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, 29 insertions, 0 deletions

diff --git a/drivers/soc/loongson/Kconfig b/drivers/soc/loongson/Kconfig
new file mode 100644
index 000000000..368344943
--- /dev/null
+++ b/drivers/soc/loongson/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Loongson-2 series SoC drivers
+#
+
+config LOONGSON2_GUTS
+	tristate "Loongson-2 SoC Global UtiliTieS (GUTS) register block"
+	depends on LOONGARCH || COMPILE_TEST
+	select SOC_BUS
+	help
+	 The global utilities block controls PCIE device enabling, alternate
+	 function selection for multiplexed signals, consistency of HDA, USB
+	 and PCIE, configuration of memory controller, rtc controller, lio
+	 controller, and clock control. This patch adds a driver to manage
+	 and access global utilities block for LoongArch architecture Loongson-2
+	 SoCs. Initially only reading SVR and registering soc device are
+	 supported. Other guts accesses, such as reading firmware configuration
+	 by default, should eventually be added into this driver as well.
+
+config LOONGSON2_PM
+	bool "Loongson-2 SoC Power Management Controller Driver"
+	depends on LOONGARCH && OF
+	depends on INPUT=y
+	help
+	  The Loongson-2's power management controller was ACPI, supports ACPI
+	  S2Idle (Suspend To Idle), ACPI S3 (Suspend To RAM), ACPI S4 (Suspend To
+	  Disk), ACPI S5 (Soft Shutdown) and supports multiple wake-up methods
+	  (USB, GMAC, PWRBTN, etc.). This driver was to add power management
+	  controller support that base on dts for Loongson-2 series SoCs.