[PATCH v3 1/2] char-stdio: avoid closing stdio fds

[Filip Hejsek <filip.hejsek@gmail.com>]

Use a duplicate of stdin and stdout fds to avoid closing the standard
descriptors when the stdio chardev is destroyed.

Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
---
 chardev/char-stdio.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/chardev/char-stdio.c b/chardev/char-stdio.c
index f63bf413c7..16b49fd924 100644
--- a/chardev/char-stdio.c
+++ b/chardev/char-stdio.c
@@ -114,6 +114,7 @@ static bool stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
     StdioChardev *s = STDIO_CHARDEV(chr);
     ChardevStdio *opts = backend->u.stdio.data;
     struct sigaction act;
+    int fd_in, fd_out;
 
     if (is_daemonized()) {
         error_setg(errp, "cannot use stdio with -daemonize");
@@ -133,7 +134,20 @@ static bool stdio_chr_open(Chardev *chr, ChardevBackend *backend, Error **errp)
         return false;
     }
 
-    if (!qemu_chr_open_fd(chr, 0, 1, errp)) {
+    fd_in = qemu_dup(0);
+    if (fd_in < 0) {
+        error_setg_errno(errp, errno, "Failed to dup stdin fd");
+        return false;
+    }
+    fd_out = qemu_dup(1);
+    if (fd_out < 0) {
+        error_setg_errno(errp, errno, "Failed to dup stdout fd");
+        qemu_close(fd_in);
+        return false;
+    }
+    if (!qemu_chr_open_fd(chr, fd_in, fd_out, errp)) {
+        qemu_close(fd_in);
+        qemu_close(fd_out);
         return false;
     }
 

-- 
2.56.0