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/touchscreen/dynapro.c | 185 ++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 drivers/input/touchscreen/dynapro.c (limited to 'drivers/input/touchscreen/dynapro.c') diff --git a/drivers/input/touchscreen/dynapro.c b/drivers/input/touchscreen/dynapro.c new file mode 100644 index 000000000..943ba8c2f --- /dev/null +++ b/drivers/input/touchscreen/dynapro.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Dynapro serial touchscreen driver + * + * Copyright (c) 2009 Tias Guns + * Based on the inexio driver (c) Vojtech Pavlik and Dan Streetman and + * Richard Lemon + */ + + +/* + * 2009/09/19 Tias Guns + * Copied inexio.c and edited for Dynapro protocol (from retired Xorg module) + */ + +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "Dynapro serial touchscreen driver" + +MODULE_AUTHOR("Tias Guns "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define DYNAPRO_FORMAT_TOUCH_BIT 0x40 +#define DYNAPRO_FORMAT_LENGTH 3 +#define DYNAPRO_RESPONSE_BEGIN_BYTE 0x80 + +#define DYNAPRO_MIN_XC 0 +#define DYNAPRO_MAX_XC 0x3ff +#define DYNAPRO_MIN_YC 0 +#define DYNAPRO_MAX_YC 0x3ff + +#define DYNAPRO_GET_XC(data) (data[1] | ((data[0] & 0x38) << 4)) +#define DYNAPRO_GET_YC(data) (data[2] | ((data[0] & 0x07) << 7)) +#define DYNAPRO_GET_TOUCHED(data) (DYNAPRO_FORMAT_TOUCH_BIT & data[0]) + +/* + * Per-touchscreen data. + */ + +struct dynapro { + struct input_dev *dev; + struct serio *serio; + int idx; + unsigned char data[DYNAPRO_FORMAT_LENGTH]; + char phys[32]; +}; + +static void dynapro_process_data(struct dynapro *pdynapro) +{ + struct input_dev *dev = pdynapro->dev; + + if (DYNAPRO_FORMAT_LENGTH == ++pdynapro->idx) { + input_report_abs(dev, ABS_X, DYNAPRO_GET_XC(pdynapro->data)); + input_report_abs(dev, ABS_Y, DYNAPRO_GET_YC(pdynapro->data)); + input_report_key(dev, BTN_TOUCH, + DYNAPRO_GET_TOUCHED(pdynapro->data)); + input_sync(dev); + + pdynapro->idx = 0; + } +} + +static irqreturn_t dynapro_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct dynapro *pdynapro = serio_get_drvdata(serio); + + pdynapro->data[pdynapro->idx] = data; + + if (DYNAPRO_RESPONSE_BEGIN_BYTE & pdynapro->data[0]) + dynapro_process_data(pdynapro); + else + dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n", + pdynapro->data[0]); + + return IRQ_HANDLED; +} + +static void dynapro_disconnect(struct serio *serio) +{ + struct dynapro *pdynapro = serio_get_drvdata(serio); + + input_get_device(pdynapro->dev); + input_unregister_device(pdynapro->dev); + serio_close(serio); + serio_set_drvdata(serio, NULL); + input_put_device(pdynapro->dev); + kfree(pdynapro); +} + +/* + * dynapro_connect() is the routine that is called when someone adds a + * new serio device that supports dynapro protocol and registers it as + * an input device. This is usually accomplished using inputattach. + */ + +static int dynapro_connect(struct serio *serio, struct serio_driver *drv) +{ + struct dynapro *pdynapro; + struct input_dev *input_dev; + int err; + + pdynapro = kzalloc_obj(*pdynapro); + input_dev = input_allocate_device(); + if (!pdynapro || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + pdynapro->serio = serio; + pdynapro->dev = input_dev; + scnprintf(pdynapro->phys, sizeof(pdynapro->phys), + "%s/input0", serio->phys); + + input_dev->name = "Dynapro Serial TouchScreen"; + input_dev->phys = pdynapro->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_DYNAPRO; + input_dev->id.product = 0; + input_dev->id.version = 0x0001; + input_dev->dev.parent = &serio->dev; + input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + input_set_abs_params(pdynapro->dev, ABS_X, + DYNAPRO_MIN_XC, DYNAPRO_MAX_XC, 0, 0); + input_set_abs_params(pdynapro->dev, ABS_Y, + DYNAPRO_MIN_YC, DYNAPRO_MAX_YC, 0, 0); + + serio_set_drvdata(serio, pdynapro); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(pdynapro->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(pdynapro); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id dynapro_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_DYNAPRO, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, dynapro_serio_ids); + +static struct serio_driver dynapro_drv = { + .driver = { + .name = "dynapro", + }, + .description = DRIVER_DESC, + .id_table = dynapro_serio_ids, + .interrupt = dynapro_interrupt, + .connect = dynapro_connect, + .disconnect = dynapro_disconnect, +}; + +module_serio_driver(dynapro_drv); -- cgit v1.3.1