[PATCH 6.12 368/567] fgraph: Initialize ftrace_ops->private for function graph ops

Greg Kroah-Hartman
2026-01-06T17:34:36Z

From: Shengming Hu <hu.shengming@zte.com.cn>

commit b5d6d3f73d0bac4a7e3a061372f6da166fc6ee5c upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/fgraph.c | 1 +
1 file changed, 1 insertion(+)

--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -943,6 +943,7 @@ void fgraph_init_ops(struct ftrace_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
}