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/sound/soc/codecs/cs35l41.h b/sound/soc/codecs/cs35l41.h
new file mode 100644
index 000000000..c85cbc1dd
--- /dev/null
+++ b/sound/soc/codecs/cs35l41.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * cs35l41.h -- CS35L41 ALSA SoC audio driver
+ *
+ * Copyright 2017-2021 Cirrus Logic, Inc.
+ *
+ * Author: David Rhodes <david.rhodes@cirrus.com>
+ */
+
+#ifndef __CS35L41_H__
+#define __CS35L41_H__
+
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/firmware.h>
+#include <sound/core.h>
+#include <sound/cs35l41.h>
+
+#include "wm_adsp.h"
+
+#define CS35L41_RX_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
+#define CS35L41_TX_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
+
+extern const struct dev_pm_ops cs35l41_pm_ops;
+
+struct cs35l41_private {
+	struct wm_adsp dsp; /* needs to be first member */
+	struct snd_soc_codec *codec;
+	struct cs35l41_hw_cfg hw_cfg;
+	struct device *dev;
+	struct regmap *regmap;
+	struct regulator_bulk_data supplies[CS35L41_NUM_SUPPLIES];
+	int irq;
+	/* GPIO for /RST */
+	struct gpio_desc *reset_gpio;
+};
+
+int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg);
+void cs35l41_remove(struct cs35l41_private *cs35l41);
+
+#endif /*__CS35L41_H__*/