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Bug 2556

Summary: glibc segfaults when using gdb on qt apps (vfprintf problem?)
Product: [Retired] Red Hat Linux Reporter: dcthomp
Component: gdbAssignee: David Lawrence <dkl>
Status: CLOSED CURRENTRELEASE QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: 6.0CC: gafton, pbrown, rwilson, sopwith
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 1999-08-23 01:04:51 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 dcthomp 1999-05-05 04:45:42 UTC
When running gdb on a Qt application, the program will
segfault in vfprintf when printing an initial debug message.
Here's the last two entries in the stack

#0  0x404dd5a8 in main_arena () from /lib/libc.so.6
#1  0x4043df06 in buffered_vfprintf (s=0x404dd500,
format=0x40171ca0 "Qt: gdb: -nograb added to command-line
options.\n\t Use the -dograb option to enforce grabbing.",
args=0xbffff2ac) at vfprintf.c:1752

I set the priority to low because you can get around this by
starting the program with "run -nograb". It seems like it
might be indicative of larger problems, though.

Comment 1 dcthomp 1999-05-06 17:30:59 UTC
The program below will demonstrate the problem. It will run
normally (do nothing) from a command line, but dies when run
from gdb.

#include <qapp.h>
int main( int argc, char** argv )
{
  QApplication a(argc,argv);
  return a.exec();
}

Comment 2 Preston Brown 1999-07-12 16:00:59 UTC
Verified.  GDB 4.18 can debug this program without problems.  I really
suggest we get an update for gdb out the door for 6.0 asap.  It isn't
just Qt -- anyone debugging moderately complex C++ applications cannot
debug with Red Hat Linux 6.0.

Comment 3 Preston Brown 1999-07-12 16:49:59 UTC
*** Bug 1772 has been marked as a duplicate of this bug. ***

1. Get the binary at the given URL.
2. gunzip it and run 'gdb linux-midi' (does not need to be run).
3. Type 'print CORBA_tk_null'.
Voila, core dump.


As an aside, why doesn't the package in 5.9 have the x86 hardware breakpoint support? The 5.2 package did.

------- Additional Comments From kingdon@redhat.com  07/12/99 11:12 -------
There is no DNS entry for
http://www.circ.us.eu.org/~sopwith/linux-midi.gz
Does this test case have a new location?

Comment 4 Jim Kingdon 1999-08-23 01:04:59 UTC
Please try gdb-4.18-3 which is now in Rawhide.