diff options
| -rw-r--r-- | kernel/trace/trace.h | 3 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 13 |
2 files changed, 16 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 217207ad60b3..9e82551dd566 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -252,6 +252,9 @@ static inline struct trace_array *top_trace_array(void) { struct trace_array *tr; + if (list_empty(ftrace_trace_arrays.prev)) + return NULL; + tr = list_entry(ftrace_trace_arrays.prev, typeof(*tr), list); WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3ddfd8f62c05..f99e0b3bca8c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -574,6 +574,9 @@ int trace_set_clr_event(const char *system, const char *event, int set) { struct trace_array *tr = top_trace_array(); + if (!tr) + return -ENODEV; + return __ftrace_set_clr_event(tr, NULL, system, event, set); } EXPORT_SYMBOL_GPL(trace_set_clr_event); @@ -2065,6 +2068,9 @@ event_enable_func(struct ftrace_hash *hash, bool enable; int ret; + if (!tr) + return -ENODEV; + /* hash funcs only work with set_ftrace_filter */ if (!enabled || !param) return -EINVAL; @@ -2396,6 +2402,9 @@ static __init int event_trace_enable(void) char *token; int ret; + if (!tr) + return -ENODEV; + for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { call = *iter; @@ -2442,6 +2451,8 @@ static __init int event_trace_init(void) int ret; tr = top_trace_array(); + if (!tr) + return -ENODEV; d_tracer = tracing_init_dentry(); if (!d_tracer) @@ -2535,6 +2546,8 @@ static __init void event_trace_self_tests(void) int ret; tr = top_trace_array(); + if (!tr) + return; pr_info("Running tests on trace events:\n"); |
