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, 71 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-at91.h b/drivers/pinctrl/pinctrl-at91.h
new file mode 100644
index 000000000..e5e01b276
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-at91.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2005 Ivan Kokshaysky
+ * Copyright (C) SAN People
+ *
+ * Parallel I/O Controller (PIO) - System peripherals registers.
+ */
+
+#ifndef __PINCTRL_AT91_H
+#define __PINCTRL_AT91_H
+
+#define PIO_PER		0x00	/* Enable Register */
+#define PIO_PDR		0x04	/* Disable Register */
+#define PIO_PSR		0x08	/* Status Register */
+#define PIO_OER		0x10	/* Output Enable Register */
+#define PIO_ODR		0x14	/* Output Disable Register */
+#define PIO_OSR		0x18	/* Output Status Register */
+#define PIO_IFER	0x20	/* Glitch Input Filter Enable */
+#define PIO_IFDR	0x24	/* Glitch Input Filter Disable */
+#define PIO_IFSR	0x28	/* Glitch Input Filter Status */
+#define PIO_SODR	0x30	/* Set Output Data Register */
+#define PIO_CODR	0x34	/* Clear Output Data Register */
+#define PIO_ODSR	0x38	/* Output Data Status Register */
+#define PIO_PDSR	0x3c	/* Pin Data Status Register */
+#define PIO_IER		0x40	/* Interrupt Enable Register */
+#define PIO_IDR		0x44	/* Interrupt Disable Register */
+#define PIO_IMR		0x48	/* Interrupt Mask Register */
+#define PIO_ISR		0x4c	/* Interrupt Status Register */
+#define PIO_MDER	0x50	/* Multi-driver Enable Register */
+#define PIO_MDDR	0x54	/* Multi-driver Disable Register */
+#define PIO_MDSR	0x58	/* Multi-driver Status Register */
+#define PIO_PUDR	0x60	/* Pull-up Disable Register */
+#define PIO_PUER	0x64	/* Pull-up Enable Register */
+#define PIO_PUSR	0x68	/* Pull-up Status Register */
+#define PIO_ASR		0x70	/* Peripheral A Select Register */
+#define PIO_ABCDSR1	0x70	/* Peripheral ABCD Select Register 1 [some sam9 only] */
+#define PIO_BSR		0x74	/* Peripheral B Select Register */
+#define PIO_ABCDSR2	0x74	/* Peripheral ABCD Select Register 2 [some sam9 only] */
+#define PIO_ABSR	0x78	/* AB Status Register */
+#define PIO_IFSCDR	0x80	/* Input Filter Slow Clock Disable Register */
+#define PIO_IFSCER	0x84	/* Input Filter Slow Clock Enable Register */
+#define PIO_IFSCSR	0x88	/* Input Filter Slow Clock Status Register */
+#define PIO_SCDR	0x8c	/* Slow Clock Divider Debouncing Register */
+#define		PIO_SCDR_DIV	(0x3fff <<  0)		/* Slow Clock Divider Mask */
+#define PIO_PPDDR	0x90	/* Pad Pull-down Disable Register */
+#define PIO_PPDER	0x94	/* Pad Pull-down Enable Register */
+#define PIO_PPDSR	0x98	/* Pad Pull-down Status Register */
+#define PIO_OWER	0xa0	/* Output Write Enable Register */
+#define PIO_OWDR	0xa4	/* Output Write Disable Register */
+#define PIO_OWSR	0xa8	/* Output Write Status Register */
+#define PIO_AIMER	0xb0	/* Additional Interrupt Modes Enable Register */
+#define PIO_AIMDR	0xb4	/* Additional Interrupt Modes Disable Register */
+#define PIO_AIMMR	0xb8	/* Additional Interrupt Modes Mask Register */
+#define PIO_ESR		0xc0	/* Edge Select Register */
+#define PIO_LSR		0xc4	/* Level Select Register */
+#define PIO_ELSR	0xc8	/* Edge/Level Status Register */
+#define PIO_FELLSR	0xd0	/* Falling Edge/Low Level Select Register */
+#define PIO_REHLSR	0xd4	/* Rising Edge/ High Level Select Register */
+#define PIO_FRLHSR	0xd8	/* Fall/Rise - Low/High Status Register */
+#define PIO_SCHMITT	0x100	/* Schmitt Trigger Register */
+
+#define SAMA5D3_PIO_DRIVER1		0x118  /*PIO Driver 1 register offset*/
+#define SAMA5D3_PIO_DRIVER2		0x11C  /*PIO Driver 2 register offset*/
+
+#define AT91SAM9X5_PIO_DRIVER1	0x114  /*PIO Driver 1 register offset*/
+#define AT91SAM9X5_PIO_DRIVER2	0x118  /*PIO Driver 2 register offset*/
+
+#define SAM9X60_PIO_SLEWR	0x110	/* PIO Slew Rate Control Register */
+#define SAM9X60_PIO_DRIVER1	0x118	/* PIO Driver 1 register offset */
+
+#endif