Control: found -1 4.6.2-3+deb10u1
Control: found -1 4.8.0-6
>>>>> On 2004-04-06 22:31:43 -0400, Allan Wind wrote:
> Package: screen
> Version: 4.0.2-3
> Severity: normal
> I have been seeing an issue for a while, where screen appears to be
> going into a busy loop when pasting data into vim. Not exactly sure
> how to reproduce this, but something along these lines seem to always
> work when the data is important (but I cannot reproduce it consistently):
[…]
> When it works, it takes ~3 sec paste the 10k lines on my box, and when
> you hit the issue I never seen it terminate.
I was able to reproduce it with both 4.6.2-3+deb10u1 and 4.8.0-6;
it seems, however, that an important part is to signal Screen
while it sends the data down to the application; such as with:
1. $ seq 1 0x100000 | fmt -w78 > /tmp/screen-exchange .
2. $ screen ; then load the file with C-a < .
3. $ vim.tiny ; start pasting the data there with C-a ] .
4. Press ^C while Screen is still sending the data.
5. Screen appears to enter an infinite loop: 100% CPU
utilization, no syscalls seen via strace(1), etc.
Given that this bug effectively results in the loss of a given
Screen session, possibly with all the (‘unsaved’) data therein,
I believe it deserves a higher Severity: .
(Could #524304 be possibly related?)
As a workaround, some applications may be salvaged with
reptyr(1); like:
1. Find out the PID of the ‘broken’ session:
$ pgrep --full -u"$(id -u)" -- ^SCREEN\\b
1234
$
(It’s possible to $ kill -STOP the process here so that it no
longer consumes CPU cycles.)
2. Find out the PIDs of the programs running under:
$ pstree -Apl -- 1234
screen(1234)-+-vim(2468)
`-lynx(5678)
3. Move said programs to another Screen session:
$ screen -t vim 10 reptyr -V -- 2468
$ screen -t lynx 11 reptyr -V -- 5678
4. Once all the programs are recovered, terminate their original
Screen instance:
$ kill -- 1234
(If the process was stopped before, as suggested above, also
resume it with $ kill -CONT , so it can process the signal
sent and terminate.)
--
FSF associate member #7257 http://am-1.org/~ivan/
