From 1507bd136fd9a516226fce8738d361a64f45b699 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Mon, 4 Jun 2018 13:30:43 +0100 Subject: [PATCH] chardev: don't splatter terminal settings on exit if not previously set MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The stdio chardev finalize method calls term_exit() to restore the original terminal settings that were saved in the "oldtty" global. If the qemu_chr_open_stdio() method exited with an error, we might not have any original terminal settings saved in "oldtty" yet. eg $ qemu-system-x86_64 -monitor stdio -daemonize qemu-system-x86_64: -monitor stdio: cannot use stdio with -daemonize will cause QEMU to splatter the terminal settings with an all-zeros "struct termios", with predictably unpleasant results. Fortunately the existing "stdio_in_use" flag is suitable witness for whether "oldtty" contains settings that need restoring. Signed-off-by: Daniel P. Berrangé Message-Id: <20180604123043.13985-1-berrange@redhat.com> Reviewed-by: Marc-André Lureau Signed-off-by: Paolo Bonzini --- chardev/char-stdio.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/chardev/char-stdio.c b/chardev/char-stdio.c index 96375f2ab8..9624220e6d 100644 --- a/chardev/char-stdio.c +++ b/chardev/char-stdio.c @@ -46,8 +46,10 @@ static bool stdio_echo_state; static void term_exit(void) { - tcsetattr(0, TCSANOW, &oldtty); - fcntl(0, F_SETFL, old_fd0_flags); + if (stdio_in_use) { + tcsetattr(0, TCSANOW, &oldtty); + fcntl(0, F_SETFL, old_fd0_flags); + } } static void qemu_chr_set_echo_stdio(Chardev *chr, bool echo)