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 --- sound/soc/codecs/cs4271-i2c.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 sound/soc/codecs/cs4271-i2c.c (limited to 'sound/soc/codecs/cs4271-i2c.c') diff --git a/sound/soc/codecs/cs4271-i2c.c b/sound/soc/codecs/cs4271-i2c.c new file mode 100644 index 000000000..869a5317f --- /dev/null +++ b/sound/soc/codecs/cs4271-i2c.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * CS4271 I2C audio driver + * + * Copyright (c) 2010 Alexander Sverdlin + */ + +#include +#include +#include +#include +#include "cs4271.h" + +static int cs4271_i2c_probe(struct i2c_client *client) +{ + struct regmap_config config; + + config = cs4271_regmap_config; + config.reg_bits = 8; + + return cs4271_probe(&client->dev, + devm_regmap_init_i2c(client, &config)); +} + +static const struct i2c_device_id cs4271_i2c_id[] = { + { .name = "cs4271" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, cs4271_i2c_id); + +static struct i2c_driver cs4271_i2c_driver = { + .driver = { + .name = "cs4271", + .of_match_table = of_match_ptr(cs4271_dt_ids), + }, + .probe = cs4271_i2c_probe, + .id_table = cs4271_i2c_id, +}; +module_i2c_driver(cs4271_i2c_driver); + +MODULE_DESCRIPTION("ASoC CS4271 I2C Driver"); +MODULE_AUTHOR("Alexander Sverdlin "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1