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, 341 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt766-sdca-sdw.c b/sound/soc/codecs/rt766-sdca-sdw.c
new file mode 100644
index 000000000..8e76bf725
--- /dev/null
+++ b/sound/soc/codecs/rt766-sdca-sdw.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// rt766-sdca-sdw.c -- rt766 SDCA ALSA SoC audio driver
+//
+// Copyright(c) 2026 Realtek Semiconductor Corp.
+//
+//
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <sound/sdca.h>
+#include <sound/sdca_function.h>
+#include "rt766-sdca.h"
+#include "rt766-sdca-sdw.h"
+
+#define RT766_PROBE_TIMEOUT 5000
+
+static bool rt766_sdca_readable_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SDW_SCP_SDCA_INT1 ... SDW_SCP_SDCA_INTMASK4:
+	case RT766_VERSION_ID ... RT766_BOND_LATCH_ID:
+	case 0xc344 ... 0xc345:
+	case 0xc900:
+	case 0xc920:
+	case 0xd540 ... 0xd542:
+	case 0xf01e:
+	case RT766_HP_POWER_STATE ... RT766_HP_FSM_CTL2_1:
+	case 0x310100:
+	case RT766_MCU_PATCH_ADDR1_START ... RT766_MCU_PATCH_ADDR1_END:
+	case RT766_MCU_PATCH_ADDR2_START ... RT766_MCU_PATCH_ADDR2_END:
+	case RT766_MUTE_REG(UAJ, USER_FU41, 1):
+	case RT766_MUTE_REG(UAJ, USER_FU41, 2):
+	case RT766_VOLUME_REG(UAJ, USER_FU41, 1):
+	case RT766_VOLUME_REG(UAJ, USER_FU41, 2):
+	case RT766_MUTE_REG(UAJ, USER_FU36, 1):
+	case RT766_MUTE_REG(UAJ, USER_FU36, 2):
+	case RT766_VOLUME_REG(UAJ, USER_FU36, 1):
+	case RT766_VOLUME_REG(UAJ, USER_FU36, 2):
+	case RT766_PDE_REQ_REG(UAJ, PDE47):
+	case RT766_PDE_REQ_REG(UAJ, PDE34):
+	case RT766_SDCA_CTL(UAJ, CS41, SDCA_CTL_CS_SAMPLERATEINDEX):
+	case RT766_SDCA_CTL(UAJ, CS36, SDCA_CTL_CS_SAMPLERATEINDEX):
+	case RT766_FUNC_STATUS_REG(UAJ): /* 0x40480000 */
+	case RT766_PDE_ACTUAL_REG(UAJ, PDE47): /* 0x40481400 */
+	case RT766_PDE_ACTUAL_REG(UAJ, PDE34): /* 0x40481480 */
+	case RT766_GAIN_REG(UAJ, PLATFORM_FU33, 1):
+	case RT766_GAIN_REG(UAJ, PLATFORM_FU33, 2):
+	case RT766_SDCA_CTL(UAJ, GE49, SDCA_CTL_GE_SELECTED_MODE):
+	case RT766_SDCA_CTL(UAJ, GE49, SDCA_CTL_GE_DETECTED_MODE): /* 0x40600490 */
+	case RT766_PDE_REQ_REG(MIC, PDE11):
+	case RT766_MUTE_REG(MIC, USER_FU113, 1):
+	case RT766_MUTE_REG(MIC, USER_FU113, 2):
+	case RT766_MUTE_REG(MIC, USER_FU113, 3):
+	case RT766_MUTE_REG(MIC, USER_FU113, 4):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 1):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 2):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 3):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 4):
+	case RT766_FUNC_STATUS_REG(MIC): /* 0x40880000 */
+	case RT766_SDCA_CTL(MIC, CS113, SDCA_CTL_CS_SAMPLERATEINDEX):
+	case RT766_PDE_ACTUAL_REG(MIC, PDE11): /* 0x40881500 */
+	case RT766_FUNC_STATUS_REG(HID): /* 0x40c80000 */
+	/* 0x40c80080 - 0x40c80098 */
+	case RT766_SDCA_CTL(HID, HID101, SDCA_CTL_HIDE_HIDTX_CURRENTOWNER) ...
