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, 45 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-hfpll.h b/drivers/clk/qcom/clk-hfpll.h
new file mode 100644
index 000000000..27b9effcb
--- /dev/null
+++ b/drivers/clk/qcom/clk-hfpll.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __QCOM_CLK_HFPLL_H__
+#define __QCOM_CLK_HFPLL_H__
+
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+#include "clk-regmap.h"
+
+struct hfpll_data {
+	u32 mode_reg;
+	u32 l_reg;
+	u32 m_reg;
+	u32 n_reg;
+	u32 user_reg;
+	u32 droop_reg;
+	u32 config_reg;
+	u32 status_reg;
+	u8  lock_bit;
+
+	u32 l_val;
+	u32 droop_val;
+	u32 config_val;
+	u32 user_val;
+	u32 user_vco_mask;
+	unsigned long low_vco_max_rate;
+
+	unsigned long min_rate;
+	unsigned long max_rate;
+};
+
+struct clk_hfpll {
+	struct hfpll_data const *d;
+	int init_done;
+
+	struct clk_regmap clkr;
+	spinlock_t lock;
+};
+
+#define to_clk_hfpll(_hw) \
+	container_of(to_clk_regmap(_hw), struct clk_hfpll, clkr)
+
+extern const struct clk_ops clk_ops_hfpll;
+
+#endif