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, 159 insertions, 0 deletions

diff --git a/drivers/hid/hid-sjoy.c b/drivers/hid/hid-sjoy.c
new file mode 100644
index 000000000..193ab2a61
--- /dev/null
+++ b/drivers/hid/hid-sjoy.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Force feedback support for SmartJoy PLUS PS2->USB adapter
+ *
+ *  Copyright (c) 2009 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ *
+ *  Based of hid-pl.c and hid-gaff.c
+ *   Copyright (c) 2007, 2009 Anssi Hannula <anssi.hannula@gmail.com>
+ *   Copyright (c) 2008 Lukasz Lubojanski <lukasz@lubojanski.info>
+ */
+
+/*
+ */
+
+/* #define DEBUG */
+
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include "hid-ids.h"
+
+#ifdef CONFIG_SMARTJOYPLUS_FF
+
+struct sjoyff_device {
+	struct hid_report *report;
+};
+
+static int hid_sjoyff_play(struct input_dev *dev, void *data,
+			 struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct sjoyff_device *sjoyff = data;
+	u32 left, right;
+
+	left = effect->u.rumble.strong_magnitude;
+	right = effect->u.rumble.weak_magnitude;
+	dev_dbg(&dev->dev, "called with 0x%08x 0x%08x\n", left, right);
+
+	left = left * 0xff / 0xffff;
+	right = (right != 0); /* on/off only */
+
+	sjoyff->report->field[0]->value[1] = right;
+	sjoyff->report->field[0]->value[2] = left;
+	dev_dbg(&dev->dev, "running with 0x%02x 0x%02x\n", left, right);
+	hid_hw_request(hid, sjoyff->report, HID_REQ_SET_REPORT);
+
+	return 0;
+}
+
+static int sjoy_input_configured(struct hid_device *hid, struct hid_input *hidinput)
+{
+	struct sjoyff_device *sjoyff;
+	struct hid_report *report;
+	struct list_head *report_list =
+			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	struct input_dev *dev = hidinput->input;
+	int error;
+
+	if (!list_is_first(&hidinput->list, &hid->inputs))
+		return 0;
+
+	report = list_first_entry_or_null(report_list, struct hid_report, list);
+	if (!report) {
+		hid_err(hid, "no output reports found\n");
+		return -ENODEV;
+	}
+	if (report->maxfield < 1) {
+		hid_err(hid, "no fields in the report\n");
+		return -ENODEV;
+	}
+
+	if (report->field[0]->report_count < 3) {
+		hid_err(hid, "not enough values in the field\n");
+		return -ENODEV;
+	}
+
+	sjoyff = kzalloc_obj(struct sjoyff_device);
+	if (!sjoyff)
+		return -ENOMEM;
+
+	set_bit(FF_RUMBLE, dev->ffbit);
+
+	sjoyff->report = report;
+	sjoyff->report->field[0]->value[0] = 0x01;
+	sjoyff->report->field[0]->value[1] = 0x00;
+	sjoyff->report->field[0]->value[2] = 0x00;
+	hid_hw_request(hid, sjoyff->report, HID_REQ_SET_REPORT);
+
+	error = input_ff_create_memless(dev, sjoyff, hid_sjoyff_play);
+	if (error) {
+		kfree(sjoyff);
+		return error;
+	}
+
+	return 0;
+}
+#else
+static inline int sjoy_input_configured(struct hid_device *hid,
+					struct hid_input *hidinput)
+{
+	return 0;
+}
+#endif
+
+static int sjoy_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+
+	hdev->quirks |= id->driver_data;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id sjoy_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP_LTD, USB_DEVICE_ID_SUPER_JOY_BOX_3_PRO),
+		.driver_data = HID_QUIRK_NOGET },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP_LTD, USB_DEVICE_ID_SUPER_DUAL_BOX_PRO),
+		.driver_data = HID_QUIRK_MULTI_INPUT | HID_QUIRK_NOGET |
+			       HID_QUIRK_SKIP_OUTPUT_REPORTS },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP_LTD, USB_DEVICE_ID_SUPER_JOY_BOX_5_PRO),
+		.driver_data = HID_QUIRK_MULTI_INPUT | HID_QUIRK_NOGET |
+			       HID_QUIRK_SKIP_OUTPUT_REPORTS },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP, USB_DEVICE_ID_SMARTJOY_PLUS) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP, USB_DEVICE_ID_SUPER_JOY_BOX_3) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_WISEGROUP, USB_DEVICE_ID_DUAL_USB_JOYPAD),
+		.driver_data = HID_QUIRK_MULTI_INPUT |
+			       HID_QUIRK_SKIP_OUTPUT_REPORTS },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PLAYDOTCOM, USB_DEVICE_ID_PLAYDOTCOM_EMS_USBII),
+		.driver_data = HID_QUIRK_MULTI_INPUT |
+			       HID_QUIRK_SKIP_OUTPUT_REPORTS },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, sjoy_devices);
+
+static struct hid_driver sjoy_driver = {
+	.name = "smartjoyplus",
+	.id_table = sjoy_devices,
+	.probe = sjoy_probe,
+	.input_configured = sjoy_input_configured,
+};
+module_hid_driver(sjoy_driver);
+
+MODULE_DESCRIPTION("Force feedback support for SmartJoy PLUS PS2->USB adapter");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jussi Kivilinna");
+