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, 56 insertions, 0 deletions

diff --git a/drivers/pinctrl/berlin/berlin.h b/drivers/pinctrl/berlin/berlin.h
new file mode 100644
index 000000000..231aab61d
--- /dev/null
+++ b/drivers/pinctrl/berlin/berlin.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Marvell Berlin SoC pinctrl driver.
+ *
+ * Copyright (C) 2014 Marvell Technology Group Ltd.
+ *
+ * Antoine Ténart <antoine.tenart@free-electrons.com>
+ */
+
+#ifndef __PINCTRL_BERLIN_H
+#define __PINCTRL_BERLIN_H
+
+struct berlin_desc_function {
+	const char	*name;
+	u8		muxval;
+};
+
+struct berlin_desc_group {
+	const char			*name;
+	u8				offset;
+	u8				bit_width;
+	u8				lsb;
+	struct berlin_desc_function	*functions;
+};
+
+struct berlin_pinctrl_desc {
+	const struct berlin_desc_group	*groups;
+	unsigned			ngroups;
+};
+
+#define BERLIN_PINCTRL_GROUP(_name, _offset, _width, _lsb, ...)		\
+	{								\
+		.name = _name,						\
+		.offset = _offset,					\
+		.bit_width = _width,					\
+		.lsb = _lsb,						\
+		.functions = (struct berlin_desc_function[]){		\
+			__VA_ARGS__, { } },				\
+	}
+
+#define BERLIN_PINCTRL_FUNCTION(_muxval, _name)		\
+	{						\
+		.name = _name,				\
+		.muxval = _muxval,			\
+	}
+
+#define BERLIN_PINCTRL_FUNCTION_UNKNOWN		{}
+
+int berlin_pinctrl_probe(struct platform_device *pdev,
+			 const struct berlin_pinctrl_desc *desc);
+
+int berlin_pinctrl_probe_regmap(struct platform_device *pdev,
+				const struct berlin_pinctrl_desc *desc,
+				struct regmap *regmap);
+
+#endif /* __PINCTRL_BERLIN_H */