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/penmount.c | 315 +++++++++++++++++++++++++++++++++++ 1 file changed, 315 insertions(+) create mode 100644 drivers/input/touchscreen/penmount.c (limited to 'drivers/input/touchscreen/penmount.c') diff --git a/drivers/input/touchscreen/penmount.c b/drivers/input/touchscreen/penmount.c new file mode 100644 index 000000000..4b57b6664 --- /dev/null +++ b/drivers/input/touchscreen/penmount.c @@ -0,0 +1,315 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Penmount serial touchscreen driver + * + * Copyright (c) 2006 Rick Koch + * Copyright (c) 2011 John Sung + * + * Based on ELO driver (drivers/input/touchscreen/elo.c) + * Copyright (c) 2004 Vojtech Pavlik + */ + + +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_DESC "PenMount serial touchscreen driver" + +MODULE_AUTHOR("Rick Koch "); +MODULE_AUTHOR("John Sung "); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +/* + * Definitions & global arrays. + */ + +#define PM_MAX_LENGTH 6 +#define PM_MAX_MTSLOT 16 +#define PM_3000_MTSLOT 2 +#define PM_6250_MTSLOT 12 + +/* + * Multi-touch slot + */ + +struct mt_slot { + unsigned short x, y; + bool active; /* is the touch valid? */ +}; + +/* + * Per-touchscreen data. + */ + +struct pm { + struct input_dev *dev; + struct serio *serio; + int idx; + unsigned char data[PM_MAX_LENGTH]; + char phys[32]; + unsigned char packetsize; + unsigned char maxcontacts; + struct mt_slot slots[PM_MAX_MTSLOT]; + void (*parse_packet)(struct pm *); +}; + +/* + * pm_mtevent() sends mt events and also emulates pointer movement + */ + +static void pm_mtevent(struct pm *pm, struct input_dev *input) +{ + int i; + + for (i = 0; i < pm->maxcontacts; ++i) { + input_mt_slot(input, i); + input_mt_report_slot_state(input, MT_TOOL_FINGER, + pm->slots[i].active); + if (pm->slots[i].active) { + input_event(input, EV_ABS, ABS_MT_POSITION_X, pm->slots[i].x); + input_event(input, EV_ABS, ABS_MT_POSITION_Y, pm->slots[i].y); + } + } + + input_mt_report_pointer_emulation(input, true); + input_sync(input); +} + +/* + * pm_checkpacket() checks if data packet is valid + */ + +static bool pm_checkpacket(unsigned char *packet) +{ + int total = 0; + int i; + + for (i = 0; i < 5; i++) + total += packet[i]; + + return packet[5] == (unsigned char)~(total & 0xff); +} + +static void pm_parse_9000(struct pm *pm) +{ + struct input_dev *dev = pm->dev; + + if ((pm->data[0] & 0x80) && pm->packetsize == ++pm->idx) { + input_report_abs(dev, ABS_X, pm->data[1] * 128 + pm->data[2]); + input_report_abs(dev, ABS_Y, pm->data[3] * 128 + pm->data[4]); + input_report_key(dev, BTN_TOUCH, !!(pm->data[0] & 0x40)); + input_sync(dev); + pm->idx = 0; + } +} + +static void pm_parse_6000(struct pm *pm) +{ + struct input_dev *dev = pm->dev; + + if ((pm->data[0] & 0xbf) == 0x30 && pm->packetsize == ++pm->idx) { + if (pm_checkpacket(pm->data)) { + input_report_abs(dev, ABS_X, + pm->data[2] * 256 + pm->data[1]); + input_report_abs(dev, ABS_Y, + pm->data[4] * 256 + pm->data[3]); + input_report_key(dev, BTN_TOUCH, pm->data[0] & 0x40); + input_sync(dev); + } + pm->idx = 0; + } +} + +static void pm_parse_3000(struct pm *pm) +{ + struct input_dev *dev = pm->dev; + + if ((pm->data[0] & 0xce) == 0x40 && pm->packetsize == ++pm->idx) { + if (pm_checkpacket(pm->data)) { + int slotnum = pm->data[0] & 0x0f; + pm->slots[slotnum].active = pm->data[0] & 0x30; + pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1]; + pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3]; + pm_mtevent(pm, dev); + } + pm->idx = 0; + } +} + +static void pm_parse_6250(struct pm *pm) +{ + struct input_dev *dev = pm->dev; + + if ((pm->data[0] & 0xb0) == 0x30 && pm->packetsize == ++pm->idx) { + if (pm_checkpacket(pm->data)) { + int slotnum = pm->data[0] & 0x0f; + pm->slots[slotnum].active = pm->data[0] & 0x40; + pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1]; + pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3]; + pm_mtevent(pm, dev); + } + pm->idx = 0; + } +} + +static irqreturn_t pm_interrupt(struct serio *serio, + unsigned char data, unsigned int flags) +{ + struct pm *pm = serio_get_drvdata(serio); + + pm->data[pm->idx] = data; + + pm->parse_packet(pm); + + return IRQ_HANDLED; +} + +/* + * pm_disconnect() is the opposite of pm_connect() + */ + +static void pm_disconnect(struct serio *serio) +{ + struct pm *pm = serio_get_drvdata(serio); + + serio_close(serio); + + input_unregister_device(pm->dev); + kfree(pm); + + serio_set_drvdata(serio, NULL); +} + +/* + * pm_connect() is the routine that is called when someone adds a + * new serio device that supports PenMount protocol and registers it as + * an input device. + */ + +static int pm_connect(struct serio *serio, struct serio_driver *drv) +{ + struct pm *pm; + struct input_dev *input_dev; + int max_x, max_y; + int err; + + pm = kzalloc_obj(*pm); + input_dev = input_allocate_device(); + if (!pm || !input_dev) { + err = -ENOMEM; + goto fail1; + } + + pm->serio = serio; + pm->dev = input_dev; + scnprintf(pm->phys, sizeof(pm->phys), "%s/input0", serio->phys); + pm->maxcontacts = 1; + + input_dev->name = "PenMount Serial TouchScreen"; + input_dev->phys = pm->phys; + input_dev->id.bustype = BUS_RS232; + input_dev->id.vendor = SERIO_PENMOUNT; + input_dev->id.product = 0; + input_dev->id.version = 0x0100; + 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); + + switch (serio->id.id) { + default: + case 0: + pm->packetsize = 5; + pm->parse_packet = pm_parse_9000; + input_dev->id.product = 0x9000; + max_x = max_y = 0x3ff; + break; + + case 1: + pm->packetsize = 6; + pm->parse_packet = pm_parse_6000; + input_dev->id.product = 0x6000; + max_x = max_y = 0x3ff; + break; + + case 2: + pm->packetsize = 6; + pm->parse_packet = pm_parse_3000; + input_dev->id.product = 0x3000; + max_x = max_y = 0x7ff; + pm->maxcontacts = PM_3000_MTSLOT; + break; + + case 3: + pm->packetsize = 6; + pm->parse_packet = pm_parse_6250; + input_dev->id.product = 0x6250; + max_x = max_y = 0x3ff; + pm->maxcontacts = PM_6250_MTSLOT; + break; + } + + input_set_abs_params(pm->dev, ABS_X, 0, max_x, 0, 0); + input_set_abs_params(pm->dev, ABS_Y, 0, max_y, 0, 0); + + if (pm->maxcontacts > 1) { + input_mt_init_slots(pm->dev, pm->maxcontacts, 0); + input_set_abs_params(pm->dev, + ABS_MT_POSITION_X, 0, max_x, 0, 0); + input_set_abs_params(pm->dev, + ABS_MT_POSITION_Y, 0, max_y, 0, 0); + } + + serio_set_drvdata(serio, pm); + + err = serio_open(serio, drv); + if (err) + goto fail2; + + err = input_register_device(pm->dev); + if (err) + goto fail3; + + return 0; + + fail3: serio_close(serio); + fail2: serio_set_drvdata(serio, NULL); + fail1: input_free_device(input_dev); + kfree(pm); + return err; +} + +/* + * The serio driver structure. + */ + +static const struct serio_device_id pm_serio_ids[] = { + { + .type = SERIO_RS232, + .proto = SERIO_PENMOUNT, + .id = SERIO_ANY, + .extra = SERIO_ANY, + }, + { 0 } +}; + +MODULE_DEVICE_TABLE(serio, pm_serio_ids); + +static struct serio_driver pm_drv = { + .driver = { + .name = "serio-penmount", + }, + .description = DRIVER_DESC, + .id_table = pm_serio_ids, + .interrupt = pm_interrupt, + .connect = pm_connect, + .disconnect = pm_disconnect, +}; + +module_serio_driver(pm_drv); -- cgit v1.3.1