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, 25 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-of-dev.h b/sound/soc/sof/sof-of-dev.h
new file mode 100644
index 000000000..b6cc70595
--- /dev/null
+++ b/sound/soc/sof/sof-of-dev.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright 2021 NXP
+ */
+
+#ifndef __SOUND_SOC_SOF_OF_H
+#define __SOUND_SOC_SOF_OF_H
+
+struct snd_sof_of_mach {
+	const char *compatible;
+	const char *drv_name;
+	const char *fw_filename;
+	const char *sof_tplg_filename;
+};
+
+extern const struct dev_pm_ops sof_of_pm;
+
+int sof_of_probe(struct platform_device *pdev);
+void sof_of_remove(struct platform_device *pdev);
+void sof_of_shutdown(struct platform_device *pdev);
+
+#endif