--- /dev/null
+From 4b6b08f2e45edda4c067ac40833e3c1f84383c0b Mon Sep 17 00:00:00 2001
+From: "Qiang.Zhang" <qiang.zhang@windriver.com>
+Date: Tue, 31 Aug 2021 10:29:19 +0800
+Subject: tracing/osnoise: Fix missed cpus_read_unlock() in start_per_cpu_kthreads()
+
+From: Qiang.Zhang <qiang.zhang@windriver.com>
+
+commit 4b6b08f2e45edda4c067ac40833e3c1f84383c0b upstream.
+
+When start_kthread() return error, the cpus_read_unlock() need
+to be called.
+
+Link: https://lkml.kernel.org/r/20210831022919.27630-1-qiang.zhang@windriver.com
+
+Cc: <stable@vger.kernel.org>
+Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations")
+Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
+Signed-off-by: Qiang.Zhang <qiang.zhang@windriver.com>
+Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/trace/trace_osnoise.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/kernel/trace/trace_osnoise.c
++++ b/kernel/trace/trace_osnoise.c
+@@ -1548,7 +1548,7 @@ static int start_kthread(unsigned int cp
+ static int start_per_cpu_kthreads(struct trace_array *tr)
+ {
+ struct cpumask *current_mask = &save_cpumask;
+- int retval;
++ int retval = 0;
+ int cpu;
+
+ get_online_cpus();
+@@ -1568,13 +1568,13 @@ static int start_per_cpu_kthreads(struct
+ retval = start_kthread(cpu);
+ if (retval) {
+ stop_per_cpu_kthreads();
+- return retval;
++ break;
+ }
+ }
+
+ put_online_cpus();
+
+- return 0;
++ return retval;
+ }
+
+ #ifdef CONFIG_HOTPLUG_CPU