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/tegra/cvb.h | 60 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 drivers/clk/tegra/cvb.h (limited to 'drivers/clk/tegra/cvb.h') diff --git a/drivers/clk/tegra/cvb.h b/drivers/clk/tegra/cvb.h new file mode 100644 index 000000000..750095fe9 --- /dev/null +++ b/drivers/clk/tegra/cvb.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Utility functions for parsing Tegra CVB voltage tables + */ + +#ifndef __DRIVERS_CLK_TEGRA_CVB_H +#define __DRIVERS_CLK_TEGRA_CVB_H + +#include + +struct device; + +#define MAX_DVFS_FREQS 40 + +struct rail_alignment { + int offset_uv; + int step_uv; +}; + +struct cvb_coefficients { + int c0; + int c1; + int c2; +}; + +struct cvb_table_freq_entry { + unsigned long freq; + struct cvb_coefficients coefficients; +}; + +struct cvb_cpu_dfll_data { + u32 tune0_low; + u32 tune0_high; + u32 tune1; + unsigned int tune_high_min_millivolts; +}; + +struct cvb_table { + int speedo_id; + int process_id; + + int min_millivolts; + int max_millivolts; + + int speedo_scale; + int voltage_scale; + struct cvb_table_freq_entry entries[MAX_DVFS_FREQS]; + struct cvb_cpu_dfll_data cpu_dfll_data; +}; + +const struct cvb_table * +tegra_cvb_add_opp_table(struct device *dev, const struct cvb_table *cvb_tables, + size_t count, struct rail_alignment *align, + int process_id, int speedo_id, int speedo_value, + unsigned long max_freq); +void tegra_cvb_remove_opp_table(struct device *dev, + const struct cvb_table *table, + unsigned long max_freq); + +#endif -- cgit v1.3.1