From 24f1fdab22421d00393b55617d56915fad3bbda4 Mon Sep 17 00:00:00 2001
From: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
Date: Tue, 25 Jun 2024 13:57:35 +0800
Subject: [PATCH] sched/group/setuptask_file: duplicate idle task fd for kernel
 thread

The file descriptors of kernel threads should be clean and should
not be generated based on user threads. Instead, an idle thread
hould be chosen.

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
---
 sched/group/group_setuptaskfiles.c | 17 +++++++++++++++--
 sched/init/nx_start.c              |  2 +-
 sched/sched/sched.h                | 10 ++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/sched/group/group_setuptaskfiles.c b/sched/group/group_setuptaskfiles.c
index 26624e4ce6139..8b4b07e49d76e 100644
--- a/sched/group/group_setuptaskfiles.c
+++ b/sched/group/group_setuptaskfiles.c
@@ -64,7 +64,7 @@ int group_setuptaskfiles(FAR struct task_tcb_s *tcb,
   FAR struct task_group_s *group = tcb->cmn.group;
   int ret = OK;
 #ifndef CONFIG_FDCLONE_DISABLE
-  FAR struct tcb_s *rtcb = this_task();
+  FAR struct tcb_s *rtcb;
 #endif
 
   sched_trace_begin();
@@ -75,7 +75,20 @@ int group_setuptaskfiles(FAR struct task_tcb_s *tcb,
 #endif
 
 #ifndef CONFIG_FDCLONE_DISABLE
-  DEBUGASSERT(rtcb->group);
+
+  /* The The file descriptors of kernel threads should be clean and
+   * should not be generated based on user threads. Instead, an idle
+   * thread should be chosen.
+   */
+
+  if ((tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL)
+    {
+      rtcb = &g_idletcb[this_cpu()];
+    }
+  else
+    {
+      rtcb = this_task();
+    }
 
   /* Duplicate the parent task's file descriptors */
 
diff --git a/sched/init/nx_start.c b/sched/init/nx_start.c
index 997612739c389..9e3c072067616 100644
--- a/sched/init/nx_start.c
+++ b/sched/init/nx_start.c
@@ -206,7 +206,7 @@ uint8_t g_nx_initstate;  /* See enum nx_initstate_e */
  * bringing up the rest of the system.
  */
 
-static struct tcb_s g_idletcb[CONFIG_SMP_NCPUS];
+struct tcb_s g_idletcb[CONFIG_SMP_NCPUS];
 
 /* This is the name of the idle task */
 
diff --git a/sched/sched/sched.h b/sched/sched/sched.h
index b14c0d50b06a0..660a997fc6c93 100644
--- a/sched/sched/sched.h
+++ b/sched/sched/sched.h
@@ -194,6 +194,16 @@ extern dq_queue_t g_assignedtasks[CONFIG_SMP_NCPUS];
 
 extern FAR struct tcb_s *g_running_tasks[CONFIG_SMP_NCPUS];
 
+/* This is an array of task control block (TCB) for the IDLE thread of each
+ * CPU.  For the non-SMP case, this is a a single TCB; For the SMP case,
+ * there is one TCB per CPU.  NOTE: The system boots on CPU0 into the IDLE
+ * task.  The IDLE task later starts the other CPUs and spawns the user
+ * initialization task.  That user initialization task is responsible for
+ * bringing up the rest of the system.
+ */
+
+extern struct tcb_s g_idletcb[CONFIG_SMP_NCPUS];
+
 /* This is the list of all tasks that are ready-to-run, but cannot be placed
  * in the g_readytorun list because:  (1) They are higher priority than the
  * currently active task at the head of the g_readytorun list, and (2) the