_pcie_parent_bus_offset() PCI/bwctrl: Fix NULL pointer dereference on bus number exhaustion PCI: xilinx-cpm: Add cpm_csr register mapping for CPM5_HOST1 variant PCI: brcmstb: Make const read-only arrays static ...
2025-02-28driver core: Introduce device_{add,remove}_of_node()Herve Codina
An of_node can be set to a device using device_set_node(), which does not prevent any of_node and/or fwnode overwrites. When adding an of_node on an already present device, the following operations need to be done: - Attach the of_node only if no of_node is already attached - Attach the of_node as a fwnode if no fwnode were already attached This is the purpose of device_add_of_node(). device_remove_of_node() reverts the operations done by device_add_of_node(). Link: https://lore.kernel.org/r/20250224141356.36325-2-herve.codina@bootlin.com Signed-off-by: Herve Codina <herve.codina@bootlin.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-20drivers: core: fix device leak in __fw_devlink_relax_cycles()Luca Ceresoli
Commit bac3b10b78e5 ("driver core: fw_devlink: Stop trying to optimize cycle detection logic") introduced a new struct device *con_dev and a get_dev_from_fwnode() call to get it, but without adding a corresponding put_device(). Closes: https://lore.kernel.org/all/20241204124826.2e055091@booty/ Fixes: bac3b10b78e5 ("driver core: fw_devlink: Stop trying to optimize cycle detection logic") Cc: stable@vger.kernel.org Reviewed-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> Link: https://lore.kernel.org/r/20250213-fix__fw_devlink_relax_cycles_missing_device_put-v2-1-8cd3b03e6a3f@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Move two simple APIs for finding child device to headerZijun Hu
The following two APIs are for finding child device, and both only have one line code in function body. device_find_child_by_name() device_find_any_child() Move them to header as static inline function. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-8-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Introduce device_iter_t for device iterating APIsZijun Hu
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 <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Correct API device_for_each_child_reverse_from() prototypeZijun Hu
For API device_for_each_child_reverse_from(..., const void *data, int (*fn)(struct device *dev, const void *data)) - Type of @data is const pointer, and means caller's data @*data is not allowed to be modified, but that usually is not proper for such non finding device iterating API. - Types for both @data and @fn are not consistent with all other for_each device iterating APIs device_for_each_child(_reverse)(), bus_for_each_dev() and (driver|class)_for_each_device(). Correct its prototype by removing const from parameter types, then adapt for various existing usages. An dedicated typedef device_iter_t will be introduced as @fn() type for various for_each device interating APIs later. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-6-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Correct parameter check for API ↵Zijun Hu
device_for_each_child_reverse_from() device_for_each_child_reverse_from() checks (!parent->p) for its parameter @parent, and that is not consistent with other APIs of its cluster as shown below: device_for_each_child_reverse_from() // check (!parent->p) device_for_each_child_reverse() // check (!parent || !parent->p) device_for_each_child() // same above device_find_child() // same above Correct the API's parameter @parent check by (!parent || !parent->p). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-5-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Move true expression out of if condition in 3 device finding APIsZijun Hu
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 <fan.ni@samsung.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-3-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Introduce an device matching API device_match_type()Zijun Hu
Introduce device_match_type() for purposes below: - Test if a device matches with a specified device type. - As argument of various device finding APIs to find a device with specified type. device_find_child() will use it to simplify operations later. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-9-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Remove match_any()Zijun Hu
Static match_any() is now exactly same as API device_match_any(). Remove the former and use the later instead. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-6-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Simplify API device_find_child_by_name() implementationZijun Hu
