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, 63 insertions, 0 deletions

diff --git a/drivers/clk/mediatek/clk-gate.h b/drivers/clk/mediatek/clk-gate.h
new file mode 100644
index 000000000..4f05b9855
--- /dev/null
+++ b/drivers/clk/mediatek/clk-gate.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: James Liao <jamesjj.liao@mediatek.com>
+ */
+
+#ifndef __DRV_CLK_GATE_H
+#define __DRV_CLK_GATE_H
+
+#include <linux/types.h>
+
+struct clk;
+struct clk_hw_onecell_data;
+struct clk_ops;
+struct device;
+struct device_node;
+
+extern const struct clk_ops mtk_clk_gate_ops_setclr;
+extern const struct clk_ops mtk_clk_gate_ops_setclr_inv;
+extern const struct clk_ops mtk_clk_gate_ops_no_setclr;
+extern const struct clk_ops mtk_clk_gate_ops_no_setclr_inv;
+extern const struct clk_ops mtk_clk_gate_hwv_ops_setclr;
+extern const struct clk_ops mtk_clk_gate_hwv_ops_setclr_inv;
+
+struct mtk_gate_regs {
+	u32 sta_ofs;
+	u32 clr_ofs;
+	u32 set_ofs;
+};
+
+struct mtk_gate {
+	int id;
+	const char *name;
+	const char *parent_name;
+	const struct mtk_gate_regs *regs;
+	const struct mtk_gate_regs *hwv_regs;
+	int shift;
+	const struct clk_ops *ops;
+	unsigned long flags;
+};
+
+#define GATE_MTK_FLAGS(_id, _name, _parent, _regs, _shift,	\
+			_ops, _flags) {				\
+		.id = _id,					\
+		.name = _name,					\
+		.parent_name = _parent,				\
+		.regs = _regs,					\
+		.shift = _shift,				\
+		.ops = _ops,					\
+		.flags = _flags,				\
+	}
+
+#define GATE_MTK(_id, _name, _parent, _regs, _shift, _ops)		\
+	GATE_MTK_FLAGS(_id, _name, _parent, _regs, _shift, _ops, 0)
+
+int mtk_clk_register_gates(struct device *dev, struct device_node *node,
+			   const struct mtk_gate *clks, int num,
+			   struct clk_hw_onecell_data *clk_data);
+
+void mtk_clk_unregister_gates(const struct mtk_gate *clks, int num,
+			      struct clk_hw_onecell_data *clk_data);
+
+#endif /* __DRV_CLK_GATE_H */