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 --- arch/m68k/coldfire/clk.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 arch/m68k/coldfire/clk.c (limited to 'arch/m68k/coldfire/clk.c') diff --git a/arch/m68k/coldfire/clk.c b/arch/m68k/coldfire/clk.c new file mode 100644 index 000000000..c120bbca6 --- /dev/null +++ b/arch/m68k/coldfire/clk.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +/***************************************************************************/ + +/* + * clk.c -- general ColdFire CPU kernel clk handling + * + * Copyright (C) 2009, Greg Ungerer (gerg@snapgear.com) + */ + +/***************************************************************************/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(clk_lock); + +#ifdef MCFPM_PPMCR0 +/* + * For more advanced ColdFire parts that have clocks that can be enabled + * we supply enable/disable functions. These must properly define their + * clocks in their platform specific code. + */ +void __clk_init_enabled(struct clk *clk) +{ + clk->enabled = 1; + clk->clk_ops->enable(clk); +} + +void __clk_init_disabled(struct clk *clk) +{ + clk->enabled = 0; + clk->clk_ops->disable(clk); +} + +static void __clk_enable0(struct clk *clk) +{ + mcf_write8(clk->slot, MCFPM_PPMCR0); +} + +static void __clk_disable0(struct clk *clk) +{ + mcf_write8(clk->slot, MCFPM_PPMSR0); +} + +struct clk_ops clk_ops0 = { + .enable = __clk_enable0, + .disable = __clk_disable0, +}; + +#ifdef MCFPM_PPMCR1 +static void __clk_enable1(struct clk *clk) +{ + mcf_write8(clk->slot, MCFPM_PPMCR1); +} + +static void __clk_disable1(struct clk *clk) +{ + mcf_write8(clk->slot, MCFPM_PPMSR1); +} + +struct clk_ops clk_ops1 = { + .enable = __clk_enable1, + .disable = __clk_disable1, +}; +#endif /* MCFPM_PPMCR1 */ +#endif /* MCFPM_PPMCR0 */ + +int clk_enable(struct clk *clk) +{ + unsigned long flags; + + if (!clk) + return 0; + + spin_lock_irqsave(&clk_lock, flags); + if ((clk->enabled++ == 0) && clk->clk_ops) + clk->clk_ops->enable(clk); + spin_unlock_irqrestore(&clk_lock, flags); + + return 0; +} +EXPORT_SYMBOL(clk_enable); + +void clk_disable(struct clk *clk) +{ + unsigned long flags; + + if (!clk) + return; + + spin_lock_irqsave(&clk_lock, flags); + if ((--clk->enabled == 0) && clk->clk_ops) + clk->clk_ops->disable(clk); + spin_unlock_irqrestore(&clk_lock, flags); +} +EXPORT_SYMBOL(clk_disable); + +unsigned long clk_get_rate(struct clk *clk) +{ + if (!clk) + return 0; + + return clk->rate; +} +EXPORT_SYMBOL(clk_get_rate); + +/* dummy functions, should not be called */ +long clk_round_rate(struct clk *clk, unsigned long rate) +{ + WARN_ON(clk); + return 0; +} +EXPORT_SYMBOL(clk_round_rate); + +int clk_set_rate(struct clk *clk, unsigned long rate) +{ + WARN_ON(clk); + return 0; +} +EXPORT_SYMBOL(clk_set_rate); + +int clk_set_parent(struct clk *clk, struct clk *parent) +{ + WARN_ON(clk); + return 0; +} +EXPORT_SYMBOL(clk_set_parent); + +struct clk *clk_get_parent(struct clk *clk) +{ + WARN_ON(clk); + return NULL; +} +EXPORT_SYMBOL(clk_get_parent); + +/***************************************************************************/ -- cgit v1.3.1