+		RT766_SDCA_CTL(HID, HID101, SDCA_CTL_HIDE_HIDTX_MESSAGELENGTH):
+	case RT766_MUTE_REG(AMP, USER_FU21, 1):
+	case RT766_MUTE_REG(AMP, USER_FU21, 2):
+	case RT766_VOLUME_REG(AMP, USER_FU21, 1):
+	case RT766_VOLUME_REG(AMP, USER_FU21, 2):
+	case RT766_PDE_REQ_REG(AMP, PDE23):
+	case RT766_FUNC_STATUS_REG(AMP): /* 0x41080000 */
+	case RT766_SDCA_CTL(AMP, PPU21, SDCA_CTL_PPU_POSTURENUMBER):
+	case RT766_SDCA_CTL(AMP, CS21, SDCA_CTL_CS_SAMPLERATEINDEX):
+	case RT766_PDE_ACTUAL_REG(AMP, PDE23): /* 0x41081980 */
+	case RT766_BUF_ADDR_HID1 ... RT766_BUF_ADDR_HID2:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rt766_sdca_volatile_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SDW_SCP_SDCA_INT1 ... SDW_SCP_SDCA_INTMASK4:
+	case RT766_VERSION_ID ... RT766_BOND_LATCH_ID:
+	case 0xc344 ... 0xc345:
+	case 0xc900:
+	case 0xc920:
+	case 0xd540 ... 0xd542:
+	case 0xf01e:
+	case RT766_HP_POWER_STATE ... RT766_HP_FSM_CTL2_1:
+	case 0x310100:
+	case RT766_MCU_PATCH_ADDR1_START ... RT766_MCU_PATCH_ADDR1_END:
+	case RT766_MCU_PATCH_ADDR2_START ... RT766_MCU_PATCH_ADDR2_END:
+	case RT766_FUNC_STATUS_REG(UAJ):
+	case RT766_PDE_ACTUAL_REG(UAJ, PDE47):
+	case RT766_PDE_ACTUAL_REG(UAJ, PDE34):
+	case RT766_SDCA_CTL(UAJ, GE49, SDCA_CTL_GE_DETECTED_MODE):
+	case RT766_FUNC_STATUS_REG(MIC):
+	case RT766_PDE_ACTUAL_REG(MIC, PDE11):
+	case RT766_FUNC_STATUS_REG(HID):
+	case RT766_SDCA_CTL(HID, HID101, SDCA_CTL_HIDE_HIDTX_CURRENTOWNER) ...
+		RT766_SDCA_CTL(HID, HID101, SDCA_CTL_HIDE_HIDTX_MESSAGELENGTH):
+	case RT766_FUNC_STATUS_REG(AMP):
+	case RT766_PDE_ACTUAL_REG(AMP, PDE23):
+	case RT766_BUF_ADDR_HID1 ... RT766_BUF_ADDR_HID2:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int rt766_sdca_mbq_size(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case RT766_VOLUME_REG(UAJ, USER_FU41, 1):
+	case RT766_VOLUME_REG(UAJ, USER_FU41, 2):
+	case RT766_VOLUME_REG(UAJ, USER_FU36, 1):
+	case RT766_VOLUME_REG(UAJ, USER_FU36, 2):
+	case RT766_GAIN_REG(UAJ, PLATFORM_FU33, 1):
+	case RT766_GAIN_REG(UAJ, PLATFORM_FU33, 2):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 1):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 2):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 3):
+	case RT766_VOLUME_REG(MIC, USER_FU113, 4):
+	case RT766_VOLUME_REG(AMP, USER_FU21, 1):
+	case RT766_VOLUME_REG(AMP, USER_FU21, 2):
+		return 2;
+	default:
+		return 1;
+	}
+}
+
+static const struct regmap_sdw_mbq_cfg rt766_sdca_mbq_cfg = {
+	.mbq_size = rt766_sdca_mbq_size,
+};
+
+static const struct regmap_config rt766_sdca_regmap = {
+	.reg_bits = 32,
+	.val_bits = 16,
+	.readable_reg = rt766_sdca_readable_register,
+	.volatile_reg = rt766_sdca_volatile_register,
+	.reg_defaults = rt766_sdca_defaults,
