Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...

[net-next-2.6.git] / kernel / trace / trace_event_perf.c

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 21db1d3a48d072ed7978a216689f0fee6f5cc6d6..4799d7047eb0f0e40c8c91f53cf244b6a08642e6 100644 (file)
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -114,7 +114,7 @@ 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;
@@ -130,8 +130,9 @@ 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);
@@ -140,6 +141,12 @@ 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;
 
@@ -149,6 +156,8 @@ 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,
@@ -167,7 +176,7 @@ __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));