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, 48 insertions, 0 deletions

diff --git a/drivers/clk/samsung/clk-cpu.h b/drivers/clk/samsung/clk-cpu.h
new file mode 100644
index 000000000..892843611
--- /dev/null
+++ b/drivers/clk/samsung/clk-cpu.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *
+ * Common Clock Framework support for all PLL's in Samsung platforms
+*/
+
+#ifndef __SAMSUNG_CLK_CPU_H
+#define __SAMSUNG_CLK_CPU_H
+
+/* The CPU clock registers have DIV1 configuration register */
+#define CLK_CPU_HAS_DIV1		BIT(0)
+/* When ALT parent is active, debug clocks need safe divider values */
+#define CLK_CPU_NEEDS_DEBUG_ALT_DIV	BIT(1)
+
+/**
+ * enum exynos_cpuclk_layout - CPU clock registers layout compatibility
+ * @CPUCLK_LAYOUT_E4210: Exynos4210 compatible layout
+ * @CPUCLK_LAYOUT_E5433: Exynos5433 compatible layout
+ * @CPUCLK_LAYOUT_E850_CL0: Exynos850 cluster 0 compatible layout
+ * @CPUCLK_LAYOUT_E850_CL1: Exynos850 cluster 1 compatible layout
+ */
+enum exynos_cpuclk_layout {
+	CPUCLK_LAYOUT_E4210,
+	CPUCLK_LAYOUT_E5433,
+	CPUCLK_LAYOUT_E850_CL0,
+	CPUCLK_LAYOUT_E850_CL1,
+};
+
+/**
+ * struct exynos_cpuclk_cfg_data - config data to setup cpu clocks
+ * @prate: frequency of the primary parent clock (in KHz)
+ * @div0: value to be programmed in the div_cpu0 register
+ * @div1: value to be programmed in the div_cpu1 register
+ *
+ * This structure holds the divider configuration data for dividers in the CPU
+ * clock domain. The parent frequency at which these divider values are valid is
+ * specified in @prate. The @prate is the frequency of the primary parent clock.
+ * For CPU clock domains that do not have a DIV1 register, the @div1 member
+ * value is not used.
+ */
+struct exynos_cpuclk_cfg_data {
+	unsigned long	prate;
+	unsigned long	div0;
+	unsigned long	div1;
+};
+
+#endif /* __SAMSUNG_CLK_CPU_H */