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, 568 insertions, 0 deletions

diff --git a/drivers/hid/hid-haptic.c b/drivers/hid/hid-haptic.c
new file mode 100644
index 000000000..8760eeb08
--- /dev/null
+++ b/drivers/hid/hid-haptic.c
@@ -0,0 +1,568 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID Haptic support for Linux
+ *
+ *  Copyright (c) 2021 Angela Czubak <acz@semihalf.com>
+ */
+
+#include <linux/input/mt.h>
+#include <linux/module.h>
+
+#include "hid-haptic.h"
+
+void hid_haptic_feature_mapping(struct hid_device *hdev,
+				struct hid_haptic_device *haptic,
+				struct hid_field *field, struct hid_usage *usage)
+{
+	u16 usage_hid;
+
+	if (usage->hid == HID_HP_AUTOTRIGGER) {
+		if (usage->usage_index >= field->report_count) {
+			dev_err(&hdev->dev,
+				"HID_HP_AUTOTRIGGER out of range\n");
+			return;
+		}
+
+		hid_device_io_start(hdev);
+		hid_hw_request(hdev, field->report, HID_REQ_GET_REPORT);
+		hid_hw_wait(hdev);
+		hid_device_io_stop(hdev);
+		haptic->default_auto_trigger =
+			field->value[usage->usage_index];
+		haptic->auto_trigger_report = field->report;
+	} else if ((usage->hid & HID_USAGE_PAGE) == HID_UP_ORDINAL) {
+		usage_hid = usage->hid & HID_USAGE;
+		switch (field->logical) {
+		case HID_HP_WAVEFORMLIST:
+			if (usage_hid > haptic->max_waveform_id)
+				haptic->max_waveform_id = usage_hid;
+			break;
+		case HID_HP_DURATIONLIST:
+			if (usage_hid > haptic->max_duration_id)
+				haptic->max_duration_id = usage_hid;
+			break;
+		default:
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(hid_haptic_feature_mapping);
+
+bool hid_haptic_check_pressure_unit(struct hid_haptic_device *haptic,
+				    struct hid_input *hi, struct hid_field *field)
+{
+	if (field->unit == HID_UNIT_GRAM || field->unit == HID_UNIT_NEWTON) {
+		haptic->force_logical_minimum = field->logical_minimum;
+		haptic->force_physical_minimum = field->physical_minimum;
+		haptic->force_resolution = input_abs_get_res(hi->input,
+							     ABS_MT_PRESSURE);
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_check_pressure_unit);
+
+int hid_haptic_input_mapping(struct hid_device *hdev,
+			     struct hid_haptic_device *haptic,
+			     struct hid_input *hi,
+			     struct hid_field *field, struct hid_usage *usage,
+			     unsigned long **bit, int *max)
+{
+	if (usage->hid == HID_HP_MANUALTRIGGER) {
+		haptic->manual_trigger_report = field->report;
+		/* we don't really want to map these fields */
+		return -1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_mapping);
+
+int hid_haptic_input_configured(struct hid_device *hdev,
+				struct hid_haptic_device *haptic,
+				struct hid_input *hi)
+{
+	int error;
+
+	if (hi->application != HID_DG_TOUCHPAD)
+		return -1;
+
+	if (!haptic->auto_trigger_report || !haptic->manual_trigger_report)
+		return 0;
+
+	__set_bit(INPUT_PROP_PRESSUREPAD, hi->input->propbit);
+
+	error = hid_haptic_init(hdev, haptic, hi->input);
+	if (error) {
+		dev_warn(&hdev->dev, "Cannot allocate haptic for %s\n",
+			 hdev->name);
+		return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_input_configured);
+
+static void parse_auto_trigger_field(struct hid_haptic_device *haptic,
+				     struct hid_field *field)
+{
