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, 46 insertions, 0 deletions

diff --git a/sound/soc/codecs/wcd-common.h b/sound/soc/codecs/wcd-common.h
new file mode 100644
index 000000000..d5c156e64
--- /dev/null
+++ b/sound/soc/codecs/wcd-common.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2025, Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#ifndef __WCD_COMMON_H__
+#define __WCD_COMMON_H__
+
+struct device;
+struct sdw_slave;
+struct sdw_bus_params;
+struct irq_domain;
+enum sdw_slave_status;
+
+#define WCD_MAX_MICBIAS		4
+
+struct wcd_sdw_ch_info {
+	int port_num;
+	unsigned int ch_mask;
+	unsigned int master_ch_mask;
+};
+
+#define WCD_SDW_CH(id, pn, cmask)	\
+	[id] = {			\
+		.port_num = pn,		\
+		.ch_mask = cmask,	\
+		.master_ch_mask = cmask,	\
+	}
+
+struct wcd_common {
+	struct device *dev;
+	int max_bias;
+	u32 micb_mv[WCD_MAX_MICBIAS];
+	u32 micb_vout[WCD_MAX_MICBIAS];
+};
+
+extern const struct component_ops wcd_sdw_component_ops;
+int wcd_get_micb_vout_ctl_val(struct device *dev, u32 micb_mv);
+int wcd_dt_parse_micbias_info(struct wcd_common *common);
+int wcd_update_status(struct sdw_slave *slave, enum sdw_slave_status status);
+int wcd_bus_config(struct sdw_slave *slave, struct sdw_bus_params *params);
+int wcd_interrupt_callback(struct sdw_slave *slave, struct irq_domain *slave_irq,
+		unsigned int wcd_intr_status0, unsigned int wcd_intr_status1,
+		unsigned int wcd_intr_status2);
+
+#endif /* __WCD_COMMON_H__  */