From: Li Liu <john.li...@huawei.com> Eeay to reproduce, just try "qemu -monitor stdio -nographic" and type "quit", then the terminal will be crashed.
There are two pathes try to call tcgetattr of stdio in vl.c: 1) Monitor_parse(optarg, "readline"); ..... qemu_opts_foreach(qemu_find_opts("chardev"), chardev_init_func, NULL, 1) != 0) 2) if (default_serial) add_device_config(DEV_SERIAL, "stdio"); .... if (foreach_device_config(DEV_SERIAL, serial_parse) < 0) Both of them will trigger qemu_chr_open_stdio which will disable ECHO attributes. First one has updated the attributes of stdio by calling qemu_chr_fe_set_echo(chr, false). And the tty attributes has been saved in oldtty. Then the second path will redo such actions, and the oldtty is overlapped. So till "quit", term_exit can't recove the correct attributes. Signed-off-by: Li Liu <john.li...@huawei.com> --- changes v1 -> v2: 1) as Markus Armbruster and Gerd Hoffmann suggested : Multiple character devices can't use the same terminal. So catch and reject the attempt if stdio is opened already. --- qemu-char.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/qemu-char.c b/qemu-char.c index d4f327a..f8f0c48 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -1017,6 +1017,7 @@ static CharDriverState *qemu_chr_open_pipe(ChardevHostdev *opts) /* init terminal so that we can grab keys */ static struct termios oldtty; static int old_fd0_flags; +static bool stdio_is_ready; static bool stdio_allow_signal; static void term_exit(void) @@ -1060,8 +1061,15 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts) error_report("cannot use stdio with -daemonize"); return NULL; } + + if (stdio_is_ready) { + error_report("cannot use stdio by multiple character devices"); + exit(1); + } + + stdio_is_ready = true; old_fd0_flags = fcntl(0, F_GETFL); - tcgetattr (0, &oldtty); + tcgetattr(0, &oldtty); qemu_set_nonblock(0); atexit(term_exit); -- 1.7.9.5