Simplify device_find_child_by_name() implementation by both existing API device_find_child() and device_match_name(). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-5-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-24drivers: base: Don't match devices with NULL of_node/fwnode/etcBrian Norris
of_find_device_by_node(), bus_find_device_by_of_node(), bus_find_device_by_fwnode(), ..., all produce arbitrary results when provided with a NULL of_node, fwnode, ACPI handle, etc. This is counterintuitive, and the source of a few bugs, such as the one fixed by commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if one actually exists"). It's hard to imagine a good reason that these device_match_*() APIs should return 'true' for a NULL argument. Augment these to return 0 (false). Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Brian Norris <briannorris@chromium.org> Acked-by: David Gow <davidgow@google.com> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/20241216201148.535115-2-briannorris@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-29Merge tag 'driver-core-6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is a small set of driver core changes for 6.13-rc1. Nothing major for this merge cycle, except for the two simple merge conflicts are here just to make life interesting. Included in here are: - sysfs core changes and preparations for more sysfs api cleanups that can come through all driver trees after -rc1 is out - fw_devlink fixes based on many reports and debugging sessions - list_for_each_reverse() removal, no one was using it! - last-minute seq_printf() format string bug found and fixed in many drivers all at once. - minor bugfixes and changes full details in the shortlog" * tag 'driver-core-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits) Fix a potential abuse of seq_printf() format string in drivers cpu: Remove spurious NULL in attribute_group definition s390/con3215: Remove spurious NULL in attribute_group definition perf: arm-ni: Remove spurious NULL in attribute_group definition driver core: Constify bin_attribute definitions sysfs: attribute_group: allow registration of const bin_attribute firmware_loader: Fix possible resource leak in fw_log_firmware_info() drivers: core: fw_devlink: Fix excess parameter description in docstring driver core: class: Correct WARN() message in APIs class_(for_each|find)_device() cacheinfo: Use of_property_present() for non-boolean properties cdx: Fix cdx_mmap_resource() after constifying attr in ->mmap() drivers: core: fw_devlink: Make the error message a bit more useful phy: tegra: xusb: Set fwnode for xusb port devices drm: display: Set fwnode for aux bus devices driver core: fw_devlink: Stop trying to optimize cycle detection logic driver core: Constify attribute arguments of binary attributes sysfs: bin_attribute: add const read/write callback variants sysfs: implement all BIN_ATTR_* macros in terms of __BIN_ATTR() sysfs: treewide: constify attribute callback of bin_attribute::llseek() sysfs: treewide: constify attribute callback of bin_attribute::mmap() ...
2024-11-20Merge tag 'spi-v6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi Pull spi updates from Mark Brown: "The only real core work we've got this time around is the completion of the transition to the new host/target naming for the core APIs, Kconfig still needs doing but that's a lot less invasive. Otherwise the big changes are the new drivers that have been added: - Completion of the conversion to spi_alloc_host()/_target() and removal of the old naming. - Cleanups for Rockchip drivers, these brought in a new logging helper in the driver core for warnings during probe. - Support for configuration of the word delay via spidev_test. - Support for AMD HID2 controllers, Apple SPI controller and Realtek SPI-NAND controllers" * tag 'spi-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (58 commits) spi: imx: support word delay spi: imx: pass struct spi_transfer to prepare_transfer() spi: cs42l43: Add GPIO speaker id support to the bridge configuration spi: Delete useless checks spi: apple: Remove unnecessary .owner for apple_spi_driver spi: spidev_test: add support for word delay spi: apple: Add driver for Apple SPI controller spi: dt-bindings: apple,spi: Add binding for Apple SPI controllers spi: Use of_property_present() for non-boolean properties spi: zynqmp-gqspi: Undo runtime PM changes at driver exit time​ spi: spi-mem: rtl-snand: Correctly handle DMA transfers spi: tegra210-quad: Avoid shift-out-of-bounds spi: axi-spi-engine: Emit trace events for spi transfers dt-bindings: spi: sprd,sc9860-spi: convert to YAML spi: Replace deprecated PCI functions spi: dt-bindings: samsung: Add a compatible for samsung,exynos8895-spi spi: spi-mem: Add Realtek SPI-NAND controller dt-bindings: spi: Add realtek,rtl9301-snand spi: make class structs const spi: dt-bindings: brcm,bcm2835-aux-spi: Convert to dtschema ...
