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/mips/Makefile.postlink | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 arch/mips/Makefile.postlink (limited to 'arch/mips/Makefile.postlink') diff --git a/arch/mips/Makefile.postlink b/arch/mips/Makefile.postlink new file mode 100644 index 000000000..ea0add7d5 --- /dev/null +++ b/arch/mips/Makefile.postlink @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0 +# =========================================================================== +# Post-link MIPS pass +# =========================================================================== +# +# 1. Check that Loongson3 LL/SC workarounds are applied correctly +# 2. Insert relocations into vmlinux + +PHONY := __archpost +__archpost: + +-include include/config/auto.conf +include $(srctree)/scripts/Kbuild.include + +CMD_LS3_LLSC = arch/mips/tools/loongson3-llsc-check +quiet_cmd_ls3_llsc = LLSCCHK $@ + cmd_ls3_llsc = $(CMD_LS3_LLSC) $@ + +CMD_RELOCS = arch/mips/boot/tools/relocs +quiet_cmd_relocs = RELOCS $@ + cmd_relocs = $(CMD_RELOCS) $@ + +# `@true` prevents complaint when there is nothing to be done + +vmlinux vmlinux.unstripped: FORCE + @true +ifeq ($(CONFIG_CPU_LOONGSON3_WORKAROUNDS),y) + $(call if_changed,ls3_llsc) +endif +ifeq ($(CONFIG_RELOCATABLE),y) + $(call if_changed,relocs) +endif + +clean: + @true + +PHONY += FORCE clean + +FORCE: + +.PHONY: $(PHONY) -- cgit v1.3.1