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/i5500_temp.c | 139 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 drivers/hwmon/i5500_temp.c (limited to 'drivers/hwmon/i5500_temp.c') diff --git a/drivers/hwmon/i5500_temp.c b/drivers/hwmon/i5500_temp.c new file mode 100644 index 000000000..bf006cb27 --- /dev/null +++ b/drivers/hwmon/i5500_temp.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * i5500_temp - Driver for Intel 5500/5520/X58 chipset thermal sensor + * + * Copyright (C) 2012, 2014 Jean Delvare + */ + +#include +#include +#include +#include +#include +#include +#include + +/* Register definitions from datasheet */ +#define REG_TSTHRCATA 0xE2 +#define REG_TSCTRL 0xE8 +#define REG_TSTHRRPEX 0xEB +#define REG_TSTHRLO 0xEC +#define REG_TSTHRHI 0xEE +#define REG_CTHINT 0xF0 +#define REG_TSFSC 0xF3 +#define REG_CTSTS 0xF4 +#define REG_TSTHRRQPI 0xF5 +#define REG_CTCTRL 0xF7 +#define REG_TSTIMER 0xF8 + +static int i5500_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, + long *val) +{ + struct pci_dev *pdev = to_pci_dev(dev->parent); + u16 tsthr; + s8 tsfsc; + u8 ctsts; + + switch (type) { + case hwmon_temp: + switch (attr) { + /* Sensor resolution : 0.5 degree C */ + case hwmon_temp_input: + pci_read_config_word(pdev, REG_TSTHRHI, &tsthr); + pci_read_config_byte(pdev, REG_TSFSC, &tsfsc); + *val = (tsthr - tsfsc) * 500; + return 0; + case hwmon_temp_max: + pci_read_config_word(pdev, REG_TSTHRHI, &tsthr); + *val = tsthr * 500; + return 0; + case hwmon_temp_max_hyst: + pci_read_config_word(pdev, REG_TSTHRLO, &tsthr); + *val = tsthr * 500; + return 0; + case hwmon_temp_crit: + pci_read_config_word(pdev, REG_TSTHRCATA, &tsthr); + *val = tsthr * 500; + return 0; + case hwmon_temp_max_alarm: + pci_read_config_byte(pdev, REG_CTSTS, &ctsts); + *val = !!(ctsts & BIT(1)); + return 0; + case hwmon_temp_crit_alarm: + pci_read_config_byte(pdev, REG_CTSTS, &ctsts); + *val = !!(ctsts & BIT(0)); + return 0; + default: + break; + } + break; + default: + break; + } + + return -EOPNOTSUPP; +} + +static const struct hwmon_ops i5500_ops = { + .visible = 0444, + .read = i5500_read, +}; + +static const struct hwmon_channel_info * const i5500_info[] = { + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST | HWMON_T_CRIT | + HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM + ), + NULL +}; + +static const struct hwmon_chip_info i5500_chip_info = { + .ops = &i5500_ops, + .info = i5500_info, +}; + +static const struct pci_device_id i5500_temp_ids[] = { + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x3438) }, + { 0 }, +}; + +MODULE_DEVICE_TABLE(pci, i5500_temp_ids); + +static int i5500_temp_probe(struct pci_dev *pdev, + const struct pci_device_id *id) +{ + int err; + struct device *hwmon_dev; + u32 tstimer; + s8 tsfsc; + + err = pcim_enable_device(pdev); + if (err) { + dev_err(&pdev->dev, "Failed to enable device\n"); + return err; + } + + pci_read_config_byte(pdev, REG_TSFSC, &tsfsc); + pci_read_config_dword(pdev, REG_TSTIMER, &tstimer); + if (tsfsc == 0x7F && tstimer == 0x07D30D40) { + dev_notice(&pdev->dev, "Sensor seems to be disabled\n"); + return -ENODEV; + } + + hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, "intel5500", NULL, + &i5500_chip_info, NULL); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static struct pci_driver i5500_temp_driver = { + .name = "i5500_temp", + .id_table = i5500_temp_ids, + .probe = i5500_temp_probe, +}; + +module_pci_driver(i5500_temp_driver); + +MODULE_AUTHOR("Jean Delvare "); +MODULE_DESCRIPTION("Intel 5500/5520/X58 chipset thermal sensor driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1