SIGILL on openVZ

I have a small openVZ slice I use for testing and personal projects.
Recently, the provider transferred to the new Xeon "Sandy Bridge"
platform; I am not sure if this is the cause of my problem or not, but
since then, I have been unable to use most of my mod_perl based
modules with apache. The apache worker receives SIGILL (Illegal
instruction) as soon as the module is called upon.

I've run httpd -X in gdb and posted an example backtrace here:

http://pastebin.com/16SrEzHM

The offending instruction is "dl_x86_64_save_sse" (I don't know any
assembly), and it is always from
/usr/src/debug/glibc-2.12.2/sysdeps/x86_64/dl-trampoline.S,
so perhaps not a strictly mod_perl issue, but I do not have the problem
with anything else. Context #5 in the backtrace relates to
Apache2::Const, and in fact a module like this:

use Apache2::Const qw(SERVER_ERROR);

sub handler {
return SERVER_ERROR;
}

Triggers the issue. Removing Apache2::Const and returning 500 does not.
Apache2::RequestRec is okay, but most other modules are not (and not
necessarily all Apache2 modules, eg, Mouse will also trigger this),
meaning most of my stuff is now non-functional. Regular perl scripts
using these modules are fine. I have tried recompiling them on "the
new platform" via CPAN; this did not make any difference.

I've been writing and using Apache/mod_perl modules for a few years and
this would be a very serious problem for me if it happened anywhere
else. I'm looking for some help in determining why this suddenly
happened and what I can do about it.

Thanks -- MK

--
"Enthusiasm is not the enemy of the intellect." (said of Irving Howe)
"The angel of history[...]is turned toward the past." (Walter Benjamin)

Re: SIGILL on openVZ

On Sun, 10 Jul 2011 08:07:05 -0400
Rick Myers wrote:
> On Sat, Jul 09, 2011 at 09:05:28AM -0400, MK wrote:
> > http://pastebin.com/16SrEzHM
> >
> > The offending instruction is "dl_x86_64_save_sse" (I don't know any
> > assembly), and it is always from
> > /usr/src/debug/glibc-2.12.2/sysdeps/x86_64/dl-trampoline.S,
>
> It appears to be an old glibc problem. Compare your trace with
>
> http://sourceware.org/bugzilla/show_bug.cgi?format=multiple& id=12113

Yeah. The "small reproducer" attached to that report does reproduce
the problem on the system, which is also Fedora 13 running glibc 2.12.
I'll have to ask the provider if they can make an upgrade available.

Thanks!

--
"Enthusiasm is not the enemy of the intellect." (said of Irving Howe)
"The angel of history[...]is turned toward the past." (Walter Benjamin)