+	int count = field->report_count;
+	int n;
+	u16 usage_hid;
+
+	for (n = 0; n < count; n++) {
+		switch (field->usage[n].hid & HID_USAGE_PAGE) {
+		case HID_UP_ORDINAL:
+			usage_hid = field->usage[n].hid & HID_USAGE;
+			switch (field->logical) {
+			case HID_HP_WAVEFORMLIST:
+				haptic->hid_usage_map[usage_hid] = field->value[n];
+				if (field->value[n] ==
+				    (HID_HP_WAVEFORMPRESS & HID_USAGE)) {
+					haptic->press_ordinal = usage_hid;
+				} else if (field->value[n] ==
+					   (HID_HP_WAVEFORMRELEASE & HID_USAGE)) {
+					haptic->release_ordinal = usage_hid;
+				}
+				break;
+			case HID_HP_DURATIONLIST:
+				haptic->duration_map[usage_hid] =
+					field->value[n];
+				break;
+			default:
+				break;
+			}
+			break;
+		case HID_UP_HAPTIC:
+			switch (field->usage[n].hid) {
+			case HID_HP_WAVEFORMVENDORID:
+				haptic->vendor_id = field->value[n];
+				break;
+			case HID_HP_WAVEFORMVENDORPAGE:
+				haptic->vendor_page = field->value[n];
+				break;
+			default:
+				break;
+			}
+			break;
+		default:
+			/* Should not really happen */
+			break;
+		}
+	}
+}
+
+static void fill_effect_buf(struct hid_haptic_device *haptic,
+			    struct ff_haptic_effect *effect,
+			    struct hid_haptic_effect *haptic_effect,
+			    int waveform_ordinal)
+{
+	struct hid_report *rep = haptic->manual_trigger_report;
+	struct hid_usage *usage;
+	struct hid_field *field;
+	s32 value;
+	int i, j;
+	u8 *buf = haptic_effect->report_buf;
+
+	mutex_lock(&haptic->manual_trigger_mutex);
+	for (i = 0; i < rep->maxfield; i++) {
+		field = rep->field[i];
+		/* Ignore if report count is out of bounds. */
+		if (field->report_count < 1)
+			continue;
+
+		for (j = 0; j < field->maxusage; j++) {
+			usage = &field->usage[j];
+
+			switch (usage->hid) {
+			case HID_HP_INTENSITY:
+				if (effect->intensity > 100) {
+					value = field->logical_maximum;
+				} else {
+					value = field->logical_minimum +
+						effect->intensity *
+						(field->logical_maximum -
+						 field->logical_minimum) / 100;
+				}
+				break;
+			case HID_HP_REPEATCOUNT:
+				value = effect->repeat_count;
+				break;
+			case HID_HP_RETRIGGERPERIOD:
+				value = effect->retrigger_period;
+				break;
+			case HID_HP_MANUALTRIGGER:
+				value = waveform_ordinal;
+				break;
+			default:
+				continue;
+			}
+
+			field->value[j] = value;
+		}
+	}
+
+	hid_output_report(rep, buf);
+	mutex_unlock(&haptic->manual_trigger_mutex);
+}
+
+static void switch_mode(struct hid_device *hdev, struct hid_haptic_device *haptic,
+			int mode)
+{
+	struct hid_report *rep = haptic->auto_trigger_report;
+	struct hid_field *field;
+	s32 value;
+	int i, j;
+
+	if (mode == HID_HAPTIC_MODE_HOST)
+		value = HID_HAPTIC_ORDINAL_WAVEFORMSTOP;
+	else
+		value = haptic->default_auto_trigger;
+
+	mutex_lock(&haptic->auto_trigger_mutex);
+	for (i = 0; i < rep->maxfield; i++) {
+		field = rep->field[i];
+		/* Ignore if report count is out of bounds. */
+		if (field->report_count < 1)
+			continue;
+
+		for (j = 0; j < field->maxusage; j++) {
+			if (field->usage[j].hid == HID_HP_AUTOTRIGGER)
+				field->value[j] = value;
+		}
+	}
+
+	/* send the report */
+	hid_hw_request(hdev, rep, HID_REQ_SET_REPORT);
+	mutex_unlock(&haptic->auto_trigger_mutex);
