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, 37 insertions, 0 deletions

diff --git a/arch/powerpc/boot/install.sh b/arch/powerpc/boot/install.sh
new file mode 100755
index 000000000..c3df6c27c
--- /dev/null
+++ b/arch/powerpc/boot/install.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1995 by Linus Torvalds
+#
+# Blatantly stolen from in arch/i386/boot/install.sh by Dave Hansen 
+#
+# "make install" script for ppc64 architecture
+#
+# Arguments:
+#   $1 - kernel version
+#   $2 - kernel image file
+#   $3 - kernel map file
+#   $4 - default install path (blank if root directory)
+
+set -e
+
+# this should work for both the pSeries zImage and the iSeries vmlinux.sm
+image_name=$(basename "$2")
+
+
+echo "Warning: '${INSTALLKERNEL}' command not available... Copying" \
+     "directly to $4/$image_name-$1" >&2
+
+if [ -f "$4"/"$image_name"-"$1" ]; then
+	mv "$4"/"$image_name"-"$1" "$4"/"$image_name"-"$1".old
+fi
+
+if [ -f "$4"/System.map-"$1" ]; then
+	mv "$4"/System.map-"$1" "$4"/System-"$1".old
+fi
+
+cat "$2" > "$4"/"$image_name"-"$1"
+cp "$3" "$4"/System.map-"$1"