selftests/bpf: Reject graph kptr use after RCU unlockgrafted

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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
new file mode 100644
index 000000000..296c2ba05
--- /dev/null
+++ b/arch/riscv/kvm/Makefile
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for RISC-V KVM support
+#
+
+ccflags-y += -I $(src)
+
+include $(srctree)/virt/kvm/Makefile.kvm
+
+obj-$(CONFIG_KVM) += kvm.o
+
+# Ordered alphabetically
+kvm-y += aia.o
+kvm-y += aia_aplic.o
+kvm-y += aia_device.o
+kvm-y += aia_imsic.o
+kvm-y += gstage.o
+kvm-y += isa.o
+kvm-y += main.o
+kvm-y += mmu.o
+kvm-y += nacl.o
+kvm-y += tlb.o
+kvm-y += vcpu.o
+kvm-y += vcpu_config.o
+kvm-y += vcpu_exit.o
+kvm-y += vcpu_fp.o
+kvm-y += vcpu_insn.o
+kvm-y += vcpu_onereg.o
+kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o
+kvm-y += vcpu_sbi.o
+kvm-y += vcpu_sbi_base.o
+kvm-y += vcpu_sbi_forward.o
+kvm-y += vcpu_sbi_fwft.o
+kvm-y += vcpu_sbi_hsm.o
+kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_sbi_pmu.o
+kvm-y += vcpu_sbi_replace.o
+kvm-y += vcpu_sbi_sta.o
+kvm-y += vcpu_sbi_system.o
+kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o
+kvm-y += vcpu_switch.o
+kvm-y += vcpu_timer.o
+kvm-y += vcpu_vector.o
+kvm-y += vm.o
+kvm-y += vmid.o