2024-11-12drivers: core: fw_devlink: Fix excess parameter description in docstringAmit Vadhavana
Replace the parameter name 'con' with 'con_handle' in the docstring of __fw_devlink_relax_cycles() to resolve the kernel-doc warning about an excess parameter description. Address the following warning: ./drivers/base/core.c:1994: warning: Excess function parameter 'con' description in '__fw_devlink_relax_cycles' Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/all/20241107223528.3781323e@canb.auug.org.au/ Signed-off-by: Amit Vadhavana <av2082000@gmail.com> Link: https://lore.kernel.org/r/20241111165253.16672-1-av2082000@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05drivers: core: fw_devlink: Make the error message a bit more usefulSaravana Kannan
It would make it easier to debugs issues similar to the ones reported[1][2] recently where some devices didn't have the fwnode set. [1] - https://lore.kernel.org/all/7b995947-4540-4b17-872e-e107adca4598@notapiano/ [2] - https://lore.kernel.org/all/20240910130019.35081-1-jonathanh@nvidia.com/ Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20241024061347.1771063-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05driver core: fw_devlink: Stop trying to optimize cycle detection logicSaravana Kannan
In attempting to optimize fw_devlink runtime, I introduced numerous cycle detection bugs by foregoing cycle detection logic under specific conditions. Each fix has further narrowed the conditions for optimization. It's time to give up on these optimization attempts and just run the cycle detection logic every time fw_devlink tries to create a device link. The specific bug report that triggered this fix involved a supplier fwnode that never gets a device created for it. Instead, the supplier fwnode is represented by the device that corresponds to an ancestor fwnode. In this case, fw_devlink didn't do any cycle detection because the cycle detection logic is only run when a device link is created between the devices that correspond to the actual consumer and supplier fwnodes. With this change, fw_devlink will run cycle detection logic even when creating SYNC_STATE_ONLY proxy device links from a device that is an ancestor of a consumer fwnode. Reported-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Closes: https://lore.kernel.org/all/1a1ab663-d068-40fb-8c94-f0715403d276@ideasonboard.com/ Fixes: 6442d79d880c ("driver core: fw_devlink: Improve detection of overlapping cycles") Cc: stable <stable@kernel.org> Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20241030171009.1853340-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05Merge 6.12-rc6 into driver-core-nextGreg Kroah-Hartman
We need the driver-core fix/revert in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-04driver core: constify devlink classBartosz Golaszewski
The devlink class object is never modified and can be made constant. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20241014122849.118766-1-brgl@bgdev.pl Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-03Merge tag 'driver-core-6.12-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core revert from Greg KH: "Here is a single driver core revert for 6.12-rc6. It reverts a change that came in -rc1 that was supposed to resolve a reported problem, but caused another one, so revert it for now so that we can get this all worked out properly in 6.13. The revert has been in linux-next all week with no reported issues" * tag 'driver-core-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: Revert "driver core: Fix uevent_show() vs driver detach race"
2024-10-29Revert "driver core: Fix uevent_show() vs driver detach race"Greg Kroah-Hartman
This reverts commit 15fffc6a5624b13b428bb1c6e9088e32a55eb82c. This commit causes a regression, so revert it for now until it can come back in a way that works for everyone. Link: https://lore.kernel.org/all/172790598832.1168608.4519484276671503678.stgit@dwillia2-xfh.jf.intel.com/ Fixes: 15fffc6a5624 ("driver core: Fix uevent_show() vs driver detach race") Cc: stable <stable@kernel.org> Cc: Ashish Sangwan <a.sangwan@samsung.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Dirk Behme <dirk.behme@de.bosch.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-25cxl/port: Fix use-after-free, permit out-of-order decoder shutdownDan Williams
