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, 76 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib-acpi.h b/drivers/gpio/gpiolib-acpi.h
new file mode 100644
index 000000000..a90267470
--- /dev/null
+++ b/drivers/gpio/gpiolib-acpi.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ACPI helpers for GPIO API
+ *
+ * Copyright (C) 2012,2019 Intel Corporation
+ */
+
+#ifndef GPIOLIB_ACPI_H
+#define GPIOLIB_ACPI_H
+
+#include <linux/err.h>
+#include <linux/types.h>
+
+#include <linux/gpio/consumer.h>
+
+struct device;
+struct fwnode_handle;
+
+struct gpio_chip;
+struct gpio_desc;
+struct gpio_device;
+
+#ifdef CONFIG_ACPI
+void acpi_gpiochip_add(struct gpio_chip *chip);
+void acpi_gpiochip_remove(struct gpio_chip *chip);
+
+void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
+void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);
+
+struct gpio_desc *acpi_find_gpio(struct fwnode_handle *fwnode,
+				 const char *con_id,
+				 unsigned int idx,
+				 enum gpiod_flags *dflags,
+				 unsigned long *lookupflags);
+
+int acpi_gpio_count(const struct fwnode_handle *fwnode, const char *con_id);
+#else
+static inline void acpi_gpiochip_add(struct gpio_chip *chip) { }
+static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { }
+
+static inline void
+acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
+
+static inline void
+acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }
+
+static inline struct gpio_desc *
+acpi_find_gpio(struct fwnode_handle *fwnode, const char *con_id,
+	       unsigned int idx, enum gpiod_flags *dflags,
+	       unsigned long *lookupflags)
+{
+	return ERR_PTR(-ENOENT);
+}
+static inline int acpi_gpio_count(const struct fwnode_handle *fwnode,
+				  const char *con_id)
+{
+	return -ENODEV;
+}
+#endif
+
+void acpi_gpio_process_deferred_list(struct list_head *list);
+
+bool acpi_gpio_add_to_deferred_list(struct list_head *list);
+void acpi_gpio_remove_from_deferred_list(struct list_head *list);
+
+int acpi_gpio_need_run_edge_events_on_boot(void);
+
+enum acpi_gpio_ignore_list {
+	ACPI_GPIO_IGNORE_WAKE,
+	ACPI_GPIO_IGNORE_INTERRUPT,
+};
+
+bool acpi_gpio_in_ignore_list(enum acpi_gpio_ignore_list list,
+			      const char *controller_in, unsigned int pin_in);
+
+#endif /* GPIOLIB_ACPI_H */