ftrace: Synchronize the initialization of ftrace_opsgrafted

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 <rostedt@goodmis.org>

1 files changed, 420 insertions, 0 deletions

diff --git a/drivers/input/joystick/tmdc.c b/drivers/input/joystick/tmdc.c
new file mode 100644
index 000000000..d419f41e6
--- /dev/null
+++ b/drivers/input/joystick/tmdc.c
@@ -0,0 +1,420 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) 1998-2001 Vojtech Pavlik
+ *
+ *   Based on the work of:
+ *	Trystan Larey-Williams
+ */
+
+/*
+ * ThrustMaster DirectConnect (BSP) joystick family driver for Linux
+ */
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/gameport.h>
+#include <linux/input.h>
+#include <linux/jiffies.h>
+
+#define DRIVER_DESC	"ThrustMaster DirectConnect joystick driver"
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define TMDC_MAX_START		600	/* 600 us */
+#define TMDC_MAX_STROBE		60	/* 60 us */
+#define TMDC_MAX_LENGTH		13
+
+#define TMDC_MODE_M3DI		1
+#define TMDC_MODE_3DRP		3
+#define TMDC_MODE_AT		4
+#define TMDC_MODE_FM		8
+#define TMDC_MODE_FGP		163
+
+#define TMDC_BYTE_ID		10
+#define TMDC_BYTE_REV		11
+#define TMDC_BYTE_DEF		12
+
+#define TMDC_ABS		7
+#define TMDC_ABS_HAT		4
+#define TMDC_BTN		16
+
+static const unsigned char tmdc_byte_a[16] = { 0, 1, 3, 4, 6, 7 };
+static const unsigned char tmdc_byte_d[16] = { 2, 5, 8, 9 };
+
+static const signed char tmdc_abs[TMDC_ABS] =
+	{ ABS_X, ABS_Y, ABS_RUDDER, ABS_THROTTLE, ABS_RX, ABS_RY, ABS_RZ };
+static const signed char tmdc_abs_hat[TMDC_ABS_HAT] =
+	{ ABS_HAT0X, ABS_HAT0Y, ABS_HAT1X, ABS_HAT1Y };
+static const signed char tmdc_abs_at[TMDC_ABS] =
+	{ ABS_X, ABS_Y, ABS_RUDDER, -1, ABS_THROTTLE };
+static const signed char tmdc_abs_fm[TMDC_ABS] =
+	{ ABS_RX, ABS_RY, ABS_X, ABS_Y };
+
+static const short tmdc_btn_pad[TMDC_BTN] =
+	{ BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_START, BTN_SELECT, BTN_TL, BTN_TR };
+static const short tmdc_btn_joy[TMDC_BTN] =
+	{ BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_THUMB2, BTN_PINKIE,
+	  BTN_BASE3, BTN_BASE4, BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z };
+static const short tmdc_btn_fm[TMDC_BTN] =
+        { BTN_TRIGGER, BTN_C, BTN_B, BTN_A, BTN_THUMB, BTN_X, BTN_Y, BTN_Z, BTN_TOP, BTN_TOP2 };
+static const short tmdc_btn_at[TMDC_BTN] =
+        { BTN_TRIGGER, BTN_THUMB2, BTN_PINKIE, BTN_THUMB, BTN_BASE6, BTN_BASE5, BTN_BASE4,
+          BTN_BASE3, BTN_BASE2, BTN_BASE };
+
+static const struct {
+        int x;
+        int y;
+} tmdc_hat_to_axis[] = {{ 0, 0}, { 1, 0}, { 0,-1}, {-1, 0}, { 0, 1}};
+
+static const struct tmdc_model {
+	unsigned char id;
+	const char *name;
+	char abs;
+	char hats;
+	char btnc[4];
+	char btno[4];