In support of investigating an initialization failure report [1], cxl_test was updated to register mock memory-devices after the mock root-port/bus device had been registered. That led to cxl_test crashing with a use-after-free bug with the following signature: cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem0:decoder7.0 @ 0 next: cxl_switch_uport.0 nr_eps: 1 nr_targets: 1 cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem4:decoder14.0 @ 1 next: cxl_switch_uport.0 nr_eps: 2 nr_targets: 1 cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[0] = cxl_switch_dport.0 for mem0:decoder7.0 @ 0 1) cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[1] = cxl_switch_dport.4 for mem4:decoder14.0 @ 1 [..] cxld_unregister: cxl decoder14.0: cxl_region_decode_reset: cxl_region region3: mock_decoder_reset: cxl_port port3: decoder3.0 reset 2) mock_decoder_reset: cxl_port port3: decoder3.0: out of order reset, expected decoder3.1 cxl_endpoint_decoder_release: cxl decoder14.0: [..] cxld_unregister: cxl decoder7.0: 3) cxl_region_decode_reset: cxl_region region3: Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP PTI [..] RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core] [..] Call Trace: <TASK> cxl_region_decode_reset+0x69/0x190 [cxl_core] cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x5d/0x60 [cxl_core] At 1) a region has been established with 2 endpoint decoders (7.0 and 14.0). Those endpoints share a common switch-decoder in the topology (3.0). At teardown, 2), decoder14.0 is the first to be removed and hits the "out of order reset case" in the switch decoder. The effect though is that region3 cleanup is aborted leaving it in-tact and referencing decoder14.0. At 3) the second attempt to teardown region3 trips over the stale decoder14.0 object which has long since been deleted. The fix here is to recognize that the CXL specification places no mandate on in-order shutdown of switch-decoders, the driver enforces in-order allocation, and hardware enforces in-order commit. So, rather than fail and leave objects dangling, always remove them. In support of making cxl_region_decode_reset() always succeed, cxl_region_invalidate_memregion() failures are turned into warnings. Crashing the kernel is ok there since system integrity is at risk if caches cannot be managed around physical address mutation events like CXL region destruction. A new device_for_each_child_reverse_from() is added to cleanup port->commit_end after all dependent decoders have been disabled. In other words if decoders are allocated 0->1->2 and disabled 1->2->0 then port->commit_end only decrements from 2 after 2 has been disabled, and it decrements all the way to zero since 1 was disabled previously. Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1] Cc: stable@vger.kernel.org Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Zijun Hu <quic_zijuhu@quicinc.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/172964782781.81806.17902885593105284330.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2024-10-08driver core: Add device probe log helper dev_warn_probe()Dragan Simic
Some drivers can still provide their functionality to a certain extent even when some of their resource acquisitions eventually fail. In such cases, emitting errors isn't the desired action, but warnings should be emitted instead. To solve this, introduce dev_warn_probe() as a new device probe log helper, which behaves identically as the already existing dev_err_probe(), while it produces warnings instead of errors. The intended use is with the resources that are actually optional for a particular driver. While there, copyedit the kerneldoc for dev_err_probe() a bit, to simplify its wording a bit, and reuse it as the kerneldoc for dev_warn_probe(), with the necessary wording adjustments, of course. Signed-off-by: Dragan Simic <dsimic@manjaro.org> Tested-by: Hélène Vulquin <oss@helene.moe> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/2be0a28538bb2a3d1bcc91e2ca1f2d0dc09146d9.1727601608.git.dsimic@manjaro.org Signed-off-by: Mark Brown <broonie@kernel.org>
2024-09-25Revert "driver core: don't always lock parent in shutdown"Greg Kroah-Hartman
This reverts commit ba6353748e71bd1d7e422fec2b5c2e2dfc2e3bd9. The series is being reverted before -rc1 as there are still reports of lockups on shutdown, so it's not quite ready for "prime time." Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com> Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local Cc: Christoph Hellwig <hch@lst.de> Cc: David Jeffery <djeffery@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Laurence Oberman <loberman@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25Revert "driver core: separate function to shutdown one device"Greg Kroah-Hartman
This reverts commit 95dc7565253a8564911190ebd1e4ffceb4de208a. The series is being reverted before -rc1 as there are still reports of lockups on shutdown, so it's not quite ready for "prime time." Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com> Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local Cc: Christoph Hellwig <hch@lst.de> Cc: David Jeffery <djeffery@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Laurence Oberman <loberman@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25Revert "driver core: shut down devices asynchronously"Greg Kroah-Hartman
