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/sprd/mux.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 drivers/clk/sprd/mux.c (limited to 'drivers/clk/sprd/mux.c') diff --git a/drivers/clk/sprd/mux.c b/drivers/clk/sprd/mux.c new file mode 100644 index 000000000..624041b60 --- /dev/null +++ b/drivers/clk/sprd/mux.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Spreadtrum multiplexer clock driver +// +// Copyright (C) 2017 Spreadtrum, Inc. +// Author: Chunyan Zhang + +#include +#include +#include + +#include "mux.h" + +u8 sprd_mux_helper_get_parent(const struct sprd_clk_common *common, + const struct sprd_mux_ssel *mux) +{ + unsigned int reg; + u8 parent; + int num_parents; + int i; + + regmap_read(common->regmap, common->reg, ®); + parent = reg >> mux->shift; + parent &= (1 << mux->width) - 1; + + if (!mux->table) + return parent; + + num_parents = clk_hw_get_num_parents(&common->hw); + + for (i = 0; i < num_parents - 1; i++) + if (parent >= mux->table[i] && parent < mux->table[i + 1]) + return i; + + return num_parents - 1; +} +EXPORT_SYMBOL_GPL(sprd_mux_helper_get_parent); + +static u8 sprd_mux_get_parent(struct clk_hw *hw) +{ + struct sprd_mux *cm = hw_to_sprd_mux(hw); + + return sprd_mux_helper_get_parent(&cm->common, &cm->mux); +} + +int sprd_mux_helper_set_parent(const struct sprd_clk_common *common, + const struct sprd_mux_ssel *mux, + u8 index) +{ + unsigned int reg; + + if (mux->table) + index = mux->table[index]; + + regmap_read(common->regmap, common->reg, ®); + reg &= ~GENMASK(mux->width + mux->shift - 1, mux->shift); + regmap_write(common->regmap, common->reg, + reg | (index << mux->shift)); + + return 0; +} +EXPORT_SYMBOL_GPL(sprd_mux_helper_set_parent); + +static int sprd_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct sprd_mux *cm = hw_to_sprd_mux(hw); + + return sprd_mux_helper_set_parent(&cm->common, &cm->mux, index); +} + +const struct clk_ops sprd_mux_ops = { + .get_parent = sprd_mux_get_parent, + .set_parent = sprd_mux_set_parent, + .determine_rate = __clk_mux_determine_rate, +}; +EXPORT_SYMBOL_GPL(sprd_mux_ops); -- cgit v1.3.1