+	haptic->mode = mode;
+}
+
+static int hid_haptic_upload_effect(struct input_dev *dev, struct ff_effect *effect,
+				    struct ff_effect *old)
+{
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct ff_device *ff = dev->ff;
+	struct hid_haptic_device *haptic = ff->private;
+	int i, ordinal = 0;
+	bool switch_modes = false;
+
+	/* If vendor range, check vendor id and page */
+	if (effect->u.haptic.hid_usage >= (HID_HP_VENDORWAVEFORMMIN & HID_USAGE) &&
+	    effect->u.haptic.hid_usage <= (HID_HP_VENDORWAVEFORMMAX & HID_USAGE) &&
+	    (effect->u.haptic.vendor_id != haptic->vendor_id ||
+	     effect->u.haptic.vendor_waveform_page != haptic->vendor_page))
+		return -EINVAL;
+
+	/* Check hid_usage */
+	for (i = 1; i <= haptic->max_waveform_id; i++) {
+		if (haptic->hid_usage_map[i] == effect->u.haptic.hid_usage) {
+			ordinal = i;
+			break;
+		}
+	}
+	if (ordinal < 1)
+		return -EINVAL;
+
+	/* Fill the buffer for the effect id */
+	fill_effect_buf(haptic, &effect->u.haptic, &haptic->effect[effect->id],
+			ordinal);
+
+	if (effect->u.haptic.hid_usage == (HID_HP_WAVEFORMPRESS & HID_USAGE) ||
+			effect->u.haptic.hid_usage == (HID_HP_WAVEFORMRELEASE & HID_USAGE))
+		switch_modes = true;
+
+	/* If device is in autonomous mode, and the uploaded effect signals userspace
+	 * wants control of the device, change modes
+	 */
+	if (switch_modes && haptic->mode == HID_HAPTIC_MODE_DEVICE)
+		switch_mode(hdev, haptic, HID_HAPTIC_MODE_HOST);
+
+	return 0;
+}
+
+static int play_effect(struct hid_device *hdev, struct hid_haptic_device *haptic,
+		       struct hid_haptic_effect *effect)
+{
+	int ret;
+
+	ret = hid_hw_output_report(hdev, effect->report_buf,
+				   haptic->manual_trigger_report_len);
+	if (ret < 0) {
+		ret = hid_hw_raw_request(hdev,
+					 haptic->manual_trigger_report->id,
+					 effect->report_buf,
+					 haptic->manual_trigger_report_len,
+					 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	}
+
+	return ret;
+}
+
+static void haptic_work_handler(struct work_struct *work)
+{
+
+	struct hid_haptic_effect *effect = container_of(work,
+							struct hid_haptic_effect,
+							work);
+	struct input_dev *dev = effect->input_dev;
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct hid_haptic_device *haptic = dev->ff->private;
+
+	mutex_lock(&haptic->manual_trigger_mutex);
+	if (effect != &haptic->stop_effect)
+		play_effect(hdev, haptic, &haptic->stop_effect);
+
+	play_effect(hdev, haptic, effect);
+	mutex_unlock(&haptic->manual_trigger_mutex);
+
+}
+
+static int hid_haptic_playback(struct input_dev *dev, int effect_id, int value)
+{
+	struct hid_haptic_device *haptic = dev->ff->private;
+
+	if (value)
+		queue_work(haptic->wq, &haptic->effect[effect_id].work);
+	else
+		queue_work(haptic->wq, &haptic->stop_effect.work);
+
+	return 0;
+}
+
+static void effect_set_default(struct ff_effect *effect)
+{
+	effect->type = FF_HAPTIC;
+	effect->id = -1;
+	effect->u.haptic.hid_usage = HID_HP_WAVEFORMNONE & HID_USAGE;
+	effect->u.haptic.intensity = 100;
+	effect->u.haptic.retrigger_period = 0;
+	effect->u.haptic.repeat_count = 0;
+}
+
+static int hid_haptic_erase(struct input_dev *dev, int effect_id)
+{
+	struct hid_haptic_device *haptic = dev->ff->private;
