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, 408 insertions, 0 deletions

diff --git a/drivers/input/joystick/grip.c b/drivers/input/joystick/grip.c
new file mode 100644
index 000000000..2a3f768a7
--- /dev/null
+++ b/drivers/input/joystick/grip.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) 1998-2001 Vojtech Pavlik
+ */
+
+/*
+ * Gravis/Kensington GrIP protocol joystick and gamepad driver for Linux
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gameport.h>
+#include <linux/input.h>
+#include <linux/jiffies.h>
+
+#define DRIVER_DESC	"Gravis GrIP protocol joystick driver"
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+#define GRIP_MODE_GPP		1
+#define GRIP_MODE_BD		2
+#define GRIP_MODE_XT		3
+#define GRIP_MODE_DC		4
+
+#define GRIP_LENGTH_GPP		24
+#define GRIP_STROBE_GPP		200	/* 200 us */
+#define GRIP_LENGTH_XT		4
+#define GRIP_STROBE_XT		64	/* 64 us */
+#define GRIP_MAX_CHUNKS_XT	10
+#define GRIP_MAX_BITS_XT	30
+
+struct grip {
+	struct gameport *gameport;
+	struct input_dev *dev[2];
+	unsigned char mode[2];
+	int reads;
+	int bads;
+	char phys[2][32];
+};
+
+static int grip_btn_gpp[] = { BTN_START, BTN_SELECT, BTN_TR2, BTN_Y, 0, BTN_TL2, BTN_A, BTN_B, BTN_X, 0, BTN_TL, BTN_TR, -1 };
+static int grip_btn_bd[] = { BTN_THUMB, BTN_THUMB2, BTN_TRIGGER, BTN_TOP, BTN_BASE, -1 };
+static int grip_btn_xt[] = { BTN_TRIGGER, BTN_THUMB, BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_SELECT, BTN_START, BTN_MODE, -1 };
+static int grip_btn_dc[] = { BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_BASE5, -1 };
+
+static int grip_abs_gpp[] = { ABS_X, ABS_Y, -1 };
+static int grip_abs_bd[] = { ABS_X, ABS_Y, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y, -1 };
+static int grip_abs_xt[] = { ABS_X, ABS_Y, ABS_BRAKE, ABS_GAS, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y, ABS_HAT1X, ABS_HAT1Y, -1 };
+static int grip_abs_dc[] = { ABS_X, ABS_Y, ABS_RX, ABS_RY, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y, -1 };
+
+static char *grip_name[] = { NULL, "Gravis GamePad Pro", "Gravis Blackhawk Digital",
+				"Gravis Xterminator Digital", "Gravis Xterminator DualControl" };
+static int *grip_abs[] = { NULL, grip_abs_gpp, grip_abs_bd, grip_abs_xt, grip_abs_dc };
+static int *grip_btn[] = { NULL, grip_btn_gpp, grip_btn_bd, grip_btn_xt, grip_btn_dc };
+static char grip_anx[] = { 0, 0, 3, 5, 5 };
+static char grip_cen[] = { 0, 0, 2, 2, 4 };
+
+/*
+ * grip_gpp_read_packet() reads a Gravis GamePad Pro packet.
+ */
+
+static int grip_gpp_read_packet(struct gameport *gameport, int shift, unsigned int *data)
+{
+	unsigned long flags;
+	unsigned char u, v;
+	unsigned int t;
+	int i;
+
+	int strobe = gameport_time(gameport, GRIP_STROBE_GPP);
+
+	data[0] = 0;
+	t = strobe;
+	i = 0;
+
+	local_irq_save(flags);
+
+	v = gameport_read(gameport) >> shift;
+
+	do {
+		t--;
+		u = v; v = (gameport_read(gameport) >> shift) & 3;
+		if (~v & u & 1) {
+			data[0] |= (v >> 1) << i++;
+			t = strobe;
+		}
+	} while (i < GRIP_LENGTH_GPP && t > 0);
+
+	local_irq_restore(flags);
+
+	if (i < GRIP_LENGTH_GPP) return -1;
+
+	for (i = 0; i < GRIP_LENGTH_GPP && (data[0] & 0xfe4210) ^ 0x7c0000; i++)
+		data[0] = data[0] >> 1 | (data[0] & 1) << (GRIP_LENGTH_GPP - 1);
+
+	return -(i == GRIP_LENGTH_GPP);
+}
+
+/*
+ * grip_xt_read_packet() reads a Gravis Xterminator packet.