+	.num_reg_defaults = ARRAY_SIZE(rt766_sdca_defaults),
+	.max_register = SDW_SDCA_MAX_REGISTER,
+	.cache_type = REGCACHE_MAPLE,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+
+static int rt766_sdca_update_status(struct sdw_slave *slave,
+				enum sdw_slave_status status)
+{
+	struct rt766_sdca_priv *rt766 = dev_get_drvdata(&slave->dev);
+
+	if (status == SDW_SLAVE_UNATTACHED)
+		rt766->hw_init = false;
+
+	if (status == SDW_SLAVE_ATTACHED) {
+		if (rt766->hs_jack) {
+			/*
+			 * Due to the SCP_SDCA_INTMASK will be cleared by any reset, and then
+			 * if the device attached again, we will need to set the setting back.
+			 * It could avoid losing the jack detection interrupt.
+			 * This also could sync with the cache value as the rt766_sdca_jack_init set.
+			 */
+			sdw_write_no_pm(rt766->slave, SDW_SCP_SDCA_INTMASK3,
+				SDW_SCP_SDCA_INTMASK_SDCA_16);
+			sdw_write_no_pm(rt766->slave, SDW_SCP_SDCA_INTMASK4,
+				SDW_SCP_SDCA_INTMASK_SDCA_24);
+		}
+	}
+
+	/*
+	 * Perform initialization only if slave status is present and
+	 * hw_init flag is false
+	 */
+	if (rt766->hw_init || status != SDW_SLAVE_ATTACHED)
+		return 0;
+
+	/* perform I/O transfers required for Slave initialization */
+	return rt766_sdca_io_init(&slave->dev, slave);
+}
+
+static int rt766_sdca_read_prop(struct sdw_slave *slave)
+{
+	struct sdw_slave_prop *prop = &slave->prop;
+	int ret;
+
+	ret = sdw_slave_read_prop(slave);
+	if (ret < 0)
+		return ret;
+
+	prop->scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;
+	prop->quirks = SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY;
+	/*
+	 * SDCA interrupts are routed through SoundWire domain IRQ.
+	 */
+	prop->use_domain_irq = true;
+
+	return 0;
+}
+
+static const struct sdw_slave_ops rt766_sdca_slave_ops = {
+	.read_prop = rt766_sdca_read_prop,
+	.update_status = rt766_sdca_update_status,
+};
+
+static int rt766_sdca_sdw_probe(struct sdw_slave *slave,
+				const struct sdw_device_id *id)
+{
+	struct regmap *regmap;
+
+	/* Regmap Initialization */
+	regmap = devm_regmap_init_sdw_mbq_cfg(&slave->dev, slave,
+					      &rt766_sdca_regmap, &rt766_sdca_mbq_cfg);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	return rt766_sdca_init(&slave->dev, regmap, slave);
+}
+
+static void rt766_sdca_sdw_remove(struct sdw_slave *slave)
+{
+	pm_runtime_disable(&slave->dev);
+}
+
+static const struct sdw_device_id rt766_sdca_id[] = {
+	SDW_SLAVE_ENTRY_EXT(0x025d, 0x766, 0x3, 0x1, 0),
+	SDW_SLAVE_ENTRY_EXT(0x025d, 0x767, 0x3, 0x1, 0),
+	SDW_SLAVE_ENTRY_EXT(0x025d, 0x766, 0x4, 0x1, 0),
+	SDW_SLAVE_ENTRY_EXT(0x025d, 0x767, 0x4, 0x1, 0),
+	{},
+};
+MODULE_DEVICE_TABLE(sdw, rt766_sdca_id);
+
+static int rt766_sdca_dev_suspend(struct device *dev)
