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, 34 insertions, 0 deletions

diff --git a/drivers/dpll/zl3073x/prop.h b/drivers/dpll/zl3073x/prop.h
new file mode 100644
index 000000000..721a18f05
--- /dev/null
+++ b/drivers/dpll/zl3073x/prop.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ZL3073X_PROP_H
+#define _ZL3073X_PROP_H
+
+#include <linux/dpll.h>
+
+#include "core.h"
+
+struct fwnode_handle;
+
+/**
+ * struct zl3073x_pin_props - pin properties
+ * @fwnode: pin firmware node
+ * @dpll_props: DPLL core pin properties
+ * @package_label: pin package label
+ * @esync_control: embedded sync support
+ */
+struct zl3073x_pin_props {
+	struct fwnode_handle		*fwnode;
+	struct dpll_pin_properties	dpll_props;
+	char				package_label[8];
+	bool				esync_control;
+};
+
+enum dpll_type zl3073x_prop_dpll_type_get(struct zl3073x_dev *zldev, u8 index);
+
+struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
+						enum dpll_pin_direction dir,
+						u8 index);
+
+void zl3073x_pin_props_put(struct zl3073x_pin_props *props);
+
+#endif /* _ZL3073X_PROP_H */