From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/hwmon/max1619.c | 399 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 399 insertions(+) create mode 100644 drivers/hwmon/max1619.c (limited to 'drivers/hwmon/max1619.c') diff --git a/drivers/hwmon/max1619.c b/drivers/hwmon/max1619.c new file mode 100644 index 000000000..77ef39e8a --- /dev/null +++ b/drivers/hwmon/max1619.c @@ -0,0 +1,399 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * max1619.c - Part of lm_sensors, Linux kernel modules for hardware + * monitoring + * Copyright (C) 2003-2004 Oleksij Rempel + * Jean Delvare + * + * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim. + * It reports up to two temperatures (its own plus up to + * one external one). Complete datasheet can be + * obtained from Maxim's website at: + * http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf + */ + +#include +#include +#include +#include +#include +#include +#include + +static const unsigned short normal_i2c[] = { + 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END }; + +#define MAX1619_REG_LOCAL_TEMP 0x00 +#define MAX1619_REG_REMOTE_TEMP 0x01 +#define MAX1619_REG_STATUS 0x02 +#define MAX1619_REG_CONFIG 0x03 +#define MAX1619_REG_CONVRATE 0x04 +#define MAX1619_REG_REMOTE_HIGH 0x07 +#define MAX1619_REG_REMOTE_LOW 0x08 +#define MAX1619_REG_REMOTE_CRIT 0x10 +#define MAX1619_REG_REMOTE_CRIT_HYST 0x11 +#define MAX1619_REG_MAN_ID 0xFE +#define MAX1619_REG_CHIP_ID 0xFF + +static int get_alarms(struct regmap *regmap) +{ + static u32 regs[2] = { MAX1619_REG_STATUS, MAX1619_REG_CONFIG }; + u8 regdata[2]; + int ret; + + ret = regmap_multi_reg_read(regmap, regs, regdata, 2); + if (ret) + return ret; + + /* OVERT status bit may be reversed */ + if (!(regdata[1] & 0x20)) + regdata[0] ^= 0x02; + + return regdata[0] & 0x1e; +} + +static int max1619_temp_read(struct regmap *regmap, u32 attr, int channel, long *val) +{ + int reg = -1, alarm_bit = 0; + u32 temp; + int ret; + + switch (attr) { + case hwmon_temp_input: + reg = channel ? MAX1619_REG_REMOTE_TEMP : MAX1619_REG_LOCAL_TEMP; + break; + case hwmon_temp_min: + reg = MAX1619_REG_REMOTE_LOW; + break; + case hwmon_temp_max: + reg = MAX1619_REG_REMOTE_HIGH; + break; + case hwmon_temp_crit: + reg = MAX1619_REG_REMOTE_CRIT; + break; + case hwmon_temp_crit_hyst: + reg = MAX1619_REG_REMOTE_CRIT_HYST; + break; + case hwmon_temp_min_alarm: + alarm_bit = 3; + break; + case hwmon_temp_max_alarm: + alarm_bit = 4; + break; + case hwmon_temp_crit_alarm: + alarm_bit = 1; + break; + case hwmon_temp_fault: + alarm_bit = 2; + break; + default: + return -EOPNOTSUPP; + } + if (reg >= 0) { + ret = regmap_read(regmap, reg, &temp); + if (ret < 0) + return ret; + *val = sign_extend32(temp, 7) * 1000; + } else { + ret = get_alarms(regmap); + if (ret < 0) + return ret; + *val = !!(ret & BIT(alarm_bit)); + } + return 0; +} + +static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 }; + +static int max1619_chip_read(struct regmap *regmap, u32 attr, long *val) +{ + int alarms, ret; + u32 regval; + + switch (attr) { + case hwmon_chip_update_interval: + ret = regmap_read(regmap, MAX1619_REG_CONVRATE, ®val); + if (ret < 0) + return ret; + *val = update_intervals[regval & 7]; + break; + case hwmon_chip_alarms: + alarms = get_alarms(regmap); + if (alarms < 0) + return alarms; + *val = alarms; + break; + default: + return -EOPNOTSUPP; + } + return 0; +} + +static int max1619_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct regmap *regmap = dev_get_drvdata(dev); + + switch (type) { + case hwmon_chip: + return max1619_chip_read(regmap, attr, val); + case hwmon_temp: + return max1619_temp_read(regmap, attr, channel, val); + default: + return -EOPNOTSUPP; + } +} + +static int max1619_chip_write(struct regmap *regmap, u32 attr, long val) +{ + switch (attr) { + case hwmon_chip_update_interval: + val = find_closest_descending(val, update_intervals, ARRAY_SIZE(update_intervals)); + return regmap_write(regmap, MAX1619_REG_CONVRATE, val); + default: + return -EOPNOTSUPP; + } +} + +static int max1619_temp_write(struct regmap *regmap, + u32 attr, int channel, long val) +{ + int reg; + + switch (attr) { + case hwmon_temp_min: + reg = MAX1619_REG_REMOTE_LOW; + break; + case hwmon_temp_max: + reg = MAX1619_REG_REMOTE_HIGH; + break; + case hwmon_temp_crit: + reg = MAX1619_REG_REMOTE_CRIT; + break; + case hwmon_temp_crit_hyst: + reg = MAX1619_REG_REMOTE_CRIT_HYST; + break; + default: + return -EOPNOTSUPP; + } + val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000); + return regmap_write(regmap, reg, val); +} + +static int max1619_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct regmap *regmap = dev_get_drvdata(dev); + + switch (type) { + case hwmon_chip: + return max1619_chip_write(regmap, attr, val); + case hwmon_temp: + return