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, 266 insertions, 0 deletions

diff --git a/sound/firewire/fireface/ff.c b/sound/firewire/fireface/ff.c
new file mode 100644
index 000000000..13472822d
--- /dev/null
+++ b/sound/firewire/fireface/ff.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ff.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ */
+
+#include "ff.h"
+
+#define OUI_RME	0x000a35
+
+MODULE_DESCRIPTION("RME Fireface series Driver");
+MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
+MODULE_LICENSE("GPL");
+
+static void name_card(struct snd_ff *ff)
+{
+	struct fw_device *fw_dev = fw_parent_device(ff->unit);
+	static const char *const names[] = {
+		[SND_FF_UNIT_VERSION_FF800]	= "Fireface800",
+		[SND_FF_UNIT_VERSION_FF400]	= "Fireface400",
+		[SND_FF_UNIT_VERSION_UFX]	= "FirefaceUFX",
+		[SND_FF_UNIT_VERSION_UCX]	= "FirefaceUCX",
+		[SND_FF_UNIT_VERSION_802]	= "Fireface802",
+	};
+	const char *name;
+
+	name = names[ff->unit_version];
+
+	strscpy(ff->card->driver, "Fireface");
+	strscpy(ff->card->shortname, name);
+	strscpy(ff->card->mixername, name);
+	snprintf(ff->card->longname, sizeof(ff->card->longname),
+		 "RME %s, GUID %08x%08x at %s, S%d", name,
+		 fw_dev->config_rom[3], fw_dev->config_rom[4],
+		 dev_name(&ff->unit->device), 100 << fw_dev->max_speed);
+}
+
+static void ff_card_free(struct snd_card *card)
+{
+	struct snd_ff *ff = card->private_data;
+
+	snd_ff_stream_destroy_duplex(ff);
+	snd_ff_transaction_unregister(ff);
+
+	kfree(ff->msg_parser);
+
+	mutex_destroy(&ff->mutex);
+	fw_unit_put(ff->unit);
+}
+
+static int snd_ff_probe(struct fw_unit *unit, const struct ieee1394_device_id *entry)
+{
+	struct snd_card *card;
+	struct snd_ff *ff;
+	int err;
+
+	err = snd_card_new(&unit->device, -1, NULL, THIS_MODULE, sizeof(*ff), &card);
+	if (err < 0)
+		return err;
+	card->private_free = ff_card_free;
+
+	ff = card->private_data;
+	ff->unit = fw_unit_get(unit);
+	dev_set_drvdata(&unit->device, ff);
+	ff->card = card;
+
+	mutex_init(&ff->mutex);
+	spin_lock_init(&ff->lock);
+	init_waitqueue_head(&ff->hwdep_wait);
+
+	ff->unit_version = entry->version;
+	ff->spec = entry->driver_data_ptr;
+
+	err = snd_ff_transaction_register(ff);
+	if (err < 0)
+		goto error;
+
+	name_card(ff);
+
+	err = snd_ff_stream_init_duplex(ff);
+	if (err < 0)
+		goto error;
+
+	snd_ff_proc_init(ff);
+
+	err = snd_ff_create_midi_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_pcm_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_hwdep_devices(ff);
+	if (err < 0)
+		goto error;
+
+	if (ff->spec->protocol->msg_parser_size > 0) {
+		ff->msg_parser = kzalloc(ff->spec->protocol->msg_parser_size, GFP_KERNEL);
+		if (!ff->msg_parser) {
+			err = -ENOMEM;
+			goto error;
+		}
+	}
+
+	err = snd_card_register(card);
+	if (err < 0)
+		goto error;
+
+	return 0;
+error:
+	snd_card_free(card);
+	return err;
+}
+
+static void snd_ff_update(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	snd_ff_transaction_reregister(ff);
+
+	snd_ff_stream_update_duplex(ff);
+}
+
+static void snd_ff_remove(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	// Block till all of ALSA character devices are released.
+	snd_card_free(ff->card);
+}
+
+static const struct snd_ff_spec spec_ff800 = {
+	.pcm_capture_channels = {28, 20, 12},
+	.pcm_playback_channels = {28, 20, 12},
+	.midi_in_ports = 1,
+	.midi_out_ports = 1,
+	.protocol = &snd_ff_protocol_ff800,
+	.midi_high_addr = 0x000200000320ull,
+	.midi_addr_range = 12,
+	.midi_rx_addrs = {0x000080180000ull, 0},
+};
+
+static const struct snd_ff_spec spec_ff400 = {
+	.pcm_capture_channels = {18, 14, 10},
+	.pcm_playback_channels = {18, 14, 10},
+	.midi_in_ports = 2,
+	.midi_out_ports = 2,
+	.protocol = &snd_ff_protocol_ff400,
+	.midi_high_addr = 0x0000801003f4ull,
+	.midi_addr_range = SND_FF_MAXIMIM_MIDI_QUADS * 4,
+	.midi_rx_addrs = {0x000080180000ull, 0x000080190000ull},
+};
+
+static const struct snd_ff_spec spec_ucx = {
+	.pcm_capture_channels = {18, 14, 12},
+	.pcm_playback_channels = {18, 14, 12},
+	.midi_in_ports = 2,
+	.midi_out_ports = 2,
+	.protocol = &snd_ff_protocol_latter,
+	.midi_high_addr = 0xffff00000034ull,
+	.midi_addr_range = 0x80,
+	.midi_rx_addrs = {0xffff00000030ull, 0xffff00000030ull},
+};
+
+static const struct snd_ff_spec spec_ufx_802 = {
+	.pcm_capture_channels = {30, 22, 14},
+	.pcm_playback_channels = {30, 22, 14},
+	.midi_in_ports = 1,
+	.midi_out_ports = 1,
+	.protocol = &snd_ff_protocol_latter,
+	.midi_high_addr = 0xffff00000034ull,
+	.midi_addr_range = 0x80,
+	.midi_rx_addrs = {0xffff00000030ull, 0xffff00000030ull},
+};
+
+static const struct ieee1394_device_id snd_ff_id_table[] = {
+	/* Fireface 800 */
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_FF800,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ff800,
+	},
+	/* Fireface 400 */
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_FF400,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ff400,
+	},
+	// Fireface UFX.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_UFX,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ufx_802,
+	},
+	// Fireface UCX.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_UCX,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ucx,
+	},
+	// Fireface 802.
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= OUI_RME,
+		.version	= SND_FF_UNIT_VERSION_802,
+		.model_id	= 0x101800,
+		.driver_data_ptr = &spec_ufx_802,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(ieee1394, snd_ff_id_table);
+
+static struct fw_driver ff_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= KBUILD_MODNAME,
+		.bus	= &fw_bus_type,
+	},
+	.probe    = snd_ff_probe,
+	.update   = snd_ff_update,
+	.remove   = snd_ff_remove,
+	.id_table = snd_ff_id_table,
+};
+
+static int __init snd_ff_init(void)
+{
+	return driver_register(&ff_driver.driver);
+}
+
+static void __exit snd_ff_exit(void)
+{
+	driver_unregister(&ff_driver.driver);
+}
+
+module_init(snd_ff_init);
+module_exit(snd_ff_exit);