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, 47 insertions, 0 deletions

diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
new file mode 100644
index 000000000..304692391
--- /dev/null
+++ b/arch/mips/mm/Makefile
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux/MIPS-specific parts of the memory manager.
+#
+
+obj-y				+= cache.o
+obj-y				+= context.o
+obj-y				+= extable.o
+obj-y				+= fault.o
+obj-y				+= init.o
+obj-y				+= mmap.o
+obj-y				+= page.o
+obj-y				+= page-funcs.o
+obj-y				+= pgtable.o
+obj-y				+= tlbex.o
+obj-y				+= tlbex-fault.o
+obj-y				+= tlb-funcs.o
+
+ifdef CONFIG_CPU_MICROMIPS
+obj-y				+= uasm-micromips.o
+else
+obj-y				+= uasm-mips.o
+endif
+
+ifndef CONFIG_EVA
+obj-y				+= maccess.o
+endif
+
+obj-$(CONFIG_32BIT)		+= ioremap.o pgtable-32.o
+obj-$(CONFIG_64BIT)		+= ioremap64.o pgtable-64.o
+obj-$(CONFIG_HIGHMEM)		+= highmem.o
+obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
+obj-$(CONFIG_DMA_NONCOHERENT)	+= dma-noncoherent.o
+
+obj-$(CONFIG_CPU_R3K_TLB)	+= tlb-r3k.o
+obj-$(CONFIG_CPU_R4K_CACHE_TLB) += c-r4k.o cex-gen.o tlb-r4k.o
+obj-$(CONFIG_CPU_R3000)		+= c-r3k.o
+obj-$(CONFIG_CPU_SB1)		+= c-r4k.o cerr-sb1.o cex-sb1.o tlb-r4k.o
+obj-$(CONFIG_CPU_CAVIUM_OCTEON) += c-octeon.o cex-oct.o tlb-r4k.o
+
+obj-$(CONFIG_IP22_CPU_SCACHE)	+= sc-ip22.o
+obj-$(CONFIG_R5000_CPU_SCACHE)	+= sc-r5k.o
+obj-$(CONFIG_RM7000_CPU_SCACHE) += sc-rm7k.o
+obj-$(CONFIG_MIPS_CPU_SCACHE)	+= sc-mips.o
+obj-$(CONFIG_SCACHE_DEBUGFS)	+= sc-debugfs.o
+
+obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o