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, 180 insertions, 0 deletions

diff --git a/drivers/mfd/max77705.c b/drivers/mfd/max77705.c
new file mode 100644
index 000000000..e98c76d6b
--- /dev/null
+++ b/drivers/mfd/max77705.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Maxim MAX77705 PMIC core driver
+ *
+ * Copyright (C) 2025 Dzmitry Sankouski <dsankouski@gmail.com>
+ **/
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max77705-private.h>
+#include <linux/mfd/max77693-common.h>
+#include <linux/pm.h>
+#include <linux/power/max17042_battery.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+
+static struct mfd_cell max77705_devs[] = {
+	MFD_CELL_OF("max77705-rgb", NULL, NULL, 0, 0, "maxim,max77705-rgb"),
+	MFD_CELL_OF("max77705-charger", NULL, NULL, 0, 0, "maxim,max77705-charger"),
+	MFD_CELL_OF("max77705-haptic", NULL, NULL, 0, 0, "maxim,max77705-haptic"),
+};
+
+static const struct regmap_range max77705_readable_ranges[] = {
+	regmap_reg_range(MAX77705_PMIC_REG_PMICID1,		MAX77705_PMIC_REG_BSTOUT_MASK),
+	regmap_reg_range(MAX77705_PMIC_REG_INTSRC,		MAX77705_PMIC_REG_RESERVED_29),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL1,	MAX77705_PMIC_REG_BOOSTCONTROL1),
+	regmap_reg_range(MAX77705_PMIC_REG_MCONFIG,		MAX77705_PMIC_REG_MCONFIG2),
+	regmap_reg_range(MAX77705_PMIC_REG_FORCE_EN_MASK,	MAX77705_PMIC_REG_FORCE_EN_MASK),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL1,	MAX77705_PMIC_REG_BOOSTCONTROL1),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL2,	MAX77705_PMIC_REG_BOOSTCONTROL2),
+	regmap_reg_range(MAX77705_PMIC_REG_SW_RESET,		MAX77705_PMIC_REG_USBC_RESET),
+};
+
+static const struct regmap_range max77705_writable_ranges[] = {
+	regmap_reg_range(MAX77705_PMIC_REG_MAINCTRL1,		MAX77705_PMIC_REG_BSTOUT_MASK),
+	regmap_reg_range(MAX77705_PMIC_REG_INTSRC,		MAX77705_PMIC_REG_RESERVED_29),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL1,	MAX77705_PMIC_REG_BOOSTCONTROL1),
+	regmap_reg_range(MAX77705_PMIC_REG_MCONFIG,		MAX77705_PMIC_REG_MCONFIG2),
+	regmap_reg_range(MAX77705_PMIC_REG_FORCE_EN_MASK,	MAX77705_PMIC_REG_FORCE_EN_MASK),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL1,	MAX77705_PMIC_REG_BOOSTCONTROL1),
+	regmap_reg_range(MAX77705_PMIC_REG_BOOSTCONTROL2,	MAX77705_PMIC_REG_BOOSTCONTROL2),
+	regmap_reg_range(MAX77705_PMIC_REG_SW_RESET,		MAX77705_PMIC_REG_USBC_RESET),
+};
+
+static const struct regmap_access_table max77705_readable_table = {
+	.yes_ranges = max77705_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max77705_readable_ranges),
+};
+
+static const struct regmap_access_table max77705_writable_table = {
+	.yes_ranges = max77705_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max77705_writable_ranges),
+};
+
+static const struct regmap_config max77705_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.rd_table = &max77705_readable_table,
+	.wr_table = &max77705_writable_table,
+	.max_register = MAX77705_PMIC_REG_USBC_RESET,
+};
+
+static const struct regmap_irq max77705_irqs[] = {
+	{ .mask = MAX77705_SRC_IRQ_CHG, },
+	{ .mask = MAX77705_SRC_IRQ_TOP, },
+	{ .mask = MAX77705_SRC_IRQ_FG, },
+	{ .mask = MAX77705_SRC_IRQ_USBC, },
+};
+
+static const struct regmap_irq_chip max77705_irq_chip = {
+	.name		= "max77705",
+	.status_base	= MAX77705_PMIC_REG_INTSRC,
+	.ack_base	= MAX77705_PMIC_REG_INTSRC,
+	.mask_base	= MAX77705_PMIC_REG_INTSRC_MASK,
+	.num_regs	= 1,
+	.irqs		= max77705_irqs,
+	.num_irqs	= ARRAY_SIZE(max77705_irqs),
+};
+
+static int max77705_i2c_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct max77693_dev *max77705;
+	struct regmap_irq_chip_data *irq_data;
+	struct irq_domain *domain;
+	enum max77705_hw_rev pmic_rev;
+	unsigned int pmic_rev_value;
+	int ret;
+
+	max77705 = devm_kzalloc(dev, sizeof(*max77705), GFP_KERNEL);
+	if (!max77705)
+		return -ENOMEM;
+
+	max77705->i2c = i2c;
+	max77705->type = TYPE_MAX77705;
+	i2c_set_clientdata(i2c, max77705);
+
+	max77705->regmap = devm_regmap_init_i2c(i2c, &max77705_regmap_config);
+	if (IS_ERR(max77705->regmap))
+		return PTR_ERR(max77705->regmap);
+
+	ret = regmap_read(max77705->regmap, MAX77705_PMIC_REG_PMICREV, &pmic_rev_value);
+	if (ret < 0)
+		return -ENODEV;
+
+	pmic_rev = pmic_rev_value & MAX77705_REVISION_MASK;
+	if (pmic_rev != MAX77705_PASS3)
+		return dev_err_probe(dev, -ENODEV, "Rev.0x%x is not tested\n", pmic_rev);
+
+	/* Active Discharge Enable */
+	regmap_update_bits(max77705->regmap, MAX77705_PMIC_REG_MAINCTRL1, 1, 1);
+
+	ret = devm_regmap_add_irq_chip(dev, max77705->regmap,
+					i2c->irq,
+					IRQF_ONESHOT, 0,
+					&max77705_irq_chip,
+					&irq_data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to add IRQ chip\n");
+
+	domain = regmap_irq_get_domain(irq_data);
+
+	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				   max77705_devs, ARRAY_SIZE(max77705_devs),
+				   NULL, 0, domain);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register child devices\n");
+
+	ret = devm_device_init_wakeup(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to init wakeup\n");
+
+	return 0;
+}
+
+static int max77705_suspend(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	disable_irq(i2c->irq);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(i2c->irq);
+
+	return 0;
+}
+
+static int max77705_resume(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(i2c->irq);
+
+	enable_irq(i2c->irq);
+
+	return 0;
+}
+static DEFINE_SIMPLE_DEV_PM_OPS(max77705_pm_ops, max77705_suspend, max77705_resume);
+
+static const struct of_device_id max77705_i2c_of_match[] = {
+	{ .compatible = "maxim,max77705" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max77705_i2c_of_match);
+
+static struct i2c_driver max77705_i2c_driver = {
+	.driver = {
+		.name			= "max77705",
+		.of_match_table		= max77705_i2c_of_match,
+		.pm			= pm_sleep_ptr(&max77705_pm_ops),
+	},
+	.probe = max77705_i2c_probe
+};
+module_i2c_driver(max77705_i2c_driver);
+
+MODULE_DESCRIPTION("Maxim MAX77705 PMIC core driver");
+MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>");
+MODULE_LICENSE("GPL");