This reverts commit 8064952c65045f05ee2671fe437770e50c151776. The series is being reverted before -rc1 as there are still reports of lockups on shutdown, so it's not quite ready for "prime time." Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com> Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local Cc: Christoph Hellwig <hch@lst.de> Cc: David Jeffery <djeffery@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Laurence Oberman <loberman@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25Revert "driver core: fix async device shutdown hang"Greg Kroah-Hartman
This reverts commit 4f2c346e621624315e2a1405e98616a0c5ac146f. The series is being reverted before -rc1 as there are still reports of lockups on shutdown, so it's not quite ready for "prime time." Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com> Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local Cc: Christoph Hellwig <hch@lst.de> Cc: David Jeffery <djeffery@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Laurence Oberman <loberman@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-21driver core: fix async device shutdown hangStuart Hayes
Modify device_shutdown() so that supplier devices do not wait for consumer devices to be shut down first when the devlink is sync state only, since the consumer is not dependent on the supplier in this case. Without this change, a circular dependency could hang the system. Fixes: 8064952c6504 ("driver core: shut down devices asynchronously") Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Tested-by: Laurence Oberman <loberman@redhat.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240919043143.1194950-1-stuart.w.hayes@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: Make parameter check consistent for API cluster ↵Zijun Hu
device_(for_each|find)_child() The following API cluster takes the same type parameter list, but do not have consistent parameter check as shown below. device_for_each_child(struct device *parent, ...) // check (!parent->p) device_for_each_child_reverse(struct device *parent, ...) // same as above device_find_child(struct device *parent, ...) // check (!parent) Fixed by using consistent check (!parent || !parent->p) which covers both existing checks for the cluster. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240824-const_dfc_prepare-v3-1-32127ea32bba@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: shut down devices asynchronouslyStuart Hayes
Add code to allow asynchronous shutdown of devices, ensuring that each device is shut down before its parents & suppliers. Only devices with drivers that have async_shutdown_enable enabled will be shut down asynchronously. This can dramatically reduce system shutdown/reboot time on systems that have multiple devices that take many seconds to shut down (like certain NVMe drives). On one system tested, the shutdown time went from 11 minutes without this patch to 55 seconds with the patch. Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: David Jeffery <djeffery@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Keith Busch <kbusch@kernel.org> Tested-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20240822202805.6379-4-stuart.w.hayes@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: separate function to shutdown one deviceStuart Hayes
Make a separate function for the part of device_shutdown() that does the shutown for a single device. This is in preparation for making device shutdown asynchronous. Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: David Jeffery <djeffery@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Keith Busch <kbusch@kernel.org> Tested-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20240822202805.6379-3-stuart.w.hayes@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: don't always lock parent in shutdownStuart Hayes
Don't lock a parent device unless it is needed in device_shutdown. This is in preparation for making device shutdown asynchronous, when it will be needed to allow children of a common parent to shut down simultaneously. Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com> Signed-off-by: David Jeffery <djeffery@redhat.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Tested-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20240822202805.6379-2-stuart.w.hayes@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: class: Check namespace relevant parameters in class_register()Zijun Hu
Device class has two namespace relevant fields which are usually associated by the following usage: struct class { ... const struct kobj_ns_type_operations *ns_type; const void *(*namespace)(const struct device *dev); ... } if (dev->class && dev->class->ns_type) dev->class->namespace(dev); (1) The usage looks weird since it checks @ns_type but calls namespace() (2) The usage implies both fields have dependency but their dependency is not currently enforced yet. It is found for all existing class definitions that the other filed is also assigned once one is assigned in current kernel tree. Fixed by enforcing above existing dependency that both fields are required for a device class to support namespace via parameter checks. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240822-class_fix-v1-1-2a6d38ba913a@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver:base:core: Adding a "Return:" line in comment for device_link_add()Yuesong Li
