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/input/keyboard/xtkbd.c | 152 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 drivers/input/keyboard/xtkbd.c (limited to 'drivers/input/keyboard/xtkbd.c') diff --git a/drivers/input/keyboard/xtkbd.c b/drivers/input/keyboard/xtkbd.c new file mode 100644 index 000000000..c0b4978a8 --- /dev/null +++ b/drivers/input/keyboard/xtkbd.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 1999-2001 Vojtech Pavlik + */ + +/* + * XT keyboard driver for Linux + */ + +#include +#include +#include +#include + +#define DRIVER_DESC "XT keyboard driver" + +MODULE_AUTHOR("Vojtech Pavlik "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +#define XTKBD_EMUL0 0xe0 +#define XTKBD_EMUL1 0xe1 +#define XTKBD_KEY 0x7f +#define XTKBD_RELEASE 0x80 + +static unsigned char xtkbd_keycode[256] = { + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, + 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, + 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, + 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, + 80, 81, 82, 83, 0, 0, 0, 87, 88, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 87, 88, 0, 0, 0, 0,110,111,103,108,105, + 106 +}; + +struct xtkbd { + unsigned char keycode[256]; + struct input_dev *dev; + struct serio *serio; + char phys[32]; +}; + +static irqreturn_t xtkbd_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct xtkbd *xtkbd = serio_get_drvdata(serio); + + switch (data) { + case XTKBD_EMUL0: + case XTKBD_EMUL1: + break; + default: + + if (xtkbd->keycode[data & XTKBD_KEY]) { + input_report_key(xtkbd->dev, xtkbd->keycode[data & XTKBD_KEY], !(data & XTKBD_RELEASE)); + input_sync(xtkbd->dev); + } else { + printk(KERN_WARNING "xtkbd.c: Unknown key (scancode %#x) %s.\n", + data & XTKBD_KEY, data & XTKBD_RELEASE ? "released" : "pressed"); + } + } + return IRQ_HANDLED; +} + +static int xtkbd_connect(struct serio *serio, struct serio_driver *drv) +{ + struct xtkbd *xtkbd; + struct input_dev *input_dev; + int err = -ENOMEM; + int i; + + xtkbd = kmalloc_obj(*xtkbd); + input_dev = input_allocate_device(); + if (!xtkbd || !input_dev) + goto fail1; + + xtkbd->serio = serio; + xtkbd->dev = input_dev; + snprintf(xtkbd->phys, sizeof(xtkbd->phys), "%s/input0", serio->phys); + memcpy(xtkbd->keycode, xtkbd_keycode, sizeof(xtkbd->keycode)); + + input_dev->name = "XT Keyboard"; + input_dev->phys = xtkbd->phys; + input_dev->id.bustype = BUS_XTKBD; + input_dev->id.vendor = 0x0001; + input_dev->id.product = 0x0001; + input_dev->id.version = 0x0100; + input_dev->dev.parent = &serio->dev; + + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); + input_dev->keycode = xtkbd->keycode; + input_dev->keycodesize = sizeof(unsigned char); + input_dev->keycodemax = ARRAY_SIZE(xtkbd_keycode); + + for (i = 0; i < 255; i++) + set_bit(xtkbd->keycode[i], input_dev->keybit); + clear_bit(0, input_dev->keybit); + + serio_set_drvdata(serio, xtkbd); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(xtkbd->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(xtkbd); + return err; +} + +static void xtkbd_disconnect(struct serio *serio) +{ + struct xtkbd *xtkbd = serio_get_drvdata(serio); + + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_unregister_device(xtkbd->dev); + kfree(xtkbd); +} + +static const struct serio_device_id xtkbd_serio_ids[] = { + { + .type = SERIO_XT, + .proto = SERIO_ANY, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, xtkbd_serio_ids); + +static struct serio_driver xtkbd_drv = { + .driver = { + .name = "xtkbd", + }, + .description = DRIVER_DESC, + .id_table = xtkbd_serio_ids, + .interrupt = xtkbd_interrupt, + .connect = xtkbd_connect, + .disconnect = xtkbd_disconnect, +}; + +module_serio_driver(xtkbd_drv); -- cgit v1.3.1