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, 21 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/Makefile b/arch/arm/mach-davinci/Makefile
new file mode 100644
index 000000000..7a210db66
--- /dev/null
+++ b/arch/arm/mach-davinci/Makefile
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+#
+#
+# Common objects
+obj-y 					:= common.o sram.o devices-da8xx.o
+
+obj-$(CONFIG_DAVINCI_MUX)		+= mux.o
+
+# Chip specific
+obj-$(CONFIG_ARCH_DAVINCI_DA850)	+= da850.o pdata-quirks.o
+
+obj-y					+= da8xx-dt.o
+
+# Power Management
+obj-$(CONFIG_HAVE_CLK)			+= pm_domain.o
+ifeq ($(CONFIG_SUSPEND),y)
+obj-$(CONFIG_ARCH_DAVINCI_DA850)	+= pm.o sleep.o
+endif