The original document doesn't explain the return value directly which leads to confusing in error checking. You can find the reason here: Link: https://lore.kernel.org/all/1d4c39e109bcf288d5900670e024a315.sboyd@kernel.org/ Signed-off-by: Yuesong Li <liyuesong@vivo.com> Link: https://lore.kernel.org/r/20240821040432.4049183-1-liyuesong@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22driver core: Use 2-argument strscpy()Andy Shevchenko
Use 2-argument strscpy(), which is not only shorter but also provides an additional check that destination buffer is an array. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240821154839.604259-6-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22driver core: Make use of returned value of dev_err_probe()Andy Shevchenko
Instead of assigning ret explicitly to the same value that is supplied to dev_err_probe(), make use of returned value of the latter. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240821154839.604259-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22driver core: Use guards for simple mutex locksAndy Shevchenko
Guards can help to make the code more readable. So use it wherever they do so. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240821154839.604259-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22driver core: Use kasprintf() instead of fixed buffer formattingAndy Shevchenko
Improve readability and maintainability by replacing a hardcoded string allocation and formatting by the use of the kasprintf() helper. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240821154839.604259-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22driver core: Sort headersAndy Shevchenko
Sort the headers in alphabetic order in order to ease the maintenance for this part. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240821154839.604259-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-12Merge 6.11-rc3 into driver-core-nextGreg Kroah-Hartman
We need the driver core fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31driver core: Remove unused parameter for virtual_device_parent()Zijun Hu
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 <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240725-virtual_kobj_fix-v1-1-36335cae4544@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31driver core: Fix error handling in driver API device_rename()Zijun Hu
For class-device, device_rename() failure maybe cause unexpected link name within its class folder as explained below: /sys/class/.../old_name -> /sys/devices/.../old_name device_rename(..., new_name) and failed /sys/class/.../new_name -> /sys/devices/.../old_name Fixed by undoing renaming link if renaming kobject failed. Fixes: f349cf34731c ("driver core: Implement ns directory support for device classes.") Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240722-device_rename_fix-v2-1-77de1a6c6495@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31driver core: Fix size calculation of symlink name for ↵Zijun Hu
devlink_(add|remove)_symlinks() devlink_(add|remove)_symlinks() kzalloc() memory to save symlink name for both supplier and consumer, but do not explicitly take into account consumer's prefix "consumer:", so cause disadvantages listed below: 1) it seems wrong for the algorithm to calculate memory size 2) readers maybe need to count characters one by one of both prefix strings to confirm calculated memory size 3) it is relatively easy to introduce new bug if either prefix string is modified in future solved by taking into account consumer's prefix as well. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240712-devlink_fix-v3-1-fa1c5172ffc7@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31driver core: Fix uevent_show() vs driver detach raceDan Williams
