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, 268 insertions, 0 deletions

diff --git a/drivers/hid/hid-creative-sb0540.c b/drivers/hid/hid-creative-sb0540.c
new file mode 100644
index 000000000..dfd6add35
--- /dev/null
+++ b/drivers/hid/hid-creative-sb0540.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID driver for the Creative SB0540 receiver
+ *
+ * Copyright (C) 2019 Red Hat Inc. All Rights Reserved
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include "hid-ids.h"
+
+MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
+MODULE_DESCRIPTION("HID Creative SB0540 receiver");
+MODULE_LICENSE("GPL");
+
+static const unsigned short creative_sb0540_key_table[] = {
+	KEY_POWER,
+	KEY_RESERVED,		/* text: 24bit */
+	KEY_RESERVED,		/* 24bit wheel up */
+	KEY_RESERVED,		/* 24bit wheel down */
+	KEY_RESERVED,		/* text: CMSS */
+	KEY_RESERVED,		/* CMSS wheel Up */
+	KEY_RESERVED,		/* CMSS wheel Down */
+	KEY_RESERVED,		/* text: EAX */
+	KEY_RESERVED,		/* EAX wheel up */
+	KEY_RESERVED,		/* EAX wheel down */
+	KEY_RESERVED,		/* text: 3D Midi */
+	KEY_RESERVED,		/* 3D Midi wheel up */
+	KEY_RESERVED,		/* 3D Midi wheel down */
+	KEY_MUTE,
+	KEY_VOLUMEUP,
+	KEY_VOLUMEDOWN,
+	KEY_UP,
+	KEY_LEFT,
+	KEY_RIGHT,
+	KEY_REWIND,
+	KEY_OK,
+	KEY_FASTFORWARD,
+	KEY_DOWN,
+	KEY_AGAIN,		/* text: Return, symbol: Jump to */
+	KEY_PLAY,		/* text: Start */
+	KEY_ESC,		/* text: Cancel */
+	KEY_RECORD,
+	KEY_OPTION,
+	KEY_MENU,		/* text: Display */
+	KEY_PREVIOUS,
+	KEY_PLAYPAUSE,
+	KEY_NEXT,
+	KEY_SLOW,
+	KEY_STOP,
+	KEY_NUMERIC_1,
+	KEY_NUMERIC_2,
+	KEY_NUMERIC_3,
+	KEY_NUMERIC_4,
+	KEY_NUMERIC_5,
+	KEY_NUMERIC_6,
+	KEY_NUMERIC_7,
+	KEY_NUMERIC_8,
+	KEY_NUMERIC_9,
+	KEY_NUMERIC_0
+};
+
+/*
+ * Codes and keys from lirc's
+ * remotes/creative/lircd.conf.alsa_usb
+ * order and size must match creative_sb0540_key_table[] above
+ */
+static const unsigned short creative_sb0540_codes[] = {
+	0x619E,
+	0x916E,
+	0x926D,
+	0x936C,
+	0x718E,
+	0x946B,
+	0x956A,
+	0x8C73,
+	0x9669,
+	0x9768,
+	0x9867,
+	0x9966,
+	0x9A65,
+	0x6E91,
+	0x629D,
+	0x639C,
+	0x7B84,
+	0x6B94,
+	0x728D,
+	0x8778,
+	0x817E,
+	0x758A,
+	0x8D72,
+	0x8E71,
+	0x8877,
+	0x7C83,
+	0x738C,
+	0x827D,
+	0x7689,
+	0x7F80,
+	0x7986,
+	0x7A85,
+	0x7D82,
+	0x857A,
+	0x8B74,
+	0x8F70,
+	0x906F,
+	0x8A75,
+	0x847B,
+	0x7887,
+	0x8976,
+	0x837C,
+	0x7788,
+	0x807F
+};
+
+struct creative_sb0540 {
+	struct input_dev *input_dev;
+	struct hid_device *hid;
+	unsigned short keymap[ARRAY_SIZE(creative_sb0540_key_table)];
+};
+
+static inline u64 reverse(u64 data, int bits)
+{
+	int i;
+	u64 c;
+
+	c = 0;
+	for (i = 0; i < bits; i++) {
+		c |= (u64) (((data & (((u64) 1) << i)) ? 1 : 0))
+			<< (bits - 1 - i);
+	}
+	return (c);
+}
+
+static int get_key(struct creative_sb0540 *creative_sb0540, u64 keycode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(creative_sb0540_codes); i++) {
+		if (creative_sb0540_codes[i] == keycode)
+			return creative_sb0540->keymap[i];
+	}
+
+	return 0;
+
+}
+
+static int creative_sb0540_raw_event(struct hid_device *hid,
+	struct hid_report *report, u8 *data, int len)
+{
+	struct creative_sb0540 *creative_sb0540 = hid_get_drvdata(hid);
