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, 19 insertions, 0 deletions

diff --git a/arch/mips/math-emu/Makefile b/arch/mips/math-emu/Makefile
new file mode 100644
index 000000000..81d25ff32
--- /dev/null
+++ b/arch/mips/math-emu/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux/MIPS kernel FPU emulation.
+#
+
+obj-y	+= cp1emu.o ieee754dp.o ieee754sp.o ieee754.o \
+	   dp_div.o dp_mul.o dp_sub.o dp_add.o dp_fsp.o dp_cmp.o dp_simple.o \
+	   dp_tint.o dp_fint.o dp_rint.o dp_maddf.o dp_2008class.o dp_fmin.o \
+	   dp_fmax.o							     \
+	   sp_div.o sp_mul.o sp_sub.o sp_add.o sp_fdp.o sp_cmp.o sp_simple.o \
+	   sp_tint.o sp_fint.o sp_rint.o sp_maddf.o sp_2008class.o sp_fmin.o \
+	   sp_fmax.o							     \
+	   dsemul.o
+
+lib-y	+= ieee754d.o \
+	   dp_tlong.o dp_flong.o dp_sqrt.o \
+	   sp_tlong.o sp_flong.o sp_sqrt.o
+
+obj-$(CONFIG_DEBUG_FS) += me-debugfs.o