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, 130 insertions, 0 deletions

diff --git a/tools/docs/gen-renames.py b/tools/docs/gen-renames.py
new file mode 100755
index 000000000..8cb3b2157
--- /dev/null
+++ b/tools/docs/gen-renames.py
@@ -0,0 +1,130 @@
+#! /usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright © 2025, Oracle and/or its affiliates.
+# Author: Vegard Nossum <vegard.nossum@oracle.com>
+
+"""Trawl repository history for renames of Documentation/**.rst files.
+
+Example:
+
+    tools/docs/gen-renames.py --rev HEAD > Documentation/.renames.txt
+"""
+
+import argparse
+import itertools
+import os
+import subprocess
+import sys
+
+parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+parser.add_argument('--rev', default='HEAD', help='generate renames up to this revision')
+
+args = parser.parse_args()
+
+def normalize(path):
+    prefix = 'Documentation/'
+    suffix = '.rst'
+
+    assert path.startswith(prefix)
+    assert path.endswith(suffix)
+
+    return path[len(prefix):-len(suffix)]
+
+class Name(object):
+    def __init__(self, name):
+        self.names = [name]
+
+    def rename(self, new_name):
+        self.names.append(new_name)
+
+names = {
+}
+
+for line in subprocess.check_output([
+    'git', 'log',
+    '--reverse',
+    '--oneline',
+    '--find-renames',
+    '--diff-filter=RD',
+    '--name-status',
+    '--format=commit %H',
+    # ~v4.8-ish is when Sphinx/.rst was added in the first place
+    f'v4.8..{args.rev}',
+    '--',
+    'Documentation/'
+], text=True).splitlines():
+    # rename
+    if line.startswith('R'):
+        _, old, new = line[1:].split('\t', 2)
+
+        if old.endswith('.rst') and new.endswith('.rst'):
+            old = normalize(old)
+            new = normalize(new)
+
+            name = names.get(old)
+            if name is None:
+                name = Name(old)
+            else:
+                del names[old]
+
+            name.rename(new)
+            names[new] = name
+
+        continue
+
+    # delete
+    if line.startswith('D'):
+        _, old = line.split('\t', 1)
+
+        if old.endswith('.rst'):
+            old = normalize(old)
+
+            # TODO: we could save added/modified files as well and propose
+            # them as alternatives
+            name = names.get(old)
+            if name is None:
+                pass
+            else:
+                del names[old]
+
+        continue
+
+#
+# Get the set of current files so we can sanity check that we aren't
+# redirecting any of those
+#
+
+current_files = set()
+for line in subprocess.check_output([
+    'git', 'ls-tree',
+    '-r',
+    '--name-only',
+    args.rev,
+    'Documentation/',
+], text=True).splitlines():
+    if line.endswith('.rst'):
+        current_files.add(normalize(line))
+
+#
+# Format/group/output result
+#
+
+result = []
+for _, v in names.items():
+    old_names = v.names[:-1]
+    new_name = v.names[-1]
+
+    for old_name in old_names:
+        if old_name == new_name:
+            # A file was renamed to its new name twice; don't redirect that
+            continue
+
+        if old_name in current_files:
+            # A file was recreated with a former name; don't redirect those
+            continue
+
+        result.append((old_name, new_name))
+
+for old_name, new_name in sorted(result):
+    print(f"{old_name} {new_name}")