[PATCH v2 2/3] fgraph: Check ftrace_pids_enabled on registration for early filtering

wang.yaxin@zte.com.cn posted 3 patches 5 days, 14 hours ago
[PATCH v2 2/3] fgraph: Check ftrace_pids_enabled on registration for early filtering
Posted by wang.yaxin@zte.com.cn 5 days, 14 hours ago
From: Shengming Hu <hu.shengming@zte.com.cn>
When registering ftrace_graph, check if ftrace_pids_enabled is active.
If enabled, assign entryfunc to fgraph_pid_func to ensure filtering
is performed before executing the saved original entry function.

Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
---
 kernel/trace/fgraph.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index f6f25d81a..65ac0f04a 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1369,6 +1369,13 @@ int register_ftrace_graph(struct fgraph_ops *gops)

 	ftrace_graph_active++;

+	/* Always save the function, and reset at unregistering */
+	gops->saved_func = gops->entryfunc;
+#ifdef CONFIG_DYNAMIC_FTRACE
+	if (ftrace_pids_enabled(&gops->ops))
+		gops->entryfunc = fgraph_pid_func;
+#endif
+
 	if (ftrace_graph_active == 2)
 		ftrace_graph_disable_direct(true);

@@ -1388,8 +1395,6 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 	} else {
 		init_task_vars(gops->idx);
 	}
-	/* Always save the function, and reset at unregistering */
-	gops->saved_func = gops->entryfunc;

 	gops->ops.flags |= FTRACE_OPS_FL_GRAPH;

-- 
2.25.1