[Bug libgomp/28468] OpenMP-parallelized program crashes when OMP_NUM_THREADS > 1

["bruno at clisp dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #3 from bruno at clisp dot org  2006-11-15 13:38 -------
> Was LinuxThreads built at least --with-tls support or without?

The glibc was built with LinuxThreads without TLS. (I gave --without-tls
explicitly to the glibc build.)

> If without and libgomp has been built without --disable-tls and your
> assembler/linker support TLS, libgomp might be using __thread eventhough
> glibc doesn't support that.

Yes, this is exactly the problem; see the analysis and patch in
http://gcc.gnu.org/ml/gcc/2006-11/msg00244.html

> There have been some patches added recently to improve gcc configure checks
> for the runtime support of TLS.

The only patch that has been committed is this one from Daniel Jacobowitz
http://gcc.gnu.org/viewcvs/trunk/config/tls.m4?r1=117049&r2=118777
It has no effect on this bug, since it applies only to the cross-compiling
case.

For the native compile, I posted a patch that is known to fix this bug:
http://gcc.gnu.org/ml/gcc/2006-11/msg00244.html
It has been approved by Richard Henderson:
http://gcc.gnu.org/ml/gcc/2006-11/msg00255.html
But noone has committed it to the GCC SVN.

Could someone please commit this patch on the HEAD and possibly on the 4.2
branch? (It is not a regression, if you argue that libgomp and -fopenmp is a
new feature. But it is a regression if you argue that there are packages out
there, such as GNU gettext 0.16, which use -fopenmp if available, and this
bug turns a program that would run unparallelized but correctly with gcc-4.1
into a program that runs parallelized but crashes with gcc-4.2.)


-- 

bruno at clisp dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu dot org
             Status|WAITING                     |UNCONFIRMED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28468