diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2025-05-02 05:41:28 +0300 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-05-02 05:44:52 +0300 |
| commit | 0a8f11f8569e7ed16cbcedeb28c4350f6378fea6 (patch) | |
| tree | b316d120db35ab3f5400a8b292daf895ace70f35 | |
| parent | 1be8e54a1e0f0a4bf70e3d65f94ca1738ee4f1f3 (diff) | |
| download | linux-0a8f11f8569e7ed16cbcedeb28c4350f6378fea6.tar.xz | |
tracing: Do not take trace_event_sem in print_event_fields()
On some paths in print_event_fields() it takes the trace_event_sem for
read, even though it should always be held when the function is called.
Remove the taking of that mutex and add a lockdep_assert_held_read() to
make sure the trace_event_sem is held when print_event_fields() is called.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250501224128.0b1f0571@batman.local.home
Fixes: 80a76994b2d88 ("tracing: Add "fields" option to show raw trace event fields")
Reported-by: syzbot+441582c1592938fccf09@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6813ff5e.050a0220.14dd7d.001b.GAE@google.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_output.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index fee40ffbd490..b9ab06c99543 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1042,11 +1042,12 @@ enum print_line_t print_event_fields(struct trace_iterator *iter, struct trace_event_call *call; struct list_head *head; + lockdep_assert_held_read(&trace_event_sem); + /* ftrace defined events have separate call structures */ if (event->type <= __TRACE_LAST_TYPE) { bool found = false; - down_read(&trace_event_sem); list_for_each_entry(call, &ftrace_events, list) { if (call->event.type == event->type) { found = true; @@ -1056,7 +1057,6 @@ enum print_line_t print_event_fields(struct trace_iterator *iter, if (call->event.type > __TRACE_LAST_TYPE) break; } - up_read(&trace_event_sem); if (!found) { trace_seq_printf(&iter->seq, "UNKNOWN TYPE %d\n", event->type); goto out; |