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/reset.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 arch/m68k/coldfire/reset.c (limited to 'arch/m68k/coldfire/reset.c') diff --git a/arch/m68k/coldfire/reset.c b/arch/m68k/coldfire/reset.c new file mode 100644 index 000000000..6e5f8ab39 --- /dev/null +++ b/arch/m68k/coldfire/reset.c @@ -0,0 +1,50 @@ +/* + * reset.c -- common ColdFire SoC reset support + * + * (C) Copyright 2012, Greg Ungerer + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include +#include +#include +#include +#include +#include + +/* + * There are 2 common methods amongst the ColdFure parts for reseting + * the CPU. But there are couple of exceptions, the 5272 and the 547x + * have something completely special to them, and we let their specific + * subarch code handle them. + */ + +#ifdef MCFSIM_SYPCR +static void mcf_cpu_reset(void) +{ + local_irq_disable(); + /* Set watchdog to soft reset, and enabled */ + mcf_write8(0xc0, MCFSIM_SYPCR); + for (;;) + /* wait for watchdog to timeout */; +} +#endif + +#ifdef MCF_RCR +static void mcf_cpu_reset(void) +{ + local_irq_disable(); + mcf_write8(MCF_RCR_SWRESET, MCF_RCR); +} +#endif + +static int __init mcf_setup_reset(void) +{ + mach_reset = mcf_cpu_reset; + return 0; +} + +arch_initcall(mcf_setup_reset); -- cgit v1.3.1