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, 267 insertions, 0 deletions

diff --git a/drivers/mfd/sec-i2c.c b/drivers/mfd/sec-i2c.c
new file mode 100644
index 000000000..4eec8f7ce
--- /dev/null
+++ b/drivers/mfd/sec-i2c.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2012 Samsung Electronics Co., Ltd
+ *                http://www.samsung.com
+ * Copyright 2025 Linaro Ltd.
+ *
+ * Samsung SxM I2C driver
+ */
+
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mfd/samsung/core.h>
+#include <linux/mfd/samsung/s2mpa01.h>
+#include <linux/mfd/samsung/s2mps11.h>
+#include <linux/mfd/samsung/s2mps13.h>
+#include <linux/mfd/samsung/s2mps14.h>
+#include <linux/mfd/samsung/s2mps15.h>
+#include <linux/mfd/samsung/s2mpu02.h>
+#include <linux/mfd/samsung/s2mu005.h>
+#include <linux/mfd/samsung/s5m8767.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include "sec-core.h"
+
+struct sec_pmic_i2c_platform_data {
+	const struct regmap_config *regmap_cfg;
+	int device_type;
+};
+
+static bool s2mpa01_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case S2MPA01_REG_INT1M:
+	case S2MPA01_REG_INT2M:
+	case S2MPA01_REG_INT3M:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static bool s2mps11_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case S2MPS11_REG_INT1M:
+	case S2MPS11_REG_INT2M:
+	case S2MPS11_REG_INT3M:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static bool s2mpu02_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case S2MPU02_REG_INT1M:
+	case S2MPU02_REG_INT2M:
+	case S2MPU02_REG_INT3M:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static bool s2mu005_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case S2MU005_REG_CHGR_INT1M:
+	case S2MU005_REG_FLED_INT1M:
+	case S2MU005_REG_MUIC_INT1M:
+	case S2MU005_REG_MUIC_INT2M:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static const struct regmap_config s2dos05_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct regmap_config s2mpa01_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPA01_REG_LDO_OVCB4,
+	.volatile_reg = s2mpa01_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mps11_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPS11_REG_L38CTRL,
+	.volatile_reg = s2mps11_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mps13_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPS13_REG_LDODSCH5,
+	.volatile_reg = s2mps11_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mps14_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPS14_REG_LDODSCH3,
+	.volatile_reg = s2mps11_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mps15_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPS15_REG_LDODSCH4,
+	.volatile_reg = s2mps11_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mpu02_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MPU02_REG_DVSDATA,
+	.volatile_reg = s2mpu02_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config s2mpu05_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct regmap_config s2mu005_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S2MU005_REG_MUIC_LDOADC_H,
+	.volatile_reg = s2mu005_volatile,
+	.cache_type = REGCACHE_FLAT_S,
+};
+
+static const struct regmap_config s5m8767_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = S5M8767_REG_LDO28CTRL,
+	.volatile_reg = s2mps11_volatile,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int sec_pmic_i2c_probe(struct i2c_client *client)
+{
+	const struct sec_pmic_i2c_platform_data *pdata;
+	struct regmap *regmap_pmic;
+
+	pdata = device_get_match_data(&client->dev);
+	if (!pdata)
+		return dev_err_probe(&client->dev, -ENODEV,
+				     "Unsupported device type\n");
+
+	regmap_pmic = devm_regmap_init_i2c(client, pdata->regmap_cfg);
+	if (IS_ERR(regmap_pmic))
+		return dev_err_probe(&client->dev, PTR_ERR(regmap_pmic),
+				     "regmap init failed\n");
+
+	return sec_pmic_probe(&client->dev, pdata->device_type, client->irq,
+			      regmap_pmic, client);
+}
+
+static void sec_pmic_i2c_shutdown(struct i2c_client *i2c)
+{
+	sec_pmic_shutdown(&i2c->dev);
+}
+
+static const struct sec_pmic_i2c_platform_data s2dos05_data = {
+	.regmap_cfg = &s2dos05_regmap_config,
+	.device_type = S2DOS05
+};
+
+static const struct sec_pmic_i2c_platform_data s2mpa01_data = {
+	.regmap_cfg = &s2mpa01_regmap_config,
+	.device_type = S2MPA01,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mps11_data = {
+	.regmap_cfg = &s2mps11_regmap_config,
+	.device_type = S2MPS11X,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mps13_data = {
+	.regmap_cfg = &s2mps13_regmap_config,
+	.device_type = S2MPS13X,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mps14_data = {
+	.regmap_cfg = &s2mps14_regmap_config,
+	.device_type = S2MPS14X,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mps15_data = {
+	.regmap_cfg = &s2mps15_regmap_config,
+	.device_type = S2MPS15X,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mpu02_data = {
+	.regmap_cfg = &s2mpu02_regmap_config,
+	.device_type = S2MPU02,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mpu05_data = {
+	.regmap_cfg = &s2mpu05_regmap_config,
+	.device_type = S2MPU05,
+};
+
+static const struct sec_pmic_i2c_platform_data s2mu005_data = {
+	.regmap_cfg = &s2mu005_regmap_config,
+	.device_type = S2MU005,
+};
+
+static const struct sec_pmic_i2c_platform_data s5m8767_data = {
+	.regmap_cfg = &s5m8767_regmap_config,
+	.device_type = S5M8767X,
+};
+
+static const struct of_device_id sec_pmic_i2c_of_match[] = {
+	{ .compatible = "samsung,s2dos05", .data = &s2dos05_data, },
+	{ .compatible = "samsung,s2mpa01-pmic", .data = &s2mpa01_data, },
+	{ .compatible = "samsung,s2mps11-pmic", .data = &s2mps11_data, },
+	{ .compatible = "samsung,s2mps13-pmic", .data = &s2mps13_data, },
+	{ .compatible = "samsung,s2mps14-pmic", .data = &s2mps14_data, },
+	{ .compatible = "samsung,s2mps15-pmic", .data = &s2mps15_data, },
+	{ .compatible = "samsung,s2mpu02-pmic", .data = &s2mpu02_data, },
+	{ .compatible = "samsung,s2mpu05-pmic", .data = &s2mpu05_data, },
+	{ .compatible = "samsung,s2mu005-pmic", .data = &s2mu005_data, },
+	{ .compatible = "samsung,s5m8767-pmic", .data = &s5m8767_data, },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sec_pmic_i2c_of_match);
+
+static struct i2c_driver sec_pmic_i2c_driver = {
+	.driver = {
+		.name = "sec-pmic-i2c",
+		.pm = pm_sleep_ptr(&sec_pmic_pm_ops),
+		.of_match_table = sec_pmic_i2c_of_match,
+	},
+	.probe = sec_pmic_i2c_probe,
+	.shutdown = sec_pmic_i2c_shutdown,
+};
+module_i2c_driver(sec_pmic_i2c_driver);
+
+MODULE_AUTHOR("Sangbeom Kim <sbkim73@samsung.com>");
+MODULE_AUTHOR("André Draszik <andre.draszik@linaro.org>");
+MODULE_DESCRIPTION("I2C driver for the Samsung S5M");
+MODULE_LICENSE("GPL");