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

Somsak Sriprayoonsakul <somsak_sr@xxxxxxxxxxxxxx> · Thu, 24 Aug 2006 15:30:55 +0700

No, LD_PRELOAD is not specified by default. It'll be specified manually 

in the job script. Also, if I specify both, the 32bit application will 

refuse to load the 64bit lib (a error message "can not preload libxxx.so 

will appearred").

Jay Scherrer wrote:

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 <somsak_sr@xxxxxxxxxxxxxx>
Reply-To:     gfarm-discuss@xxxxxxxxxx
Organization:     Thai National Grid Center
To:     gfarm-discuss@xxxxxxxxxx

References:     

<452F37AE49199D49B1702D7D45038C4D6B0E13@xxxxxxxxxxxxxx> 

<44E2A2A1.3030804@xxxxxxxxxxxxxx> 

<17635.2643.47481.577333@xxxxxxxxxxxxxxxxxxx>

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 

<somsak_sr@xxxxxxxxxxxxxx> 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
somsak_sr@xxxxxxxxxxxxxx

----------------------------------------------------------------------------------- 

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

--
-----------------------------------------------------------------------------------
Somsak Sriprayoonsakul

Thai National Grid Center
Software Industry Promotion Agency
Ministry of ICT, Thailand
somsak_sr@xxxxxxxxxxxxxx
-----------------------------------------------------------------------------------

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