+ */
+
+static int grip_xt_read_packet(struct gameport *gameport, int shift, unsigned int *data)
+{
+	unsigned int i, j, buf, crc;
+	unsigned char u, v, w;
+	unsigned long flags;
+	unsigned int t;
+	char status;
+
+	int strobe = gameport_time(gameport, GRIP_STROBE_XT);
+
+	data[0] = data[1] = data[2] = data[3] = 0;
+	status = buf = i = j = 0;
+	t = strobe;
+
+	local_irq_save(flags);
+
+	v = w = (gameport_read(gameport) >> shift) & 3;
+
+	do {
+		t--;
+		u = (gameport_read(gameport) >> shift) & 3;
+
+		if (u ^ v) {
+
+			if ((u ^ v) & 1) {
+				buf = (buf << 1) | (u >> 1);
+				t = strobe;
+				i++;
+			} else
+
+			if ((((u ^ v) & (v ^ w)) >> 1) & ~(u | v | w) & 1) {
+				if (i == 20) {
+					crc = buf ^ (buf >> 7) ^ (buf >> 14);
+					if (!((crc ^ (0x25cb9e70 >> ((crc >> 2) & 0x1c))) & 0xf)) {
+						data[buf >> 18] = buf >> 4;
+						status |= 1 << (buf >> 18);
+					}
+					j++;
+				}
+				t = strobe;
+				buf = 0;
+				i = 0;
+			}
+			w = v;
+			v = u;
+		}
+
+	} while (status != 0xf && i < GRIP_MAX_BITS_XT && j < GRIP_MAX_CHUNKS_XT && t > 0);
+
+	local_irq_restore(flags);
+
+	return -(status != 0xf);
+}
+
+/*
+ * grip_timer() repeatedly polls the joysticks and generates events.
+ */
+
+static void grip_poll(struct gameport *gameport)
+{
+	struct grip *grip = gameport_get_drvdata(gameport);
+	unsigned int data[GRIP_LENGTH_XT];
+	struct input_dev *dev;
+	int i, j;
+
+	for (i = 0; i < 2; i++) {
+
+		dev = grip->dev[i];
+		if (!dev)
+			continue;
+
+		grip->reads++;
+
+		switch (grip->mode[i]) {
+
+			case GRIP_MODE_GPP:
+
+				if (grip_gpp_read_packet(grip->gameport, (i << 1) + 4, data)) {
+					grip->bads++;
+					break;
+				}
+
+				input_report_abs(dev, ABS_X, ((*data >> 15) & 1) - ((*data >> 16) & 1));
+				input_report_abs(dev, ABS_Y, ((*data >> 13) & 1) - ((*data >> 12) & 1));
+
+				for (j = 0; j < 12; j++)
+					if (grip_btn_gpp[j])
+						input_report_key(dev, grip_btn_gpp[j], (*data >> j) & 1);
+
+				break;
+
+			case GRIP_MODE_BD:
+
+				if (grip_xt_read_packet(grip->gameport, (i << 1) + 4, data)) {
+					grip->bads++;
+					break;
+				}
+
+				input_report_abs(dev, ABS_X,        (data[0] >> 2) & 0x3f);
+				input_report_abs(dev, ABS_Y,  63 - ((data[0] >> 8) & 0x3f));
+				input_report_abs(dev, ABS_THROTTLE, (data[2] >> 8) & 0x3f);
+
+				input_report_abs(dev, ABS_HAT0X, ((data[2] >> 1) & 1) - ( data[2]       & 1));
+				input_report_abs(dev, ABS_HAT0Y, ((data[2] >> 2) & 1) - ((data[2] >> 3) & 1));
+
+				for (j = 0; j < 5; j++)
+					input_report_key(dev, grip_btn_bd[j], (data[3] >> (j + 4)) & 1);
