diff options
Diffstat (limited to 'kernel/trace/trace_dynevent.c')
| -rw-r--r-- | kernel/trace/trace_dynevent.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index e57cc0870892..e34e8182ee4b 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -13,11 +13,49 @@ #include <linux/tracefs.h> #include "trace.h" +#include "trace_output.h" /* for trace_event_sem */ #include "trace_dynevent.h" static DEFINE_MUTEX(dyn_event_ops_mutex); static LIST_HEAD(dyn_event_ops_list); +bool trace_event_dyn_try_get_ref(struct trace_event_call *dyn_call) +{ + struct trace_event_call *call; + bool ret = false; + + if (WARN_ON_ONCE(!(dyn_call->flags & TRACE_EVENT_FL_DYNAMIC))) + return false; + + down_read(&trace_event_sem); + list_for_each_entry(call, &ftrace_events, list) { + if (call == dyn_call) { + atomic_inc(&dyn_call->refcnt); + ret = true; + } + } + up_read(&trace_event_sem); + return ret; +} + +void trace_event_dyn_put_ref(struct trace_event_call *call) +{ + if (WARN_ON_ONCE(!(call->flags & TRACE_EVENT_FL_DYNAMIC))) + return; + + if (WARN_ON_ONCE(atomic_read(&call->refcnt) <= 0)) { + atomic_set(&call->refcnt, 0); + return; + } + + atomic_dec(&call->refcnt); +} + +bool trace_event_dyn_busy(struct trace_event_call *call) +{ + return atomic_read(&call->refcnt) != 0; +} + int dyn_event_register(struct dyn_event_operations *ops) { if (!ops || !ops->create || !ops->show || !ops->is_busy || @@ -224,7 +262,7 @@ static __init int init_dynamic_event(void) if (ret) return 0; - entry = tracefs_create_file("dynamic_events", 0644, NULL, + entry = tracefs_create_file("dynamic_events", TRACE_MODE_WRITE, NULL, NULL, &dynamic_events_ops); /* Event list interface */ |