CentOS - Jun 2016 - CentOS 6, gdb

Got a user who claims he was running this program, then it broke recently.
Almost no updates in a while, and none relevant. I'm guessing the
program's compiled from fortran to c.... Anyway, the issue's on two
servers. On one, I installed a couple of compat libs, and it runs. The
other still fails (but it doesn't have some of the i686 libs. When it
fails, it's immediate, and reports dying with a SIGKILL. ldd claims it's
not a dynamic executable, but file tells me it's a 32 bit ELF.... Running
it under strace gives me no more. So, as one last resort (Confess! You
have three last resorts!), I'm trying to run it under gdb. On the system
it runs on, I can b main, and it gets there when I tell it run. On the
other... the address appears to be the same, it's in his NFS-mounted home
directory - it never gets to main, it just reports the sigkill.

So, what I'd *really* like to do is not tell it run, but next, or step,
but I can't.

Anyone heavy enough into gdb to be able to suggest where I can tell it to
break during the program initialization phase, before it gets to main?

        mark

On 2016-06-07 17:21, m.roth at 5-cent.us wrote:
> Got a user who claims he was running this program, then it broke recently.
> Almost no updates in a while, and none relevant. I'm guessing the
> program's compiled from fortran to c.... Anyway, the issue's on two
> servers. On one, I installed a couple of compat libs, and it runs. The
> other still fails (but it doesn't have some of the i686 libs. When it
> fails, it's immediate, and reports dying with a SIGKILL. ldd claims
it's
> not a dynamic executable, but file tells me it's a 32 bit ELF....
Running
> it under strace gives me no more. So, as one last resort (Confess! You
> have three last resorts!), I'm trying to run it under gdb. On the
system
> it runs on, I can b main, and it gets there when I tell it run. On the
> other... the address appears to be the same, it's in his NFS-mounted
home
> directory - it never gets to main, it just reports the sigkill.
> 
> So, what I'd *really* like to do is not tell it run, but next, or step,
> but I can't.
> 
> Anyone heavy enough into gdb to be able to suggest where I can tell it to
> break during the program initialization phase, before it gets to main?
Possibly something still not right in the execution environment.
Try "export LD_DEBUG=all" then run the program. ("unset
LD_DEBUG" to reverse.) Did you edit ld.so.conf and run ldconfig
on the second machine?  Also check "sudo ausearch --success no
--interpret -ts today"