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 --- scripts/dtc/Makefile | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 scripts/dtc/Makefile (limited to 'scripts/dtc/Makefile') diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile new file mode 100644 index 000000000..b47f4daa4 --- /dev/null +++ b/scripts/dtc/Makefile @@ -0,0 +1,27 @@ +# SPDX-License-Identifier: GPL-2.0 +# scripts/dtc makefile + +# *** Also keep .gitignore in sync when changing *** +hostprogs-always-$(CONFIG_DTC) += dtc fdtoverlay +hostprogs-always-$(CHECK_DTBS) += dtc + +dtc-objs := dtc.o flattree.o fstree.o data.o livetree.o treesource.o \ + srcpos.o checks.o util.o +dtc-objs += dtc-lexer.lex.o dtc-parser.tab.o + +# The upstream project builds libfdt as a separate library. We are choosing to +# instead directly link the libfdt object files into fdtoverlay. +libfdt-objs := fdt.o fdt_ro.o fdt_wip.o fdt_sw.o fdt_rw.o fdt_strerror.o fdt_empty_tree.o fdt_addresses.o fdt_overlay.o +libfdt = $(addprefix libfdt/,$(libfdt-objs)) +fdtoverlay-objs := $(libfdt) fdtoverlay.o util.o + +# Source files need to get at the userspace version of libfdt_env.h to compile +HOST_EXTRACFLAGS += -I $(src)/libfdt +HOST_EXTRACFLAGS += -DNO_YAML + +# Generated files need one more search path to include headers in source tree +HOSTCFLAGS_dtc-lexer.lex.o := -I $(src) +HOSTCFLAGS_dtc-parser.tab.o := -I $(src) + +# dependencies on generated files need to be listed explicitly +$(obj)/dtc-lexer.lex.o: $(obj)/dtc-parser.tab.h -- cgit v1.3.1