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/sky81452.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 drivers/mfd/sky81452.c (limited to 'drivers/mfd/sky81452.c') diff --git a/drivers/mfd/sky81452.c b/drivers/mfd/sky81452.c new file mode 100644 index 000000000..771b62a5c --- /dev/null +++ b/drivers/mfd/sky81452.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sky81452.c SKY81452 MFD driver + * + * Copyright 2014 Skyworks Solutions Inc. + * Author : Gyungoh Yoo + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static const struct regmap_config sky81452_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int sky81452_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + const struct sky81452_platform_data *pdata = dev_get_platdata(dev); + struct mfd_cell cells[2]; + struct regmap *regmap; + int ret; + + if (!pdata) { + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + } + + regmap = devm_regmap_init_i2c(client, &sky81452_config); + if (IS_ERR(regmap)) { + dev_err(dev, "failed to initialize.err=%ld\n", PTR_ERR(regmap)); + return PTR_ERR(regmap); + } + + i2c_set_clientdata(client, regmap); + + memset(cells, 0, sizeof(cells)); + cells[0].name = "sky81452-backlight"; + cells[0].of_compatible = "skyworks,sky81452-backlight"; + cells[1].name = "sky81452-regulator"; + cells[1].platform_data = pdata->regulator_init_data; + cells[1].pdata_size = sizeof(*pdata->regulator_init_data); + + ret = devm_mfd_add_devices(dev, -1, cells, ARRAY_SIZE(cells), + NULL, 0, NULL); + if (ret) + dev_err(dev, "failed to add child devices. err=%d\n", ret); + + return ret; +} + +static const struct i2c_device_id sky81452_ids[] = { + { "sky81452" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, sky81452_ids); + +#ifdef CONFIG_OF +static const struct of_device_id sky81452_of_match[] = { + { .compatible = "skyworks,sky81452", }, + { } +}; +MODULE_DEVICE_TABLE(of, sky81452_of_match); +#endif + +static struct i2c_driver sky81452_driver = { + .driver = { + .name = "sky81452", + .of_match_table = of_match_ptr(sky81452_of_match), + }, + .probe = sky81452_probe, + .id_table = sky81452_ids, +}; + +module_i2c_driver(sky81452_driver); + +MODULE_DESCRIPTION("Skyworks SKY81452 MFD driver"); +MODULE_AUTHOR("Gyungoh Yoo "); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1