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Re: [Qemu-devel] [PATCH] qemu-char: fix terminal crash when using "-moni
From: |
Li Liu |
Subject: |
Re: [Qemu-devel] [PATCH] qemu-char: fix terminal crash when using "-monitor stdio -nographic" |
Date: |
Wed, 27 Aug 2014 15:40:45 +0800 |
User-agent: |
Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 |
On 2014/8/27 14:44, Markus Armbruster wrote:
> "john.liuli" <address@hidden> writes:
>
>> From: Li Liu <address@hidden>
>>
>> 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 <address@hidden>
>
> Yes, failure to restore tty settings is a bug.
>
> But is having multiple character devices use the same terminal valid?
I'm not sure. But I have found such comments in vl.c
"According to documentation and historically, -nographic redirects
serial port, parallel port and monitor to stdio"
Best regards
Li.
> If no, can we catch and reject the attempt?
>
> [...]
>
>