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, 390 insertions, 0 deletions

diff --git a/drivers/regulator/s2mpa01.c b/drivers/regulator/s2mpa01.c
new file mode 100644
index 000000000..817150386
--- /dev/null
+++ b/drivers/regulator/s2mpa01.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright (c) 2013 Samsung Electronics Co., Ltd
+//		http://www.samsung.com
+
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/mfd/samsung/core.h>
+#include <linux/mfd/samsung/s2mpa01.h>
+
+struct s2mpa01_info {
+	int ramp_delay24;
+	int ramp_delay3;
+	int ramp_delay5;
+	int ramp_delay16;
+	int ramp_delay7;
+	int ramp_delay8910;
+};
+
+static int get_ramp_delay(int ramp_delay)
+{
+	unsigned char cnt = 0;
+
+	ramp_delay /= 6250;
+
+	while (true) {
+		ramp_delay = ramp_delay >> 1;
+		if (ramp_delay == 0)
+			break;
+		cnt++;
+	}
+
+	if (cnt > 3)
+		cnt = 3;
+
+	return cnt;
+}
+
+static int s2mpa01_regulator_set_voltage_time_sel(struct regulator_dev *rdev,
+				   unsigned int old_selector,
+				   unsigned int new_selector)
+{
+	struct s2mpa01_info *s2mpa01 = rdev_get_drvdata(rdev);
+	unsigned int ramp_delay = 0;
+	int old_volt, new_volt;
+
+	switch (rdev_get_id(rdev)) {
+	case S2MPA01_BUCK2:
+	case S2MPA01_BUCK4:
+		ramp_delay = s2mpa01->ramp_delay24;
+		break;
+	case S2MPA01_BUCK3:
+		ramp_delay = s2mpa01->ramp_delay3;
+		break;
+	case S2MPA01_BUCK5:
+		ramp_delay = s2mpa01->ramp_delay5;
+		break;
+	case S2MPA01_BUCK1:
+	case S2MPA01_BUCK6:
+		ramp_delay = s2mpa01->ramp_delay16;
+		break;
+	case S2MPA01_BUCK7:
+		ramp_delay = s2mpa01->ramp_delay7;
+		break;
+	case S2MPA01_BUCK8:
+	case S2MPA01_BUCK9:
+	case S2MPA01_BUCK10:
+		ramp_delay = s2mpa01->ramp_delay8910;
+		break;
+	}
+
+	if (ramp_delay == 0)
+		ramp_delay = rdev->desc->ramp_delay;
+
+	old_volt = rdev->desc->min_uV + (rdev->desc->uV_step * old_selector);
+	new_volt = rdev->desc->min_uV + (rdev->desc->uV_step * new_selector);
+
+	return DIV_ROUND_UP(abs(new_volt - old_volt), ramp_delay);
+}
+
+static int s2mpa01_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
+{
+	struct s2mpa01_info *s2mpa01 = rdev_get_drvdata(rdev);
+	unsigned int ramp_val, ramp_shift, ramp_reg = S2MPA01_REG_RAMP2;
+	unsigned int ramp_enable = 1, enable_shift = 0;
+	int ret;
+
+	switch (rdev_get_id(rdev)) {
+	case S2MPA01_BUCK1:
+		enable_shift = S2MPA01_BUCK1_RAMP_EN_SHIFT;
+		if (!ramp_delay) {
+			ramp_enable = 0;
+			break;
+		}
+
+		if (ramp_delay > s2mpa01->ramp_delay16)
+			s2mpa01->ramp_delay16 = ramp_delay;
+		else
+			ramp_delay = s2mpa01->ramp_delay16;
+
+		ramp_shift = S2MPA01_BUCK16_RAMP_SHIFT;
+		break;
+	case S2MPA01_BUCK2:
+		enable_shift = S2MPA01_BUCK2_RAMP_EN_SHIFT;
+		if (!ramp_delay) {