+	struct hid_device *hdev = input_get_drvdata(dev);
+	struct ff_effect effect;
+	int ordinal;
+
+	effect_set_default(&effect);
+
+	if (effect.u.haptic.hid_usage == (HID_HP_WAVEFORMRELEASE & HID_USAGE)) {
+		ordinal = haptic->release_ordinal;
+		if (!ordinal) {
+			ordinal = HID_HAPTIC_ORDINAL_WAVEFORMNONE;
+			if (haptic->mode == HID_HAPTIC_MODE_HOST)
+				switch_mode(hdev, haptic, HID_HAPTIC_MODE_DEVICE);
+		} else
+			effect.u.haptic.hid_usage = HID_HP_WAVEFORMRELEASE & HID_USAGE;
+
+		fill_effect_buf(haptic, &effect.u.haptic, &haptic->effect[effect_id],
+				ordinal);
+	} else if (effect.u.haptic.hid_usage == (HID_HP_WAVEFORMPRESS & HID_USAGE)) {
+		ordinal = haptic->press_ordinal;
+		if (!ordinal) {
+			ordinal = HID_HAPTIC_ORDINAL_WAVEFORMNONE;
+			if (haptic->mode == HID_HAPTIC_MODE_HOST)
+				switch_mode(hdev, haptic, HID_HAPTIC_MODE_DEVICE);
+		}
+		else
+			effect.u.haptic.hid_usage = HID_HP_WAVEFORMPRESS & HID_USAGE;
+
+		fill_effect_buf(haptic, &effect.u.haptic, &haptic->effect[effect_id],
+				ordinal);
+	}
+
+	return 0;
+}
+
+static void hid_haptic_destroy(struct ff_device *ff)
+{
+	struct hid_haptic_device *haptic = ff->private;
+	struct hid_device *hdev = haptic->hdev;
+	int r;
+
+	if (hdev)
+		put_device(&hdev->dev);
+
+	kfree(haptic->stop_effect.report_buf);
+	haptic->stop_effect.report_buf = NULL;
+
+	if (haptic->effect) {
+		for (r = 0; r < ff->max_effects; r++)
+			kfree(haptic->effect[r].report_buf);
+		kfree(haptic->effect);
+	}
+	haptic->effect = NULL;
+
+	destroy_workqueue(haptic->wq);
+	haptic->wq = NULL;
+
+	kfree(haptic->duration_map);
+	haptic->duration_map = NULL;
+
+	kfree(haptic->hid_usage_map);
+	haptic->hid_usage_map = NULL;
+
+	module_put(THIS_MODULE);
+}
+
+int hid_haptic_init(struct hid_device *hdev,
+		    struct hid_haptic_device *haptic,
+		    struct input_dev *dev)
+{
+	struct ff_device *ff;
+	int ret = 0, r;
+	struct ff_haptic_effect stop_effect = {
+		.hid_usage = HID_HP_WAVEFORMSTOP & HID_USAGE,
+	};
+	const char *prefix = "hid-haptic";
+	char *name;
+	int (*flush)(struct input_dev *dev, struct file *file);
+	int (*event)(struct input_dev *dev, unsigned int type, unsigned int code, int value);
+
+	haptic->hdev = hdev;
+	haptic->max_waveform_id = max(2u, haptic->max_waveform_id);
+	haptic->max_duration_id = max(2u, haptic->max_duration_id);
+
+	haptic->hid_usage_map = kcalloc(haptic->max_waveform_id + 1,
+					sizeof(u16), GFP_KERNEL);
+	if (!haptic->hid_usage_map) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	haptic->duration_map = kcalloc(haptic->max_duration_id + 1,
+				       sizeof(u32), GFP_KERNEL);
+	if (!haptic->duration_map) {
+		ret = -ENOMEM;
+		goto usage_map;
+	}
+
+	if (haptic->max_waveform_id != haptic->max_duration_id)
+		dev_warn(&hdev->dev,
+			 "Haptic duration and waveform lists have different max id (%u and %u).\n",
+			 haptic->max_duration_id, haptic->max_waveform_id);
+
+	haptic->hid_usage_map[HID_HAPTIC_ORDINAL_WAVEFORMNONE] =
+		HID_HP_WAVEFORMNONE & HID_USAGE;
+	haptic->hid_usage_map[HID_HAPTIC_ORDINAL_WAVEFORMSTOP] =
+		HID_HP_WAVEFORMSTOP & HID_USAGE;
+
+	mutex_init(&haptic->auto_trigger_mutex);
+	for (r = 0; r < haptic->auto_trigger_report->maxfield; r++)
