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, 95 insertions, 0 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
new file mode 100644
index 000000000..a7144d275
--- /dev/null
+++ b/drivers/video/Kconfig
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Video configuration
+#
+
+menu "Graphics support"
+
+config APERTURE_HELPERS
+	bool
+	help
+	  Support tracking and hand-over of aperture ownership. Required
+	  by graphics drivers for firmware-provided framebuffers.
+
+config SCREEN_INFO
+	bool
+	default n
+
+config STI_CORE
+	bool
+	depends on PARISC
+	help
+	  STI refers to the HP "Standard Text Interface" which is a set of
+	  BIOS routines contained in a ROM chip in HP PA-RISC based machines.
+
+config VIDEO
+	bool
+	default n
+
+source "drivers/auxdisplay/Kconfig"
+
+if HAS_IOMEM
+
+config HAVE_FB_ATMEL
+	bool
+
+source "drivers/char/agp/Kconfig"
+
+source "drivers/gpu/vga/Kconfig"
+
+source "drivers/gpu/Kconfig"
+source "drivers/gpu/host1x/Kconfig"
+source "drivers/gpu/ipu-v3/Kconfig"
+source "drivers/gpu/nova-core/Kconfig"
+
+source "drivers/gpu/drm/Kconfig"
+
+menu "Frame buffer Devices"
+source "drivers/video/fbdev/Kconfig"
+endmenu
+
+source "drivers/video/backlight/Kconfig"
+
+config VGASTATE
+       tristate
+       default n
+
+config VIDEOMODE_HELPERS
+	bool
+
+config HDMI
+	bool
+
+endif # HAS_IOMEM
+
+config FIRMWARE_EDID
+	bool "Enable firmware EDID"
+	depends on EFI_GENERIC_STUB || X86
+	help
+	  This enables access to the EDID transferred from the firmware.
+	  On EFI systems, the EDID comes from the same device as the
+	  primary GOP. On x86 with BIOS, it comes from the VESA BIOS.
+	  DRM display drivers will be able to export the information
+	  to userspace.
+
+	  Also enable this if DDC/I2C transfers do not work for your driver
+	  and if you are using nvidiafb, i810fb or savagefb.
+
+	  In general, choosing Y for this option is safe.  If you
+	  experience extremely long delays while booting before you get
+	  something on your display, try setting this to N.  Matrox cards in
+	  combination with certain motherboards and monitors are known to
+	  suffer from this problem.
+
+if VT
+	source "drivers/video/console/Kconfig"
+endif
+
+if FB_CORE || SGI_NEWPORT_CONSOLE
+	source "drivers/video/logo/Kconfig"
+
+endif
+
+source "drivers/gpu/trace/Kconfig"
+
+endmenu