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, 73 insertions, 0 deletions

diff --git a/drivers/clk/actions/owl-gate.h b/drivers/clk/actions/owl-gate.h
new file mode 100644
index 000000000..ac458d438
--- /dev/null
+++ b/drivers/clk/actions/owl-gate.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+//
+// OWL gate clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#ifndef _OWL_GATE_H_
+#define _OWL_GATE_H_
+
+#include "owl-common.h"
+
+struct owl_gate_hw {
+	u32			reg;
+	u8			bit_idx;
+	u8			gate_flags;
+};
+
+struct owl_gate {
+	struct owl_gate_hw	gate_hw;
+	struct owl_clk_common	common;
+};
+
+#define OWL_GATE_HW(_reg, _bit_idx, _gate_flags)	\
+	{						\
+		.reg		= _reg,			\
+		.bit_idx	= _bit_idx,		\
+		.gate_flags	= _gate_flags,		\
+	}
+
+#define OWL_GATE(_struct, _name, _parent, _reg,				\
+		_bit_idx, _gate_flags, _flags)				\
+	struct owl_gate _struct = {					\
+		.gate_hw = OWL_GATE_HW(_reg, _bit_idx, _gate_flags),	\
+		.common = {						\
+			.regmap		= NULL,				\
+			.hw.init	= CLK_HW_INIT(_name,		\
+						      _parent,		\
+						      &owl_gate_ops,	\
+						      _flags),		\
+		}							\
+	}								\
+
+#define OWL_GATE_NO_PARENT(_struct, _name, _reg,			\
+		_bit_idx, _gate_flags, _flags)				\
+	struct owl_gate _struct = {					\
+		.gate_hw = OWL_GATE_HW(_reg, _bit_idx, _gate_flags),	\
+		.common = {						\
+			.regmap		= NULL,				\
+			.hw.init	= CLK_HW_INIT_NO_PARENT(_name,	\
+						      &owl_gate_ops,	\
+						      _flags),		\
+		},							\
+	}								\
+
+static inline struct owl_gate *hw_to_owl_gate(struct clk_hw *hw)
+{
+	struct owl_clk_common *common = hw_to_owl_clk_common(hw);
+
+	return container_of(common, struct owl_gate, common);
+}
+
+void owl_gate_set(const struct owl_clk_common *common,
+		 const struct owl_gate_hw *gate_hw, bool enable);
+int owl_gate_clk_is_enabled(const struct owl_clk_common *common,
+		   const struct owl_gate_hw *gate_hw);
+
+extern const struct clk_ops owl_gate_ops;
+
+#endif /* _OWL_GATE_H_ */