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, 284 insertions, 0 deletions

diff --git a/drivers/hid/hid-dr.c b/drivers/hid/hid-dr.c
new file mode 100644
index 000000000..a1e10ee8d
--- /dev/null
+++ b/drivers/hid/hid-dr.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Force feedback support for DragonRise Inc. game controllers
+ *
+ * From what I have gathered, these devices are mass produced in China and are
+ * distributed under several vendors. They often share the same design as
+ * the original PlayStation DualShock controller.
+ *
+ * 0079:0006 "DragonRise Inc.   Generic   USB  Joystick  "
+ *  - tested with a Tesun USB-703 game controller.
+ *
+ * Copyright (c) 2009 Richard Walmsley <richwalm@gmail.com>
+ */
+
+/*
+ */
+
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#ifdef CONFIG_DRAGONRISE_FF
+
+struct drff_device {
+	struct hid_report *report;
+};
+
+static int drff_play(struct input_dev *dev, void *data,
+				 struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct drff_device *drff = data;
+	int strong, weak;
+
+	strong = effect->u.rumble.strong_magnitude;
+	weak = effect->u.rumble.weak_magnitude;
+
+	dbg_hid("called with 0x%04x 0x%04x", strong, weak);
+
+	if (strong || weak) {
+		strong = strong * 0xff / 0xffff;
+		weak = weak * 0xff / 0xffff;
+
+		/* While reverse engineering this device, I found that when
+		   this value is set, it causes the strong rumble to function
+		   at a near maximum speed, so we'll bypass it. */
+		if (weak == 0x0a)
+			weak = 0x0b;
+
+		drff->report->field[0]->value[0] = 0x51;
+		drff->report->field[0]->value[1] = 0x00;
+		drff->report->field[0]->value[2] = weak;
+		drff->report->field[0]->value[4] = strong;
+		hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT);
+
+		drff->report->field[0]->value[0] = 0xfa;
+		drff->report->field[0]->value[1] = 0xfe;
+	} else {
+		drff->report->field[0]->value[0] = 0xf3;
+		drff->report->field[0]->value[1] = 0x00;
+	}
+
+	drff->report->field[0]->value[2] = 0x00;
+	drff->report->field[0]->value[4] = 0x00;
+	dbg_hid("running with 0x%02x 0x%02x", strong, weak);
+	hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT);
+
+	return 0;
+}
+
+static int dr_input_configured(struct hid_device *hid, struct hid_input *hidinput)
+{
+	struct drff_device *drff;
+	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;
+
+	if (hid->product != 0x0006)
+		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 < 7) {
+		hid_err(hid, "not enough values in the field\n");
+		return -ENODEV;
+	}
+
+	drff = kzalloc_obj(struct drff_device);
+	if (!drff)
+		return -ENOMEM;
+
+	drff->report = report;
+	set_bit(FF_RUMBLE, dev->ffbit);
+
+	error = input_ff_create_memless(dev, drff, drff_play);
+	if (error) {
+		kfree(drff);
+		return error;
+	}
+
+	drff->report->field[0]->value[0] = 0xf3;
+	drff->report->field[0]->value[1] = 0x00;
+	drff->report->field[0]->value[2] = 0x00;
+	drff->report->field[0]->value[3] = 0x00;
+	drff->report->field[0]->value[4] = 0x00;
+	drff->report->field[0]->value[5] = 0x00;
+	drff->report->field[0]->value[6] = 0x00;
+	hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT);
+
+	hid_info(hid, "Force Feedback for DragonRise Inc. "
+		 "game controllers by Richard Walmsley <richwalm@gmail.com>\n");
+
+	return 0;
+}
+#else
+static inline int dr_input_configured(struct hid_device *hid,
+				      struct hid_input *hidinput)
+{
+	return 0;
+}
+#endif
+
+/*
+ * The original descriptor of joystick with PID 0x0011, represented by DVTech PC
+ * JS19. It seems both copied from another device and a result of confusion
+ * either about the specification or about the program used to create the
+ * descriptor. In any case, it's a wonder it works on Windows.
