[OPTERON/x86_64] - can debug while setting breakpoint

[OPTERON/x86_64] - can debug while setting breakpoint

[François Chenais]

Hello,

Something strange happens while trying to debug on x86_64 system.

I have a simple C code in t.c file ...

     #include <stdio.h>
      void main (int argc, char **argv) { printf("Hello World !"\n); }
 
... built with ...

    # gcc -g t.c

... and run it

    # a.out
    Hello World !

ldd is ok

    libc.so.6 => /lib64/libc.so.6 (0x000000304f200000)
    /lib64/ld-linux-x86-64.so.2 (0x000000304da00000)


Now running it with gdb :

    # gdb a.out
    blah blah blah
    (gdb) run
    Starting program: /home/francois/src/a.out
    Hello World !

    Program exited with code 016.
    (gdb)  b main
    Breakpoint 1 at 0x80483b5: file t.c, line 2.

    (gdb) run


At this moment, a  SIGSEGV occurs before stopping on the breakpoint !!!
The stack is buggy !


More informations that can help
=====================

The same error occurs with others debuggers : totalview, sun dbx, intel idb
and while using  intel icc or  g++ compilers  :/

The same error occurs while building with -static option.

I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
     - The error occurs on 3/5.



Any idea ???

    Thanks a lot by advance

            François







  

Re: [OPTERON/x86_64] - can debug while setting breakpoint

[Daniel Jacobowitz]

On Thu, Feb 05, 2009 at 07:49:08PM +0100, François Chenais wrote:
> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>     - The error occurs on 3/5.

Check that they're all running the same kernel version, check for
kernel updates.  This does not sound like a GDB problem.

-- 
Daniel Jacobowitz
CodeSourcery

Re: [OPTERON/x86_64] - can't debug while setting breakpoint

[François Chenais]

Daniel Jacobowitz a écrit :
> On Thu, Feb 05, 2009 at 07:49:08PM +0100, François Chenais wrote:
>> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>>     - The error occurs on 3/5.
> 
> Check that they're all running the same kernel version, check for
> kernel updates.  This does not sound like a GDB problem.
> 

They are running the same kernel !

Effectively, I don't think it's a gdb problem because the error occurs 
for the others debuggers.

I have checked the list and the versions of packages installed, the 
configuration, all seems identical.

What can make the debuggers fail while setting breakpoints ?

Re: [OPTERON/x86_64] - can't debug while setting breakpoint

[François Chenais]

François Chenais a écrit :
> Daniel Jacobowitz a écrit :
>> On Thu, Feb 05, 2009 at 07:49:08PM +0100, François Chenais wrote:
>>> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>>>     - The error occurs on 3/5.
>>
>> Check that they're all running the same kernel version, check for
>> kernel updates.  This does not sound like a GDB problem.
>>
> 
> They are running the same kernel !
> 
> Effectively, I don't think it's a gdb problem because the error occurs 
> for the others debuggers.
> 
> I have checked the list and the versions of packages installed, the 
> configuration, all seems identical.
> 
> What can make the debuggers fail while setting breakpoints ?
> 
>
The error occurs on HP 585 G2 not on G1 !:/

Re: [OPTERON/x86_64] - can't debug while setting breakpoint

[François Chenais]

François Chenais a écrit :
> François Chenais a écrit :
>> Daniel Jacobowitz a écrit :
>>> On Thu, Feb 05, 2009 at 07:49:08PM +0100, François Chenais wrote:
>>>> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>>>>     - The error occurs on 3/5.
>>>
>>> Check that they're all running the same kernel version, check for
>>> kernel updates.  This does not sound like a GDB problem.
>>>
>>
>> They are running the same kernel !
>>
>> Effectively, I don't think it's a gdb problem because the error occurs 
>> for the others debuggers.
>>
>> I have checked the list and the versions of packages installed, the 
>> configuration, all seems identical.
>>
>> What can make the debuggers fail while setting breakpoints ?
>>
>>
> The error occurs on HP 585 G2 not on G1 !:/
> 
> 
Something new.

I tried to build new gdb on this system but it fails during configure.
It fails in the conftest cheking division by zero.

I built the conftest and run gdb on it.
The error occurs when catching SIGFPE signal, gdb is blocked waiting!

   François

Re: [OPTERON/x86_64] - can debug while setting breakpoint

[Jan Kratochvil]

On Thu, 05 Feb 2009 19:49:08 +0100, François Chenais wrote:
> The same error occurs with others debuggers : totalview, sun dbx, intel idb
> and while using  intel icc or  g++ compilers  :/
...
> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>     - The error occurs on 3/5.

RHEL-5.2 kernel was unfortunately very "unfriendly" to the debuggers due to
utrace and the ptrace emulation on top of it.  RHEL-5.3 has all the commonly
visible problems fixed.


Regards,
Jan

Re: [OPTERON/x86_64] - can debug while setting breakpoint

[François Chenais]

Jan Kratochvil a écrit :
> On Thu, 05 Feb 2009 19:49:08 +0100, François Chenais wrote:
>> The same error occurs with others debuggers : totalview, sun dbx, intel idb
>> and while using  intel icc or  g++ compilers  :/
> ...
>> I've done the test on 5 Amd opteron x86_64 hosts with Cent OS 5.2
>>     - The error occurs on 3/5.
> 
> RHEL-5.2 kernel was unfortunately very "unfriendly" to the debuggers due to
> utrace and the ptrace emulation on top of it.  RHEL-5.3 has all the commonly
> visible problems fixed.
>
I'm waiting centos 5.3 to try the update.
Thnaks a lot !

		François
> 
> Regards,
> Jan
>