+	u64 code, main_code;
+	int key;
+
+	if (len != 6 || !(hid->claimed & HID_CLAIMED_INPUT))
+		return 0;
+
+	/* From daemons/hw_hiddev.c sb0540_rec() in lirc */
+	code = reverse(data[5], 8);
+	main_code = (code << 8) + ((~code) & 0xff);
+
+	/*
+	 * Flip to get values in the same format as
+	 * remotes/creative/lircd.conf.alsa_usb in lirc
+	 */
+	main_code = ((main_code & 0xff) << 8) +
+		((main_code & 0xff00) >> 8);
+
+	key = get_key(creative_sb0540, main_code);
+	if (key == 0 || key == KEY_RESERVED) {
+		hid_err(hid, "Could not get a key for main_code %llX\n",
+			main_code);
+		return 0;
+	}
+
+	input_report_key(creative_sb0540->input_dev, key, 1);
+	input_report_key(creative_sb0540->input_dev, key, 0);
+	input_sync(creative_sb0540->input_dev);
+
+	/* let hidraw and hiddev handle the report */
+	return 0;
+}
+
+static int creative_sb0540_input_configured(struct hid_device *hid,
+		struct hid_input *hidinput)
+{
+	struct input_dev *input_dev = hidinput->input;
+	struct creative_sb0540 *creative_sb0540 = hid_get_drvdata(hid);
+	int i;
+
+	creative_sb0540->input_dev = input_dev;
+
+	input_dev->keycode = creative_sb0540->keymap;
+	input_dev->keycodesize = sizeof(unsigned short);
+	input_dev->keycodemax = ARRAY_SIZE(creative_sb0540->keymap);
+
+	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_REP);
+
+	memcpy(creative_sb0540->keymap, creative_sb0540_key_table,
+		sizeof(creative_sb0540->keymap));
+	for (i = 0; i < ARRAY_SIZE(creative_sb0540_key_table); i++)
+		set_bit(creative_sb0540->keymap[i], input_dev->keybit);
+	clear_bit(KEY_RESERVED, input_dev->keybit);
+
+	return 0;
+}
+
+static int creative_sb0540_input_mapping(struct hid_device *hid,
+		struct hid_input *hi, struct hid_field *field,
+		struct hid_usage *usage, unsigned long **bit, int *max)
+{
+	/*
+	 * We are remapping the keys ourselves, so ignore the hid-input
+	 * keymap processing.
+	 */
+	return -1;
+}
+
+static int creative_sb0540_probe(struct hid_device *hid,
+		const struct hid_device_id *id)
+{
+	int ret;
+	struct creative_sb0540 *creative_sb0540;
+
+	creative_sb0540 = devm_kzalloc(&hid->dev,
+		sizeof(struct creative_sb0540), GFP_KERNEL);
+
+	if (!creative_sb0540)
+		return -ENOMEM;
+
+	creative_sb0540->hid = hid;
+
+	/* force input as some remotes bypass the input registration */
+	hid->quirks |= HID_QUIRK_HIDINPUT_FORCE;
+
+	hid_set_drvdata(hid, creative_sb0540);
+
+	ret = hid_parse(hid);
+	if (ret) {
+		hid_err(hid, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hid, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hid, "hw start failed\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct hid_device_id creative_sb0540_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_CREATIVE_SB0540) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, creative_sb0540_devices);
+
+static struct hid_driver creative_sb0540_driver = {
+	.name = "creative-sb0540",
+	.id_table = creative_sb0540_devices,
+	.raw_event = creative_sb0540_raw_event,
+	.input_configured = creative_sb0540_input_configured,
+	.probe = creative_sb0540_probe,
+	.input_mapping = creative_sb0540_input_mapping,
+};
+module_hid_driver(creative_sb0540_driver);