From f57a5a68022684d76c435f8f91fc5d0338d158d3 Mon Sep 17 00:00:00 2001
From: zhangshoukui <zhangshoukui@xiaomi.com>
Date: Fri, 9 May 2025 15:49:36 +0800
Subject: [PATCH] fs/vfs/fs_dup.c: before file_allocate should restore minfd if
 define FDCHECK
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When we use fcntl for dup, an fd is directly passed. If we have opened FDCHECK. we need to restore this file descriptor.

open FDCHECK and test this：

`
int main(int ac, char **av)
{
  int fd1= open("./1.txt", O_WRONLY | O_CREAT, 0666);
  if (fd1 < 0)
    {
      printf("open err\n");
      return fd1;
  }

  int fd2= open("./2.txt", O_WRONLY | O_CREAT, 0666);
  if (fd2 < 0)
    {
      printf("open err\n");
      close(fd1);
      return fd2;
    }

  //close(fd2);
  int fd3 = fcntl(fd1, F_DUPFD, fd2);
  printf("fd3 = %d\n", fd3);
  close(fd1);
  close(fd3);
  return 0;
}
`

Signed-off-by: zhangshoukui <zhangshoukui@xiaomi.com>
---
 fs/vfs/fs_dup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/vfs/fs_dup.c b/fs/vfs/fs_dup.c
index 3b2492ba4a8..56f0454b876 100644
--- a/fs/vfs/fs_dup.c
+++ b/fs/vfs/fs_dup.c
@@ -63,6 +63,8 @@ int file_dup(FAR struct file *filep, int minfd, int flags)
 
 #ifdef CONFIG_FDCHECK
   uint8_t f_tag_fdcheck; /* File owner fdcheck tag, init to 0 */
+
+  minfd = fdcheck_restore(minfd);
 #endif
 
   fd2 = file_allocate(g_root_inode, 0, 0, NULL, minfd, true);