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Diffstat (limited to 'kernel/trace/fgraph.c')
-rw-r--r--kernel/trace/fgraph.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index c5b207992fb4..f4d200f0c610 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1325,6 +1325,10 @@ int register_ftrace_graph(struct fgraph_ops *gops)
int ret = 0;
int i = -1;
+ if (WARN_ONCE(gops->ops.flags & FTRACE_OPS_FL_GRAPH,
+ "function graph ops registered again"))
+ return -EBUSY;
+
guard(mutex)(&ftrace_lock);
if (!fgraph_stack_cachep) {
@@ -1401,17 +1405,21 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
{
int command = 0;
+ if (WARN_ONCE(!(gops->ops.flags & FTRACE_OPS_FL_GRAPH),
+ "function graph ops unregistered without registering"))
+ return;
+
guard(mutex)(&ftrace_lock);
if (unlikely(!ftrace_graph_active))
- return;
+ goto out;
if (unlikely(gops->idx < 0 || gops->idx >= FGRAPH_ARRAY_SIZE ||
fgraph_array[gops->idx] != gops))
- return;
+ goto out;
if (fgraph_lru_release_index(gops->idx) < 0)
- return;
+ goto out;
fgraph_array[gops->idx] = &fgraph_stub;
@@ -1434,4 +1442,6 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
}
gops->saved_func = NULL;
+ out:
+ gops->ops.flags &= ~FTRACE_OPS_FL_GRAPH;
}