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/ingenic/pm.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 drivers/clk/ingenic/pm.c (limited to 'drivers/clk/ingenic/pm.c') diff --git a/drivers/clk/ingenic/pm.c b/drivers/clk/ingenic/pm.c new file mode 100644 index 000000000..206d5cf28 --- /dev/null +++ b/drivers/clk/ingenic/pm.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Paul Cercueil + */ + +#include "cgu.h" +#include "pm.h" + +#include +#include + +#define CGU_REG_LCR 0x04 + +#define LCR_LOW_POWER_MODE BIT(0) + +static void __iomem * __maybe_unused ingenic_cgu_base; + +static int __maybe_unused ingenic_cgu_pm_suspend(void *data) +{ + u32 val = readl(ingenic_cgu_base + CGU_REG_LCR); + + writel(val | LCR_LOW_POWER_MODE, ingenic_cgu_base + CGU_REG_LCR); + + return 0; +} + +static void __maybe_unused ingenic_cgu_pm_resume(void *data) +{ + u32 val = readl(ingenic_cgu_base + CGU_REG_LCR); + + writel(val & ~LCR_LOW_POWER_MODE, ingenic_cgu_base + CGU_REG_LCR); +} + +static const struct syscore_ops __maybe_unused ingenic_cgu_pm_ops = { + .suspend = ingenic_cgu_pm_suspend, + .resume = ingenic_cgu_pm_resume, +}; + +static struct syscore __maybe_unused ingenic_cgu_pm = { + .ops = &ingenic_cgu_pm_ops, +}; + +void ingenic_cgu_register_syscore(struct ingenic_cgu *cgu) +{ + if (IS_ENABLED(CONFIG_PM_SLEEP)) { + ingenic_cgu_base = cgu->base; + register_syscore(&ingenic_cgu_pm); + } +} -- cgit v1.3.1