linux-kernel - [PATCH rcu 5/5] checkpatch: Complain about unexpected uses of RCU Tasks Trace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230717180454.1097714-5-paulmck@kernel.org>
Date:   Mon, 17 Jul 2023 11:04:54 -0700
From:   "Paul E. McKenney" <paulmck@...nel.org>
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel-team@...a.com,
        rostedt@...dmis.org, "Paul E. McKenney" <paulmck@...nel.org>,
        Andy Whitcroft <apw@...onical.com>,
        Joe Perches <joe@...ches.com>,
        Dwaipayan Ray <dwaipayanray1@...il.com>,
        Lukas Bulwahn <lukas.bulwahn@...il.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        John Fastabend <john.fastabend@...il.com>, bpf@...r.kernel.org
Subject: [PATCH rcu 5/5] checkpatch: Complain about unexpected uses of RCU Tasks Trace

RCU Tasks Trace is quite specialized, having been created specifically
for sleepable BPF programs.  Because it allows general blocking within
readers, any new use of RCU Tasks Trace must take current use cases into
account.  Therefore, update checkpatch.pl to complain about use of any of
the RCU Tasks Trace API members outside of BPF and outside of RCU itself.

Cc: Andy Whitcroft <apw@...onical.com> (maintainer:CHECKPATCH)
Cc: Joe Perches <joe@...ches.com> (maintainer:CHECKPATCH)
Cc: Dwaipayan Ray <dwaipayanray1@...il.com> (reviewer:CHECKPATCH)
Cc: Lukas Bulwahn <lukas.bulwahn@...il.com>
Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Daniel Borkmann <daniel@...earbox.net>
Cc: John Fastabend <john.fastabend@...il.com>
Cc: <bpf@...r.kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
 scripts/checkpatch.pl | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 880fde13d9b8..24bab980bc6f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -7457,6 +7457,24 @@ sub process {
 			}
 		}
 
+# Complain about RCU Tasks Trace used outside of BPF (and of course, RCU).
+		if ($line =~ /\brcu_read_lock_trace\s*\(/ ||
+		    $line =~ /\brcu_read_lock_trace_held\s*\(/ ||
+		    $line =~ /\brcu_read_unlock_trace\s*\(/ ||
+		    $line =~ /\bcall_rcu_tasks_trace\s*\(/ ||
+		    $line =~ /\bsynchronize_rcu_tasks_trace\s*\(/ ||
+		    $line =~ /\brcu_barrier_tasks_trace\s*\(/ ||
+		    $line =~ /\brcu_request_urgent_qs_task\s*\(/) {
+			if ($realfile !~ m@...rnel/bpf@ &&
+			    $realfile !~ m@...clude/linux/bpf@ &&
+			    $realfile !~ m@...t/bpf@ &&
+			    $realfile !~ m@...rnel/rcu@ &&
+			    $realfile !~ m@...clude/linux/rcu@) {
+				WARN("RCU_TASKS_TRACE",
+				     "use of RCU tasks trace is incorrect outside BPF or core RCU code\n" . $herecurr);
+			}
+		}
+
 # check for lockdep_set_novalidate_class
 		if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||
 		    $line =~ /__lockdep_no_validate__\s*\)/ ) {
-- 
2.40.1