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, 53 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtmips.h b/drivers/pinctrl/mediatek/pinctrl-mtmips.h
new file mode 100644
index 000000000..a7c3dd724
--- /dev/null
+++ b/drivers/pinctrl/mediatek/pinctrl-mtmips.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  Copyright (C) 2012 John Crispin <john@phrozen.org>
+ */
+
+#ifndef _PINCTRL_MTMIPS_H__
+#define _PINCTRL_MTMIPS_H__
+
+#define FUNC(name, value, pin_first, pin_count) \
+	{ name, value, pin_first, pin_count }
+
+#define GRP(_name, _func, _mask, _shift) \
+	{ .name = _name, .mask = _mask, .shift = _shift, \
+	  .func = _func, .gpio = _mask, \
+	  .func_count = ARRAY_SIZE(_func) }
+
+#define GRP_G(_name, _func, _mask, _gpio, _shift) \
+	{ .name = _name, .mask = _mask, .shift = _shift, \
+	  .func = _func, .gpio = _gpio, \
+	  .func_count = ARRAY_SIZE(_func) }
+
+struct mtmips_pmx_group;
+
+struct mtmips_pmx_func {
+	const char *name;
+	const char value;
+
+	int pin_first;
+	int pin_count;
+	int *pins;
+
+	int *groups;
+	int group_count;
+
+	int enabled;
+};
+
+struct mtmips_pmx_group {
+	const char *name;
+	int enabled;
+
+	const u32 shift;
+	const char mask;
+	const char gpio;
+
+	struct mtmips_pmx_func *func;
+	int func_count;
+};
+
+int mtmips_pinctrl_init(struct platform_device *pdev,
+			struct mtmips_pmx_group *data);
+
+#endif