uevent_show() wants to de-reference dev->driver->name. There is no clean way for a device attribute to de-reference dev->driver unless that attribute is defined via (struct device_driver).dev_groups. Instead, the anti-pattern of taking the device_lock() in the attribute handler risks deadlocks with code paths that remove device attributes while holding the lock. This deadlock is typically invisible to lockdep given the device_lock() is marked lockdep_set_novalidate_class(), but some subsystems allocate a local lockdep key for @dev->mutex to reveal reports of the form: ====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc7+ #275 Tainted: G OE N ------------------------------------------------------ modprobe/2374 is trying to acquire lock: ffff8c2270070de0 (kn->active#6){++++}-{0:0}, at: __kernfs_remove+0xde/0x220 but task is already holding lock: ffff8c22016e88f8 (&cxl_root_key){+.+.}-{3:3}, at: device_release_driver_internal+0x39/0x210 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&cxl_root_key){+.+.}-{3:3}: __mutex_lock+0x99/0xc30 uevent_show+0xac/0x130 dev_attr_show+0x18/0x40 sysfs_kf_seq_show+0xac/0xf0 seq_read_iter+0x110/0x450 vfs_read+0x25b/0x340 ksys_read+0x67/0xf0 do_syscall_64+0x75/0x190 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (kn->active#6){++++}-{0:0}: __lock_acquire+0x121a/0x1fa0 lock_acquire+0xd6/0x2e0 kernfs_drain+0x1e9/0x200 __kernfs_remove+0xde/0x220 kernfs_remove_by_name_ns+0x5e/0xa0 device_del+0x168/0x410 device_unregister+0x13/0x60 devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1c7/0x210 driver_detach+0x47/0x90 bus_remove_driver+0x6c/0xf0 cxl_acpi_exit+0xc/0x11 [cxl_acpi] __do_sys_delete_module.isra.0+0x181/0x260 do_syscall_64+0x75/0x190 entry_SYSCALL_64_after_hwframe+0x76/0x7e The observation though is that driver objects are typically much longer lived than device objects. It is reasonable to perform lockless de-reference of a @driver pointer even if it is racing detach from a device. Given the infrequency of driver unregistration, use synchronize_rcu() in module_remove_driver() to close any potential races. It is potentially overkill to suffer synchronize_rcu() just to handle the rare module removal racing uevent_show() event. Thanks to Tetsuo Handa for the debug analysis of the syzbot report [1]. Fixes: c0a40097f0bc ("drivers: core: synchronize really_probe() and dev_uevent()") Reported-by: syzbot+4762dd74e32532cda5ff@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Closes: http://lore.kernel.org/5aa5558f-90a4-4864-b1b1-5d6784c5607d@I-love.SAKURA.ne.jp [1] Link: http://lore.kernel.org/669073b8ea479_5fffa294c1@dwillia2-xfh.jf.intel.com.notmuch Cc: stable@vger.kernel.org Cc: Ashish Sangwan <a.sangwan@samsung.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Dirk Behme <dirk.behme@de.bosch.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/172081332794.577428.9738802016494057132.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-20driver core: Make dev_err_probe() silent for -ENOMEMUwe Kleine-König
For an out-of-memory error there should be no additional output. Adapt dev_err_probe() to not emit the error message when err is -ENOMEM. This simplifies handling errors that might among others be -ENOMEM. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/3d1e308d45cddf67749522ca42d83f5b4f0b9634.1718311756.git.u.kleine-koenig@baylibre.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04drivers: core: synchronize really_probe() and dev_uevent()Dirk Behme
Synchronize the dev->driver usage in really_probe() and dev_uevent(). These can run in different threads, what can result in the following race condition for dev->driver uninitialization: Thread #1: ========== really_probe() { ... probe_failed: ... device_unbind_cleanup(dev) { ... dev->driver = NULL; // <= Failed probe sets dev->driver to NULL ... } ... } Thread #2: ========== dev_uevent() { ... if (dev->driver) // If dev->driver is NULLed from really_probe() from here on, // after above check, the system crashes add_uevent_var(env, "DRIVER=%s", dev->driver->name); ... } really_probe() holds the lock, already. So nothing needs to be done there. dev_uevent() is called with lock held, often, too. But not always. What implies that we can't add any locking in dev_uevent() itself. So fix this race by adding the lock to the non-protected path. This is the path where above race is observed: dev_uevent+0x235/0x380 uevent_show+0x10c/0x1f0 <= Add lock here dev_attr_show+0x3a/0xa0 sysfs_kf_seq_show+0x17c/0x250 kernfs_seq_show+0x7c/0x90 seq_read_iter+0x2d7/0x940 kernfs_fop_read_iter+0xc6/0x310 vfs_read+0x5bc/0x6b0 ksys_read+0xeb/0x1b0 __x64_sys_read+0x42/0x50 x64_sys_call+0x27ad/0x2d30 do_syscall_64+0xcd/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Similar cases are reported by syzkaller in https://syzkaller.appspot.com/bug?extid=ffa8143439596313a85a But these are regarding the *initialization* of dev->driver dev->driver = drv; As this switches dev->driver to non-NULL these reports can be considered to be false-positives (which should be "fixed" by this commit, as well, though). The same issue was reported and tried to be fixed back in 2015 in https://lore.kernel.org/lkml/1421259054-2574-1-git-send-email-a.sangwan@samsung.com/ already. Fixes: 239378f16aa1 ("Driver core: add uevent vars for devices of a class") Cc: stable <stable@kernel.org> Cc: syzbot+ffa8143439596313a85a@syzkaller.appspotmail.com Cc: Ashish Sangwan <a.sangwan@samsung.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20240513050634.3964461-1-dirk.behme@de.bosch.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>