+
+				break;
+
+			case GRIP_MODE_XT:
+
+				if (grip_xt_read_packet(grip->gameport, (i << 1) + 4, data)) {
+					grip->bads++;
+					break;
+				}
+
+				input_report_abs(dev, ABS_X,        (data[0] >> 2) & 0x3f);
+				input_report_abs(dev, ABS_Y,  63 - ((data[0] >> 8) & 0x3f));
+				input_report_abs(dev, ABS_BRAKE,    (data[1] >> 2) & 0x3f);
+				input_report_abs(dev, ABS_GAS,	    (data[1] >> 8) & 0x3f);
+				input_report_abs(dev, ABS_THROTTLE, (data[2] >> 8) & 0x3f);
+
+				input_report_abs(dev, ABS_HAT0X, ((data[2] >> 1) & 1) - ( data[2]       & 1));
+				input_report_abs(dev, ABS_HAT0Y, ((data[2] >> 2) & 1) - ((data[2] >> 3) & 1));
+				input_report_abs(dev, ABS_HAT1X, ((data[2] >> 5) & 1) - ((data[2] >> 4) & 1));
+				input_report_abs(dev, ABS_HAT1Y, ((data[2] >> 6) & 1) - ((data[2] >> 7) & 1));
+
+				for (j = 0; j < 11; j++)
+					input_report_key(dev, grip_btn_xt[j], (data[3] >> (j + 3)) & 1);
+				break;
+
+			case GRIP_MODE_DC:
+
+				if (grip_xt_read_packet(grip->gameport, (i << 1) + 4, data)) {
+					grip->bads++;
+					break;
+				}
+
+				input_report_abs(dev, ABS_X,        (data[0] >> 2) & 0x3f);
+				input_report_abs(dev, ABS_Y,        (data[0] >> 8) & 0x3f);
+				input_report_abs(dev, ABS_RX,       (data[1] >> 2) & 0x3f);
+				input_report_abs(dev, ABS_RY,	    (data[1] >> 8) & 0x3f);
+				input_report_abs(dev, ABS_THROTTLE, (data[2] >> 8) & 0x3f);
+
+				input_report_abs(dev, ABS_HAT0X, ((data[2] >> 1) & 1) - ( data[2]       & 1));
+				input_report_abs(dev, ABS_HAT0Y, ((data[2] >> 2) & 1) - ((data[2] >> 3) & 1));
+
+				for (j = 0; j < 9; j++)
+					input_report_key(dev, grip_btn_dc[j], (data[3] >> (j + 3)) & 1);
+				break;
+
+
+		}
+
+		input_sync(dev);
+	}
+}
+
+static int grip_open(struct input_dev *dev)
+{
+	struct grip *grip = input_get_drvdata(dev);
+
+	gameport_start_polling(grip->gameport);
+	return 0;
+}
+
+static void grip_close(struct input_dev *dev)
+{
+	struct grip *grip = input_get_drvdata(dev);
+
+	gameport_stop_polling(grip->gameport);
+}
+
+static int grip_connect(struct gameport *gameport, struct gameport_driver *drv)
+{
+	struct grip *grip;
+	struct input_dev *input_dev;
+	unsigned int data[GRIP_LENGTH_XT];
+	int i, j, t;
+	int err;
+
+	grip = kzalloc_obj(*grip);
+	if (!grip)
+		return -ENOMEM;
+
+	grip->gameport = gameport;
+
+	gameport_set_drvdata(gameport, grip);
+
+	err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
+	if (err)
+		goto fail1;
+
+	for (i = 0; i < 2; i++) {
+		if (!grip_gpp_read_packet(gameport, (i << 1) + 4, data)) {
+			grip->mode[i] = GRIP_MODE_GPP;
