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, 90 insertions, 0 deletions

diff --git a/sound/soc/codecs/ak4458.h b/sound/soc/codecs/ak4458.h
new file mode 100644
index 000000000..9ad869575
--- /dev/null
+++ b/sound/soc/codecs/ak4458.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Audio driver for AK4458
+ *
+ * Copyright (C) 2016 Asahi Kasei Microdevices Corporation
+ * Copyright 2018 NXP
+ */
+
+#ifndef _AK4458_H
+#define _AK4458_H
+
+#include <linux/regmap.h>
+
+/* Settings */
+
+#define AK4458_00_CONTROL1			0x00
+#define AK4458_01_CONTROL2			0x01
+#define AK4458_02_CONTROL3			0x02
+#define AK4458_03_LCHATT			0x03
+#define AK4458_04_RCHATT			0x04
+#define AK4458_05_CONTROL4			0x05
+#define AK4458_06_DSD1				0x06
+#define AK4458_07_CONTROL5			0x07
+#define AK4458_08_SOUND_CONTROL			0x08
+#define AK4458_09_DSD2				0x09
+#define AK4458_0A_CONTROL6			0x0A
+#define AK4458_0B_CONTROL7			0x0B
+#define AK4458_0C_CONTROL8			0x0C
+#define AK4458_0D_CONTROL9			0x0D
+#define AK4458_0E_CONTROL10			0x0E
+#define AK4458_0F_L2CHATT			0x0F
+#define AK4458_10_R2CHATT			0x10
+#define AK4458_11_L3CHATT			0x11
+#define AK4458_12_R3CHATT			0x12
+#define AK4458_13_L4CHATT			0x13
+#define AK4458_14_R4CHATT			0x14
+
+/* Bitfield Definitions */
+
+/* AK4458_00_CONTROL1 (0x00) Fields
+ * Addr Register Name  D7     D6    D5    D4    D3    D2    D1    D0
+ * 00H  Control 1      ACKS   0     0     0     DIF2  DIF1  DIF0  RSTN
+ */
+
+/* Digital Filter (SD, SLOW, SSLOW) */
+#define AK4458_SD_MASK		GENMASK(5, 5)
+#define AK4458_SLOW_MASK	GENMASK(0, 0)
+#define AK4458_SSLOW_MASK	GENMASK(0, 0)
+
+/* DIF2	1 0
+ *  x	1 0 MSB justified  Figure 3 (default)
+ *  x	1 1 I2S Compliment  Figure 4
+ */
+#define AK4458_DIF_SHIFT	1
+#define AK4458_DIF_MASK		GENMASK(3, 1)
+
+#define AK4458_DIF_16BIT_LSB	(0 << 1)
+#define AK4458_DIF_24BIT_I2S	(3 << 1)
+#define AK4458_DIF_32BIT_LSB	(5 << 1)
+#define AK4458_DIF_32BIT_MSB	(6 << 1)
+#define AK4458_DIF_32BIT_I2S	(7 << 1)
+
+/* AK4458_00_CONTROL1 (0x00) D0 bit */
+#define AK4458_RSTN_MASK	GENMASK(0, 0)
+#define AK4458_RSTN		(0x1 << 0)
+
+/* AK4458_0A_CONTROL6 Mode bits */
+#define AK4458_MODE_SHIFT	6
+#define AK4458_MODE_MASK	GENMASK(7, 6)
+#define AK4458_MODE_NORMAL	(0 << AK4458_MODE_SHIFT)
+#define AK4458_MODE_TDM128	(1 << AK4458_MODE_SHIFT)
+#define AK4458_MODE_TDM256	(2 << AK4458_MODE_SHIFT)
+#define AK4458_MODE_TDM512	(3 << AK4458_MODE_SHIFT)
+
+/* DAC Digital attenuator transition time setting
+ * Table 19
+ * Mode	ATS1	ATS2	ATT speed
+ * 0	0	0	4080/fs
+ * 1	0	1	2040/fs
+ * 2	1	0	510/fs
+ * 3	1	1	255/fs
+ * */
+#define AK4458_ATS_SHIFT	6
+#define AK4458_ATS_MASK		GENMASK(7, 6)
+#define AK4458_DCHAIN_MASK	(0x1 << 1)
+
+#define AK4458_DSDSEL_MASK		(0x1 << 0)
+#define AK4458_DP_MASK			(0x1 << 7)
+
+#endif