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/spear/clk.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 drivers/clk/spear/clk.c (limited to 'drivers/clk/spear/clk.c') diff --git a/drivers/clk/spear/clk.c b/drivers/clk/spear/clk.c new file mode 100644 index 000000000..50847cccd --- /dev/null +++ b/drivers/clk/spear/clk.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012 ST Microelectronics + * Viresh Kumar + * + * SPEAr clk - Common routines + */ + +#include +#include +#include "clk.h" + +long clk_round_rate_index(struct clk_hw *hw, unsigned long drate, + unsigned long parent_rate, clk_calc_rate calc_rate, u8 rtbl_cnt, + int *index) +{ + unsigned long prev_rate, rate = 0; + + for (*index = 0; *index < rtbl_cnt; (*index)++) { + prev_rate = rate; + rate = calc_rate(hw, parent_rate, *index); + if (drate < rate) { + /* previous clock was best */ + if (*index) { + rate = prev_rate; + (*index)--; + } + break; + } + } + + if ((*index) == rtbl_cnt) + (*index)--; + + return rate; +} -- cgit v1.3.1