+			ramp_enable = 0;
+			break;
+		}
+
+		if (ramp_delay > s2mpa01->ramp_delay24)
+			s2mpa01->ramp_delay24 = ramp_delay;
+		else
+			ramp_delay = s2mpa01->ramp_delay24;
+
+		ramp_shift = S2MPA01_BUCK24_RAMP_SHIFT;
+		ramp_reg = S2MPA01_REG_RAMP1;
+		break;
+	case S2MPA01_BUCK3:
+		enable_shift = S2MPA01_BUCK3_RAMP_EN_SHIFT;
+		if (!ramp_delay) {
+			ramp_enable = 0;
+			break;
+		}
+
+		s2mpa01->ramp_delay3 = ramp_delay;
+		ramp_shift = S2MPA01_BUCK3_RAMP_SHIFT;
+		ramp_reg = S2MPA01_REG_RAMP1;
+		break;
+	case S2MPA01_BUCK4:
+		enable_shift = S2MPA01_BUCK4_RAMP_EN_SHIFT;
+		if (!ramp_delay) {
+			ramp_enable = 0;
+			break;
+		}
+
+		if (ramp_delay > s2mpa01->ramp_delay24)
+			s2mpa01->ramp_delay24 = ramp_delay;
+		else
+			ramp_delay = s2mpa01->ramp_delay24;
+
+		ramp_shift = S2MPA01_BUCK24_RAMP_SHIFT;
+		ramp_reg = S2MPA01_REG_RAMP1;
+		break;
+	case S2MPA01_BUCK5:
+		s2mpa01->ramp_delay5 = ramp_delay;
+		ramp_shift = S2MPA01_BUCK5_RAMP_SHIFT;
+		break;
+	case S2MPA01_BUCK6:
+		if (ramp_delay > s2mpa01->ramp_delay16)
+			s2mpa01->ramp_delay16 = ramp_delay;
+		else
+			ramp_delay = s2mpa01->ramp_delay16;
+
+		ramp_shift = S2MPA01_BUCK16_RAMP_SHIFT;
+		break;
+	case S2MPA01_BUCK7:
+		s2mpa01->ramp_delay7 = ramp_delay;
+		ramp_shift = S2MPA01_BUCK7_RAMP_SHIFT;
+		break;
+	case S2MPA01_BUCK8:
+	case S2MPA01_BUCK9:
+	case S2MPA01_BUCK10:
+		if (ramp_delay > s2mpa01->ramp_delay8910)
+			s2mpa01->ramp_delay8910 = ramp_delay;
+		else
+			ramp_delay = s2mpa01->ramp_delay8910;
+
+		ramp_shift = S2MPA01_BUCK8910_RAMP_SHIFT;
+		break;
+	default:
+		return 0;
+	}
+
+	if (!ramp_enable)
+		goto ramp_disable;
+
+	/* Ramp delay can be enabled/disabled only for buck[1234] */
+	if (rdev_get_id(rdev) >= S2MPA01_BUCK1 &&
+			rdev_get_id(rdev) <= S2MPA01_BUCK4) {
+		ret = regmap_update_bits(rdev->regmap, S2MPA01_REG_RAMP1,
+					 1 << enable_shift, 1 << enable_shift);
+		if (ret) {
+			dev_err(&rdev->dev, "failed to enable ramp rate\n");
+			return ret;
+		}
+	}
+
+	ramp_val = get_ramp_delay(ramp_delay);
+
+	return regmap_update_bits(rdev->regmap, ramp_reg, 0x3 << ramp_shift,
+				  ramp_val << ramp_shift);
+
+ramp_disable:
+	return regmap_update_bits(rdev->regmap, S2MPA01_REG_RAMP1,
+				  1 << enable_shift, 0);
+}
+
+static const struct regulator_ops s2mpa01_ldo_ops = {
+	.list_voltage		= regulator_list_voltage_linear,
+	.map_voltage		= regulator_map_voltage_linear,
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
+};
+
+static const struct regulator_ops s2mpa01_buck_ops = {
+	.list_voltage		= regulator_list_voltage_linear,
+	.map_voltage		= regulator_map_voltage_linear,
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.set_voltage_time_sel	= s2mpa01_regulator_set_voltage_time_sel,