+			continue;
+		}
+		if (!grip_xt_read_packet(gameport, (i << 1) + 4, data)) {
+			if (!(data[3] & 7)) {
+				grip->mode[i] = GRIP_MODE_BD;
+				continue;
+			}
+			if (!(data[2] & 0xf0)) {
+				grip->mode[i] = GRIP_MODE_XT;
+				continue;
+			}
+			grip->mode[i] = GRIP_MODE_DC;
+			continue;
+		}
+	}
+
+	if (!grip->mode[0] && !grip->mode[1]) {
+		err = -ENODEV;
+		goto fail2;
+	}
+
+	gameport_set_poll_handler(gameport, grip_poll);
+	gameport_set_poll_interval(gameport, 20);
+
+	for (i = 0; i < 2; i++) {
+		if (!grip->mode[i])
+			continue;
+
+		grip->dev[i] = input_dev = input_allocate_device();
+		if (!input_dev) {
+			err = -ENOMEM;
+			goto fail3;
+		}
+
+		snprintf(grip->phys[i], sizeof(grip->phys[i]),
+			 "%s/input%d", gameport->phys, i);
+
+		input_dev->name = grip_name[grip->mode[i]];
+		input_dev->phys = grip->phys[i];
+		input_dev->id.bustype = BUS_GAMEPORT;
+		input_dev->id.vendor = GAMEPORT_ID_VENDOR_GRAVIS;
+		input_dev->id.product = grip->mode[i];
+		input_dev->id.version = 0x0100;
+		input_dev->dev.parent = &gameport->dev;
+
+		input_set_drvdata(input_dev, grip);
+
+		input_dev->open = grip_open;
+		input_dev->close = grip_close;
+
+		input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+
+		for (j = 0; (t = grip_abs[grip->mode[i]][j]) >= 0; j++) {
+
+			if (j < grip_cen[grip->mode[i]])
+				input_set_abs_params(input_dev, t, 14, 52, 1, 2);
+			else if (j < grip_anx[grip->mode[i]])
+				input_set_abs_params(input_dev, t, 3, 57, 1, 0);
+			else
+				input_set_abs_params(input_dev, t, -1, 1, 0, 0);
+		}
+
+		for (j = 0; (t = grip_btn[grip->mode[i]][j]) >= 0; j++)
+			if (t > 0)
+				set_bit(t, input_dev->keybit);
+
+		err = input_register_device(grip->dev[i]);
+		if (err)
+			goto fail4;
+	}
+
+	return 0;
+
+ fail4:	input_free_device(grip->dev[i]);
+ fail3:	while (--i >= 0)
+		if (grip->dev[i])
+			input_unregister_device(grip->dev[i]);
+ fail2:	gameport_close(gameport);
+ fail1:	gameport_set_drvdata(gameport, NULL);
+	kfree(grip);
+	return err;
+}
+
+static void grip_disconnect(struct gameport *gameport)
+{
+	struct grip *grip = gameport_get_drvdata(gameport);
+	int i;
+
+	for (i = 0; i < 2; i++)
+		if (grip->dev[i])
+			input_unregister_device(grip->dev[i]);
+	gameport_close(gameport);
+	gameport_set_drvdata(gameport, NULL);
+	kfree(grip);
+}
+
+static struct gameport_driver grip_drv = {
+	.driver		= {
+		.name	= "grip",
+		.owner	= THIS_MODULE,
+	},
+	.description	= DRIVER_DESC,
+	.connect	= grip_connect,
+	.disconnect	= grip_disconnect,
+};
+
+module_gameport_driver(grip_drv);