From 5c5f1dec08390cbb92484a2efbd2cbe5b75b3188 Mon Sep 17 00:00:00 2001
From: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Mon, 31 Jan 2022 23:19:44 +0800
Subject: [PATCH] sched: Don't duplicate caller file handler when creating
 kernel thread

kernel thread should have only the starndard file i/o just like idle thread

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
---
 fs/inode/fs_files.c                | 26 +++++++++++++++-----------
 include/nuttx/fs/fs.h              |  3 ++-
 sched/group/group_setuptaskfiles.c | 16 ++++++++++------
 3 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/fs/inode/fs_files.c b/fs/inode/fs_files.c
index 50ec037b78..96116546d0 100644
--- a/fs/inode/fs_files.c
+++ b/fs/inode/fs_files.c
@@ -250,7 +250,8 @@ int files_allocate(FAR struct inode *inode, int oflags, off_t pos,
  *
  ****************************************************************************/
 
-int files_duplist(FAR struct filelist *plist, FAR struct filelist *clist)
+int files_duplist(FAR struct filelist *plist,
+                  FAR struct filelist *clist, bool stdio_only)
 {
   int ret;
   int i;
@@ -264,25 +265,28 @@ int files_duplist(FAR struct filelist *plist, FAR struct filelist *clist)
       return ret;
     }
 
+#ifdef CONFIG_FDCLONE_STDIO
+
+  /* Determine how many file descriptors to clone.  If
+   * CONFIG_FDCLONE_DISABLE is set, no file descriptors will be
+   * cloned.  If CONFIG_FDCLONE_STDIO is set, only the first
+   * three descriptors (stdin, stdout, and stderr) will be
+   * cloned.  Otherwise all file descriptors will be cloned.
+   */
+
+  stdio_only = true;
+#endif
+
   for (i = 0; i < plist->fl_rows; i++)
     {
       for (j = 0; j < CONFIG_NFILE_DESCRIPTORS_PER_BLOCK; j++)
         {
           FAR struct file *filep;
-#ifdef CONFIG_FDCLONE_STDIO
 
-          /* Determine how many file descriptors to clone.  If
-           * CONFIG_FDCLONE_DISABLE is set, no file descriptors will be
-           * cloned.  If CONFIG_FDCLONE_STDIO is set, only the first
-           * three descriptors (stdin, stdout, and stderr) will be
-           * cloned.  Otherwise all file descriptors will be cloned.
-           */
-
-          if (i * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK + j >= 3)
+          if (stdio_only && i * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK + j >= 3)
             {
               goto out;
             }
-#endif
 
           filep = &plist->fl_files[i][j];
           if (filep->f_inode == NULL || (filep->f_oflags & O_CLOEXEC) != 0)
diff --git a/include/nuttx/fs/fs.h b/include/nuttx/fs/fs.h
index 2408077641..cde396ff53 100644
--- a/include/nuttx/fs/fs.h
+++ b/include/nuttx/fs/fs.h
@@ -759,7 +759,8 @@ void files_releaselist(FAR struct filelist *list);
  *
  ****************************************************************************/
 
-int files_duplist(FAR struct filelist *plist, FAR struct filelist *clist);
+int files_duplist(FAR struct filelist *plist,
+                  FAR struct filelist *clist, bool stdio_only);
 
 /****************************************************************************
  * Name: file_dup
diff --git a/sched/group/group_setuptaskfiles.c b/sched/group/group_setuptaskfiles.c
index ca9a8e886b..4f55fba6ca 100644
--- a/sched/group/group_setuptaskfiles.c
+++ b/sched/group/group_setuptaskfiles.c
@@ -57,16 +57,14 @@
 int group_setuptaskfiles(FAR struct task_tcb_s *tcb)
 {
   FAR struct task_group_s *group = tcb->cmn.group;
+  uint8_t ttype = tcb->cmn.flags & TCB_FLAG_TTYPE_MASK;
 #ifndef CONFIG_FDCLONE_DISABLE
   FAR struct tcb_s *rtcb = this_task();
   int ret;
 #endif
 
   DEBUGASSERT(group);
-#ifndef CONFIG_DISABLE_PTHREAD
-  DEBUGASSERT((tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) !=
-              TCB_FLAG_TTYPE_PTHREAD);
-#endif
+  DEBUGASSERT(ttype != TCB_FLAG_TTYPE_PTHREAD);
 
   /* Initialize file descriptors for the TCB */
 
@@ -75,9 +73,15 @@ int group_setuptaskfiles(FAR struct task_tcb_s *tcb)
 #ifndef CONFIG_FDCLONE_DISABLE
   DEBUGASSERT(rtcb->group);
 
-  /* Duplicate the parent task's file descriptors */
+  /* Duplicate the parent task's file descriptors.
+   * If it's a kernel thread, only the first three
+   * descriptors (stdin, stdout, and stderr) will
+   * be cloned.
+   */
 
-  ret = files_duplist(&rtcb->group->tg_filelist, &group->tg_filelist);
+  ret = files_duplist(&rtcb->group->tg_filelist,
+                      &group->tg_filelist,
+                      ttype == TCB_FLAG_TTYPE_KERNEL);
   if (ret < 0)
     {
       return ret;