[Buildroot] segfault when running a simple c program on env build with buildroot

[Buildroot] segfault when running a simple c program on env build with buildroot

[Eial Czerwacki]

Hello All,

I have a small env built with buildroot based on busybox-1.19.2 and
uclibc-0.9.32.
I've included gcc into it and I'm trying to build and run the following
program but it segfaults:

sh-4.1# cat test.c
int main() { return 0; }
sh-4.1# gcc -o a test.c
sh-4.1# ls -l a
-rwxr-xr-x    1 root     root         11553 Feb  9 07:44 a
sh-4.1# ./a
Segmentation fault
sh-4.1# dmesg | tail -1
<6>[634724.545000] a[24405]: segfault at 0 ip (null) sp bfd8fc7c error 4

my buildroot config is attached and the version in use a snapshot from
the date 10/9/2011.

any ideas why?

Eial.
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[Buildroot] segfault when running a simple c program on env build with buildroot

[Thomas Petazzoni]

Le Thu, 09 Feb 2012 16:48:30 +0200,
Eial Czerwacki <eial@scalemp.com> a ?crit :

> my buildroot config is attached and the version in use a snapshot from
> the date 10/9/2011.

What is your hardware platform?

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] segfault when running a simple c program on env build with buildroot

[Thomas Petazzoni]

Le Thu, 09 Feb 2012 16:48:30 +0200,
Eial Czerwacki <eial@scalemp.com> a ?crit :

> sh-4.1# gcc -o a test.c

You're using the native gcc on the target, while Buildroot is mostly
designed for cross-compilation. Our native gcc on the target mechanism
isn't used/tested a lot, so I would really recommend using the
cross-compiler on the build machine to build your applications.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] segfault when running a simple c program on env build with buildroot

[Eial Czerwacki]

On 02/09/2012 05:09 PM, Thomas Petazzoni wrote:

> Le Thu, 09 Feb 2012 16:48:30 +0200,
> Eial Czerwacki <eial@scalemp.com> a ?crit :
>
>> my buildroot config is attached and the version in use a snapshot from
>> the date 10/9/2011.
>
> What is your hardware platform?
>
> Thomas

any generic Intel/AMD cpu

On 02/09/2012 05:11 PM, Thomas Petazzoni wrote:

> Le Thu, 09 Feb 2012 16:48:30 +0200,
> Eial Czerwacki <eial@scalemp.com> a ?crit :
> 
>> sh-4.1# gcc -o a test.c
> 
> You're using the native gcc on the target, while Buildroot is mostly
> designed for cross-compilation. Our native gcc on the target mechanism
> isn't used/tested a lot, so I would really recommend using the
> cross-compiler on the build machine to build your applications.
> 
> Thomas


I've compiled iasl, dmidecode and biosdecode with same image, you say
that I cannot do that?
I need the bin linked to uclibc and my desktop doesn't support uclibc

Thanks,

Eial.

[Buildroot] segfault when running a simple c program on env build with buildroot

[Thomas Petazzoni]

Le Thu, 09 Feb 2012 17:16:51 +0200,
Eial Czerwacki <eial@scalemp.com> a ?crit :

> > What is your hardware platform?
> >
> > Thomas
> 
> any generic Intel/AMD cpu

Sorry this does not exist. Your configuration states i686. If your
processor is only i486 or i586 compatible, then those segfaults are
expected since the generated code might use instructions that do not
exist on your processor.

> I've compiled iasl, dmidecode and biosdecode with same image, you say
> that I cannot do that?
> I need the bin linked to uclibc and my desktop doesn't support uclibc

Buildroot generates for you an uClibc cross-compilation toolchain in
output/host/usr/bin that you can use to cross-compile applications for
the target platform.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] segfault when running a simple c program on env build with buildroot

[Eial Czerwacki]

On 02/09/2012 05:54 PM, Thomas Petazzoni wrote:

> Le Thu, 09 Feb 2012 17:16:51 +0200,
> Eial Czerwacki <eial@scalemp.com> a ?crit :
> 
>>> What is your hardware platform?
>>>
>>> Thomas
>>
>> any generic Intel/AMD cpu
> 
> Sorry this does not exist. Your configuration states i686. If your
> processor is only i486 or i586 compatible, then those segfaults are
> expected since the generated code might use instructions that do not
> exist on your processor.
> 

correction, the cpus are any cpus from the last 4-5 years, my cpu is
e6600 for the matter.
all of them are i686

>> I've compiled iasl, dmidecode and biosdecode with same image, you say
>> that I cannot do that?
>> I need the bin linked to uclibc and my desktop doesn't support uclibc
> 
> Buildroot generates for you an uClibc cross-compilation toolchain in
> output/host/usr/bin that you can use to cross-compile applications for
> the target platform.
> 
> Best regards,
> 
> Thomas


that is what I need.

Eial.

[Buildroot] segfault when running a simple c program on env build with buildroot

[Eial Czerwacki]

On 02/12/2012 09:14 AM, Eial Czerwacki wrote:

> On 02/09/2012 05:54 PM, Thomas Petazzoni wrote:
> 
>> Le Thu, 09 Feb 2012 17:16:51 +0200,
>> Eial Czerwacki <eial@scalemp.com> a ?crit :
>>
>>>> What is your hardware platform?
>>>>
>>>> Thomas
>>>
>>> any generic Intel/AMD cpu
>>
>> Sorry this does not exist. Your configuration states i686. If your
>> processor is only i486 or i586 compatible, then those segfaults are
>> expected since the generated code might use instructions that do not
>> exist on your processor.
>>
> 
> correction, the cpus are any cpus from the last 4-5 years, my cpu is
> e6600 for the matter.
> all of them are i686
> 
>>> I've compiled iasl, dmidecode and biosdecode with same image, you say
>>> that I cannot do that?
>>> I need the bin linked to uclibc and my desktop doesn't support uclibc
>>
>> Buildroot generates for you an uClibc cross-compilation toolchain in
>> output/host/usr/bin that you can use to cross-compile applications for
>> the target platform.
>>
>> Best regards,
>>
>> Thomas
> 
> 
> that is what I need.
> 
> Eial.
> 


ok, I've found my issue, for some reason, although I was inside the
busybox (using chroot to compile it), configure used the host's compiler
and not the uclibc based compiler, passing the
--host=i686-unknown-linux-uclibc solved this issue.

Thanks for the help.