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, 34 insertions, 0 deletions

diff --git a/sound/soc/codecs/ak4535.h b/sound/soc/codecs/ak4535.h
new file mode 100644
index 000000000..978caf521
--- /dev/null
+++ b/sound/soc/codecs/ak4535.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ak4535.h  --  AK4535 Soc Audio driver
+ *
+ * Copyright 2005 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <richard@openedhand.com>
+ *
+ * Based on wm8753.h
+ */
+
+#ifndef _AK4535_H
+#define _AK4535_H
+
+/* AK4535 register space */
+
+#define AK4535_PM1		0x0
+#define AK4535_PM2		0x1
+#define AK4535_SIG1		0x2
+#define AK4535_SIG2		0x3
+#define AK4535_MODE1		0x4
+#define AK4535_MODE2		0x5
+#define AK4535_DAC		0x6
+#define AK4535_MIC		0x7
+#define AK4535_TIMER		0x8
+#define AK4535_ALC1		0x9
+#define AK4535_ALC2		0xa
+#define AK4535_PGA		0xb
+#define AK4535_LATT		0xc
+#define AK4535_RATT		0xd
+#define AK4535_VOL		0xe
+#define AK4535_STATUS		0xf
+
+#endif