From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H . J . Lu" <hjl@lucon.org>
To: GDB <gdb@sourceware.cygnus.com>
Subject: Re: Is the current gdb 5.1 broken for Linuxthreads?
Date: Mon, 17 Sep 2001 19:13:00 -0000
Message-id: <20010917191357.A28300@lucon.org>
References: <20010917124710.A21992@lucon.org> <20010917161350.A25349@lucon.org>
X-SW-Source: 2001-09/msg00141.html

On Mon, Sep 17, 2001 at 04:13:50PM -0700, H . J . Lu wrote:
> On Mon, Sep 17, 2001 at 12:47:10PM -0700, H . J . Lu wrote:
> > Here is a modified example from glibc.
> > 
> > # gcc -g ex11.c -lpthread -lrt -D_GNU_SOURCE
> > # ./a.out&
> > # ps -xal | grep a.out
> > 000  1103 27904  3705   9   0 247300 600 rt_sig S    pts/17     0:00 ./a.out
> > 040  1103 27905 27904  11   0 247300 600 do_pol S    pts/17     0:00 ./a.out
> > 040  1103 27906 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27907 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27908 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27909 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27910 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27911 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27912 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27913 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27914 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27915 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27916 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27917 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27918 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27919 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27920 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27921 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27922 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27923 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27924 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27925 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27926 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27927 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27928 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27929 27905   9   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27930 27905  10   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27931 27905  10   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27932 27905  10   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27933 27905  11   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 040  1103 27934 27905  10   0 247300 600 nanosl S    pts/17     0:00 ./a.out
> > 
> > # gdb a.out
> > ...
> > (gdb) att 27934
> > Attaching to program: /home/hjl/bugs/gdb/thread/./a.out, process 27934
> > Child process unexpectedly missing: No child processes.
> > 
> > Program terminated with signal ?, Unknown signal.
> > The program no longer exists.
> > (gdb)
> > 
> > But
> > 
> > (gdb) att 27904
> > 
> > worked fine. It is a serious regression from gdb 4.18 from RedHat
> > 6.2.
> > 
> 
> The more I looked at it, the more borken gdb is with linuxthreads:
> 
> # gcc -g ex11.c -lpthread -lrt -D_GNU_SOURCE -static
> # a.out
> # gdb a.out
> ...
> (gdb) att 14226
> Attaching to program: /home/hjl/bugs/gdb/thread/a.out, process 14226
> ...
> lin-lwp.c:620: gdb-internal-error: stop_wait_callback: Assertion `pid ==
> GET_LWP (lp->ptid)' failed.
> An internal GDB error was detected.  This may make further

It looks like with gdb 5.1, I have to attach the very first thread. Is
that documented anywhere? Shouldn't gdb find the very first thread
and attach it for me?


H.J.