pthread_db innitializing error

pthread_db innitializing error

[nak26]

Hi:

I am fighting problems I have when trying to remotely debug multithreaded 
applications.

The host machine's solib-absolute-prefix is messed up, so when I start I set 
the solib search path to look for libraries at the right places (it was 
looking at /lib/i686 instead of just in /lib). Then after hitting a breakpoint 
I need to issue shared to load the libararies.

At this point on the target terminal I see this (the application is a 
multithreaded toy example):

[localhost ~/src/c/threads]$ ~/.local/src/gdb-5.3/gdb/gdbserver/gdbserver 
:7000 hello_world_thread
Process hello_world_thread created; pid = 2486
Remote debugging from host 192.168.66.59
gdb: error initializing thread_db library.
gdb: error initializing thread_db library.
gdb: error initializing thread_db library.

Anybody with ideas why I am getting the error?

Both host and target are IA32 RedHat 8.0s.

Thanks,
Nik

Re: pthread_db innitializing error

[Daniel Jacobowitz]

On Wed, Jun 25, 2003 at 12:38:44PM -0400, nak26 wrote:
> Hi:
> 
> I am fighting problems I have when trying to remotely debug multithreaded 
> applications.
> 
> The host machine's solib-absolute-prefix is messed up, so when I start I set 
> the solib search path to look for libraries at the right places (it was 
> looking at /lib/i686 instead of just in /lib). Then after hitting a breakpoint 
> I need to issue shared to load the libararies.

Eh?  It sounds like you're not using the right libraries at all. 
solib-absolute-prefix should point to a copy of the target filesystem
layout - the target's versions of libraries.  It shouldn't search /lib
at all.

> At this point on the target terminal I see this (the application is a 
> multithreaded toy example):
> 
> [localhost ~/src/c/threads]$ ~/.local/src/gdb-5.3/gdb/gdbserver/gdbserver 
> :7000 hello_world_thread
> Process hello_world_thread created; pid = 2486
> Remote debugging from host 192.168.66.59
> gdb: error initializing thread_db library.
> gdb: error initializing thread_db library.
> gdb: error initializing thread_db library.
> 
> Anybody with ideas why I am getting the error?
> 
> Both host and target are IA32 RedHat 8.0s.

Probably symbol resolution is not working; most likely because you have
the wrong libpthread on the host.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: pthread_db innitializing error

[Daniel Jacobowitz]

On Thu, Jun 26, 2003 at 10:34:37AM -0400, nak26 wrote:
> >
> >Is GDB on the host finding the _host's_ libpthread, or the _target's_
> >libpthread copied to the host?
> >
> >It must be the latter if you want it to work.
> >
> 
> It finds the latter, but errors when trying to load it automatically.
> I guess the warning that comes out after the connection is made points to
> why this is happening.
> 
> ----------------------------------
> GDB console's output
> ----------------------------------
> (gdb) b main
> Breakpoint 1 at 0x82a2cc2: file ../cp/tlpcp.cxx, line 332.
> (gdb) target remote 192.168.139.14:7000
> Remote debugging using 192.168.139.14:7000
> 0x40001390 in ?? ()
> warning: Unable to find dynamic linker breakpoint function.
> GDB will be unable to debug shared library initializers
> and track explicitly loaded dynamic code.
> (gdb) c
> Continuing.
> Error while mapping shared library sections:
> /lib/libnsl.so.1: No such file or directory.
> Error while mapping shared library sections:
> /lib/librt.so.1: No such file or directory.
> Error while mapping shared library sections:
> /lib/libpthread.so.0: No such file or directory.
> Error while mapping shared library sections:
> /opt/intel/mkl/lib/32/libmkl_p4.so: No such file or directory.
> Error while mapping shared library sections:
> /opt/intel/mkl/lib/32/libguide.so: No such file or directory.
> Error while mapping shared library sections:
> /usr/lib/libstdc++.so.5: No such file or directory.
> Error while mapping shared library sections:
> /lib/libm.so.6: No such file or directory.
> Error while mapping shared library sections:
> /lib/libgcc_s.so.1: No such file or directory.
> Error while mapping shared library sections:
> /lib/libc.so.6: No such file or directory.
> Error while mapping shared library sections:
> /lib/ld-linux.so.2: No such file or directory.
> --------------------------------------------
> GDBSERVER's console output
> --------------------------------------------
> Process tlpSim created; pid = 2884
> Remote debugging from host 192.168.66.59
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> gdb: Unable to set global thread event mask: generic error
> 
> Is this a (_remote_) linker issue or gdbserver issue or (_local_)
> gdb issue?
> Furthermore, does gdb load the shared libraries from the remote
> machine over the network or they need to reside locally?

They need to reside locally, and this is a local gdb issue.

From the error message above, GDB is not finding the library -
otherwise you wouldn't get "No such file or directory".  Please take
another look at the documentation for solib-absolute-prefix.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

RE: pthread_db innitializing error

[nak26]

>
>Is GDB on the host finding the _host's_ libpthread, or the _target's_
>libpthread copied to the host?
>
>It must be the latter if you want it to work.
>

It finds the latter, but errors when trying to load it automatically.
I guess the warning that comes out after the connection is made points to
why this is happening.

----------------------------------
GDB console's output
----------------------------------
(gdb) b main
Breakpoint 1 at 0x82a2cc2: file ../cp/tlpcp.cxx, line 332.
(gdb) target remote 192.168.139.14:7000
Remote debugging using 192.168.139.14:7000
0x40001390 in ?? ()
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
(gdb) c
Continuing.
Error while mapping shared library sections:
/lib/libnsl.so.1: No such file or directory.
Error while mapping shared library sections:
/lib/librt.so.1: No such file or directory.
Error while mapping shared library sections:
/lib/libpthread.so.0: No such file or directory.
Error while mapping shared library sections:
/opt/intel/mkl/lib/32/libmkl_p4.so: No such file or directory.
Error while mapping shared library sections:
/opt/intel/mkl/lib/32/libguide.so: No such file or directory.
Error while mapping shared library sections:
/usr/lib/libstdc++.so.5: No such file or directory.
Error while mapping shared library sections:
/lib/libm.so.6: No such file or directory.
Error while mapping shared library sections:
/lib/libgcc_s.so.1: No such file or directory.
Error while mapping shared library sections:
/lib/libc.so.6: No such file or directory.
Error while mapping shared library sections:
/lib/ld-linux.so.2: No such file or directory.
--------------------------------------------
GDBSERVER's console output
--------------------------------------------
Process tlpSim created; pid = 2884
Remote debugging from host 192.168.66.59
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error
gdb: Unable to set global thread event mask: generic error

Is this a (_remote_) linker issue or gdbserver issue or (_local_)
gdb issue?
Furthermore, does gdb load the shared libraries from the remote
machine over the network or they need to reside locally?

Thanks,
--Nik

Re: pthread_db innitializing error

[Daniel Jacobowitz]

On Wed, Jun 25, 2003 at 01:42:18PM -0400, nak26 wrote:
> >
> >Eh?  It sounds like you're not using the right libraries at all.
> >solib-absolute-prefix should point to a copy of the target filesystem
> >layout - the target's versions of libraries.  It shouldn't search /lib
> >at all.
> >
> 
> I meant to say solib-search-path...
> 
> >
> >Probably symbol resolution is not working; most likely because you have
> >the wrong libpthread on the host.
> >
> 
> What do you mean by "you have the wrong libpthread on the host"?
> How can I doctor this?

Is GDB on the host finding the _host's_ libpthread, or the _target's_
libpthread copied to the host?

It must be the latter if you want it to work.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

RE: pthread_db innitializing error

[nak26]

>
>Eh?  It sounds like you're not using the right libraries at all.
>solib-absolute-prefix should point to a copy of the target filesystem
>layout - the target's versions of libraries.  It shouldn't search /lib
>at all.
>

I meant to say solib-search-path...

>
>Probably symbol resolution is not working; most likely because you have
>the wrong libpthread on the host.
>

What do you mean by "you have the wrong libpthread on the host"?
How can I doctor this?

Thanks,
--Nik