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/ltc2947-i2c.c | 48 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 drivers/hwmon/ltc2947-i2c.c (limited to 'drivers/hwmon/ltc2947-i2c.c') diff --git a/drivers/hwmon/ltc2947-i2c.c b/drivers/hwmon/ltc2947-i2c.c new file mode 100644 index 000000000..e07d33983 --- /dev/null +++ b/drivers/hwmon/ltc2947-i2c.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Analog Devices LTC2947 high precision power and energy monitor over I2C + * + * Copyright 2019 Analog Devices Inc. + */ +#include +#include +#include + +#include "ltc2947.h" + +static const struct regmap_config ltc2947_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int ltc2947_probe(struct i2c_client *i2c) +{ + struct regmap *map; + + map = devm_regmap_init_i2c(i2c, <c2947_regmap_config); + if (IS_ERR(map)) + return PTR_ERR(map); + + return ltc2947_core_probe(map, i2c->name); +} + +static const struct i2c_device_id ltc2947_id[] = { + { .name = "ltc2947" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ltc2947_id); + +static struct i2c_driver ltc2947_driver = { + .driver = { + .name = "ltc2947", + .of_match_table = ltc2947_of_match, + .pm = pm_sleep_ptr(<c2947_pm_ops), + }, + .probe = ltc2947_probe, + .id_table = ltc2947_id, +}; +module_i2c_driver(ltc2947_driver); + +MODULE_AUTHOR("Nuno Sa "); +MODULE_DESCRIPTION("LTC2947 I2C power and energy monitor driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1