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, 63 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8731.h b/sound/soc/codecs/wm8731.h
new file mode 100644
index 000000000..8d5a7a9ca
--- /dev/null
+++ b/sound/soc/codecs/wm8731.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * wm8731.h  --  WM8731 Soc Audio driver
+ *
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <richard@openedhand.com>
+ *
+ * Based on wm8753.h
+ */
+
+#ifndef _WM8731_H
+#define _WM8731_H
+
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+struct clk;
+struct snd_pcm_hw_constraint_list;
+
+/* WM8731 register space */
+
+#define WM8731_LINVOL   0x00
+#define WM8731_RINVOL   0x01
+#define WM8731_LOUT1V   0x02
+#define WM8731_ROUT1V   0x03
+#define WM8731_APANA    0x04
+#define WM8731_APDIGI   0x05
+#define WM8731_PWR      0x06
+#define WM8731_IFACE    0x07
+#define WM8731_SRATE    0x08
+#define WM8731_ACTIVE   0x09
+#define WM8731_RESET	0x0f
+
+#define WM8731_CACHEREGNUM 	10
+
+#define WM8731_SYSCLK_MCLK 0
+#define WM8731_SYSCLK_XTAL 1
+
+#define WM8731_DAI		0
+
+#define WM8731_NUM_SUPPLIES 4
+
+/* codec private data */
+struct wm8731_priv {
+	struct regmap *regmap;
+	struct clk *mclk;
+	struct regulator_bulk_data supplies[WM8731_NUM_SUPPLIES];
+	const struct snd_pcm_hw_constraint_list *constraints;
+	unsigned int sysclk;
+	int sysclk_type;
+	int playback_fs;
+	bool deemph;
+
+	struct mutex lock;
+};
+
+extern const struct regmap_config wm8731_regmap;
+
+int wm8731_init(struct device *dev, struct wm8731_priv *wm8731);
+
+#endif