max1619_temp_write(regmap, attr, channel, val); + default: + return -EOPNOTSUPP; + } +} + +static umode_t max1619_is_visible(const void *_data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_chip: + switch (attr) { + case hwmon_chip_update_interval: + return 0644; + case hwmon_chip_alarms: + return 0444; + default: + break; + } + break; + case hwmon_temp: + switch (attr) { + case hwmon_temp_input: + return 0444; + case hwmon_temp_min: + case hwmon_temp_max: + case hwmon_temp_crit: + case hwmon_temp_crit_hyst: + return 0644; + case hwmon_temp_min_alarm: + case hwmon_temp_max_alarm: + case hwmon_temp_crit_alarm: + case hwmon_temp_fault: + return 0444; + default: + break; + } + break; + default: + break; + } + return 0; +} + +static const struct hwmon_channel_info * const max1619_info[] = { + HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS | HWMON_C_UPDATE_INTERVAL), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT, + HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | + HWMON_T_CRIT | HWMON_T_CRIT_HYST | + HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM | + HWMON_T_CRIT_ALARM | HWMON_T_FAULT), + NULL +}; + +static const struct hwmon_ops max1619_hwmon_ops = { + .is_visible = max1619_is_visible, + .read = max1619_read, + .write = max1619_write, +}; + +static const struct hwmon_chip_info max1619_chip_info = { + .ops = &max1619_hwmon_ops, + .info = max1619_info, +}; + +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int max1619_detect(struct i2c_client *client, + struct i2c_board_info *info) +{ + struct i2c_adapter *adapter = client->adapter; + int regval; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -ENODEV; + + regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG); + if (regval < 0 || (regval & 0x03)) + return -ENODEV; + regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE); + if (regval < 0 || regval > 0x07) + return -ENODEV; + regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS); + if (regval < 0 || (regval & 0x61)) + return -ENODEV; + + regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID); + if (regval != 0x4d) + return -ENODEV; + regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID); + if (regval != 0x04) + return -ENODEV; + + strscpy(info->type, "max1619", I2C_NAME_SIZE); + + return 0; +} + +static int max1619_init_chip(struct regmap *regmap) +{ + int ret; + + ret = regmap_write(regmap, MAX1619_REG_CONVRATE, 5); /* 2 Hz */ + if (ret) + return ret; + + /* Start conversions */ + return regmap_clear_bits(regmap, MAX1619_REG_CONFIG, 0x40); +} + +/* regmap */ + +static int max1619_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + int ret; + + ret = i2c_smbus_read_byte_data(context, reg); + if (ret < 0) + return ret; + + *val = ret; + return 0; +} + +static int max1619_reg_write(void *context, unsigned int reg, unsigned int val) +{ + int offset = reg < MAX1619_REG_REMOTE_CRIT ? 6 : 2; + + return i2c_smbus_write_byte_data(context, reg + offset, val); +} + +static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg) +{ + return reg <= MAX1619_REG_STATUS; +} + +static bool max1619_regmap_is_writeable(struct device *dev, unsigned int reg) +{ + return reg > MAX1619_REG_STATUS && reg <= MAX1619_REG_REMOTE_CRIT_HYST; +} + +static const struct regmap_config max1619_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = MAX1619_REG_REMOTE_CRIT_HYST, + .cache_type = REGCACHE_MAPLE, + .volatile_reg = max1619_regmap_is_volatile, + .writeable_reg = max1619_regmap_is_writeable, +}; + +static const struct regmap_bus max1619_regmap_bus = { + .reg_write = max1619_reg_write, + .reg_read = max1619_reg_read, +}; + +static int max1619_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct regmap *regmap; + int ret; + + regmap = devm_regmap_init(dev, &max1619_regmap_bus, client, + &max1619_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + ret = max1619_init_chip(regmap); + if (ret) + return ret; + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, + regmap, &max1619_chip_info, NULL); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id max1619_id[] = { + { .name = "max1619" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max1619_id); + +#ifdef CONFIG_OF +static const struct of_device_id max1619_of_match[] = { + { .compatible = "maxim,max1619", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, max1619_of_match); +#endif + +static struct i2c_driver max1619_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "max1619", + .of_match_table = of_match_ptr(max1619_of_match), + }, + .probe = max1619_probe, + .id_table = max1619_id, + .detect = max1619_detect, + .address_list = normal_i2c, +}; + +module_i2c_driver(max1619_driver); + +MODULE_AUTHOR("Oleksij Rempel , Jean Delvare "); +MODULE_DESCRIPTION("MAX1619 sensor driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1