+	.set_ramp_delay		= s2mpa01_set_ramp_delay,
+};
+
+#define regulator_desc_ldo(num, step) {			\
+	.name		= "LDO"#num,			\
+	.of_match	= of_match_ptr("LDO"#num),	\
+	.regulators_node = of_match_ptr("regulators"),	\
+	.id		= S2MPA01_LDO##num,		\
+	.ops		= &s2mpa01_ldo_ops,		\
+	.type		= REGULATOR_VOLTAGE,		\
+	.owner		= THIS_MODULE,			\
+	.min_uV		= MIN_800_MV,			\
+	.uV_step	= step,				\
+	.n_voltages	= S2MPA01_LDO_N_VOLTAGES,	\
+	.vsel_reg	= S2MPA01_REG_L1CTRL + num - 1,	\
+	.vsel_mask	= S2MPA01_LDO_VSEL_MASK,	\
+	.enable_reg	= S2MPA01_REG_L1CTRL + num - 1,	\
+	.enable_mask	= S2MPA01_ENABLE_MASK		\
+}
+
+#define regulator_desc_buck1_4(num)	{			\
+	.name		= "BUCK"#num,				\
+	.of_match	= of_match_ptr("BUCK"#num),		\
+	.regulators_node = of_match_ptr("regulators"),		\
+	.id		= S2MPA01_BUCK##num,			\
+	.ops		= &s2mpa01_buck_ops,			\
+	.type		= REGULATOR_VOLTAGE,			\
+	.owner		= THIS_MODULE,				\
+	.min_uV		= MIN_600_MV,				\
+	.uV_step	= STEP_6_25_MV,				\
+	.n_voltages	= S2MPA01_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPA01_RAMP_DELAY,			\
+	.vsel_reg	= S2MPA01_REG_B1CTRL2 + (num - 1) * 2,	\
+	.vsel_mask	= S2MPA01_BUCK_VSEL_MASK,		\
+	.enable_reg	= S2MPA01_REG_B1CTRL1 + (num - 1) * 2,	\
+	.enable_mask	= S2MPA01_ENABLE_MASK			\
+}
+
+#define regulator_desc_buck5	{				\
+	.name		= "BUCK5",				\
+	.of_match	= of_match_ptr("BUCK5"),		\
+	.regulators_node = of_match_ptr("regulators"),		\
+	.id		= S2MPA01_BUCK5,			\
+	.ops		= &s2mpa01_buck_ops,			\
+	.type		= REGULATOR_VOLTAGE,			\
+	.owner		= THIS_MODULE,				\
+	.min_uV		= MIN_800_MV,				\
+	.uV_step	= STEP_6_25_MV,				\
+	.n_voltages	= S2MPA01_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPA01_RAMP_DELAY,			\
+	.vsel_reg	= S2MPA01_REG_B5CTRL2,			\
+	.vsel_mask	= S2MPA01_BUCK_VSEL_MASK,		\
+	.enable_reg	= S2MPA01_REG_B5CTRL1,			\
+	.enable_mask	= S2MPA01_ENABLE_MASK			\
+}
+
+#define regulator_desc_buck6_10(num, min, step) {			\
+	.name		= "BUCK"#num,				\
+	.of_match	= of_match_ptr("BUCK"#num),		\
+	.regulators_node = of_match_ptr("regulators"),		\
+	.id		= S2MPA01_BUCK##num,			\
+	.ops		= &s2mpa01_buck_ops,			\
+	.type		= REGULATOR_VOLTAGE,			\
+	.owner		= THIS_MODULE,				\
+	.min_uV		= min,					\
+	.uV_step	= step,					\
+	.n_voltages	= S2MPA01_BUCK_N_VOLTAGES,		\
+	.ramp_delay	= S2MPA01_RAMP_DELAY,			\
+	.vsel_reg	= S2MPA01_REG_B6CTRL2 + (num - 6) * 2,	\
+	.vsel_mask	= S2MPA01_BUCK_VSEL_MASK,		\
+	.enable_reg	= S2MPA01_REG_B6CTRL1 + (num - 6) * 2,	\
+	.enable_mask	= S2MPA01_ENABLE_MASK			\
+}
+
+static const struct regulator_desc regulators[] = {
+	regulator_desc_ldo(1, STEP_25_MV),
+	regulator_desc_ldo(2, STEP_50_MV),
