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, 71 insertions, 0 deletions

diff --git a/arch/microblaze/Kconfig.platform b/arch/microblaze/Kconfig.platform
new file mode 100644
index 000000000..9cf9007ed
--- /dev/null
+++ b/arch/microblaze/Kconfig.platform
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.rst.
+#
+# Platform selection Kconfig menu for MicroBlaze targets
+#
+
+menu "Platform options"
+
+config OPT_LIB_FUNCTION
+	bool "Optimized lib function"
+	default y
+	help
+	  Turns on optimized library functions (memcpy and memmove).
+	  They are optimized by using word alignment. This will work
+	  fine if both source and destination are aligned on the same
+	  boundary. However, if they are aligned on different boundaries
+	  shifts will be necessary. This might result in bad performance
+	  on MicroBlaze systems without a barrel shifter.
+
+config OPT_LIB_ASM
+	bool "Optimized lib function ASM"
+	depends on OPT_LIB_FUNCTION && (XILINX_MICROBLAZE0_USE_BARREL = 1)
+	depends on CPU_BIG_ENDIAN
+	default n
+	help
+	  Turns on optimized library functions (memcpy and memmove).
+	  They are written in assembly.
+
+# Definitions for MICROBLAZE0
+comment "Definitions for MICROBLAZE0"
+
+config KERNEL_BASE_ADDR
+	hex "Physical address where Linux Kernel is"
+	default "0x90000000"
+	help
+	  BASE Address for kernel
+
+config XILINX_MICROBLAZE0_FAMILY
+	string "Targeted FPGA family"
+	default "virtex5"
+
+config XILINX_MICROBLAZE0_USE_MSR_INSTR
+	int "USE_MSR_INSTR range (0:1)"
+	default 0
+
+config XILINX_MICROBLAZE0_USE_PCMP_INSTR
+	int "USE_PCMP_INSTR range (0:1)"
+	default 0
+
+config XILINX_MICROBLAZE0_USE_BARREL
+	int "USE_BARREL range (0:1)"
+	default 0
+
+config XILINX_MICROBLAZE0_USE_DIV
+	int "USE_DIV range (0:1)"
+	default 0
+
+config XILINX_MICROBLAZE0_USE_HW_MUL
+	int "USE_HW_MUL values (0=NONE, 1=MUL32, 2=MUL64)"
+	default 0
+
+config XILINX_MICROBLAZE0_USE_FPU
+	int "USE_FPU values (0=NONE, 1=BASIC, 2=EXTENDED)"
+	default 0
+
+config XILINX_MICROBLAZE0_HW_VER
+	string "Core version number"
+	default "7.10.d"
+
+endmenu