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/wm8350-i2c.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 drivers/mfd/wm8350-i2c.c (limited to 'drivers/mfd/wm8350-i2c.c') diff --git a/drivers/mfd/wm8350-i2c.c b/drivers/mfd/wm8350-i2c.c new file mode 100644 index 000000000..767c176b1 --- /dev/null +++ b/drivers/mfd/wm8350-i2c.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * wm8350-i2c.c -- Generic I2C driver for Wolfson WM8350 PMIC + * + * Copyright 2007, 2008 Wolfson Microelectronics PLC. + * + * Author: Liam Girdwood + * linux@wolfsonmicro.com + */ + +#include +#include +#include +#include +#include +#include +#include + +static int wm8350_i2c_probe(struct i2c_client *i2c) +{ + struct wm8350 *wm8350; + struct wm8350_platform_data *pdata = dev_get_platdata(&i2c->dev); + int ret = 0; + + wm8350 = devm_kzalloc(&i2c->dev, sizeof(struct wm8350), GFP_KERNEL); + if (wm8350 == NULL) + return -ENOMEM; + + wm8350->regmap = devm_regmap_init_i2c(i2c, &wm8350_regmap); + if (IS_ERR(wm8350->regmap)) { + ret = PTR_ERR(wm8350->regmap); + dev_err(&i2c->dev, "Failed to allocate register map: %d\n", + ret); + return ret; + } + + i2c_set_clientdata(i2c, wm8350); + wm8350->dev = &i2c->dev; + + return wm8350_device_init(wm8350, i2c->irq, pdata); +} + +static const struct i2c_device_id wm8350_i2c_id[] = { + { "wm8350" }, + { "wm8351" }, + { "wm8352" }, + { } +}; + +static struct i2c_driver wm8350_i2c_driver = { + .driver = { + .name = "wm8350", + .suppress_bind_attrs = true, + }, + .probe = wm8350_i2c_probe, + .id_table = wm8350_i2c_id, +}; + +static int __init wm8350_i2c_init(void) +{ + return i2c_add_driver(&wm8350_i2c_driver); +} +/* init early so consumer devices can complete system boot */ +subsys_initcall(wm8350_i2c_init); -- cgit v1.3.1