From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- drivers/regulator/max8893.c | 184 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 drivers/regulator/max8893.c (limited to 'drivers/regulator/max8893.c') diff --git a/drivers/regulator/max8893.c b/drivers/regulator/max8893.c new file mode 100644 index 000000000..7a0e44a16 --- /dev/null +++ b/drivers/regulator/max8893.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include +#include +#include +#include +#include + +static const struct regulator_ops max8893_ops = { + .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, + .list_voltage = regulator_list_voltage_linear, + .map_voltage = regulator_map_voltage_linear, +}; + +static const struct regulator_desc max8893_regulators[] = { + { + .name = "BUCK", + .supply_name = "in-buck", + .of_match = of_match_ptr("buck"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x11, + .id = 6, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 800000, + .uV_step = 100000, + .vsel_reg = 0x4, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(7), + }, + { + .name = "LDO1", + .supply_name = "in-ldo1", + .of_match = of_match_ptr("ldo1"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x12, + .id = 1, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 1600000, + .uV_step = 100000, + .vsel_reg = 0x5, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(5), + }, + { + .name = "LDO2", + .supply_name = "in-ldo2", + .of_match = of_match_ptr("ldo2"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x16, + .id = 2, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 1200000, + .uV_step = 100000, + .vsel_reg = 0x6, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(4), + }, + { + .name = "LDO3", + .supply_name = "in-ldo3", + .of_match = of_match_ptr("ldo3"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x12, + .id = 3, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 1600000, + .uV_step = 100000, + .vsel_reg = 0x7, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(3), + }, + { + .name = "LDO4", + .supply_name = "in-ldo4", + .of_match = of_match_ptr("ldo4"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x1a, + .id = 4, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 800000, + .uV_step = 100000, + .vsel_reg = 0x8, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(2), + }, + { + .name = "LDO5", + .supply_name = "in-ldo5", + .of_match = of_match_ptr("ldo5"), + .regulators_node = of_match_ptr("regulators"), + .n_voltages = 0x1a, + .id = 5, + .ops = &max8893_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .min_uV = 800000, + .uV_step = 100000, + .vsel_reg = 0x9, + .vsel_mask = 0x1f, + .enable_reg = 0x0, + .enable_mask = BIT(1), + } +}; + +static const struct regmap_config max8893_regmap = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int max8893_probe(struct i2c_client *i2c) +{ + int id, ret; + struct regulator_config config = {.dev = &i2c->dev}; + struct regmap *regmap = devm_regmap_init_i2c(i2c, &max8893_regmap); + + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(&i2c->dev, "regmap init failed: %d\n", ret); + return ret; + } + + for (id = 0; id < ARRAY_SIZE(max8893_regulators); id++) { + struct regulator_dev *rdev; + rdev = devm_regulator_register(&i2c->dev, + &max8893_regulators[id], + &config); + if (IS_ERR(rdev)) { + ret = PTR_ERR(rdev); + dev_err(&i2c->dev, "failed to register %s: %d\n", + max8893_regulators[id].name, ret); + return ret; + } + } + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id max8893_dt_match[] = { + { .compatible = "maxim,max8893" }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, max8893_dt_match); +#endif + +static const struct i2c_device_id max8893_ids[] = { + { .name = "max8893" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max8893_ids); + +static struct i2c_driver max8893_driver = { + .probe = max8893_probe, + .driver = { + .name = "max8893", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = of_match_ptr(max8893_dt_match), + }, + .id_table = max8893_ids, +}; + +module_i2c_driver(max8893_driver); + +MODULE_DESCRIPTION("Maxim MAX8893 PMIC driver"); +MODULE_AUTHOR("Sergey Larin "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1