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, 52 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt1316-sdw.h b/sound/soc/codecs/rt1316-sdw.h
new file mode 100644
index 000000000..dc1bfe40e
--- /dev/null
+++ b/sound/soc/codecs/rt1316-sdw.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * rt1316-sdw.h -- RT1316 SDCA ALSA SoC audio driver header
+ *
+ * Copyright(c) 2021 Realtek Semiconductor Corp.
+ */
+
+#ifndef __RT1316_SDW_H__
+#define __RT1316_SDW_H__
+
+#include <linux/regmap.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_type.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <sound/soc.h>
+
+/* RT1316 SDCA Control - function number */
+#define FUNC_NUM_SMART_AMP 0x04
+
+/* RT1316 SDCA entity */
+#define RT1316_SDCA_ENT_PDE23 0x31
+#define RT1316_SDCA_ENT_PDE27 0x32
+#define RT1316_SDCA_ENT_PDE22 0x33
+#define RT1316_SDCA_ENT_PDE24 0x34
+#define RT1316_SDCA_ENT_XU24 0x24
+#define RT1316_SDCA_ENT_FU21 0x03
+#define RT1316_SDCA_ENT_UDMPU21 0x02
+
+/* RT1316 SDCA control */
+#define RT1316_SDCA_CTL_SAMPLE_FREQ_INDEX 0x10
+#define RT1316_SDCA_CTL_REQ_POWER_STATE 0x01
+#define RT1316_SDCA_CTL_BYPASS 0x01
+#define RT1316_SDCA_CTL_FU_MUTE 0x01
+#define RT1316_SDCA_CTL_FU_VOLUME 0x02
+#define RT1316_SDCA_CTL_UDMPU_CLUSTER 0x10
+
+/* RT1316 SDCA channel */
+#define CH_L 0x01
+#define CH_R 0x02
+
+struct rt1316_sdw_priv {
+	struct snd_soc_component *component;
+	struct regmap *regmap;
+	struct sdw_slave *sdw_slave;
+	struct sdw_bus_params params;
+	bool hw_init;
+	bool first_hw_init;
+	unsigned char *bq_params;
+	unsigned int bq_params_cnt;
+};
+
+#endif /* __RT1316_SDW_H__ */