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, 41 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile
new file mode 100644
index 000000000..f7bf17b7a
--- /dev/null
+++ b/arch/arm/mach-shmobile/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+# Common objects
+obj-y				:= timer.o
+
+# CPU objects
+obj-$(CONFIG_ARCH_SH73A0)	+= setup-sh73a0.o
+obj-$(CONFIG_ARCH_R8A73A4)	+= setup-r8a73a4.o
+obj-$(CONFIG_ARCH_R8A7740)	+= setup-r8a7740.o
+obj-$(CONFIG_ARCH_R8A7778)	+= setup-r8a7778.o
+obj-$(CONFIG_ARCH_R8A7779)	+= setup-r8a7779.o
+obj-$(CONFIG_ARCH_EMEV2)	+= setup-emev2.o
+obj-$(CONFIG_ARCH_R7S72100)	+= setup-r7s72100.o
+obj-$(CONFIG_ARCH_R7S9210)	+= setup-r7s9210.o
+
+# CPU reset vector handling objects
+cpu-y				:= platsmp.o headsmp.o
+
+# Shared SoC family objects
+obj-$(CONFIG_ARCH_RCAR_GEN2)	+= setup-rcar-gen2.o platsmp-apmu.o $(cpu-y)
+CFLAGS_setup-rcar-gen2.o	+= -march=armv7-a
+obj-$(CONFIG_ARCH_R8A7790)	+= regulator-quirk-rcar-gen2.o
+obj-$(CONFIG_ARCH_R8A7791)	+= regulator-quirk-rcar-gen2.o
+obj-$(CONFIG_ARCH_R8A7793)	+= regulator-quirk-rcar-gen2.o
+
+# SMP objects
+smp-y				:= $(cpu-y)
+smp-$(CONFIG_ARCH_RCAR_GEN2)	+= headsmp-apmu.o
+smp-$(CONFIG_ARCH_SH73A0)	+= smp-sh73a0.o headsmp-scu.o platsmp-scu.o
+smp-$(CONFIG_ARCH_R8A7779)	+= smp-r8a7779.o headsmp-scu.o platsmp-scu.o
+smp-$(CONFIG_ARCH_EMEV2)	+= smp-emev2.o headsmp-scu.o platsmp-scu.o
+
+# PM objects
+obj-$(CONFIG_SUSPEND)		+= suspend.o
+obj-$(CONFIG_ARCH_RCAR_GEN2)	+= pm-rcar-gen2.o
+
+# Framework support
+obj-$(CONFIG_SMP)		+= $(smp-y)