function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled

The ftrace subops is only defined if CONFIG_DYNAMIC_FTRACE is enabled. If
it is not, function tracing is extremely limited, and the subops in the
ftrace_ops structure is not defined (and will fail to compile). If
DYNAMIC_FTRACE is not enabled, then function graph filtering will not
work (as it shouldn't).

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

Cc: Mark Rutland <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Andrew Morton <[email protected]>
Fixes: df3ec5d ("function_graph: Add pid tracing back to function graph tracer")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: rostedt

kernel/trace/fgraph.c

@@ -1177,6 +1177,7 @@ void fgraph_update_pid_func(void)
 	if (!(graph_ops.flags & FTRACE_OPS_FL_INITIALIZED))
 		return;
 
+#ifdef CONFIG_DYNAMIC_FTRACE
 	list_for_each_entry(op, &graph_ops.subop_list, list) {
 		if (op->flags & FTRACE_OPS_FL_PID) {
 			gops = container_of(op, struct fgraph_ops, ops);
@@ -1186,6 +1187,7 @@ void fgraph_update_pid_func(void)
 				static_call_update(fgraph_func, gops->entryfunc);
 		}
 	}
+#endif
 }
 
 /* Allocate a return stack for each task */