+	const signed char *axes;
+	const short *buttons;
+} tmdc_models[] = {
+	{   1, "ThrustMaster Millennium 3D Inceptor",	  6, 2, { 4, 2 }, { 4, 6 }, tmdc_abs, tmdc_btn_joy },
+	{   3, "ThrustMaster Rage 3D Gamepad",		  2, 0, { 8, 2 }, { 0, 0 }, tmdc_abs, tmdc_btn_pad },
+	{   4, "ThrustMaster Attack Throttle",		  5, 2, { 4, 6 }, { 4, 2 }, tmdc_abs_at, tmdc_btn_at },
+	{   8, "ThrustMaster FragMaster",		  4, 0, { 8, 2 }, { 0, 0 }, tmdc_abs_fm, tmdc_btn_fm },
+	{ 163, "Thrustmaster Fusion GamePad",		  2, 0, { 8, 2 }, { 0, 0 }, tmdc_abs, tmdc_btn_pad },
+	{   0, "Unknown %d-axis, %d-button TM device %d", 0, 0, { 0, 0 }, { 0, 0 }, tmdc_abs, tmdc_btn_joy }
+};
+
+
+struct tmdc_port {
+	struct input_dev *dev;
+	char name[64];
+	char phys[32];
+	int mode;
+	const signed char *abs;
+	const short *btn;
+	unsigned char absc;
+	unsigned char btnc[4];
+	unsigned char btno[4];
+};
+
+struct tmdc {
+	struct gameport *gameport;
+	struct tmdc_port *port[2];
+#if 0
+	struct input_dev *dev[2];
+	char name[2][64];
+	char phys[2][32];
+	int mode[2];
+	signed char *abs[2];
+	short *btn[2];
+	unsigned char absc[2];
+	unsigned char btnc[2][4];
+	unsigned char btno[2][4];
+#endif
+	int reads;
+	int bads;
+	unsigned char exists;
+};
+
+/*
+ * tmdc_read_packet() reads a ThrustMaster packet.
+ */
+
+static int tmdc_read_packet(struct gameport *gameport, unsigned char data[2][TMDC_MAX_LENGTH])
+{
+	unsigned char u, v, w, x;
+	unsigned long flags;
+	int i[2], j[2], t[2], p, k;
+
+	p = gameport_time(gameport, TMDC_MAX_STROBE);
+
+	for (k = 0; k < 2; k++) {
+		t[k] = gameport_time(gameport, TMDC_MAX_START);
+		i[k] = j[k] = 0;
+	}
+
+	local_irq_save(flags);
+	gameport_trigger(gameport);
+
+	w = gameport_read(gameport) >> 4;
+
+	do {
+		x = w;
+		w = gameport_read(gameport) >> 4;
+
+		for (k = 0, v = w, u = x; k < 2; k++, v >>= 2, u >>= 2) {
+			if (~v & u & 2) {
+				if (t[k] <= 0 || i[k] >= TMDC_MAX_LENGTH) continue;
+				t[k] = p;
+				if (j[k] == 0) {				 /* Start bit */
+					if (~v & 1) t[k] = 0;
+					data[k][i[k]] = 0; j[k]++; continue;
+				}
+				if (j[k] == 9) {				/* Stop bit */
+					if (v & 1) t[k] = 0;
+					j[k] = 0; i[k]++; continue;
+				}
+				data[k][i[k]] |= (~v & 1) << (j[k]++ - 1);	/* Data bit */
+			}
+			t[k]--;
+		}
+	} while (t[0] > 0 || t[1] > 0);
+
+	local_irq_restore(flags);
+
+	return (i[0] == TMDC_MAX_LENGTH) | ((i[1] == TMDC_MAX_LENGTH) << 1);
+}
+
+static int tmdc_parse_packet(struct tmdc_port *port, unsigned char *data)
+{
+	int i, k, l;
+
+	if (data[TMDC_BYTE_ID] != port->mode)
+		return -1;
+
+	for (i = 0; i < port->absc; i++) {
+		if (port->abs[i] < 0)
+			return 0;
+
+		input_report_abs(port->dev, port->abs[i], data[tmdc_byte_a[i]]);
+	}
+
