BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:935
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/5
1 lock held by swapper/5/0:
#0: ffff80001002bd90 (samples/ftrace/sample-trace-array.c:38){+.-.}-{0:0},
at: call_timer_fn+0x8/0x3e0
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.7.0+ #8
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
dump_backtrace+0x0/0x1a0
show_stack+0x20/0x30
dump_stack+0xe4/0x150
___might_sleep+0x160/0x200
__might_sleep+0x58/0x90
__mutex_lock+0x64/0x948
mutex_lock_nested+0x3c/0x58
__ftrace_set_clr_event+0x44/0x88
trace_array_set_clr_event+0x24/0x38
mytimer_handler+0x34/0x40 [sample_trace_array]
mutex_lock() will be called in interrupt context, using workqueueu to fix it.
Signed-off-by: Kefeng Wang <wangkefeng.w...@huawei.com>
---
samples/ftrace/sample-trace-array.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/samples/ftrace/sample-trace-array.c
b/samples/ftrace/sample-trace-array.c
index d523450d73eb..41684c7dbd7b 100644
--- a/samples/ftrace/sample-trace-array.c
+++ b/samples/ftrace/sample-trace-array.c
@@ -20,6 +20,16 @@ struct trace_array *tr;
static void mytimer_handler(struct timer_list *unused);
static struct task_struct *simple_tsk;
+static void trace_work_fn(struct work_struct *work)
+{
+ /*
+ * Disable tracing for event "sample_event".
+ */
+ trace_array_set_clr_event(tr, "sample-subsystem", "sample_event",
+ false);
+}
+static DECLARE_WORK(trace_work, trace_work_fn);
+
/*
* mytimer: Timer setup to disable tracing for event "sample_event". This
* timer is only for the purposes of the sample module to demonstrate access of
@@ -29,11 +39,7 @@ static DEFINE_TIMER(mytimer, mytimer_handler);
static void mytimer_handler(struct timer_list *unused)
{
- /*
- * Disable tracing for event "sample_event".
- */
- trace_array_set_clr_event(tr, "sample-subsystem", "sample_event",
- false);
+ schedule_work(&trace_work);
}
static void simple_thread_func(int count)
--
2.27.0
