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, 31 insertions, 0 deletions

diff --git a/sound/soc/codecs/rl6347a.h b/sound/soc/codecs/rl6347a.h
new file mode 100644
index 000000000..761455a2f
--- /dev/null
+++ b/sound/soc/codecs/rl6347a.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * rl6347a.h - RL6347A class device shared support
+ *
+ * Copyright 2015 Realtek Semiconductor Corp.
+ *
+ * Author: Oder Chiou <oder_chiou@realtek.com>
+ */
+#ifndef __RL6347A_H__
+#define __RL6347A_H__
+
+#include <sound/hda_verbs.h>
+
+#define VERB_CMD(V, N, D) ((N << 20) | (V << 8) | D)
+
+#define RL6347A_VENDOR_REGISTERS	0x20
+
+#define RL6347A_COEF_INDEX\
+	VERB_CMD(AC_VERB_SET_COEF_INDEX, RL6347A_VENDOR_REGISTERS, 0)
+#define RL6347A_PROC_COEF\
+	VERB_CMD(AC_VERB_SET_PROC_COEF, RL6347A_VENDOR_REGISTERS, 0)
+
+struct rl6347a_priv {
+	struct reg_default *index_cache;
+	int index_cache_size;
+};
+
+int rl6347a_hw_write(void *context, unsigned int reg, unsigned int value);
+int rl6347a_hw_read(void *context, unsigned int reg, unsigned int *value);
+
+#endif /* __RL6347A_H__ */