Error accessing memory address 0x0 - Using wdb 4.0

[Clive Quinn]

Hi all,

I am currently experiencing problems when using the graphical debugger wdb on Itanium HP-UX B.11.23 U ia64 1657134542. Basically I am getting the error message:
Error accessing memory address 0x0 :Invalid argument

when I debug my code. I have compiled with the -g option and also I have tried -g0 flag. This happens when trying to print out the value of a simple char *. I also see similar errors in the options Watch and Local Variables.

I would be grateful for any help with this.
Again the version is:
HP WDB-GUI - HP Debugger Graphical User Interface - Version 4.0
Rev: 20030619.010541

Clive

[A. Clay Stephenson · Accepted solution]

I am going to make the assumption that you are not trying to display the contents of a thingy pointed to by a NULL pointer (0x0). There is a patch, PHSS_29659, which indicates thats WDB must be upgraded to 4.1 or later.

[Clive Quinn]

Hi,

I have done as requested and I am still having problems with the wdb 4.1 debugger.

I still cannot go into certain parts of my codebase. I am crashing with core message:

Program received signal SIGSEGV, Segmentation
fault (si_code: 1).
0xfffffff800000000 in ()

Please look at the core file (see GDBcore.txt) attached.

I currently have the following patches on my ia64 machine:
PHSS_29655
PHSS_29656
PHSS_29657
PHSS_29659

aCC -V returns aCC version aCC: HP aC++/ANSI C B3910B A.05.52 .

wdb -version returns HP WDB-GUI - HP Debugger Graphical User Interface - Version 4.1
Rev: 20030917.095208.

Please note that debugging does work in certain areas of the code base but seems to fail consistently in one area where we read and write to and from a binary file. When we read and write to/from a text file we have no problems.

Fundamentally our port from PA-Risc architecture to ia64 (IPF) has caused us many problems but this we believe is the only outstanding issue.

I would be grateful if you could give us any idea as to what we may be doing wrong. We are simply compiling using -AP -g0 +O2 flags. We have turned off optimization but to no avail.

These problems do not exist on PA Risc architecture. The wdb debugger on PA risc allows us to step into all areas of code base.

Any comments or ideas appreciated.

Regards,
Clive Quinn

(I would be grateful if you could also forward any respones to ajit.bhat@iona.com as I will not be in the office for a couple of weeks.)