HID: core: store the unique system identifier in hid_device

[ Upstream commit 1e839143d6 ]

This unique identifier is currently used only for ensuring uniqueness in
sysfs. However, this could be handful for userspace to refer to a specific
hid_device by this id.

2 use cases are in my mind: LEDs (and their naming convention), and
HID-BPF.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220902132938.2409206-9-benjamin.tissoires@redhat.com
Stable-dep-of: fc43e9c857 ("HID: fix HID device resource race between HID core and debugging support")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Benjamin Tissoires 2022-09-02 15:29:23 +02:00 committed by Greg Kroah-Hartman
parent 221be624a5
commit 52badc06b1
2 changed files with 5 additions and 1 deletions

View File

@ -2442,10 +2442,12 @@ int hid_add_device(struct hid_device *hdev)
hid_warn(hdev, "bad device descriptor (%d)\n", ret);
}
hdev->id = atomic_inc_return(&id);
/* XXX hack, any other cleaner solution after the driver core
* is converted to allow more than 20 bytes as the device name? */
dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
hdev->vendor, hdev->product, atomic_inc_return(&id));
hdev->vendor, hdev->product, hdev->id);
hid_debug_register(hdev, dev_name(&hdev->dev));
ret = device_add(&hdev->dev);

View File

@ -630,6 +630,8 @@ struct hid_device { /* device report descriptor */
struct list_head debug_list;
spinlock_t debug_list_lock;
wait_queue_head_t debug_wait;
unsigned int id; /* system unique id */
};
#define to_hid_device(pdev) \