libstdc++ bus errors

libstdc++ bus errors

[Sean Callanan]

(Sorry if you've already seen this; I'm having SMTP server problems)

Dear mailing list:

I am currently rebuilding my system from scratch (using the instructions at 
www.linuxfromscratch.org) with GCC 3.0.2 and glibc 2.2.4.
I have simply compiled GCC 3.0.2 for sparc-linux (32-bit) with dynamic 
linking against the new libc. However, even a test program:
--
#include <iostream.h>

void main()
{
	cout << "Hello C++!\n";
	exit(0);
}
--
has a bus error. Are there known issues with sparc and libstdc++ 3.0.2? 
(Incidentally, I try to run the library itself, and get a segmentation 
fault, but I suspect that isn't such a big issue since the c++ library on 
my original SuSE install does the exact same thing.

Incidentally, I have the C++ library for 32-bit in /usr/lib, and the C++ 
library for 64-bit in /usr/lib64. There should be no issues with libs 
conflicting.

Sincerely,
Sean Callanan 

Re: libstdc++ bus errors

[Jeff Sturm]

On Mon, 12 Nov 2001, Sean Callanan wrote:
> I am currently rebuilding my system from scratch (using the instructions at 
> www.linuxfromscratch.org) with GCC 3.0.2 and glibc 2.2.4.
> I have simply compiled GCC 3.0.2 for sparc-linux (32-bit) with dynamic 
> linking against the new libc. However, even a test program:
> --
> #include <iostream.h>
> 
> void main()
> {
> 	cout << "Hello C++!\n";
> 	exit(0);
> }
> --
> has a bus error. Are there known issues with sparc and libstdc++ 3.0.2? 
> (Incidentally, I try to run the library itself, and get a segmentation 
> fault, but I suspect that isn't such a big issue since the c++ library on 
> my original SuSE install does the exact same thing.

I've seen this too, using slackware-current on sparc.  The cause is
twofold: GNU ld incorrectly generates a R_SPARC_32 reloc for an unaligned
word, which ld.so cannot fix because unaligned stores cause a trap on
sparc.

Upgrading binutils to 2.11.2 doesn't solve the problem, because ld.so
doesn't understand R_SPARC_UA32 relocations:

./a.out: error while loading shared libraries: /home/jsturm/junk.so:
unexpected reloc type 0x17

Before I tackle it, anyone know if there is a fixed libc for sparc-linux?

(Meanwhile, configuring gcc with --enable-sjlj-exceptions might be an
effective workaround.)

Jeff

Re: libstdc++ bus errors

[David S. Miller]

   From: Jeff Sturm <jsturm@one-point.com>
   Date: Tue, 13 Nov 2001 01:29:09 -0500 (EST)

   Upgrading binutils to 2.11.2 doesn't solve the problem, because ld.so
   doesn't understand R_SPARC_UA32 relocations:
   
   ./a.out: error while loading shared libraries: /home/jsturm/junk.so:
   unexpected reloc type 0x17

Upgrade glibc, then binutils :-)  Current glibc understands
the UA32 relocs properly.

Franks a lot,
David S. Miller
davem@redhat.com

Re: libstdc++ bus errors

[Jeff Sturm]

On Mon, 12 Nov 2001, David S. Miller wrote:
>    
>    ./a.out: error while loading shared libraries: /home/jsturm/junk.so:
>    unexpected reloc type 0x17
> 
> Upgrade glibc, then binutils :-)  Current glibc understands
> the UA32 relocs properly.

Ah yes, I found the requisite patch... thanks.

http://sources.redhat.com/ml/libc-alpha/2001-07/msg00021.html

Jeff

Re: libstdc++ bus errors

[sc843]

> > Upgrading binutils to 2.11.2 doesn't solve the problem, because ld.so
> > doesn't understand R_SPARC_UA32 relocations...
> Upgrade glibc, then binutils :-)  Current glibc understands
> the UA32 relocs properly.

I don't think this is the sole cause of the problem. I have glibc 2.2.4, which 
(according to my hand-checking) includes the fix for R_SPARC_UA32 
mentioned in an earlier message:

> Ah yes, I found the requisite patch... thanks.
> http://sources.redhat.com/ml/libc-alpha/2001-07/msg00021.html

...but still C++ programs have bus errors.

Perhaps a related issue could be that I overrode the default behavior of 
the 32->64 cross compiler to copy all the system headers into 
$PREFIX/sparc64-linux/sys-includes 
and instead symlinked that directory to 
$PREFIX/include
I don't know what else the problem might be. Must I upgrade to a CVS 
version of binutils? (I have 2.11)

Would it help if I build gdb and tried to figure out the source of the error 
more precisely, or is this well-known?

Sincerely,
Sean Callanan