From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/hid/hid-speedlink.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 drivers/hid/hid-speedlink.c (limited to 'drivers/hid/hid-speedlink.c') diff --git a/drivers/hid/hid-speedlink.c b/drivers/hid/hid-speedlink.c new file mode 100644 index 000000000..22ee078c4 --- /dev/null +++ b/drivers/hid/hid-speedlink.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Speedlink Vicious and Divine Cezanne (USB mouse). + * Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from + * the HID descriptor. + * + * Copyright (c) 2011, 2013 Stefan Kriwanek + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +static const struct hid_device_id speedlink_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)}, + { } +}; + +static int speedlink_input_mapping(struct hid_device *hdev, + struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + /* + * The Cezanne mouse has a second "keyboard" USB endpoint for it is + * able to map keyboard events to the button presses. + * It sends a standard keyboard report descriptor, though, whose + * LEDs we ignore. + */ + switch (usage->hid & HID_USAGE_PAGE) { + case HID_UP_LED: + return -1; + } + return 0; +} + +static int speedlink_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + /* No other conditions due to usage_table. */ + + /* This fixes the "jumpy" cursor occuring due to invalid events sent + * by the device. Some devices only send them with value==+256, others + * don't. However, catching abs(value)>=256 is restrictive enough not + * to interfere with devices that were bug-free (has been tested). + */ + if (abs(value) >= 256) + return 1; + /* Drop useless distance 0 events (on button clicks etc.) as well */ + if (value == 0) + return 1; + + return 0; +} + +MODULE_DEVICE_TABLE(hid, speedlink_devices); + +static const struct hid_usage_id speedlink_grabbed_usages[] = { + { HID_GD_X, EV_REL, 0 }, + { HID_GD_Y, EV_REL, 1 }, + { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} +}; + +static struct hid_driver speedlink_driver = { + .name = "speedlink", + .id_table = speedlink_devices, + .usage_table = speedlink_grabbed_usages, + .input_mapping = speedlink_input_mapping, + .event = speedlink_event, +}; +module_hid_driver(speedlink_driver); + +MODULE_DESCRIPTION("HID driver for Speedlink Vicious and Divine Cezanne (USB mouse)"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1