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/clk/qcom/reset.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 drivers/clk/qcom/reset.c (limited to 'drivers/clk/qcom/reset.c') diff --git a/drivers/clk/qcom/reset.c b/drivers/clk/qcom/reset.c new file mode 100644 index 000000000..d96c96a90 --- /dev/null +++ b/drivers/clk/qcom/reset.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2013, The Linux Foundation. All rights reserved. + */ + +#include +#include +#include +#include +#include + +#include "reset.h" + +static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id) +{ + struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev); + + rcdev->ops->assert(rcdev, id); + fsleep(rst->reset_map[id].udelay ?: 1); /* use 1 us as default */ + + rcdev->ops->deassert(rcdev, id); + return 0; +} + +static int qcom_reset_set_assert(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct qcom_reset_controller *rst; + const struct qcom_reset_map *map; + u32 mask; + + rst = to_qcom_reset_controller(rcdev); + map = &rst->reset_map[id]; + mask = map->bitmask ? map->bitmask : BIT(map->bit); + + regmap_update_bits(rst->regmap, map->reg, mask, assert ? mask : 0); + + /* Read back the register to ensure write completion, ignore the value */ + regmap_read(rst->regmap, map->reg, &mask); + + return 0; +} + +static int qcom_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) +{ + return qcom_reset_set_assert(rcdev, id, true); +} + +static int qcom_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) +{ + return qcom_reset_set_assert(rcdev, id, false); +} + +const struct reset_control_ops qcom_reset_ops = { + .reset = qcom_reset, + .assert = qcom_reset_assert, + .deassert = qcom_reset_deassert, +}; +EXPORT_SYMBOL_GPL(qcom_reset_ops); -- cgit v1.3.1