Bug 84954

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Description of problem:
Tracing a live process with -p <pid> sometimes puts this process
into "STOPPED" state and doesn't resume it when strace is finished.

This seems to be a known bug in strace-4.4 (in the current release
4.4.94 there is

* Fixed bugs with attach/detach leaving things stopped.

in the NEWS file.



Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Open two windows on a RH 7.3 host.
2. Start a new bash in one of the windows. Get its PID with echo $$
3. Trace this new shell from the second window. In my example:

window1%  bash
window1%  echo $$
28305

window2%  strace -f -p 28305
read(0, 

Now enter ^C in window2
window2%

And in window1:
[1]+  Stopped                 bash
bash-2.05a$ 
   

Actual Results:  ===> The bash gets stopped and never restarted by the strace. 


Expected Results:  The bash should continue running after the tracer detached.



Additional info:

This is ugly for an interactive process like "bash" and deadly
for a daemon process.

I put this bug on "high" level, because "normal" admins might trace
daemon processes like sendmail or named to check for problems and
suddently the daemon process no longer runs (because it stays in
stopped state).