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, 20 insertions, 0 deletions

diff --git a/sound/Makefile b/sound/Makefile
new file mode 100644
index 000000000..5942311a4
--- /dev/null
+++ b/sound/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for the Linux sound card driver
+#
+
+obj-$(CONFIG_SOUND) += soundcore.o
+obj-$(CONFIG_DMASOUND) += oss/dmasound/
+obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \
+	firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ \
+	virtio/
+obj-$(CONFIG_SND_AOA) += aoa/
+
+# This one must be compilable even if sound is configured out
+obj-$(CONFIG_AC97_BUS) += ac97_bus.o
+obj-$(CONFIG_AC97_BUS_NEW) += ac97/
+
+ifeq ($(CONFIG_SND),y)
+  obj-y += last.o
+endif
+
+soundcore-y  := sound_core.o