Re: gdb/2455: Cannot reattach to multithreaded process

Re: gdb/2455: Cannot reattach to multithreaded process

[Daniel Jacobowitz]

The following reply was made to PR gdb/2455; it has been noted by GNATS.

From: Daniel Jacobowitz <drow@false.org>
To: mikbini@gmail.com
Cc: gdb-gnats@sources.redhat.com
Subject: Re: gdb/2455: Cannot reattach to multithreaded process
Date: Tue, 6 May 2008 08:33:05 -0400

 On Tue, May 06, 2008 at 11:23:16AM -0000, mikbini@gmail.com wrote:
 > >Release:        6.5-25.el5_1.1rh
 
 This version is provided by Red Hat; since I can not reproduce the bug
 in GDB 6.8, you may wish to contact Red Hat about bugs in their
 version.
 
 -- 
 Daniel Jacobowitz
 CodeSourcery

gdb/2455: Cannot reattach to multithreaded process

[mikbini]

>Number:         2455
>Category:       gdb
>Synopsis:       Cannot reattach to multithreaded process
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue May 06 11:28:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     mikbini@gmail.com
>Release:        6.5-25.el5_1.1rh
>Organization:
>Environment:
Linux nestor.focuseek.com 2.6.18-53.1.14.el5.centos.plus #1 SMP Fri Mar 7 08:37:13 EST 2008 i686 i686 i386 GNU/Linux
>Description:
If I re-attach to a multithreaded program after re-running the  executable (even if the executable binary didn't change) I get the following error message:

Cannot find new threads: generic error
>How-To-Repeat:
You need a multithreaded a.out

$ ./a.out
# Let's say a.out has pid 12345

# On another tty
$ gdb a.out 12345
# You can now debug, but if you detach...
(gdb) detach

# On the first tty
$ ./a.out
# Let's say the new run of a.out has pid 12355

# Back to gdb tty
(gdb) attach 12355

gdb says:

Attaching to program: a.out, process 12355
Cannot find new threads: generic error
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: