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 --- include/drm/Makefile | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 include/drm/Makefile (limited to 'include/drm/Makefile') diff --git a/include/drm/Makefile b/include/drm/Makefile new file mode 100644 index 000000000..48fae3f16 --- /dev/null +++ b/include/drm/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +# Ensure drm headers are self-contained and pass kernel-doc +hdrtest-files := \ + $(shell cd $(src) && find * -name '*.h' 2>/dev/null) + +always-$(CONFIG_DRM_HEADER_TEST) += \ + $(patsubst %.h,%.hdrtest, $(hdrtest-files)) + +# Include the header twice to detect missing include guard. +quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@) + cmd_hdrtest = \ + $(CC) $(c_flags) -fsyntax-only -x c /dev/null -include $< -include $<; \ + PYTHONDONTWRITEBYTECODE=1 $(PYTHON3) $(KERNELDOC) -none $(if $(CONFIG_WERROR)$(CONFIG_DRM_WERROR),-Werror) $<; \ + touch $@ + +$(obj)/%.hdrtest: $(src)/%.h FORCE + $(call if_changed_dep,hdrtest) -- cgit v1.3.1