diff options
Diffstat (limited to 'kernel/trace/fgraph.c')
| -rw-r--r-- | kernel/trace/fgraph.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 8d925cbdce3a..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) { @@ -1382,6 +1386,8 @@ int register_ftrace_graph(struct fgraph_ops *gops) /* Always save the function, and reset at unregistering */ gops->saved_func = gops->entryfunc; + gops->ops.flags |= FTRACE_OPS_FL_GRAPH; + ret = ftrace_startup_subops(&graph_ops, &gops->ops, command); if (!ret) fgraph_array[i] = gops; @@ -1399,17 +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; @@ -1432,4 +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; } |