ftrace: Clean comments related to FTRACE_OPS_FL_PER_CPU

Commit b3a88803 ("ftrace: Kill FTRACE_OPS_FL_PER_CPU") didn't
completely remove the comments related to FTRACE_OPS_FL_PER_CPU.

Link: https://lkml.kernel.org/r/20221025153923.1995973-1-zhengyejian1@huawei.com

Fixes: b3a88803 ("ftrace: Kill FTRACE_OPS_FL_PER_CPU")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -163,7 +163,7 @@ static void ftrace_sync_ipi(void *data)
 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
 {
 	/*
-	 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
+	 * If this is a dynamic or RCU ops, or we force list func,
 	 * then it needs to call the list anyway.
 	 */
 	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
@@ -3071,8 +3071,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	/*
 	 * Dynamic ops may be freed, we must make sure that all
 	 * callers are done before leaving this function.
-	 * The same goes for freeing the per_cpu data of the per_cpu
-	 * ops.
 	 */
 	if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
 		/*
@@ -7519,8 +7517,6 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 		/*
 		 * Check the following for each ops before calling their func:
 		 *  if RCU flag is set, then rcu_is_watching() must be true
-		 *  if PER_CPU is set, then ftrace_function_local_disable()
-		 *                          must be false
 		 *  Otherwise test if the ip matches the ops filter
 		 *
 		 * If any of the above fails then the op->func() is not executed.
@@ -7570,8 +7566,8 @@ NOKPROBE_SYMBOL(arch_ftrace_ops_list_func);
 
 /*
  * If there's only one function registered but it does not support
- * recursion, needs RCU protection and/or requires per cpu handling, then
- * this function will be called by the mcount trampoline.
+ * recursion, needs RCU protection, then this function will be called
+ * by the mcount trampoline.
  */
 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
 				   struct ftrace_ops *op, struct ftrace_regs *fregs)