+{
+	struct rt766_sdca_priv *rt766 = dev_get_drvdata(dev);
+
+	if (!rt766->hw_init)
+		return 0;
+
+	regcache_cache_only(rt766->regmap, true);
+	return 0;
+}
+
+static int rt766_sdca_dev_system_suspend(struct device *dev)
+{
+	struct rt766_sdca_priv *rt766 = dev_get_drvdata(dev);
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+	int ret1, ret2;
+
+	if (!rt766->hw_init)
+		return 0;
+
+	/*
+	 * prevent new interrupts from being handled after the
+	 * deferred work completes and before the parent disables
+	 * interrupts on the link
+	 */
+	mutex_lock(&rt766->disable_irq_lock);
+	rt766->disable_irq = true;
+	ret1 = sdw_update_no_pm(slave, SDW_SCP_SDCA_INTMASK3,
+				SDW_SCP_SDCA_INTMASK_SDCA_16, 0);
+	ret2 = sdw_update_no_pm(slave, SDW_SCP_SDCA_INTMASK4,
+				SDW_SCP_SDCA_INTMASK_SDCA_24, 0);
+	mutex_unlock(&rt766->disable_irq_lock);
+
+	if (ret1 < 0 || ret2 < 0) {
+		/* log but don't prevent suspend from happening */
+		dev_dbg(&slave->dev, "%s: could not disable SDCA interrupts\n:", __func__);
+	}
+
+	return rt766_sdca_dev_suspend(dev);
+}
+
+static int rt766_sdca_dev_resume(struct device *dev)
+{
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+	struct rt766_sdca_priv *rt766 = dev_get_drvdata(dev);
+	int ret;
+
+	if (!rt766->first_hw_init)
+		return 0;
+
+	if (!slave->unattach_request) {
+		mutex_lock(&rt766->disable_irq_lock);
+		if (rt766->disable_irq == true) {
+			sdw_write_no_pm(slave, SDW_SCP_SDCA_INTMASK3, SDW_SCP_SDCA_INTMASK_SDCA_16);
+			sdw_write_no_pm(slave, SDW_SCP_SDCA_INTMASK4, SDW_SCP_SDCA_INTMASK_SDCA_24);
+			rt766->disable_irq = false;
+		}
+		mutex_unlock(&rt766->disable_irq_lock);
+		goto regmap_sync;
+	}
+
+	ret = sdw_slave_wait_for_init(slave, RT766_PROBE_TIMEOUT);
+	if (ret) {
+		sdw_show_ping_status(slave->bus, true);
+		return ret;
+	}
+
+regmap_sync:
+	regcache_cache_only(rt766->regmap, false);
+	ret = regcache_sync(rt766->regmap);
+	if (ret) {
+		regcache_cache_only(rt766->regmap, true);
+		regcache_mark_dirty(rt766->regmap);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops rt766_sdca_pm = {
+	SYSTEM_SLEEP_PM_OPS(rt766_sdca_dev_system_suspend, rt766_sdca_dev_resume)
+	RUNTIME_PM_OPS(rt766_sdca_dev_suspend, rt766_sdca_dev_resume, NULL)
+};
+
+static struct sdw_driver rt766_sdca_sdw_driver = {
+	.driver = {
+		.name = "rt766-sdca",
+		.pm = pm_ptr(&rt766_sdca_pm),
+	},
+	.probe = rt766_sdca_sdw_probe,
+	.remove = rt766_sdca_sdw_remove,
+	.ops = &rt766_sdca_slave_ops,
+	.id_table = rt766_sdca_id,
+};
+module_sdw_driver(rt766_sdca_sdw_driver);
+
+MODULE_DESCRIPTION("ASoC RT766 SDCA SDW driver");
+MODULE_AUTHOR("Shuming Fan <shumingf@realtek.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("SND_SOC_SDCA");