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, 33 insertions, 0 deletions

diff --git a/arch/arm/mach-versatile/Makefile b/arch/arm/mach-versatile/Makefile
new file mode 100644
index 000000000..d819fb2fc
--- /dev/null
+++ b/arch/arm/mach-versatile/Makefile
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the linux kernel.
+#
+
+# versatile
+obj-$(CONFIG_ARCH_VERSATILE)		+= versatile.o
+
+# integrator
+obj-$(CONFIG_ARCH_INTEGRATOR)		+= integrator.o
+obj-$(CONFIG_ARCH_INTEGRATOR_AP)	+= integrator_ap.o
+obj-$(CONFIG_ARCH_INTEGRATOR_CP)	+= integrator_cp.o
+
+# realview
+obj-$(CONFIG_ARCH_REALVIEW)		+= realview.o
+
+# vexpress
+obj-$(CONFIG_ARCH_VEXPRESS)		:= v2m.o
+obj-$(CONFIG_ARCH_VEXPRESS_SPC)		+= spc.o
+CFLAGS_REMOVE_spc.o			= -pg
+obj-$(CONFIG_ARCH_VEXPRESS_TC2_PM)	+= tc2_pm.o
+CFLAGS_tc2_pm.o				+= -march=armv7-a
+CFLAGS_REMOVE_tc2_pm.o			= -pg
+
+# mps2
+obj-$(CONFIG_ARCH_MPS2)			+= v2m-mps2.o
+
+ifdef CONFIG_SMP
+obj-y					+= headsmp.o platsmp.o
+obj-$(CONFIG_ARCH_REALVIEW)		+= platsmp-realview.o
+obj-$(CONFIG_ARCH_VEXPRESS)		+= platsmp-vexpress.o
+obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o
+endif