fgraph: Initialize ftrace_ops->private for function graph ops

The ftrace_pids_enabled(op) check relies on op->private being properly
initialized, but fgraph_ops's underlying ftrace_ops->private was left
uninitialized. This caused ftrace_pids_enabled() to always return false,
effectively disabling PID filtering for function graph tracing.

Fix this by copying src_ops->private to dst_ops->private in
fgraph_init_ops(), ensuring PID filter state is correctly propagated.

Cc: stable@vger.kernel.org
Cc: <wang.yaxin@zte.com.cn>
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <zhang.run@zte.com.cn>
Cc: <yang.yang29@zte.com.cn>
Fixes: c132be2c4fcc1 ("function_graph: Have the instances use their own ftrace_ops for filtering")
Link: https://patch.msgid.link/20251126172926004y3hC8QyU4WFOjBkU_UxLC@zte.com.cn
Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 484ad7a18463a9637fbde170dd79a7f7b782bf5b..d6222bb99d1d758004532497323a966650c8cb51 100644 (file)
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1019,6 +1019,7 @@ void fgraph_init_ops(struct ftrace_ops *dst_ops,
                mutex_init(&dst_ops->local_hash.regex_lock);
                INIT_LIST_HEAD(&dst_ops->subop_list);
                dst_ops->flags |= FTRACE_OPS_FL_INITIALIZED;
+               dst_ops->private = src_ops->private;
        }
 #endif
 }