diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2025-07-01 19:44:51 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-07-22 20:06:02 -0400 |
| commit | 218d372ce8d56c08f08d028e4c7845bc121e719f (patch) | |
| tree | 7bc7eabf5ee0409aa0a919e6640da1da99f27185 | |
| parent | 437889b926b30093048eba31cd1fde00ca8df316 (diff) | |
fgraph: Keep track of when fgraph_ops are registered or not
Add a warning if unregister_ftrace_graph() is called without ever
registering it, or if register_ftrace_graph() is called twice. This can
detect errors when they happen and not later when there's a side effect:
Link: https://lore.kernel.org/all/20250617120830.24fbdd62@gandalf.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250701194451.22e34724@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/fgraph.c | 16 |
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; } |