+	regulator_desc_ldo(3, STEP_50_MV),
+	regulator_desc_ldo(4, STEP_50_MV),
+	regulator_desc_ldo(5, STEP_25_MV),
+	regulator_desc_ldo(6, STEP_25_MV),
+	regulator_desc_ldo(7, STEP_50_MV),
+	regulator_desc_ldo(8, STEP_50_MV),
+	regulator_desc_ldo(9, STEP_50_MV),
+	regulator_desc_ldo(10, STEP_50_MV),
+	regulator_desc_ldo(11, STEP_50_MV),
+	regulator_desc_ldo(12, STEP_50_MV),
+	regulator_desc_ldo(13, STEP_50_MV),
+	regulator_desc_ldo(14, STEP_50_MV),
+	regulator_desc_ldo(15, STEP_50_MV),
+	regulator_desc_ldo(16, STEP_50_MV),
+	regulator_desc_ldo(17, STEP_50_MV),
+	regulator_desc_ldo(18, STEP_50_MV),
+	regulator_desc_ldo(19, STEP_50_MV),
+	regulator_desc_ldo(20, STEP_50_MV),
+	regulator_desc_ldo(21, STEP_50_MV),
+	regulator_desc_ldo(22, STEP_50_MV),
+	regulator_desc_ldo(23, STEP_50_MV),
+	regulator_desc_ldo(24, STEP_50_MV),
+	regulator_desc_ldo(25, STEP_50_MV),
+	regulator_desc_ldo(26, STEP_25_MV),
+	regulator_desc_buck1_4(1),
+	regulator_desc_buck1_4(2),
+	regulator_desc_buck1_4(3),
+	regulator_desc_buck1_4(4),
+	regulator_desc_buck5,
+	regulator_desc_buck6_10(6, MIN_600_MV, STEP_6_25_MV),
+	regulator_desc_buck6_10(7, MIN_600_MV, STEP_6_25_MV),
+	regulator_desc_buck6_10(8, MIN_800_MV, STEP_12_5_MV),
+	regulator_desc_buck6_10(9, MIN_1500_MV, STEP_12_5_MV),
+	regulator_desc_buck6_10(10, MIN_1000_MV, STEP_12_5_MV),
+};
+
+static int s2mpa01_pmic_probe(struct platform_device *pdev)
+{
+	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+	struct regulator_config config = { };
+	struct s2mpa01_info *s2mpa01;
+	int i;
+
+	s2mpa01 = devm_kzalloc(&pdev->dev, sizeof(*s2mpa01), GFP_KERNEL);
+	if (!s2mpa01)
+		return -ENOMEM;
+
+	config.dev = iodev->dev;
+	config.regmap = iodev->regmap_pmic;
+	config.driver_data = s2mpa01;
+
+	for (i = 0; i < S2MPA01_REGULATOR_MAX; i++) {
+		struct regulator_dev *rdev;
+
+		rdev = devm_regulator_register(&pdev->dev,
+						&regulators[i], &config);
+		if (IS_ERR(rdev)) {
+			dev_err(&pdev->dev, "regulator init failed for %d\n",
+				i);
+			return PTR_ERR(rdev);
+		}
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id s2mpa01_pmic_id[] = {
+	{ .name = "s2mpa01-pmic" },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, s2mpa01_pmic_id);
+
+static struct platform_driver s2mpa01_pmic_driver = {
+	.driver = {
+		.name = "s2mpa01-pmic",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.probe = s2mpa01_pmic_probe,
+	.id_table = s2mpa01_pmic_id,
+};
+
+module_platform_driver(s2mpa01_pmic_driver);
+
+/* Module information */
+MODULE_AUTHOR("Sangbeom Kim <sbkim73@samsung.com>");
+MODULE_AUTHOR("Sachin Kamat <sachin.kamat@samsung.com>");
+MODULE_DESCRIPTION("Samsung S2MPA01 Regulator Driver");
+MODULE_LICENSE("GPL");