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-rw-r--r--kernel/trace/trace.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7a93c663e52a..33549537f30f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -44,13 +44,14 @@
44unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; 44unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
45unsigned long __read_mostly tracing_thresh; 45unsigned long __read_mostly tracing_thresh;
46 46
47/* We need to change this state when a selftest is running. 47/*
48 * We need to change this state when a selftest is running.
48 * A selftest will lurk into the ring-buffer to count the 49 * A selftest will lurk into the ring-buffer to count the
49 * entries inserted during the selftest although some concurrent 50 * entries inserted during the selftest although some concurrent
50 * insertions into the ring-buffer such as ftrace_printk could occurred 51 * insertions into the ring-buffer such as ftrace_printk could occurred
51 * at the same time, giving false positive or negative results. 52 * at the same time, giving false positive or negative results.
52 */ 53 */
53static atomic_t tracing_selftest_running = ATOMIC_INIT(0); 54static bool __read_mostly tracing_selftest_running;
54 55
55/* For tracers that don't implement custom flags */ 56/* For tracers that don't implement custom flags */
56static struct tracer_opt dummy_tracer_opt[] = { 57static struct tracer_opt dummy_tracer_opt[] = {
@@ -574,6 +575,8 @@ int register_tracer(struct tracer *type)
574 unlock_kernel(); 575 unlock_kernel();
575 mutex_lock(&trace_types_lock); 576 mutex_lock(&trace_types_lock);
576 577
578 tracing_selftest_running = true;
579
577 for (t = trace_types; t; t = t->next) { 580 for (t = trace_types; t; t = t->next) {
578 if (strcmp(type->name, t->name) == 0) { 581 if (strcmp(type->name, t->name) == 0) {
579 /* already found */ 582 /* already found */
@@ -598,7 +601,6 @@ int register_tracer(struct tracer *type)
598 struct trace_array *tr = &global_trace; 601 struct trace_array *tr = &global_trace;
599 int i; 602 int i;
600 603
601 atomic_set(&tracing_selftest_running, 1);
602 /* 604 /*
603 * Run a selftest on this tracer. 605 * Run a selftest on this tracer.
604 * Here we reset the trace buffer, and set the current 606 * Here we reset the trace buffer, and set the current
@@ -613,7 +615,6 @@ int register_tracer(struct tracer *type)
613 /* the test is responsible for initializing and enabling */ 615 /* the test is responsible for initializing and enabling */
614 pr_info("Testing tracer %s: ", type->name); 616 pr_info("Testing tracer %s: ", type->name);
615 ret = type->selftest(type, tr); 617 ret = type->selftest(type, tr);
616 atomic_set(&tracing_selftest_running, 0);
617 /* the test is responsible for resetting too */ 618 /* the test is responsible for resetting too */
618 current_trace = saved_tracer; 619 current_trace = saved_tracer;
619 if (ret) { 620 if (ret) {
@@ -635,6 +636,7 @@ int register_tracer(struct tracer *type)
635 max_tracer_type_len = len; 636 max_tracer_type_len = len;
636 637
637 out: 638 out:
639 tracing_selftest_running = false;
638 mutex_unlock(&trace_types_lock); 640 mutex_unlock(&trace_types_lock);
639 lock_kernel(); 641 lock_kernel();
640 642
@@ -3605,7 +3607,7 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
3605 unsigned long flags, irq_flags; 3607 unsigned long flags, irq_flags;
3606 int cpu, len = 0, size, pc; 3608 int cpu, len = 0, size, pc;
3607 3609
3608 if (tracing_disabled || atomic_read(&tracing_selftest_running)) 3610 if (tracing_disabled || tracing_selftest_running)
3609 return 0; 3611 return 0;
3610 3612
3611 pc = preempt_count(); 3613 pc = preempt_count();