+ *
+ *  Usage Page (Desktop),             ; Generic desktop controls (01h)
+ *  Usage (Joystick),                 ; Joystick (04h, application collection)
+ *  Collection (Application),
+ *    Collection (Logical),
+ *      Report Size (8),
+ *      Report Count (5),
+ *      Logical Minimum (0),
+ *      Logical Maximum (255),
+ *      Physical Minimum (0),
+ *      Physical Maximum (255),
+ *      Usage (X),                    ; X (30h, dynamic value)
+ *      Usage (X),                    ; X (30h, dynamic value)
+ *      Usage (X),                    ; X (30h, dynamic value)
+ *      Usage (X),                    ; X (30h, dynamic value)
+ *      Usage (Y),                    ; Y (31h, dynamic value)
+ *      Input (Variable),
+ *      Report Size (4),
+ *      Report Count (1),
+ *      Logical Maximum (7),
+ *      Physical Maximum (315),
+ *      Unit (Degrees),
+ *      Usage (00h),
+ *      Input (Variable, Null State),
+ *      Unit,
+ *      Report Size (1),
+ *      Report Count (10),
+ *      Logical Maximum (1),
+ *      Physical Maximum (1),
+ *      Usage Page (Button),          ; Button (09h)
+ *      Usage Minimum (01h),
+ *      Usage Maximum (0Ah),
+ *      Input (Variable),
+ *      Usage Page (FF00h),           ; FF00h, vendor-defined
+ *      Report Size (1),
+ *      Report Count (10),
+ *      Logical Maximum (1),
+ *      Physical Maximum (1),
+ *      Usage (01h),
+ *      Input (Variable),
+ *    End Collection,
+ *    Collection (Logical),
+ *      Report Size (8),
+ *      Report Count (4),
+ *      Physical Maximum (255),
+ *      Logical Maximum (255),
+ *      Usage (02h),
+ *      Output (Variable),
+ *    End Collection,
+ *  End Collection
+ */
+
+/* Size of the original descriptor of the PID 0x0011 joystick */
+#define PID0011_RDESC_ORIG_SIZE	101
+
+/* Fixed report descriptor for PID 0x011 joystick */
+static const __u8 pid0011_rdesc_fixed[] = {
+	0x05, 0x01,         /*  Usage Page (Desktop),           */
+	0x09, 0x04,         /*  Usage (Joystick),               */
+	0xA1, 0x01,         /*  Collection (Application),       */
+	0xA1, 0x02,         /*      Collection (Logical),       */
+	0x14,               /*          Logical Minimum (0),    */
+	0x75, 0x08,         /*          Report Size (8),        */
+	0x95, 0x03,         /*          Report Count (3),       */
+	0x81, 0x01,         /*          Input (Constant),       */
+	0x26, 0xFF, 0x00,   /*          Logical Maximum (255),  */
+	0x95, 0x02,         /*          Report Count (2),       */
+	0x09, 0x30,         /*          Usage (X),              */
+	0x09, 0x31,         /*          Usage (Y),              */
+	0x81, 0x02,         /*          Input (Variable),       */
+	0x75, 0x01,         /*          Report Size (1),        */
+	0x95, 0x04,         /*          Report Count (4),       */
+	0x81, 0x01,         /*          Input (Constant),       */
+	0x25, 0x01,         /*          Logical Maximum (1),    */
+	0x95, 0x0A,         /*          Report Count (10),      */
+	0x05, 0x09,         /*          Usage Page (Button),    */
+	0x19, 0x01,         /*          Usage Minimum (01h),    */
+	0x29, 0x0A,         /*          Usage Maximum (0Ah),    */
+	0x81, 0x02,         /*          Input (Variable),       */
+	0x95, 0x0A,         /*          Report Count (10),      */
+	0x81, 0x01,         /*          Input (Constant),       */
+	0xC0,               /*      End Collection,             */
+	0xC0                /*  End Collection                  */
+};
+
+static const __u8 *dr_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+				   unsigned int *rsize)
+{
+	switch (hdev->product) {
+	case 0x0011:
+		if (*rsize == PID0011_RDESC_ORIG_SIZE) {
+			*rsize = sizeof(pid0011_rdesc_fixed);
+			return pid0011_rdesc_fixed;
+		}
+		break;
+	}
+	return rdesc;
+}
+
+#define map_abs(c)      hid_map_usage(hi, usage, bit, max, EV_ABS, (c))
+#define map_rel(c)      hid_map_usage(hi, usage, bit, max, EV_REL, (c))
+
+static int dr_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+			    struct hid_field *field, struct hid_usage *usage,
+			    unsigned long **bit, int *max)
+{
+	switch (usage->hid) {
+	/*
+	 * revert to the old hid-input behavior where axes
+	 * can be randomly assigned when hid->usage is reused.
+	 */
+	case HID_GD_X: case HID_GD_Y: case HID_GD_Z:
+	case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ:
+		if (field->flags & HID_MAIN_ITEM_RELATIVE)
+			map_rel(usage->hid & 0xf);
+		else
+			map_abs(usage->hid & 0xf);
+		return 1;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id dr_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0006), },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_DRAGONRISE, 0x0011), },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, dr_devices);
+
+static struct hid_driver dr_driver = {
+	.name = "dragonrise",
+	.id_table = dr_devices,
+	.report_fixup = dr_report_fixup,
+	.input_mapping = dr_input_mapping,
+	.input_configured = dr_input_configured,
+};
+module_hid_driver(dr_driver);
+
+MODULE_DESCRIPTION("Force feedback support for DragonRise Inc. game controllers");
+MODULE_LICENSE("GPL");