Re: [Fwd: [gfarm-discuss:03663] Re: 32bit application segmentation fault on 64bit]

Somsak Sriprayoonsakul wrote:
> Hello,
>
>     I'm trying to LD_PRELOAD an user-level file system library for 
> 32bit application on x86_64 machine (CentOS 4.3/RHEL4). Somehow the 
> application segfault everytime. I've install both 32bit and 64bit 
> libraries, and the test application is just a simple "ls" command (the 
> real one will be an proprietary animation rendering program so I can't 
> recompile it to 64bit). Below and attach file are all logs.
>
>     My question is, is it possible to do this on x86_64? LD_PRELOAD 
> either 32bit or 64bit application, while providing all necessary 
> library for the applicaion. The answer from google seems to be yes, 
> but what've I done wrong?
>
> -------- Original Message --------
> Subject: 	[gfarm-discuss:03663] Re: 32bit application segmentation 
> fault on 64bit
> Date: 	Fri, 18 Aug 2006 16:33:44 +0700
> From: 	Somsak Sriprayoonsakul <[email protected]>
> Reply-To: 	[email protected]
> Organization: 	Thai National Grid Center
> To: 	[email protected]
> References: 	<[email protected]> 
> <[email protected]> 
> <[email protected]>
>
>
>
> The problem is less serious now since we successfully using gfarm-fuse 
> with the application. Anyways I've done strace log and here it is
>
> 1. Normal case
>
> [somsak_sr@anatta ~]$ LD_PRELOAD="/usr/lib64/gfarm/libc-not-hidden.so" 
> /bin/ls
> bash           clusterscores-1.0b0         globus-4.0.2-1.src.rpm  
> magi                src
> benchmark      clusterscores-1.0b0.tar.gz  globus_povray_stub      
> rocksmountdirty.sh  tmp
> bin            clusterscores_result        log                     
> rpm                 usr
> clusterscores  gfarm-1.3.1-0.src.rpm       ls                      
> software            work
> [somsak_sr@anatta ~]$ LD_PRELOAD="/usr/lib/gfarm/libc-not-hidden.so" 
> $PWD/ls                     
> Segmentation fault
> [somsak_sr@anatta ~]$ file $PWD/ls
> /home/somsak_sr/ls: ELF 32-bit LSB executable, Intel 80386, version 1 
> (SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), stripped
> [somsak_sr@anatta ~]$
>
> 2. Invoke through 32bit bash
>
> [somsak_sr@anatta ~]$ file ./bash
> ./bash: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for 
> GNU/Linux 2.2.5, dynamically linked (uses shared libs), stripped
> [somsak_sr@anatta ~]$ file ./ls
> ./ls: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for 
> GNU/Linux 2.2.5, dynamically linked (uses shared libs), stripped
> [somsak_sr@anatta ~]$ export LD_PRELOAD=""
> [somsak_sr@anatta ~]$ /bin/bash -c 
> "LD_PRELOAD='/usr/lib64/gfarm/libc-not-hidden.so' /bin/ls"     
> bash           clusterscores-1.0b0         globus-4.0.2-1.src.rpm  
> magi                src
> benchmark      clusterscores-1.0b0.tar.gz  globus_povray_stub      
> rocksmountdirty.sh  tmp
> bin            clusterscores_result        log                     
> rpm                 usr
> clusterscores  gfarm-1.3.1-0.src.rpm       ls                      
> software            work
> [somsak_sr@anatta ~]$ /bin/bash -c 
> "LD_PRELOAD='/usr/lib/gfarm/libc-not-hidden.so' $PWD/ls"      
> Segmentation fault
> [somsak_sr@anatta ~]$
>
> 3. strace log - strace log is attached wit this e-mail (it's too long). 
> Note that, I'm using 32bit strace.
>
> You'll see that I only set single file, libc-not-hidden, no gfarm-libs, 
> and it still segfault. I think this is not problem regarding gfarm anymore.
>
>
> SODA Noriyuki wrote:
> >>>>>> On Wed, 16 Aug 2006 11:44:17 +0700,
> >>>>>>             
> >       Somsak Sriprayoonsakul <[email protected]> said:
> >
> >   
> >>> Maybe it's worthwhile to check out Gfarm-Fuse system. In our experience,
> >>> the Gfarm-Fuse is much more stable in supporting preexisting
> >>> applications.
> >>>       
> >
> >   
> >> Yes. Actually we already tested that and gfarm-fuse work great in term 
> >> of performance. Somehow gfarm-fuse only accept single user per mounted 
> >> file system, also it does not support lseek system call, which is 
> >> required by some application. That's why we're trying to use user-level 
> >> instead.
> >>     
> >
> > Hmm? What is the problem about lseek?
> > As far as I know, lseek just does work with GfarmFS-FUSE.
> > Thus, if you could allow your users to mount gfarm filesystem via
> > GfarmFS-FUSE, certainly it could be an option as Wilfred said.
> >
> > If your problem with lseek was a data coherency problem, please try
> > "-unbuf" option of GfarmFS-FUSE.
> >   
>
>
> -- 
> -----------------------------------------------------------------------------------
> Somsak Sriprayoonsakul
>
> Thai National Grid Center
> Software Industry Promotion Agency
> Ministry of ICT, Thailand
> [email protected]
> -----------------------------------------------------------------------------------
The real question is: are you calling both libraries at the same time. 
This used to be a problem with apt-get also. It would load both 
libraries X_32 and X_64 to cause a clash.
Have you tried specifying either the X_32 or the X_64 only while compiling?

Jay Scherrer