+		parse_auto_trigger_field(haptic, haptic->auto_trigger_report->field[r]);
+
+	haptic->input_dev = dev;
+	haptic->manual_trigger_report_len =
+		hid_report_len(haptic->manual_trigger_report);
+	mutex_init(&haptic->manual_trigger_mutex);
+	name = kmalloc(strlen(prefix) + strlen(hdev->name) + 2, GFP_KERNEL);
+	if (name) {
+		sprintf(name, "%s %s", prefix, hdev->name);
+		haptic->wq = create_singlethread_workqueue(name);
+		kfree(name);
+	}
+	if (!haptic->wq) {
+		ret = -ENOMEM;
+		goto duration_map;
+	}
+	haptic->effect = kzalloc_objs(struct hid_haptic_effect, FF_MAX_EFFECTS);
+	if (!haptic->effect) {
+		ret = -ENOMEM;
+		goto output_queue;
+	}
+	for (r = 0; r < FF_MAX_EFFECTS; r++) {
+		haptic->effect[r].report_buf =
+			hid_alloc_report_buf(haptic->manual_trigger_report,
+					     GFP_KERNEL);
+		if (!haptic->effect[r].report_buf) {
+			dev_err(&hdev->dev,
+				"Failed to allocate a buffer for an effect.\n");
+			ret = -ENOMEM;
+			goto buffer_free;
+		}
+		haptic->effect[r].input_dev = dev;
+		INIT_WORK(&haptic->effect[r].work, haptic_work_handler);
+	}
+	haptic->stop_effect.report_buf =
+		hid_alloc_report_buf(haptic->manual_trigger_report,
+				     GFP_KERNEL);
+	if (!haptic->stop_effect.report_buf) {
+		dev_err(&hdev->dev,
+			"Failed to allocate a buffer for stop effect.\n");
+		ret = -ENOMEM;
+		goto buffer_free;
+	}
+	haptic->stop_effect.input_dev = dev;
+	INIT_WORK(&haptic->stop_effect.work, haptic_work_handler);
+	fill_effect_buf(haptic, &stop_effect, &haptic->stop_effect,
+			HID_HAPTIC_ORDINAL_WAVEFORMSTOP);
+
+	input_set_capability(dev, EV_FF, FF_HAPTIC);
+
+	flush = dev->flush;
+	event = dev->event;
+	ret = input_ff_create(dev, FF_MAX_EFFECTS);
+	if (ret) {
+		dev_err(&hdev->dev, "Failed to create ff device.\n");
+		goto stop_buffer_free;
+	}
+
+	ff = dev->ff;
+	ff->private = haptic;
+	ff->upload = hid_haptic_upload_effect;
+	ff->playback = hid_haptic_playback;
+	ff->erase = hid_haptic_erase;
+	ff->destroy = hid_haptic_destroy;
+	if (!try_module_get(THIS_MODULE)) {
+		dev_err(&hdev->dev, "Failed to increase module count.\n");
+		goto input_free;
+	}
+	if (!get_device(&hdev->dev)) {
+		dev_err(&hdev->dev, "Failed to get hdev device.\n");
+		module_put(THIS_MODULE);
+		goto input_free;
+	}
+	return 0;
+
+input_free:
+	input_ff_destroy(dev);
+	/* Restore dev flush and event */
+	dev->flush = flush;
+	dev->event = event;
+	return ret;
+stop_buffer_free:
+	kfree(haptic->stop_effect.report_buf);
+	haptic->stop_effect.report_buf = NULL;
+buffer_free:
+	while (--r >= 0)
+		kfree(haptic->effect[r].report_buf);
+	kfree(haptic->effect);
+	haptic->effect = NULL;
+output_queue:
+	destroy_workqueue(haptic->wq);
+	haptic->wq = NULL;
+duration_map:
+	kfree(haptic->duration_map);
+	haptic->duration_map = NULL;
+usage_map:
+	kfree(haptic->hid_usage_map);
+	haptic->hid_usage_map = NULL;
+exit:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_init);
+
+void hid_haptic_pressure_reset(struct hid_haptic_device *haptic)
+{
+	haptic->pressure_sum = 0;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_reset);
+
+void hid_haptic_pressure_increase(struct hid_haptic_device *haptic,
+				 __s32 pressure)
+{
+	haptic->pressure_sum += pressure;
+}
+EXPORT_SYMBOL_GPL(hid_haptic_pressure_increase);