Article View: gnu.gdb.bug
Article #2433Re: pthreads + execv causes gdb to get confused
From: Srini
Date: Thu, 21 Mar 2002 07:18
Date: Thu, 21 Mar 2002 07:18
76 lines
3488 bytes
3488 bytes
Hi,
I am also facing the same problem.
I am using RH 7.2 on IA32 box, with kernel 2.4.7-10.
U can reproduce (is it a bug????) this as follows. Use the test case given below.
[root@nadda randd]# cat test.c
#include <stdlib.h>
int main(int argc, char **argv) {
char *p=getenv("MYTEST");
printf("start of mytest\n");
if (p==NULL) {
printf("p is null\n");
putenv("MYTEST=yes");
printf("calling execvp %s\n",argv[0]);
execvp(argv[0], argv);
} else {
printf("p = %s\n",p);
}
printf("rest of program...\n");
printf("end of mytest\n");
exit(0);
}
[root@nadda randd]# gcc -g -o test -lpthread test.c
[root@nadda randd]# gdb test
GNU gdb Red Hat Linux (5.1-1)
Copyright 2001 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux"...
(gdb) r
Starting program: /home/ansriniv/randd/test
[New Thread 1024 (LWP 4162)]
start of mytest
p is null
calling execvp /home/ansriniv/randd/test
Cannot find user-level thread for LWP 4162: generic error
(gdb) c
Continuing.
Cannot find thread 1024: generic error
(gdb)
doylep@eecg.toronto.edu (Patrick Doyle) wrote in message news:<699e3226.0203191209.403ad50e@posting.google.com>...
> Hi. I hope this is helpful...
>
> When debugging a program that uses pthreads, a call to execv causes
> gdb to get mighty confused:
>
> (gdb) run
> Starting program: abc
> [New Thread 1024 (LWP 8440)]
> Breakpoint 2 (...)
> 736 execvp(argv[0], argv);
> (gdb) cont
> Continuing.
> Cannot find user-level thread for LWP 8445: generic error
> (gdb) bt
> Cannot find thread 1024: generic error
> (gdb) quit
> The program is running. Exit anyway? (y or n) y
> Cannot find thread 1024: generic error
> (gdb) [5] Terminated gdb abc
>
> [6]+ Stopped gdb abc
> [bash]$ kill %
>
> [6]+ Stopped gdb abc
> [bash]$
> [6]+ Terminated gdb abc
> [bash]$
>
> This is Red Hat 7.2 and GNU gdb 20020225.
Technical Details
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f5053,9a65a43ad455212b X-Google-Attributes: gidf5053,public X-Google-ArrivalTime: 2002-03-20 23:18:31 PST x-uunet-gateway: chi6sosrv13.alter.net from bug-gdb to gnu.gdb.bug; Thu, 21 Mar 2002 07:18:29 GMT Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!news-hub.siol.net!zur.uu.net!ash.uu.net!spool0901.news.uu.net!wendy-fate.uu.net!not-for-mail From: srinivas_av@rediffmail.com (Srini) Subject: Re: pthreads + execv causes gdb to get confused Date: 20 Mar 2002 23:18:10 -0800 Organization: http://groups.google.com/ Message-ID: <2f641791.0203202318.8fb3aff@posting.google.com> References: <699e3226.0203191209.403ad50e@posting.google.com> NNTP-Posting-Host: 202.135.142.194 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1016695090 23599 127.0.0.1 (21 Mar 2002 07:18:10 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 21 Mar 2002 07:18:10 GMT Approved: bug-gdb-request@mail.gnu.org Newsgroups: gnu.gdb.bug Sender: bug-gdb-request@mail.gnu.org Lines: 76