linux-kernel - [for-linus][PATCH 05/11] tracing/osnoise: Use built-in RCU list checking

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: <20230125162010.631776115@goodmis.org>
Date:   Wed, 25 Jan 2023 11:18:29 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     linux-kernel@...r.kernel.org
Cc:     Masami Hiramatsu <mhiramat@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Daniel Bristot de Oliveira <bristot@...nel.org>,
        Chuang Wang <nashuiliang@...il.com>
Subject: [for-linus][PATCH 05/11] tracing/osnoise: Use built-in RCU list checking

From: Chuang Wang <nashuiliang@...il.com>

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence false lockdep
warning when CONFIG_PROVE_RCU_LIST is enabled.

Execute as follow:

 [tracing]# echo osnoise > current_tracer
 [tracing]# echo 1 > tracing_on
 [tracing]# echo 0 > tracing_on

The trace_types_lock is held when osnoise_tracer_stop() or
timerlat_tracer_stop() are called in the non-RCU read side section.
So, pass lockdep_is_held(&trace_types_lock) to silence false lockdep
warning.

Link: https://lkml.kernel.org/r/20221227023036.784337-1-nashuiliang@gmail.com

Cc: Masami Hiramatsu <mhiramat@...nel.org>
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Acked-by: Daniel Bristot de Oliveira <bristot@...nel.org>
Signed-off-by: Chuang Wang <nashuiliang@...il.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@...dmis.org>
---
 kernel/trace/trace_osnoise.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 94c1b5eb1dc0..210e1f168392 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -147,9 +147,8 @@ static void osnoise_unregister_instance(struct trace_array *tr)
 	 * register/unregister serialization is provided by trace's
 	 * trace_types_lock.
 	 */
-	lockdep_assert_held(&trace_types_lock);
-
-	list_for_each_entry_rcu(inst, &osnoise_instances, list) {
+	list_for_each_entry_rcu(inst, &osnoise_instances, list,
+				lockdep_is_held(&trace_types_lock)) {
 		if (inst->tr == tr) {
 			list_del_rcu(&inst->list);
 			found = 1;
-- 
2.39.0