1 files changed, 15 insertions, 4 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index cb6f365016e4..8a2b73f7c068 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -96,7 +96,9 @@ int perf_trace_init(struct perf_event *p_event)
         mutex_lock(&event_mutex);
         list_for_each_entry(tp_event, &ftrace_events, list) {
                 if (tp_event->event.type == event_id &&
-                    tp_event->class && tp_event->class->perf_probe &&
+                    tp_event->class &&
+                    (tp_event->class->perf_probe ||
+                     tp_event->class->reg) &&
                     try_module_get(tp_event->mod)) {
                         ret = perf_trace_event_init(tp_event, p_event);
                         break;
@@ -116,7 +118,7 @@ int perf_trace_enable(struct perf_event *p_event)
         if (WARN_ON_ONCE(!list))
                 return -EINVAL;
 
-        list = per_cpu_ptr(list, smp_processor_id());
+        list = this_cpu_ptr(list);
         hlist_add_head_rcu(&p_event->hlist_entry, list);
 
         return 0;
@@ -132,8 +134,9 @@ void perf_trace_destroy(struct perf_event *p_event)
         struct ftrace_event_call *tp_event = p_event->tp_event;
         int i;
 
+        mutex_lock(&event_mutex);
         if (--tp_event->perf_refcount > 0)
-                return;
+                goto out;
 
         if (tp_event->class->reg)
                 tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER);
@@ -142,6 +145,12 @@ void perf_trace_destroy(struct perf_event *p_event)
                                             tp_event->class->perf_probe,
                                             tp_event);
 
+        /*
+         * Ensure our callback won't be called anymore. See
+         * tracepoint_probe_unregister() and __DO_TRACE().
+         */
+        synchronize_sched();
+
         free_percpu(tp_event->perf_events);
         tp_event->perf_events = NULL;
 
@@ -151,6 +160,8 @@ void perf_trace_destroy(struct perf_event *p_event)
                         perf_trace_buf[i] = NULL;
                 }
         }
+out:
+        mutex_unlock(&event_mutex);
 }
 
 __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
@@ -169,7 +180,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
         if (*rctxp < 0)
                 return NULL;
 
-        raw_data = per_cpu_ptr(perf_trace_buf[*rctxp], smp_processor_id());
+        raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]);
 
         /* zero the dead bytes from align to not leak stack to user */
         memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));