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, 81 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-pll.h b/drivers/clk/qcom/clk-pll.h
new file mode 100644
index 000000000..532f5a9d2
--- /dev/null
+++ b/drivers/clk/qcom/clk-pll.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef __QCOM_CLK_PLL_H__
+#define __QCOM_CLK_PLL_H__
+
+#include <linux/clk-provider.h>
+#include "clk-regmap.h"
+
+/**
+ * struct pll_freq_tbl - PLL frequency table
+ * @l: L value
+ * @m: M value
+ * @n: N value
+ * @ibits: internal values
+ */
+struct pll_freq_tbl {
+	unsigned long freq;
+	u16 l;
+	u16 m;
+	u16 n;
+	u32 ibits;
+};
+
+/**
+ * struct clk_pll - phase locked loop (PLL)
+ * @l_reg: L register
+ * @m_reg: M register
+ * @n_reg: N register
+ * @config_reg: config register
+ * @mode_reg: mode register
+ * @status_reg: status register
+ * @status_bit: ANDed with @status_reg to determine if PLL is enabled
+ * @freq_tbl: PLL frequency table
+ * @hw: handle between common and hardware-specific interfaces
+ */
+struct clk_pll {
+	u32	l_reg;
+	u32	m_reg;
+	u32	n_reg;
+	u32	config_reg;
+	u32	mode_reg;
+	u32	status_reg;
+	u8	status_bit;
+	u8	post_div_width;
+	u8	post_div_shift;
+
+	const struct pll_freq_tbl *freq_tbl;
+
+	struct clk_regmap clkr;
+};
+
+extern const struct clk_ops clk_pll_ops;
+extern const struct clk_ops clk_pll_vote_ops;
+extern const struct clk_ops clk_pll_sr2_ops;
+
+#define to_clk_pll(_hw) container_of(to_clk_regmap(_hw), struct clk_pll, clkr)
+
+struct pll_config {
+	u16 l;
+	u32 m;
+	u32 n;
+	u32 vco_val;
+	u32 vco_mask;
+	u32 pre_div_val;
+	u32 pre_div_mask;
+	u32 post_div_val;
+	u32 post_div_mask;
+	u32 mn_ena_mask;
+	u32 main_output_mask;
+	u32 aux_output_mask;
+};
+
+void clk_pll_configure_sr(struct clk_pll *pll, struct regmap *regmap,
+		const struct pll_config *config, bool fsm_mode);
+void clk_pll_configure_sr_hpm_lp(struct clk_pll *pll, struct regmap *regmap,
+		const struct pll_config *config, bool fsm_mode);
+
+#endif