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/occ/common.h | 137 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 drivers/hwmon/occ/common.h (limited to 'drivers/hwmon/occ/common.h') diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h new file mode 100644 index 000000000..82f600093 --- /dev/null +++ b/drivers/hwmon/occ/common.h @@ -0,0 +1,137 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* Copyright IBM Corp 2019 */ + +#ifndef OCC_COMMON_H +#define OCC_COMMON_H + +#include +#include +#include + +struct device; + +#define OCC_RESP_DATA_BYTES 4089 + +/* + * Same response format for all OCC versions. + * Allocate the largest possible response. + */ +struct occ_response { + u8 seq_no; + u8 cmd_type; + u8 return_status; + __be16 data_length; + u8 data[OCC_RESP_DATA_BYTES]; + __be16 checksum; +} __packed; + +struct occ_sensor_data_block_header { + u8 eye_catcher[4]; + u8 reserved; + u8 sensor_format; + u8 sensor_length; + u8 num_sensors; +} __packed; + +struct occ_sensor_data_block { + struct occ_sensor_data_block_header header; + u32 data; +} __packed; + +struct occ_poll_response_header { + u8 status; + u8 ext_status; + u8 occs_present; + u8 config_data; + u8 occ_state; + u8 mode; + u8 ips_status; + u8 error_log_id; + __be32 error_log_start_address; + __be16 error_log_length; + u16 reserved; + u8 occ_code_level[16]; + u8 eye_catcher[6]; + u8 num_sensor_data_blocks; + u8 sensor_data_block_header_version; +} __packed; + +struct occ_poll_response { + struct occ_poll_response_header header; + struct occ_sensor_data_block block; +} __packed; + +struct occ_sensor { + u8 num_sensors; + u8 version; + void *data; /* pointer to sensor data start within response */ +}; + +/* + * OCC only provides one sensor data block of each type, but any number of + * sensors within that block. + */ +struct occ_sensors { + struct occ_sensor temp; + struct occ_sensor freq; + struct occ_sensor power; + struct occ_sensor caps; + struct occ_sensor extended; +}; + +/* + * Use our own attribute struct so we can dynamically allocate space for the + * name. + */ +struct occ_attribute { + char name[32]; + struct sensor_device_attribute_2 sensor; +}; + +struct occ { + struct device *bus_dev; + + struct occ_response resp; + struct occ_sensors sensors; + + int powr_sample_time_us; /* average power sample time */ + u8 poll_cmd_data; /* to perform OCC poll command */ + int (*send_cmd)(struct occ *occ, u8 *cmd, size_t len, void *resp, + size_t resp_len); + + unsigned long next_update; + struct mutex lock; /* lock OCC access */ + struct mutex hwmon_lock; /* serialize hwmon registration/removal */ + + struct device *hwmon; + struct occ_attribute *attrs; + struct attribute_group group; + const struct attribute_group *groups[2]; + + bool active; + int error; /* final transfer error after retry */ + int last_error; /* latest transfer error */ + unsigned int error_count; /* number of xfr errors observed */ + unsigned long last_safe; /* time OCC entered "safe" state */ + + /* + * Store the previous state data for comparison in order to notify + * sysfs readers of state changes. + */ + int prev_error; + u8 prev_stat; + u8 prev_ext_stat; + u8 prev_occs_present; + u8 prev_ips_status; + u8 prev_mode; +}; + +int occ_active(struct occ *occ, bool active); +int occ_setup(struct occ *occ); +int occ_setup_sysfs(struct occ *occ); +void occ_shutdown(struct occ *occ); +void occ_shutdown_sysfs(struct occ *occ); +void occ_sysfs_poll_done(struct occ *occ); +int occ_update_response(struct occ *occ); + +#endif /* OCC_COMMON_H */ -- cgit v1.3.1