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/arm64/Kconfig.debug | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 arch/arm64/Kconfig.debug (limited to 'arch/arm64/Kconfig.debug') diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug new file mode 100644 index 000000000..265c44610 --- /dev/null +++ b/arch/arm64/Kconfig.debug @@ -0,0 +1,23 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config PID_IN_CONTEXTIDR + bool "Write the current PID to the CONTEXTIDR register" + help + Enabling this option causes the kernel to write the current PID to + the CONTEXTIDR register, at the expense of some additional + instructions during context switch. Say Y here only if you are + planning to use hardware trace tools with this kernel. + +config DEBUG_EFI + depends on EFI && DEBUG_INFO + bool "UEFI debugging" + help + Enable this option to include EFI specific debugging features into + the kernel that are only useful when using a debug build of the + UEFI firmware + +config ARM64_RELOC_TEST + depends on m + tristate "Relocation testing module" + +source "drivers/hwtracing/coresight/Kconfig" -- cgit v1.3.1