Bug 84954

Summary: strace sometimes leaves processes in "STOPPED" state
Product: [Retired] Red Hat Linux Reporter: Henning Schmiedehausen <hps>
Component: straceAssignee: Roland McGrath <roland>
Status: CLOSED DUPLICATE QA Contact: Brian Brock <bbrock>
Severity: high Docs Contact:
Priority: medium    
Version: 7.3   
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-02-21 18:51:57 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Henning Schmiedehausen 2003-02-24 10:10:28 UTC
From Bugzilla Helper:
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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:

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 $$

window2%  strace -f -p 28305

Now enter ^C in window2

And in window1:
[1]+  Stopped                 bash

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).

Comment 1 Roland McGrath 2003-02-24 21:14:36 UTC

*** This bug has been marked as a duplicate of 71166 ***

Comment 2 Red Hat Bugzilla 2006-02-21 18:51:57 UTC
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.