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, 50 insertions, 0 deletions

diff --git a/sound/soc/codecs/ad1836.h b/sound/soc/codecs/ad1836.h
new file mode 100644
index 000000000..05711fab6
--- /dev/null
+++ b/sound/soc/codecs/ad1836.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Audio Codec driver supporting:
+ *  AD1835A, AD1836, AD1837A, AD1838A, AD1839A
+ *
+ * Copyright 2009-2011 Analog Devices Inc.
+ */
+
+#ifndef __AD1836_H__
+#define __AD1836_H__
+
+#define AD1836_DAC_CTRL1               0
+#define AD1836_DAC_POWERDOWN           2
+#define AD1836_DAC_SERFMT_MASK         0xE0
+#define AD1836_DAC_SERFMT_PCK256       (0x4 << 5)
+#define AD1836_DAC_SERFMT_PCK128       (0x5 << 5)
+#define AD1836_DAC_WORD_LEN_MASK       0x18
+#define AD1836_DAC_WORD_LEN_OFFSET     3
+
+#define AD1836_DAC_CTRL2               1
+
+/* These macros are one-based. So AD183X_MUTE_LEFT(1) will return the mute bit
+ * for the first ADC/DAC */
+#define AD1836_MUTE_LEFT(x) (((x) * 2) - 2)
+#define AD1836_MUTE_RIGHT(x) (((x) * 2) - 1)
+
+#define AD1836_DAC_L_VOL(x) ((x) * 2)
+#define AD1836_DAC_R_VOL(x) (1 + ((x) * 2))
+
+#define AD1836_ADC_CTRL1               12
+#define AD1836_ADC_POWERDOWN           7
+#define AD1836_ADC_HIGHPASS_FILTER     8
+
+#define AD1836_ADC_CTRL2               13
+#define AD1836_ADC_WORD_LEN_MASK       0x30
+#define AD1836_ADC_WORD_OFFSET         4
+#define AD1836_ADC_SERFMT_MASK         (7 << 6)
+#define AD1836_ADC_SERFMT_PCK256       (0x4 << 6)
+#define AD1836_ADC_SERFMT_PCK128       (0x5 << 6)
+#define AD1836_ADC_AUX                 (0x6 << 6)
+
+#define AD1836_ADC_CTRL3               14
+
+#define AD1836_NUM_REGS                16
+
+#define AD1836_WORD_LEN_24 0x0
+#define AD1836_WORD_LEN_20 0x1
+#define AD1836_WORD_LEN_16 0x2
+
+#endif