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/mfd/atc260x-i2c.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/mfd/atc260x-i2c.c (limited to 'drivers/mfd/atc260x-i2c.c') diff --git a/drivers/mfd/atc260x-i2c.c b/drivers/mfd/atc260x-i2c.c new file mode 100644 index 000000000..fb53b0432 --- /dev/null +++ b/drivers/mfd/atc260x-i2c.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * I2C bus interface for ATC260x PMICs + * + * Copyright (C) 2019 Manivannan Sadhasivam + * Copyright (C) 2020 Cristian Ciocaltea + */ + +#include +#include +#include +#include +#include + +static int atc260x_i2c_probe(struct i2c_client *client) +{ + struct atc260x *atc260x; + struct regmap_config regmap_cfg; + int ret; + + atc260x = devm_kzalloc(&client->dev, sizeof(*atc260x), GFP_KERNEL); + if (!atc260x) + return -ENOMEM; + + atc260x->dev = &client->dev; + atc260x->irq = client->irq; + + ret = atc260x_match_device(atc260x, ®map_cfg); + if (ret) + return ret; + + i2c_set_clientdata(client, atc260x); + + atc260x->regmap = devm_regmap_init_i2c(client, ®map_cfg); + if (IS_ERR(atc260x->regmap)) { + ret = PTR_ERR(atc260x->regmap); + dev_err(&client->dev, "failed to init regmap: %d\n", ret); + return ret; + } + + return atc260x_device_probe(atc260x); +} + +static const struct of_device_id atc260x_i2c_of_match[] = { + { .compatible = "actions,atc2603c", .data = (void *)ATC2603C }, + { .compatible = "actions,atc2609a", .data = (void *)ATC2609A }, + { } +}; +MODULE_DEVICE_TABLE(of, atc260x_i2c_of_match); + +static struct i2c_driver atc260x_i2c_driver = { + .driver = { + .name = "atc260x", + .of_match_table = atc260x_i2c_of_match, + }, + .probe = atc260x_i2c_probe, +}; +module_i2c_driver(atc260x_i2c_driver); + +MODULE_DESCRIPTION("ATC260x PMICs I2C bus interface"); +MODULE_AUTHOR("Manivannan Sadhasivam "); +MODULE_AUTHOR("Cristian Ciocaltea "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1