bin/45478: /bin/sh coredump

[Giorgos Keramidas]

The following reply was made to PR bin/45478; it has been noted by GNATS.

From: Giorgos Keramidas <keramida at freebsd.org>
To: Oliver Fromme <olli at secnetix.de>
Cc: bug-followup at freebsd.org, Oliver Fromme <olli at fromme.com>
Subject: Re: bin/45478: /bin/sh coredump
Date: Fri, 15 Apr 2005 18:52:32 +0300

 On 2002-11-19 13:43, Oliver Fromme <olli at secnetix.de> wrote:
 > Responsible-Changed-By: tjr
 > Responsible-Changed-Why:
 > I believe this is caused by the SIGINT handler longjmp()'ing
 > out when it's in the middle of a malloc() call. Calls to malloc()
 > and free() should be bracketed in INTON and INTOFF.
 >
 > I haven't had much luck tracking this down in the past, but
 > I'll try again to find the missing INTON/INTOFF.
 
 I just happened to stumble upon this bug today.  It's still with us in
 FreeBSD 6.0-CURRENT.  It seems that the inner for loop in the following:
 
 	while for true; do false; done; do true; done
 
 is not stopped by sh(1) when ^C is hit.  Even after the interrupt is
 received, sh consumes at least 5-15% of CPU on my test here, while it
 appears to be sitting at a PS1 prompt, waiting for more input.
 
   PID USERNAME   THR PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU COMMAND
  2352 keramida     1   5    0  1668K  1192K ttyin    0:03 25.48% 10.79% sh
 
 After a few of these commands have been run, sh may reach CPU
 utilizations of even more:
 
   PID USERNAME   THR PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU COMMAND
  2352 keramida     1 123    0  1672K  1196K RUN      1:11 63.21% 63.18% sh