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, 61 insertions, 0 deletions

diff --git a/arch/m68k/Kconfig.bus b/arch/m68k/Kconfig.bus
new file mode 100644
index 000000000..d5c0b2990
--- /dev/null
+++ b/arch/m68k/Kconfig.bus
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: GPL-2.0
+if MMU
+
+comment "Bus Support"
+
+config DIO
+	bool "DIO bus support"
+	depends on HP300
+	default y
+	help
+	  Say Y here to enable support for the "DIO" expansion bus used in
+	  HP300 machines. If you are using such a system you almost certainly
+	  want this.
+
+config NUBUS
+	bool
+	depends on MAC
+	default y
+
+config ZORRO
+	bool "Amiga Zorro (AutoConfig) bus support"
+	depends on AMIGA
+	help
+	  This enables support for the Zorro bus in the Amiga. If you have
+	  expansion cards in your Amiga that conform to the Amiga
+	  AutoConfig(tm) specification, say Y, otherwise N. Note that even
+	  expansion cards that do not fit in the Zorro slots but fit in e.g.
+	  the CPU slot may fall in this category, so you have to say Y to let
+	  Linux use these.
+
+config AMIGA_PCMCIA
+	bool "Amiga 1200/600 PCMCIA support"
+	depends on AMIGA
+	help
+	  Include support in the kernel for pcmcia on Amiga 1200 and Amiga
+	  600. If you intend to use pcmcia cards say Y; otherwise say N.
+
+config ISA
+	bool
+	depends on Q40 || AMIGA_PCMCIA
+	default y
+	help
+	  Find out whether you have ISA slots on your motherboard.  ISA is the
+	  name of a bus system, i.e. the way the CPU talks to the other stuff
+	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
+	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
+	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
+
+config ATARI_ROM_ISA
+	bool "Atari ROM port ISA adapter support"
+	depends on ATARI
+	help
+	  This option enables support for the ROM port ISA adapter used to
+	  operate ISA cards on Atari. Only 8  bit cards are supported, and
+	  no interrupt lines are connected.
+	  The only driver currently using this adapter is the EtherNEC
+	  driver for RTL8019AS based NE2000 compatible network cards.
+
+source "drivers/zorro/Kconfig"
+
+endif