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, 98 insertions, 0 deletions

diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
new file mode 100644
index 000000000..428458c62
--- /dev/null
+++ b/drivers/acpi/apei/Kconfig
@@ -0,0 +1,98 @@
+# SPDX-License-Identifier: GPL-2.0
+config HAVE_ACPI_APEI
+	bool
+
+config HAVE_ACPI_APEI_NMI
+	bool
+
+config ACPI_APEI
+	bool "ACPI Platform Error Interface (APEI)"
+	select MISC_FILESYSTEMS
+	select PSTORE
+	select UEFI_CPER
+	depends on HAVE_ACPI_APEI
+	help
+	  APEI allows to report errors (for example from the chipset)
+	  to the operating system. This improves NMI handling
+	  especially. In addition it supports error serialization and
+	  error injection.
+
+config ACPI_APEI_GHES
+	bool "APEI Generic Hardware Error Source"
+	depends on ACPI_APEI
+	select ACPI_HED
+	select IRQ_WORK
+	select GENERIC_ALLOCATOR
+	select ARM_SDE_INTERFACE if ARM64
+	help
+	  Generic Hardware Error Source provides a way to report
+	  platform hardware errors (such as that from chipset). It
+	  works in so called "Firmware First" mode, that is, hardware
+	  errors are reported to firmware firstly, then reported to
+	  Linux by firmware. This way, some non-standard hardware
+	  error registers or non-standard hardware link can be checked
+	  by firmware to produce more valuable hardware error
+	  information for Linux.
+
+config ACPI_APEI_PCIEAER
+	bool "APEI PCIe AER logging/recovering support"
+	depends on ACPI_APEI && PCIEAER
+	help
+	  PCIe AER errors may be reported via APEI firmware first mode.
+	  Turn on this option to enable the corresponding support.
+
+config ACPI_APEI_SEA
+	bool
+	depends on ARM64 && ACPI_APEI_GHES
+	default y
+
+config ACPI_APEI_MEMORY_FAILURE
+	bool "APEI memory error recovering support"
+	depends on ACPI_APEI && MEMORY_FAILURE
+	help
+	  Memory errors may be reported via APEI firmware first mode.
+	  Turn on this option to enable the memory recovering support.
+
+config ACPI_APEI_EINJ
+	tristate "APEI Error INJection (EINJ)"
+	depends on ACPI_APEI && DEBUG_FS
+	help
+	  EINJ provides a hardware error injection mechanism, it is
+	  mainly used for debugging and testing the other parts of
+	  APEI and some other RAS features.
+
+config ACPI_APEI_EINJ_CXL
+	bool "CXL Error INJection Support"
+	default ACPI_APEI_EINJ
+	depends on ACPI_APEI_EINJ
+	depends on CXL_BUS && CXL_BUS <= ACPI_APEI_EINJ
+	help
+	  Support for CXL protocol Error INJection through debugfs/cxl.
+	  Availability and which errors are supported is dependent on
+	  the host platform. Look to ACPI v6.5 section 18.6.4 and kernel
+	  EINJ documentation for more information.
+
+	  If unsure say 'n'
+
+config ACPI_APEI_GHES_NVIDIA
+	tristate "NVIDIA GHES vendor record handler"
+	depends on ACPI_APEI_GHES
+	help
+	  Support for decoding NVIDIA-specific CPER sections delivered via
+	  the APEI GHES vendor record notifier chain. Registers a handler
+	  for the NVIDIA section GUID and logs error signatures, severity,
+	  socket, and diagnostic register address-value pairs.
+
+	  Enable on NVIDIA server platforms (e.g. DGX, HGX) that expose
+	  ACPI device NVDA2012 in their firmware tables.
+
+	  If unsure, say N.
+
+config ACPI_APEI_ERST_DEBUG
+	tristate "APEI Error Record Serialization Table (ERST) Debug Support"
+	depends on ACPI_APEI
+	help
+	  ERST is a way provided by APEI to save and retrieve hardware
+	  error information to and from a persistent store. Enable this
+	  if you want to debugging and testing the ERST kernel support
+	  and firmware implementation.