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, 138 insertions, 0 deletions

diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
new file mode 100644
index 000000000..9f81af350
--- /dev/null
+++ b/drivers/video/console/Kconfig
@@ -0,0 +1,138 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Video configuration
+#
+
+menu "Console display driver support"
+
+config VGA_CONSOLE
+	bool "VGA text console" if EXPERT || !X86
+	depends on ALPHA || X86 || \
+		(ARM && ARCH_FOOTBRIDGE) || \
+		(MIPS && (MIPS_MALTA || SIBYTE_BCM112X || SIBYTE_SB1250 || SIBYTE_BCM1x80 || SNI_RM))
+	select APERTURE_HELPERS if (DRM || FB || VFIO_PCI_CORE)
+	default y
+	help
+	  Saying Y here will allow you to use Linux in text mode through a
+	  display that complies with the generic VGA standard. Virtually
+	  everyone wants that.
+
+	  The program SVGATextMode can be used to utilize SVGA video cards to
+	  their full potential in text mode. Download it from
+	  <ftp://ibiblio.org/pub/Linux/utils/console/>.
+
+	  Say Y.
+
+config SGI_NEWPORT_CONSOLE
+	tristate "SGI Newport Console support"
+	depends on SGI_IP22 && HAS_IOMEM
+	select FONT_SUPPORT
+	help
+	  Say Y here if you want the console on the Newport aka XL graphics
+	  card of your Indy.  Most people say Y here.
+
+config DUMMY_CONSOLE
+	def_bool VT || VGA_CONSOLE || FRAMEBUFFER_CONSOLE
+
+config DUMMY_CONSOLE_COLUMNS
+	int "Initial number of console screen columns"
+	depends on DUMMY_CONSOLE && !(ARCH_FOOTBRIDGE && VGA_CONSOLE)
+	default 160 if PARISC
+	default 80
+	help
+	  On PA-RISC, the default value is 160, which should fit a 1280x1024
+	  monitor.
+	  Select 80 if you use a 640x480 resolution by default.
+
+config DUMMY_CONSOLE_ROWS
+	int "Initial number of console screen rows"
+	depends on DUMMY_CONSOLE && !(ARCH_FOOTBRIDGE && VGA_CONSOLE)
+	default 64 if PARISC
+	default 30 if ARM
+	default 25
+	help
+	  On PA-RISC, the default value is 64, which should fit a 1280x1024
+	  monitor.
+	  Select 25 if you use a 640x480 resolution by default.
+
+config FRAMEBUFFER_CONSOLE
+	bool "Framebuffer Console support"
+	depends on FB_CORE && !UML
+	default DRM_FBDEV_EMULATION
+	select VT_HW_CONSOLE_BINDING
+	select CRC32
+	select FONT_SUPPORT
+	help
+	  Low-level framebuffer-based console driver.
+
+config FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
+	bool "Enable legacy fbcon hardware acceleration code"
+	depends on FRAMEBUFFER_CONSOLE
+	default y if PARISC
+	default n
+	help
+	  This option enables the fbcon (framebuffer text-based) hardware
+	  acceleration for graphics drivers which were written for the fbdev
+	  graphics interface.
+
+	  On modern machines, on mainstream machines (like x86-64) or when
+	  using a modern Linux distribution those fbdev drivers usually aren't used.
+	  So enabling this option wouldn't have any effect, which is why you want
+	  to disable this option on such newer machines.
+
+	  If you compile this kernel for older machines which still require the
+	  fbdev drivers, you may want to say Y.
+
+	  If unsure, select n.
+
+config FRAMEBUFFER_CONSOLE_DETECT_PRIMARY
+       bool "Map the console to the primary display device"
+       depends on FRAMEBUFFER_CONSOLE
+       default n
+	help
+	 If this option is selected, the framebuffer console will
+	 automatically select the primary display device (if the architecture
+	 supports this feature).  Otherwise, the framebuffer console will
+	 always select the first framebuffer driver that is loaded. The latter
+	 is the default behavior.
+
+	 You can always override the automatic selection of the primary device
+	 by using the fbcon=map: boot option.
+
+	 If unsure, select n.
+
+config FRAMEBUFFER_CONSOLE_ROTATION
+       bool "Framebuffer Console Rotation"
+       depends on FRAMEBUFFER_CONSOLE
+       help
+	 Enable display rotation for the framebuffer console.  This is done
+	 in software and may be significantly slower than a normally oriented
+	 display.  Note that the rotation is done at the console level only
+	 such that other users of the framebuffer will remain normally
+	 oriented.
+
+config FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
+	bool "Framebuffer Console Deferred Takeover"
+	depends on FB=y && FRAMEBUFFER_CONSOLE && DUMMY_CONSOLE
+	help
+	  If enabled this defers the framebuffer console taking over the
+	  console from the dummy console until the first text is displayed on
+	  the console. This is useful in combination with the "quiet" kernel
+	  commandline option to keep the framebuffer contents initially put up
+	  by the firmware in place, rather then replacing the contents with a
+	  black screen as soon as fbcon loads.
+
+config STI_CONSOLE
+	bool "STI text console"
+	depends on PARISC && HAS_IOMEM
+	select FONT_SUPPORT
+	select CRC32
+	select STI_CORE
+	default y
+	help
+	  The STI console is the builtin display/keyboard on HP-PARISC
+	  machines.  Say Y here to build support for it into your kernel.
+	  The alternative is to use your primary serial port as a console.
+
+endmenu
+