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

sysfs: treewide: switch back to attribute_group::bin_attrs

2025-06-17T08:44:15+00:00

The normal bin_attrs field can now handle const pointers. This makes the _new variant unnecessary. Switch all users back. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20250530-sysfs-const-bin_attr-final-v3-4-724bfcf05b99@weissschuh.net Signed-off-by: Greg Kroah-Hartman

usb: core: sysfs: Constify 'struct bin_attribute'

2024-12-24T07:56:04+00:00

The sysfs core now allows instances of 'struct bin_attribute' to be moved into read-only memory. Make use of that to protect them against accidental or malicious modifications. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20241222-sysfs-const-bin_attr-usb-v1-1-19a137c0f20a@weissschuh.net Signed-off-by: Greg Kroah-Hartman

sysfs: treewide: constify attribute callback of bin_is_visible()

2024-11-05T13:00:28+00:00

The is_bin_visible() callbacks should not modify the struct bin_attribute passed as argument. Enforce this by marking the argument as const. As there are not many callback implementers perform this change throughout the tree at once. Signed-off-by: Thomas Weißschuh Acked-by: Martin K. Petersen Acked-by: Jason Gunthorpe Acked-by: Ira Weiny Acked-by: Krzysztof Wilczyński Link: https://lore.kernel.org/r/20241103-sysfs-const-bin_attr-v2-5-71110628844c@weissschuh.net Signed-off-by: Greg Kroah-Hartman

usb: core: sysfs: Unmerge @usb3_hardware_lpm_attr_group in remove_power_attributes()

2024-08-22T09:29:50+00:00

Device attribute group @usb3_hardware_lpm_attr_group is merged by add_power_attributes(), but it is not unmerged explicitly, fixed by unmerging it in remove_power_attributes(). Fixes: 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3 hardware LPM") Cc: stable@vger.kernel.org Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240820-sysfs_fix-v2-1-a9441487077e@quicinc.com Signed-off-by: Greg Kroah-Hartman

USB: core: Fix deadlock in usb_deauthorize_interface()

2024-03-26T10:02:47+00:00

Among the attribute file callback routines in drivers/usb/core/sysfs.c, the interface_authorized_store() function is the only one which acquires a device lock on an ancestor device: It calls usb_deauthorize_interface(), which locks the interface's parent USB device. The will lead to deadlock if another process already owns that lock and tries to remove the interface, whether through a configuration change or because the device has been disconnected. As part of the removal procedure, device_del() waits for all ongoing sysfs attribute callbacks to complete. But usb_deauthorize_interface() can't complete until the device lock has been released, and the lock won't be released until the removal has finished. The mechanism provided by sysfs to prevent this kind of deadlock is to use the sysfs_break_active_protection() function, which tells sysfs not to wait for the attribute callback. Reported-and-tested by: Yue Sun Reported by: xingwei lee Signed-off-by: Alan Stern Link: https://lore.kernel.org/linux-usb/CAEkJfYO6jRVC8Tfrd_R=cjO0hguhrV31fDPrLrNOOHocDkPoAA@mail.gmail.com/#r Fixes: 310d2b4124c0 ("usb: interface authorization: SysFS part of USB interface authorization") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1c37eea1-9f56-4534-b9d8-b443438dc869@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

usb: Clarify expected behavior of dev_bin_attrs_are_visible()

2024-03-06T11:35:26+00:00

The commit "usb: Export BOS descriptor to sysfs" added a binary attribute group to sysfs. It doesn't check if the descriptors attribute should be visible, which is by design and not an oversight. Update a comment so that it better explains this in the dev_bin_attrs_are_visible() function. Signed-off-by: Elbert Mai Link: https://lore.kernel.org/r/20240306001503.313028-1-code@elbertmai.com Signed-off-by: Greg Kroah-Hartman

usb: Export BOS descriptor to sysfs

2024-03-05T07:57:23+00:00

Motivation ---------- The binary device object store (BOS) of a USB device consists of the BOS descriptor followed by a set of device capability descriptors. One that is of interest to users is the platform descriptor. This contains a 128-bit UUID and arbitrary data, and it allows parties outside of USB-IF to add additional metadata about a USB device in a standards-compliant manner. Notable examples include the WebUSB and Microsoft OS 2.0 descriptors. The kernel already retrieves and caches the BOS from USB devices if its bcdUSB is >= 0x0201. Because the BOS is flexible and extensible, we export the entire BOS to sysfs so users can retrieve whatever device capabilities they desire, without requiring USB I/O or elevated permissions. Implementation -------------- Add bos_descriptors attribute to sysfs. This is a binary file and it works the same way as the existing descriptors attribute. The file exists only if the BOS is present in the USB device. Also create a binary attribute group, so the driver core can handle the creation of both the descriptors and bos_descriptors attributes in sysfs. Signed-off-by: Elbert Mai Link: https://lore.kernel.org/r/20240305002301.95323-1-code@elbertmai.com Signed-off-by: Greg Kroah-Hartman

usb: sysfs: use kstrtobool() if possible

2024-02-17T16:00:33+00:00

Replace the self-rolled implementations with kstrtobool(). This reduces the maintenance efforts in the future. Signed-off-by: Guan-Yu Lin Link: https://lore.kernel.org/r/20240202030301.2396374-1-guanyulin@google.com Signed-off-by: Greg Kroah-Hartman

USB: Remove remnants of Wireless USB and UWB

2023-08-09T12:17:06+00:00

Wireless USB has long been defunct, and kernel support for it was removed in 2020 by commit caa6772db4c1 ("Staging: remove wusbcore and UWB from the kernel tree."). Nevertheless, some vestiges of the old implementation still clutter up the USB subsystem and one or two other places. Let's get rid of them once and for all. The only parts still left are the user-facing APIs in include/uapi/linux/usb/ch9.h. (There are also a couple of misleading instances, such as the Sierra Wireless USB modem, which is a USB modem made by Sierra Wireless.) Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/b4f2710f-a2de-4fb0-b50f-76776f3a961b@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

USB: core: Add wireless_status sysfs attribute

2023-04-03T11:30:08+00:00

Add a wireless_status sysfs attribute to USB devices to keep track of whether a USB device that's comprised of a receiver dongle and an emitter device over a, most of the time proprietary, wireless link has its emitter connected or disconnected. This will be used by user-space OS components to determine whether the battery-powered part of the device is wirelessly connected or not, allowing, for example: - upower to hide the battery for devices where the device is turned off but the receiver plugged in, rather than showing 0%, or other values that could be confusing to users - Pipewire to hide a headset from the list of possible inputs or outputs or route audio appropriately if the headset is suddenly turned off, or turned on - libinput to determine whether a keyboard or mouse is present when its receiver is plugged in. This is done at the USB interface level as: - the interface on which the wireless status is detected is sometimes not the same as where it could be consumed (eg. the audio interface on a headset dongle will still appear even if the headset is turned off), and we cannot have synchronisation of status across subsystems. - this behaviour is not specific to HID devices, even if the protocols used to determine whether or not the remote device is connected can be HID. This is not an attribute that is meant to replace protocol specific APIs, such as the ones available for WWAN, WLAN/Wi-Fi, or Bluetooth or any other sort of networking, but solely for wireless devices with an ad-hoc “lose it and your device is e-waste” receiver dongle. The USB interface will only be exporting the wireless_status sysfs attribute if it gets set through the API exported in the next commit. Signed-off-by: Bastien Nocera Acked-by: Greg Kroah-Hartman Acked-by: Alan Stern Link: https://lore.kernel.org/r/20230302105555.51417-4-hadess@hadess.net Signed-off-by: Benjamin Tissoires