[svlug] Running 32-bit apps under 64-bit kernel

[Alan DuBoff]

On Tue, 5 Jan 2010, Rick Moen wrote:

> Specifically, you need to be able to run _binary_ 32-bit 
> applications on x86_64-architecture Debian.  That means it's 
> not possible to tweak source and recompile to make it resolve 
> its lib calls to /usr/lib32 or /usr/lib/i486-linux-gnu , 
> because the binary is already set to ask the dynamic linker 
> for the bare sonames, resulting in them finding the distro's 
> /usr/lib libs, which are for x86_64, hence incompatible, 
> /usr/lib being a symlink to /usr/lib/x86_64-linux-gnu or 
> something like that.  (That's my understanding.  If wrong in 
> some details, my apologies.)

Rick,

That is exactly my problem, the Adobe compiled binary seems to 
be looking in /usr/lib and libxml2.so.2 is the wrong 
architecture. The error message it initially gives is bogus, it 
says it can't find the library...after some looking I found it 
in /usr/lib, took me a few minutes of scratching my head to 
realize what was going on.

>
> If you want to read up on the background of this tale of woe, here are
> two relevant Web searches:
>
>   debian biarch
>         That'll find information about the original suggestion about
>         how to deal with this problem systematically.
>   debian multiarch
>         That'll find information on what I believe is the officially
>         approved approach that is being implemented by Debian and
>         Ubuntu, which will get you links like these:
>         http://wiki.debian.org/multiarch
>         https://wiki.ubuntu.com/MultiarchSpec

I will check these out.

> But you just want to run Acroread.  Maybe you want just a simple IA32
> chroot:   http://ornellas.apanela.com/dokuwiki/pub:multiarch

That could work, possibly.

> My understanding is that RHEL / CentOS / OpenSUSE / SLED/SLES / Gentoo
> all went with the biarch approach.

Hmmm...that's interesting...but Ubuntu must be like Debian since 
Debian is the base, right?

I don't think I could give up Debian in favor of one of those 
other OSs...nah...another approach would be to run VirtualBox 
with a 32-bit VM, and mount from the host system.

> Incidentally, Acroread is why my DNS nameserver has since 2005 declared
> itself authoritative for the "remoteapproach.com" DNS domain, so that
> users of my DNS who execute Adobe Acrobat Reader v.7 and up aren't being
> spied on by Adobe's business partner Remote Approach.  See:
> http://lwn.net/Articles/129729/

That's interesting, I wasn't away of Adobe's deceiving tactics 
there...:-/

> I don't know if Remote Approach is still in business, but, if Adobe's
> software has been known to spy on you in the past, the most reasonable
> expectation is that it should be expected to do so in the future --
> which is why I personally think Evince, xpdf, etc. are to be preferred
> (but choose your own poison, of course).

Evince works pretty good these days, and I would probably opt to 
using it on Debian rather than switch to another linux distro. 
Just my preference. But in the past I sometimes have problems 
with locales in Evince, where docs are created to support a 
variety of locales and the fonts don't work properly.

Thanks for the info, I need to digest and ponder on it.

--

Alan DuBoff - Software Orchestration
http://www.softorchestra.com:8080/roller/blog/