+	switch (port->mode) {
+
+		case TMDC_MODE_M3DI:
+
+			i = tmdc_byte_d[0];
+			input_report_abs(port->dev, ABS_HAT0X, ((data[i] >> 3) & 1) - ((data[i] >> 1) & 1));
+			input_report_abs(port->dev, ABS_HAT0Y, ((data[i] >> 2) & 1) - ( data[i]       & 1));
+			break;
+
+		case TMDC_MODE_AT:
+
+			i = tmdc_byte_a[3];
+			input_report_abs(port->dev, ABS_HAT0X, tmdc_hat_to_axis[(data[i] - 141) / 25].x);
+			input_report_abs(port->dev, ABS_HAT0Y, tmdc_hat_to_axis[(data[i] - 141) / 25].y);
+			break;
+
+	}
+
+	for (k = l = 0; k < 4; k++) {
+		for (i = 0; i < port->btnc[k]; i++)
+			input_report_key(port->dev, port->btn[i + l],
+				((data[tmdc_byte_d[k]] >> (i + port->btno[k])) & 1));
+		l += port->btnc[k];
+	}
+
+	input_sync(port->dev);
+
+	return 0;
+}
+
+/*
+ * tmdc_poll() reads and analyzes ThrustMaster joystick data.
+ */
+
+static void tmdc_poll(struct gameport *gameport)
+{
+	unsigned char data[2][TMDC_MAX_LENGTH];
+	struct tmdc *tmdc = gameport_get_drvdata(gameport);
+	unsigned char r, bad = 0;
+	int i;
+
+	tmdc->reads++;
+
+	if ((r = tmdc_read_packet(tmdc->gameport, data)) != tmdc->exists)
+		bad = 1;
+	else {
+		for (i = 0; i < 2; i++) {
+			if (r & (1 << i) & tmdc->exists) {
+
+				if (tmdc_parse_packet(tmdc->port[i], data[i]))
+					bad = 1;
+			}
+		}
+	}
+
+	tmdc->bads += bad;
+}
+
+static int tmdc_open(struct input_dev *dev)
+{
+	struct tmdc *tmdc = input_get_drvdata(dev);
+
+	gameport_start_polling(tmdc->gameport);
+	return 0;
+}
+
+static void tmdc_close(struct input_dev *dev)
+{
+	struct tmdc *tmdc = input_get_drvdata(dev);
+
+	gameport_stop_polling(tmdc->gameport);
+}
+
+static int tmdc_setup_port(struct tmdc *tmdc, int idx, unsigned char *data)
+{
+	const struct tmdc_model *model;
+	struct tmdc_port *port;
+	struct input_dev *input_dev;
+	int i, j, b = 0;
+	int err;
+
+	tmdc->port[idx] = port = kzalloc_obj(struct tmdc_port);
+	input_dev = input_allocate_device();
+	if (!port || !input_dev) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	port->mode = data[TMDC_BYTE_ID];
+
+	for (model = tmdc_models; model->id && model->id != port->mode; model++)
+		/* empty */;
+
+	port->abs = model->axes;
+	port->btn = model->buttons;
+
+	if (!model->id) {
+		port->absc = data[TMDC_BYTE_DEF] >> 4;
+		for (i = 0; i < 4; i++)
+			port->btnc[i] = i < (data[TMDC_BYTE_DEF] & 0xf) ? 8 : 0;
+	} else {
+		port->absc = model->abs;
+		for (i = 0; i < 4; i++)
+			port->btnc[i] = model->btnc[i];
+	}
+
+	for (i = 0; i < 4; i++)
+		port->btno[i] = model->btno[i];
+
+	snprintf(port->name, sizeof(port->name), model->name,
+		 port->absc, (data[TMDC_BYTE_DEF] & 0xf) << 3, port->mode);
+	snprintf(port->phys, sizeof(port->phys), "%s/input%d", tmdc->gameport->phys, i);
+
+	port->dev = input_dev;
