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-primax.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 drivers/hid/hid-primax.c (limited to 'drivers/hid/hid-primax.c') diff --git a/drivers/hid/hid-primax.c b/drivers/hid/hid-primax.c new file mode 100644 index 000000000..8db054280 --- /dev/null +++ b/drivers/hid/hid-primax.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HID driver for primax and similar keyboards with in-band modifiers + * + * Copyright 2011 Google Inc. All Rights Reserved + * + * Author: + * Terry Lambert + */ + +#include +#include +#include + +#include "hid-ids.h" + +static int px_raw_event(struct hid_device *hid, struct hid_report *report, + u8 *data, int size) +{ + int idx = size; + + switch (report->id) { + case 0: /* keyboard input */ + /* + * Convert in-band modifier key values into out of band + * modifier bits and pull the key strokes from the report. + * Thus a report data set which looked like: + * + * [00][00][E0][30][00][00][00][00] + * (no modifier bits + "Left Shift" key + "1" key) + * + * Would be converted to: + * + * [01][00][00][30][00][00][00][00] + * (Left Shift modifier bit + "1" key) + * + * As long as it's in the size range, the upper level + * drivers don't particularly care if there are in-band + * 0-valued keys, so they don't stop parsing. + */ + while (--idx > 1) { + if (data[idx] < 0xE0 || data[idx] > 0xE7) + continue; + data[0] |= (1 << (data[idx] - 0xE0)); + data[idx] = 0; + } + hid_report_raw_event(hid, HID_INPUT_REPORT, data, size, size, 0); + return 1; + + default: /* unknown report */ + /* Unknown report type; pass upstream */ + hid_info(hid, "unknown report type %d\n", report->id); + break; + } + + return 0; +} + +static const struct hid_device_id px_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) }, + { } +}; +MODULE_DEVICE_TABLE(hid, px_devices); + +static struct hid_driver px_driver = { + .name = "primax", + .id_table = px_devices, + .raw_event = px_raw_event, +}; +module_hid_driver(px_driver); + +MODULE_AUTHOR("Terry Lambert "); +MODULE_DESCRIPTION("HID driver for primax and similar keyboards with in-band modifiers"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1