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, 23 insertions, 0 deletions

diff --git a/drivers/accel/qaic/Kconfig b/drivers/accel/qaic/Kconfig
new file mode 100644
index 000000000..116e42d15
--- /dev/null
+++ b/drivers/accel/qaic/Kconfig
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Qualcomm Cloud AI accelerators driver
+#
+
+config DRM_ACCEL_QAIC
+	tristate "Qualcomm Cloud AI accelerators"
+	depends on DRM_ACCEL
+	depends on PCI && HAS_IOMEM
+	depends on MHI_BUS
+	select CRC32
+	select WANT_DEV_COREDUMP
+	help
+	  Enables driver for Qualcomm's Cloud AI accelerator PCIe cards that are
+	  designed to accelerate Deep Learning inference workloads.
+
+	  The driver manages the PCIe devices and provides an IOCTL interface
+	  for users to submit workloads to the devices.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called qaic.