+
+	input_dev->name = port->name;
+	input_dev->phys = port->phys;
+	input_dev->id.bustype = BUS_GAMEPORT;
+	input_dev->id.vendor = GAMEPORT_ID_VENDOR_THRUSTMASTER;
+	input_dev->id.product = model->id;
+	input_dev->id.version = 0x0100;
+	input_dev->dev.parent = &tmdc->gameport->dev;
+
+	input_set_drvdata(input_dev, tmdc);
+
+	input_dev->open = tmdc_open;
+	input_dev->close = tmdc_close;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+
+	for (i = 0; i < port->absc && i < TMDC_ABS; i++)
+		if (port->abs[i] >= 0)
+			input_set_abs_params(input_dev, port->abs[i], 8, 248, 2, 4);
+
+	for (i = 0; i < model->hats && i < TMDC_ABS_HAT; i++)
+		input_set_abs_params(input_dev, tmdc_abs_hat[i], -1, 1, 0, 0);
+
+	for (i = 0; i < 4; i++) {
+		for (j = 0; j < port->btnc[i] && j < TMDC_BTN; j++)
+			set_bit(port->btn[j + b], input_dev->keybit);
+		b += port->btnc[i];
+	}
+
+	err = input_register_device(port->dev);
+	if (err)
+		goto fail;
+
+	return 0;
+
+ fail:	input_free_device(input_dev);
+	kfree(port);
+	return err;
+}
+
+/*
+ * tmdc_probe() probes for ThrustMaster type joysticks.
+ */
+
+static int tmdc_connect(struct gameport *gameport, struct gameport_driver *drv)
+{
+	unsigned char data[2][TMDC_MAX_LENGTH];
+	struct tmdc *tmdc;
+	int i;
+	int err;
+
+	tmdc = kzalloc_obj(*tmdc);
+	if (!tmdc)
+		return -ENOMEM;
+
+	tmdc->gameport = gameport;
+
+	gameport_set_drvdata(gameport, tmdc);
+
+	err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
+	if (err)
+		goto fail1;
+
+	if (!(tmdc->exists = tmdc_read_packet(gameport, data))) {
+		err = -ENODEV;
+		goto fail2;
+	}
+
+	gameport_set_poll_handler(gameport, tmdc_poll);
+	gameport_set_poll_interval(gameport, 20);
+
+	for (i = 0; i < 2; i++) {
+		if (tmdc->exists & (1 << i)) {
+
+			err = tmdc_setup_port(tmdc, i, data[i]);
+			if (err)
+				goto fail3;
+		}
+	}
+
+	return 0;
+
+ fail3: while (--i >= 0) {
+		if (tmdc->port[i]) {
+			input_unregister_device(tmdc->port[i]->dev);
+			kfree(tmdc->port[i]);
+		}
+	}
+ fail2:	gameport_close(gameport);
+ fail1:	gameport_set_drvdata(gameport, NULL);
+	kfree(tmdc);
+	return err;
+}
+
+static void tmdc_disconnect(struct gameport *gameport)
+{
+	struct tmdc *tmdc = gameport_get_drvdata(gameport);
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		if (tmdc->port[i]) {
+			input_unregister_device(tmdc->port[i]->dev);
+			kfree(tmdc->port[i]);
+		}
+	}
+	gameport_close(gameport);
+	gameport_set_drvdata(gameport, NULL);
+	kfree(tmdc);
+}
+
+static struct gameport_driver tmdc_drv = {
+	.driver		= {
+		.name	= "tmdc",
+		.owner	= THIS_MODULE,
+	},
+	.description	= DRIVER_DESC,
+	.connect	= tmdc_connect,
+	.disconnect	= tmdc_disconnect,
+};
+
+module_gameport_driver(tmdc_drv);