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, 78 insertions, 0 deletions

diff --git a/drivers/clk/berlin/berlin2-div.h b/drivers/clk/berlin/berlin2-div.h
new file mode 100644
index 000000000..d4da64325
--- /dev/null
+++ b/drivers/clk/berlin/berlin2-div.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2014 Marvell Technology Group Ltd.
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
+ */
+#ifndef __BERLIN2_DIV_H
+#define __BERLIN2_DIV_H
+
+struct clk_hw;
+
+#define BERLIN2_DIV_HAS_GATE		BIT(0)
+#define BERLIN2_DIV_HAS_MUX		BIT(1)
+
+#define BERLIN2_PLL_SELECT(_off, _sh)	\
+	.pll_select_offs = _off,	\
+	.pll_select_shift = _sh
+
+#define BERLIN2_PLL_SWITCH(_off, _sh)	\
+	.pll_switch_offs = _off,	\
+	.pll_switch_shift = _sh
+
+#define BERLIN2_DIV_SELECT(_off, _sh)	\
+	.div_select_offs = _off,	\
+	.div_select_shift = _sh
+
+#define BERLIN2_DIV_SWITCH(_off, _sh)	\
+	.div_switch_offs = _off,	\
+	.div_switch_shift = _sh
+
+#define BERLIN2_DIV_D3SWITCH(_off, _sh)	\
+	.div3_switch_offs = _off,	\
+	.div3_switch_shift = _sh
+
+#define BERLIN2_DIV_GATE(_off, _sh)	\
+	.gate_offs = _off,		\
+	.gate_shift = _sh
+
+#define BERLIN2_SINGLE_DIV(_off)	\
+	BERLIN2_DIV_GATE(_off, 0),	\
+	BERLIN2_PLL_SELECT(_off, 1),	\
+	BERLIN2_PLL_SWITCH(_off, 4),	\
+	BERLIN2_DIV_SWITCH(_off, 5),	\
+	BERLIN2_DIV_D3SWITCH(_off, 6),	\
+	BERLIN2_DIV_SELECT(_off, 7)
+
+struct berlin2_div_map {
+	u16 pll_select_offs;
+	u16 pll_switch_offs;
+	u16 div_select_offs;
+	u16 div_switch_offs;
+	u16 div3_switch_offs;
+	u16 gate_offs;
+	u8 pll_select_shift;
+	u8 pll_switch_shift;
+	u8 div_select_shift;
+	u8 div_switch_shift;
+	u8 div3_switch_shift;
+	u8 gate_shift;
+};
+
+struct berlin2_div_data {
+	const char *name;
+	const u8 *parent_ids;
+	int num_parents;
+	unsigned long flags;
+	struct berlin2_div_map map;
+	u8 div_flags;
+};
+
+struct clk_hw *
+berlin2_div_register(const struct berlin2_div_map *map,
+	     void __iomem *base,  const char *name, u8 div_flags,
+	     const char **parent_names, int num_parents,
+	     unsigned long flags,  spinlock_t *lock);
+
+#endif /* __BERLIN2_DIV_H */