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/Makefile.gcc-plugins | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 scripts/Makefile.gcc-plugins (limited to 'scripts/Makefile.gcc-plugins') diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins new file mode 100644 index 000000000..b0e1423b0 --- /dev/null +++ b/scripts/Makefile.gcc-plugins @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: GPL-2.0 + +gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so +gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) \ + += -DLATENT_ENTROPY_PLUGIN +ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY + DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable -ULATENT_ENTROPY_PLUGIN +endif +export DISABLE_LATENT_ENTROPY_PLUGIN + +# All the plugin CFLAGS are collected here in case a build target needs to +# filter them out of the KBUILD_CFLAGS. +GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) -DGCC_PLUGINS +export GCC_PLUGINS_CFLAGS + +# Add the flags to the build! +KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS) + +# Some plugins are enabled outside of this Makefile, but they still need to +# be included in GCC_PLUGIN so they can get built. +gcc-plugin-external-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) \ + += randomize_layout_plugin.so +gcc-plugin-external-$(CONFIG_GCC_PLUGIN_STACKLEAK) \ + += stackleak_plugin.so + +# All enabled GCC plugins are collected here for building in +# scripts/gcc-scripts/Makefile. +GCC_PLUGIN := $(gcc-plugin-y) $(gcc-plugin-external-y) +export GCC_PLUGIN -- cgit v1.3.1