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/arm/mach-versatile/realview.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 arch/arm/mach-versatile/realview.c (limited to 'arch/arm/mach-versatile/realview.c') diff --git a/arch/arm/mach-versatile/realview.c b/arch/arm/mach-versatile/realview.c new file mode 100644 index 000000000..36a6f6bc4 --- /dev/null +++ b/arch/arm/mach-versatile/realview.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2014 Linaro Ltd. + * + * Author: Linus Walleij + */ +#include + +static const char *const realview_dt_platform_compat[] __initconst = { + "arm,realview-eb", + "arm,realview-pb1176", + "arm,realview-pba8", + "arm,realview-pbx", + NULL, +}; + +DT_MACHINE_START(REALVIEW_DT, "ARM RealView Machine (Device Tree Support)") +#ifdef CONFIG_ZONE_DMA + .dma_zone_size = SZ_256M, +#endif + .dt_compat = realview_dt_platform_compat, + .l2c_aux_val = 0x0, + .l2c_aux_mask = ~0x0, +MACHINE_END -- cgit v1.3.1