Latest stable (r287104) bash leaves zombies on exit

[Konstantin Belousov]

On Thu, Aug 27, 2015 at 02:04:05PM +0200, Mark Martinec wrote:
> Pete French wrote:
> 
> > I updated to stable yesterday, plus updated all my porst to
> > the latest pecompiled packages, but I am now seeing odd problems
> > with bash on exit. Sometimes it quits, but leaves a zombie
> > process... e.g
> > 
> >  PID TT  STAT    TIME COMMAND
> > 44308 v0  IW   0:00.00 -bash (bash)
> > 44312 v0  IW+  0:00.00 /bin/sh /usr/local/bin/startx -listen_tcp
> > 44325 v0  IW+  0:00.00 xinit xterm -listen_tcp -- /usr/local/bin/X :0 
> > -auth /ho
> > 44328 v0  IW   0:00.00 /usr/local/bin/wmaker
> > 44340 v0  S    0:03.35 /usr/local/bin/wmaker --for-real
> > 49101  0- Z+   0:02.73 <defunct>
> > 49314  1- Z+   0:00.17 <defunct>
> > 56068  2  Ss   0:00.01 bash
> > 56498  2  R+   0:00.00 ps
> > 56074  3  Is   0:00.01 bash
> > 56076  3  S+   0:00.00 mail freebsd-stable at freebsd.org
> > 56308  4  Is+  0:00.01 bash
> > 
> > Thats the current 'ps' on this machine. The bash processes are running
> > inside an xterm, so am not sure if the issue is with bash or the
> > terminal. Kind of puzzled!
> 
> I can reproduce this easily, although not every time.
> 
> Running 10.2 under KDE, with bash as a default shell:
> start xterm from a KDE 'konsole', then move to within the xterm
> and try closing it (^D or exit). More often than not the xterm
> will block and stay open, the bash process within goes <defunct>.
> 
> A normal kill of xterm has no effect, although a kill -9 to the
> xterm blows away the xterm and the init process then clears
> the bash zombie leftover. Seems like running a simple command
> like 'date' in xterm before trying to close it does increase
> the likelihood that xterm will block on exit.
> 
> 
> > Currently I have to reboot the machine periodicly once I have 
> > accumulated
> > enough zombies to be annoying. Its not really a long term solution 
> > though.
> 
> There is no need to reboot, just kill -9 the hanging xterm processes
> and the init will clear the zombies.

Try to obtain the backtrace from the hung xterm. Ideally, you would
rebuild xterm and the system libraries (rtld+libc+libthr) with debug
symbols and get the backtraces after that.