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, 121 insertions, 0 deletions

diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
new file mode 100644
index 000000000..8e5c39b02
--- /dev/null
+++ b/drivers/clk/meson/clk-regmap.h
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 BayLibre, SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ */
+
+#ifndef __CLK_REGMAP_H
+#define __CLK_REGMAP_H
+
+#include <linux/device.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+/**
+ * struct clk_regmap - regmap backed clock
+ *
+ * @hw:		handle between common and hardware-specific interfaces
+ * @map:	pointer to the regmap structure controlling the clock
+ * @data:	data specific to the clock type
+ *
+ * Clock which is controlled by regmap backed registers. The actual type of
+ * of the clock is controlled by the clock_ops and data.
+ */
+struct clk_regmap {
+	struct clk_hw	hw;
+	struct regmap	*map;
+	void		*data;
+};
+
+static inline struct clk_regmap *to_clk_regmap(struct clk_hw *hw)
+{
+	return container_of(hw, struct clk_regmap, hw);
+}
+
+/* clk_regmap init op to get and cache regmap from the controllers */
+int clk_regmap_init(struct clk_hw *hw);
+
+/**
+ * struct clk_regmap_gate_data - regmap backed gate specific data
+ *
+ * @offset:	offset of the register controlling gate
+ * @bit_idx:	single bit controlling gate
+ * @flags:	hardware-specific flags
+ *
+ * Flags:
+ * Same as clk_gate except CLK_GATE_HIWORD_MASK which is ignored
+ */
+struct clk_regmap_gate_data {
+	unsigned int	offset;
+	u8		bit_idx;
+	u8		flags;
+};
+
+static inline struct clk_regmap_gate_data *
+clk_get_regmap_gate_data(struct clk_regmap *clk)
+{
+	return (struct clk_regmap_gate_data *)clk->data;
+}
+
+extern const struct clk_ops clk_regmap_gate_ops;
+extern const struct clk_ops clk_regmap_gate_ro_ops;
+
+/**
+ * struct clk_regmap_div_data - regmap backed adjustable divider specific data
+ *
+ * @offset:	offset of the register controlling the divider
+ * @shift:	shift to the divider bit field
+ * @width:	width of the divider bit field
+ * @table:	array of value/divider pairs, last entry should have div = 0
+ *
+ * Flags:
+ * Same as clk_divider except CLK_DIVIDER_HIWORD_MASK which is ignored
+ */
+struct clk_regmap_div_data {
+	unsigned int	offset;
+	u8		shift;
+	u8		width;
+	u8		flags;
+	const struct clk_div_table	*table;
+};
+
+static inline struct clk_regmap_div_data *
+clk_get_regmap_div_data(struct clk_regmap *clk)
+{
+	return (struct clk_regmap_div_data *)clk->data;
+}
+
+extern const struct clk_ops clk_regmap_divider_ops;
+extern const struct clk_ops clk_regmap_divider_ro_ops;
+
+/**
+ * struct clk_regmap_mux_data - regmap backed multiplexer clock specific data
+ *
+ * @hw:		handle between common and hardware-specific interfaces
+ * @offset:	offset of theregister controlling multiplexer
+ * @table:	array of parent indexed register values
+ * @shift:	shift to multiplexer bit field
+ * @mask:	mask of mutliplexer bit field
+ * @flags:	hardware-specific flags
+ *
+ * Flags:
+ * Same as clk_divider except CLK_MUX_HIWORD_MASK which is ignored
+ */
+struct clk_regmap_mux_data {
+	unsigned int	offset;
+	u32		*table;
+	u32		mask;
+	u8		shift;
+	u8		flags;
+};
+
+static inline struct clk_regmap_mux_data *
+clk_get_regmap_mux_data(struct clk_regmap *clk)
+{
+	return (struct clk_regmap_mux_data *)clk->data;
+}
+
+extern const struct clk_ops clk_regmap_mux_ops;
+extern const struct clk_ops clk_regmap_mux_ro_ops;
+
+#endif /* __CLK_REGMAP_H */