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From: ridg...@inls3.tmc.edu (Doug Ridgway)
Subject: Unixware binaries?
Date: 1996/08/05
Message-ID: <4u45mv$k24@news1.ucsd.edu>#1/1
X-Deja-AN: 172188757
references: <4u2snn$36t@nadine.teleport.com>
organization: Institute for NonLinear Science, UCSD
newsgroups: comp.os.linux.misc


Can one run Unixware binaries under Linux using iBCS? How is it supposed
to work? A friend sent me a couple of Hello world binaries compiled on
his Unixware box, and I've been unable to get them to run. The dynamically
linked one (http://wessex.ucsd.edu/alp/a.out) generates ``Command not found''
while the static linked one (http://wessex.ucsd.edu/alp/as.out) generates
a seg fault. The iBCS module appears to be loaded into my kernel. I'm
running 1.2.13, Red Hat 3.0.3.

Anybody have a clue what I'm doing wrong? Or is it not possible?

Thanks for the help,
doug.
dridg...@uscd.edu
(Please mail in addition to following up, UCSD's news feed is flaky...)

From: Mike Jagdis <ja...@purplet.demon.co.uk>
Subject: Unixware binaries?
Date: 1996/08/06
Message-ID: <1006.32090753@purplet.demon.co.uk>#1/1
X-Deja-AN: 172816491
x-mail2news-path: purplet.demon.co.uk
x-nntp-posting-host: purplet.demon.co.uk
sender: "newsout1.26" <ufg...@purplet.demon.co.uk>
organization: FidoNet node 2:252/305 - The Purple Tentacle, Reading
newsgroups: comp.os.linux.misc


* In a message originally to All, Doug Ridgway said:
DR> Message-ID: <4u45mv$...@news1.ucsd.edu>

DR> Can one run Unixware binaries under Linux using iBCS?

In theory, yes. It's a long time since I tried any Unixware stuff against it 
and even then it was only Unixware 1.x stuff ('cos that's all I had).

DR> How is it supposed to work?

You just run them.

DR> A friend sent me a couple of Hello world binaries
DR> compiled on
DR> his Unixware box, and I've been unable to get them to run.
DR> The dynamically
DR> linked one (http://wessex.ucsd.edu/alp/a.out) generates
DR> ``Command not found''

The ELF loader can't find the dynamic loader required for the program 
(/usr/lib/libc.so.1). Eric's substitute library 
(tsx-11.mit.edu:/pub/linux/BETA/ibcs2/) works for many SVR4 things.

DR> while the static linked one
DR> (http://wessex.ucsd.edu/alp/as.out) generates
DR> a seg fault.

A static binary won't be recognised as non-native until it makes a non-Linux 
system call. Because of this the ELF loader does not know that SVR4 
behaviour is required and leaves page 0 unmapped for the process (where as 
SVR4 maps it read only I believe - see linux/fs/binfmt_elf.c for true 
enlightenment).

  Three possibilities: 1. iBCS is broken for Unixware in some way (use the 
iBCS trace program - see the iBCS docs for details). 2. The SVR4 library 
code dereferences a null pointer when it shouldn't - and gets away with it 
on a real SVR4 system. 3. Your friend's code is broken and dereferences a 
null pointer - and gets away with it on a real SVR4 system.

                                Mike  

From: r...@rmkhome.com (Rick Kelly)
Subject: Re: Unixware binaries?
Date: 1996/08/26
Message-ID: <4vrg3v$ceh@news-central.tiac.net>#1/1
X-Deja-AN: 176497514
references: <1006.32090753@purplet.demon.co.uk>
organization: The Man With Ten Cats
reply-to: r...@seahag.rmkhome.com
newsgroups: comp.os.linux.misc


Mike Jagdis (ja...@purplet.demon.co.uk) wrote:

: A static binary won't be recognised as non-native until it makes a non-Linux 
: system call. Because of this the ELF loader does not know that SVR4 
: behaviour is required and leaves page 0 unmapped for the process (where as 
: SVR4 maps it read only I believe - see linux/fs/binfmt_elf.c for true 
: enlightenment).

:   Three possibilities: 1. iBCS is broken for Unixware in some way (use the 
: iBCS trace program - see the iBCS docs for details). 2. The SVR4 library 
: code dereferences a null pointer when it shouldn't - and gets away with it 
: on a real SVR4 system. 3. Your friend's code is broken and dereferences a 
: null pointer - and gets away with it on a real SVR4 system.

Just a matter of semantics but:

iBCS = SVR3 = COFF
iBCS2 = SVR4 = ELF

Unixware handles both COFF and ELF binaries.
--
Rick Kelly  r...@seahag.rmkhome.com  r...@rmkhome.com 
            http://tencats.rmkhome.com

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