From 0c667775fe25eeff988fb5124f390dcf923e93cf Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 19 Feb 2025 13:50:40 -0500 Subject: [PATCH] ftrace: Have ftrace_free_filter() WARN and exit if ops is active The ftrace_free_filter() is used to reset the ops filters. But it must be done if the ops is not currently active (tracing). If it is, it will mess up the ftrace accounting of what functions are attached and what is not. WARN and exit the ftrace_free_filter() if the ops is active when it is called. Currently, it doesn't seem if anything does this, but it may in the future. Link: https://lore.kernel.org/all/20250219095330.2e9f171c@gandalf.local.home/ Cc: Mark Rutland Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250219135040.3a9fbe00@gandalf.local.home Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6b0c25761ccb..de25c0505b6b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1296,6 +1296,8 @@ static void free_ftrace_hash_rcu(struct ftrace_hash *hash) void ftrace_free_filter(struct ftrace_ops *ops) { ftrace_ops_init(ops); + if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) + return; free_ftrace_hash(ops->func_hash->filter_hash); free_ftrace_hash(ops->func_hash->notrace_hash); }