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/actions/owl-gate.c | 77 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 drivers/clk/actions/owl-gate.c (limited to 'drivers/clk/actions/owl-gate.c') diff --git a/drivers/clk/actions/owl-gate.c b/drivers/clk/actions/owl-gate.c new file mode 100644 index 000000000..f11500ba4 --- /dev/null +++ b/drivers/clk/actions/owl-gate.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// OWL gate clock driver +// +// Copyright (c) 2014 Actions Semi Inc. +// Author: David Liu +// +// Copyright (c) 2018 Linaro Ltd. +// Author: Manivannan Sadhasivam + +#include +#include + +#include "owl-gate.h" + +void owl_gate_set(const struct owl_clk_common *common, + const struct owl_gate_hw *gate_hw, bool enable) +{ + int set = gate_hw->gate_flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0; + u32 reg; + + set ^= enable; + + regmap_read(common->regmap, gate_hw->reg, ®); + + if (set) + reg |= BIT(gate_hw->bit_idx); + else + reg &= ~BIT(gate_hw->bit_idx); + + regmap_write(common->regmap, gate_hw->reg, reg); +} + +static void owl_gate_disable(struct clk_hw *hw) +{ + struct owl_gate *gate = hw_to_owl_gate(hw); + struct owl_clk_common *common = &gate->common; + + owl_gate_set(common, &gate->gate_hw, false); +} + +static int owl_gate_enable(struct clk_hw *hw) +{ + struct owl_gate *gate = hw_to_owl_gate(hw); + struct owl_clk_common *common = &gate->common; + + owl_gate_set(common, &gate->gate_hw, true); + + return 0; +} + +int owl_gate_clk_is_enabled(const struct owl_clk_common *common, + const struct owl_gate_hw *gate_hw) +{ + u32 reg; + + regmap_read(common->regmap, gate_hw->reg, ®); + + if (gate_hw->gate_flags & CLK_GATE_SET_TO_DISABLE) + reg ^= BIT(gate_hw->bit_idx); + + return !!(reg & BIT(gate_hw->bit_idx)); +} + +static int owl_gate_is_enabled(struct clk_hw *hw) +{ + struct owl_gate *gate = hw_to_owl_gate(hw); + struct owl_clk_common *common = &gate->common; + + return owl_gate_clk_is_enabled(common, &gate->gate_hw); +} + +const struct clk_ops owl_gate_ops = { + .disable = owl_gate_disable, + .enable = owl_gate_enable, + .is_enabled = owl_gate_is_enabled, +}; -- cgit v1.3.1