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Diffstat (limited to 'kernel/trace/trace_event_perf.c')
-rw-r--r--kernel/trace/trace_event_perf.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index cb6f365..e6f6588 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -116,7 +116,7 @@ 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 +132,9 @@ 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 +143,12 @@ 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 +158,8 @@ 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 +178,7 @@ __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));